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Sample records for hydraulic analysis sproedbruchsicherheitsnachweise

  1. Aircraft Hydraulic Systems Dynamic Analysis

    Science.gov (United States)

    1978-10-01

    4400 PSIG OUTLET PRESSURE ~’f UM5 S1 l .( FIF ~0RV lR 1 .I. AP (c R (V) IFWM) APPROX C ASE !VPý :iI S ReUN N•;MRF.. r p kN i t, isI A! f IN, I:E • ’l...and 1F.GI pump modelo were assumed from data supplied by CECO. 165 _ -- --- - SECTION V HYDRAULIC MOTOR MODEL DEVELOPMENT AND VERIFICATION A fixed...3 70 P.,0 601 ~4 M24.0 3 1p ’, 4 r I 1 1 ISIS 2411 APPENDIX E (CONT.) HSFR TECHNICAL MANUAL (AFAPL-TR-76-43, VOL. IV) 4.15 VANE PU`MP SUBROUTINE 4.15A

  2. Hydraulics.

    Science.gov (United States)

    Decker, Robert L.; Kirby, Klane

    This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

  3. Thermal-hydraulic modeling and analysis of hydraulic system by pseudo-bond graph

    Institute of Scientific and Technical Information of China (English)

    胡均平; 李科军

    2015-01-01

    To increase the efficiency and reliability of the thermodynamics analysis of the hydraulic system, the method based on pseudo-bond graph is introduced. According to the working mechanism of hydraulic components, they can be separated into two categories: capacitive components and resistive components. Then, the thermal-hydraulic pseudo-bond graphs of capacitive C element and resistance R element were developed, based on the conservation of mass and energy. Subsequently, the connection rule for the pseudo-bond graph elements and the method to construct the complete thermal-hydraulic system model were proposed. On the basis of heat transfer analysis of a typical hydraulic circuit containing a piston pump, the lumped parameter mathematical model of the system was given. The good agreement between the simulation results and experimental data demonstrates the validity of the modeling method.

  4. Pressure Characteristic Analysis of a Hydraulic System

    Science.gov (United States)

    Cho, H. Y.; Yang, H. J.

    2017-02-01

    EPPR(ElectroProportional Pressure Reducing) valve control the MCV(Main Control Valve) built on the mobile heavy machine. The EPPR valve was tested in the experimental setup and the performance of the valve was compared with that of the existing EPPR valve. On thisstudy, electromagnetic properties analysis using AMESim program was performed to optimize the designing of EPPR Valve (Electric Proportional Pressure Reducing Valve) and by applying its results to the hydraulic system analytical model, performance of the valve could be predicted. Also by comparing the results of the actual experiment and the simulation, The results of thisstudy is that the 3 factor(cone angle, tip width, clearance between sleeve and plunger) have much effectiveness than other components in the EPPR valve.

  5. Predictive Maintenance of Hydraulic Lifts through Lubricating Oil Analysis

    OpenAIRE

    Stamatios S. Kalligeros

    2013-01-01

    This article examines the possibility of measuring lift maintenance through analysis of used hydraulic oil. Hydraulic oils have proved to be a reliable indicator for the maintenance performed on elevators. It has also been proved that the end users or the maintenance personnel do not always conform to the instructions of the elevators’ hydraulic machine manufacturer. Furthermore, by examining the proportion of the metals, an estimation of the corrosion and the wear resistance of the joined mo...

  6. Predictive Maintenance of Hydraulic Lifts through Lubricating Oil Analysis

    Directory of Open Access Journals (Sweden)

    Stamatios S. Kalligeros

    2013-12-01

    Full Text Available This article examines the possibility of measuring lift maintenance through analysis of used hydraulic oil. Hydraulic oils have proved to be a reliable indicator for the maintenance performed on elevators. It has also been proved that the end users or the maintenance personnel do not always conform to the instructions of the elevators’ hydraulic machine manufacturer. Furthermore, by examining the proportion of the metals, an estimation of the corrosion and the wear resistance of the joined moving parts can be observed. Additionally, the presence of chlorine and calcium in hydraulic oils demonstrates their function in a highly corrosive environment.

  7. Hydraulic analysis of cell-network treatment wetlands

    Science.gov (United States)

    Wang, Huaguo; Jawitz, James W.

    2006-11-01

    SummaryWhen individual cells of a multiple-cell treatment wetland are hydraulically connected, the wetland has a cell-network structure. The hydraulic performance of treatment wetlands is often characterized using tracer residence time distributions (RTDs) measured between the wetland inlet and outlet, such that the wetland is considered as a single hydraulic unit, regardless of the extent of networking between individual internal cells. This work extends the single hydraulic unit approach to enable the specification of moments and RTD parameters for individual cells, or clusters of cells, within the cell-network based on inert tracer tests with injection only at the network inlet. Hydraulic performance is quantified in terms of hydraulic efficiency and travel time dimensionless variance using both the method of moments and RTD modeling. Cell-network analysis was applied to a case study from the Orlando Easterly Wetland (OEW), demonstrating the improvement in hydraulic performance of individual wetland cells following wetland restoration activities. Furthermore, cell-network analysis indicated that the location of water quality sampling station locations within the cell network can significantly affect the accuracy of pollutant removal effectiveness estimation when the individual sample station RTD does not represent the hydraulic unit RTD. At the OEW, it was determined that historical nutrient removal effectiveness estimation may be underestimated for one area and overestimated for another, and recommendations were provided for sample station locations to minimize future performance estimation errors.

  8. Efficiency limit factor analysis for the Francis-99 hydraulic turbine

    Science.gov (United States)

    Zeng, Y.; Zhang, L. X.; Guo, J. P.; Guo, Y. K.; Pan, Q. L.; Qian, J.

    2017-01-01

    The energy loss in hydraulic turbine is the most direct factor that affects the efficiency of the hydraulic turbine. Based on the analysis theory of inner energy loss of hydraulic turbine, combining the measurement data of the Francis-99, this paper calculates characteristic parameters of inner energy loss of the hydraulic turbine, and establishes the calculation model of the hydraulic turbine power. Taken the start-up test conditions given by Francis-99 as case, characteristics of the inner energy of the hydraulic turbine in transient and transformation law are researched. Further, analyzing mechanical friction in hydraulic turbine, we think that main ingredients of mechanical friction loss is the rotation friction loss between rotating runner and water body, and defined as the inner mechanical friction loss. The calculation method of the inner mechanical friction loss is given roughly. Our purpose is that explore and research the method and way increasing transformation efficiency of water flow by means of analysis energy losses in hydraulic turbine.

  9. Thermal-hydraulic analysis of nuclear reactors

    CERN Document Server

    Zohuri, Bahman

    2015-01-01

    This text covers the fundamentals of thermodynamics required to understand electrical power generation systems and the application of these principles to nuclear reactor power plant systems. It is not a traditional general thermodynamics text, per se, but a practical thermodynamics volume intended to explain the fundamentals and apply them to the challenges facing actual nuclear power plants systems, where thermal hydraulics comes to play.  Written in a lucid, straight-forward style while retaining scientific rigor, the content is accessible to upper division undergraduate students and aimed at practicing engineers in nuclear power facilities and engineering scientists and technicians in industry, academic research groups, and national laboratories. The book is also a valuable resource for students and faculty in various engineering programs concerned with nuclear reactors. This book also: Provides extensive coverage of thermal hydraulics with thermodynamics in nuclear reactors, beginning with fundamental ...

  10. Analysis of hydraulic characteristics for stream diversion in small stream

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang-Jin; Jun, Kye-Won [Chungbuk National University, Cheongju(Korea)

    2001-10-31

    This study is the analysis of hydraulic characteristics for stream diversion reach by numerical model test. Through it we can provide the basis data in flood, and in grasping stream flow characteristics. Analysis of hydraulic characteristics in Seoknam stream were implemented by using computer model HEC-RAS(one-dimensional model) and RMA2(two-dimensional finite element model). As a result we became to know that RMA2 to simulate left, main channel, right in stream is more effective method in analysing flow in channel bends, steep slope, complex bed form effect stream flow characteristics, than HEC-RAS. (author). 13 refs., 3 tabs., 5 figs.

  11. CFD analysis of a hydraulic valve for cavitating flow

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, A.; Goyal, P.; Singh, R.K.; Gosh, A.K. [Bhabha Atomic Research Centre (BARC), Trombay, Mumbai (India). Reactor Safety Div.

    2012-03-15

    A successful design of high pressure hydraulic valves requires a thorough analysis of both velocity and pressure fields, with the aim of improving the geometry to avoid cavitation. Cavitation behavior prediction of hydraulic valves and its associated performance drop is of high interest for the manufacturers and for the users. The paper presents a CFD analysis of the flow inside a high pressure hydraulic valve. First, the analysis was carried out without using cavitation model (single phase). It was observed that absolute pressure was going below the vapor pressure. Hence, it was required to turn on the cavitation model. This model enables formation of vapor from liquid when the pressure drops below the vaporization pressure. Since the cavitation bubble grows in a liquid at low temperature, the latent heat of evaporation can be neglected and the system can be considered isothermal. Under these conditions the pressure inside the bubble remains practically constant and the growth of the bubble radius can be approximated by the simplified Rayleigh equation. For typical poppet valve geometry, of computational domain is assumed, with pressure inlet and outlet boundary conditions, and a steady flow solution is computed. Because of the highly complex geometry of the hydraulic valve, the computational domain was meshed using unstructured grids using tetrahedral cells only. The paper presents a numerical investigation of the flow inside a hydraulic valve using commercial CFD code CFD-ACE. The aim of the study is to provide a good basis for future designing of the hydraulic valve. The result indicated the cavitation zones which in turn suggest needs of modification of present geometry. (orig.)

  12. Horizontal steam generator PGV-1000 thermal-hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ubra, O. [Skoda Company, Prague (Switzerland); Doubek, M. [Czech Technical Univ., Prague (Switzerland)

    1995-12-31

    A computer program for the steady state thermal-hydraulic analysis of horizontal steam generator PGV-1000 is presented. The program provides the capability to analyze steam generator PGV-1000 primary side flow and temperature distribution, primary side pressure drops, heat transfer between the primary and secondary sides and multidimensional heat flux distribution. A special attention is paid to the thermal-hydraulics of the secondary side. The code predicts 3-D distribution of the void fraction at the secondary side, mass redistribution under the submerged perforated sheet and the steam generator level profile. By means of developed computer program a detailed thermal-hydraulic study of the PGV-1000 has been carried out. A wide range of calculations has been performed and a set of important steam generator characteristics has been obtained. Some of them are presented in the paper. (orig.). 5 refs.

  13. Analysis and control of flows in pressurized hydraulic networks

    NARCIS (Netherlands)

    Gupta, R.K.

    2006-01-01

    Analysis, design and flow control problems in pressurized hydraulic networks such as water transmission and distribution systems consisting of pipes and other appurtenant components such as reservoirs, pumps, valves and surge devices are dealt with from the prospective of network synthesis aiming at

  14. Analysis and control of flows in pressurized hydraulic networks

    NARCIS (Netherlands)

    Gupta, R.K.

    2006-01-01

    Analysis, design and flow control problems in pressurized hydraulic networks such as water transmission and distribution systems consisting of pipes and other appurtenant components such as reservoirs, pumps, valves and surge devices are dealt with from the prospective of network synthesis aiming at

  15. Thermal hydraulic and mechanical analysis of CH HCSB TBM

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-yu; FENG Kai-ming; ZHANG Guo-shu; YUAN Tao

    2006-01-01

    Based on the structure design and results of neutronics analysis of the CH HCSB TBM (Chinese helium cooled solid breeder test blanket module), thermal hydraulic and mechanical analyses have been carried out. Results show that the design of the CH HCSB TBM is reasonable and acceptable.

  16. Design and Analysis of Hydraulic Chassis with Obstacle Avoidance Function

    Science.gov (United States)

    Hong, Yingjie; Zhang, Xiang

    2017-07-01

    This article mainly expounds the design of hydraulic system for the hydraulic chassis with obstacle avoidance function. Including the selection of hydraulic motor wheels, hydraulic pump, digital hydraulic cylinder and the matching of engine power. And briefly introduces the principle of obstacle avoidance.

  17. Design and Performance Analysis of a new Rotary Hydraulic Joint

    Science.gov (United States)

    Feng, Yong; Yang, Junhong; Shang, Jianzhong; Wang, Zhuo; Fang, Delei

    2017-07-01

    To improve the driving torque of the robots joint, a wobble plate hydraulic joint is proposed, and the structure and working principle are described. Then mathematical models of kinematics and dynamics was established. On the basis of this, dynamic simulation and characteristic analysis are carried out. Results show that the motion curve of the joint is continuous and the impact is small. Moreover the output torque of the joint characterized by simple structure and easy processing is large and can be rotated continuously.

  18. The analysis of thermal-hydraulic models in MELCOR code

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M. H.; Hur, C.; Kim, D. K.; Cho, H. J. [POhang Univ., of Science and TECHnology, Pohang (Korea, Republic of)

    1996-07-15

    The objective of the present work is to verify the prediction and analysis capability of MELCOR code about the progression of severe accidents in light water reactor and also to evaluate appropriateness of thermal-hydraulic models used in MELCOR code. Comparing the results of experiment and calculation with MELCOR code is carried out to achieve the above objective. Specially, the comparison between the CORA-13 experiment and the MELCOR code calculation was performed.

  19. Nonlinear mathematical modeling and sensitivity analysis of hydraulic drive unit

    Science.gov (United States)

    Kong, Xiangdong; Yu, Bin; Quan, Lingxiao; Ba, Kaixian; Wu, Liujie

    2015-09-01

    The previous sensitivity analysis researches are not accurate enough and also have the limited reference value, because those mathematical models are relatively simple and the change of the load and the initial displacement changes of the piston are ignored, even experiment verification is not conducted. Therefore, in view of deficiencies above, a nonlinear mathematical model is established in this paper, including dynamic characteristics of servo valve, nonlinear characteristics of pressure-flow, initial displacement of servo cylinder piston and friction nonlinearity. The transfer function block diagram is built for the hydraulic drive unit closed loop position control, as well as the state equations. Through deriving the time-varying coefficient items matrix and time-varying free items matrix of sensitivity equations respectively, the expression of sensitivity equations based on the nonlinear mathematical model are obtained. According to structure parameters of hydraulic drive unit, working parameters, fluid transmission characteristics and measured friction-velocity curves, the simulation analysis of hydraulic drive unit is completed on the MATLAB/Simulink simulation platform with the displacement step 2 mm, 5 mm and 10 mm, respectively. The simulation results indicate that the developed nonlinear mathematical model is sufficient by comparing the characteristic curves of experimental step response and simulation step response under different constant load. Then, the sensitivity function time-history curves of seventeen parameters are obtained, basing on each state vector time-history curve of step response characteristic. The maximum value of displacement variation percentage and the sum of displacement variation absolute values in the sampling time are both taken as sensitivity indexes. The sensitivity indexes values above are calculated and shown visually in histograms under different working conditions, and change rules are analyzed. Then the sensitivity

  20. Portable Life Support Subsystem Thermal Hydraulic Performance Analysis

    Science.gov (United States)

    Barnes, Bruce; Pinckney, John; Conger, Bruce

    2010-01-01

    This paper presents the current state of the thermal hydraulic modeling efforts being conducted for the Constellation Space Suit Element (CSSE) Portable Life Support Subsystem (PLSS). The goal of these efforts is to provide realistic simulations of the PLSS under various modes of operation. The PLSS thermal hydraulic model simulates the thermal, pressure, flow characteristics, and human thermal comfort related to the PLSS performance. This paper presents modeling approaches and assumptions as well as component model descriptions. Results from the models are presented that show PLSS operations at steady-state and transient conditions. Finally, conclusions and recommendations are offered that summarize results, identify PLSS design weaknesses uncovered during review of the analysis results, and propose areas for improvement to increase model fidelity and accuracy.

  1. Hydraulic analysis of the operation of oil and gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Gabor, T.; Szaharov, V.A.; Szilas, A.P.

    1984-01-01

    The results are cited of a study of the operation of operational oil and gas wells. A hydraulic system of operational wells is identified for the first time, which consists of elements of a stratum, well and surface equipment system. After a brief presentation of the rating methods which describe the operation of the elements, the methods for hydraulic analysis of the complete system are detailed. After theoretical presentation of the methods, the course of computer (EVM) programs, developed for practical purposes, is shown. These programs may be used to solve two basic problems in gusher extraction of oil: identification of the maximal flow rate of a gusher well and the operational point of a well which has a wellhead coupling.

  2. Hydraulic analysis of the Wendelstein 7-X cooling loops

    Energy Technology Data Exchange (ETDEWEB)

    Smirnow, M., E-mail: michael.smirnow@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Orozco, G.; Boscary, J. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Peacock, A. [European Commission c/o Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany)

    2013-10-15

    Highlights: • A hydraulic simulation model of the W7-X cooling loops and plasma facing components. • CFD analysis of orifice components. • Optimization and flow balancing of cooling loops. -- Abstract: Actively water cooled in vessel components (IVC) are required for the long pulse operation of the stellarator Wendelstein 7-X (W7-X). In total, the cooling pipes have a length of about 4.5 km, supplying the coolant via 304 cooling circuits for the IVC. Within each cooling loop, the IVC are organized mostly in parallel. A homogeneous flow through all branches or at least the minimum specified flow in all of the branches of a circuit is crucial for the IVC to withstand the loading conditions. A detailed hydraulic simulation model of the W7-X cooling loops was built with the commercial code Flowmaster, which is a 1-D computational fluid dynamics software. In order to handle the huge amount of pipe-work data that had to be modelled, a pre- and post-processing macro was developed to transfer the 3D Catia V5 CAD model to the 1-D piping model. Within this model, the hydraulic characteristics of different types of first wall components were simulated, and compared with their pressure drop measurements. As a result of this work, the need for optimization of some cooling loops has been identified and feasible modified solutions were selected.

  3. Hydraulic manipulator design, analysis, and control at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.; Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States); Basher, A.M.H. [South Carolina State Univ., Orangeburg, SC (United States)

    1996-09-01

    To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned to hydraulics as a means of actuation. Hydraulics have always been the actuator of choice when designing heavy-life construction and mining equipment such as bulldozers, backhoes, and tunneling devices. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem) sophisticated modeling, analysis, and control experiments are usually needed. To support the development and deployment of new hydraulic manipulators Oak Ridge National Laboratory (ORNL) has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The hydraulics laboratory at ORNL has three different manipulators. First is a 6-Degree-of-Freedom (6-DoF), multi-planer, teleoperated, flexible controls test bed used for the development of waste tank clean-up manipulator controls, thermal studies, system characterization, and manipulator tracking. Finally, is a human amplifier test bed used for the development of an entire new class of teleoperated systems. To compliment the hardware in the hydraulics laboratory, ORNL has developed a hydraulics simulation capability including a custom package to model the hydraulic systems and manipulators for performance studies and control development. This paper outlines the history of hydraulic manipulator developments at ORNL, describes the hydraulics laboratory, discusses the use of the equipment within the laboratory, and presents some of the initial results from experiments and modeling associated with these hydraulic manipulators. Included are some of the results from the development of the human amplifier/de-amplifier concepts, the characterization of the thermal sensitivity of hydraulic systems, and end-point tracking accuracy studies. Experimental and analytical

  4. Analysis of Innovative Design of Energy Efficient Hydraulic Actuators

    OpenAIRE

    M Osman Abdalla

    2013-01-01

    Hydraulic cylinder actuators are used extensively in industrial, construction and agricultural works. The small sized outlet ports of the cylinders resist the flow of discharged oil; and as a result the piston motion is slowed down. This causes a lot of heat generation and energy loss within the actuators. The study investigates and analyzes the possibilities of reducing the hydraulic resistance and increasing efficiency of the hydraulic actuator. Conventional hydraulic cylinders are simulate...

  5. Thermal Hydraulic Analysis on Containment Filtered Venting System

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong; Lee, Byung Chul [FNC Technology Co. Ltd., Yongin (Korea, Republic of); Lee, Sang Won; Kim, Hyeong Taek [KHNP-Central Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this study, the thermal hydraulic conditions (e. g. pressure and flow rate) at each component have been examined and the sensitivity analysis on CFVS design parameters (e. g. water inventory, volumetric flow rate). The purpose is to know the possible range of flow conditions at each component to determine the optimum size of filtration system. GOTHIC code has been used to simulate the thermal-hydraulic behavior inside of CFVS. The behavior of flows in the CFVS has been investigated. The vessel water level and the flow rates during the CFVS operation are examined. It was observed that the vessel water level would be changed significantly due to steam condensation/thermal expansion and steam evaporation. Therefore, the vessel size and the initial water inventory should be carefully determined to keep the minimum water level required for filtration components and not to flood the components in the upper side of the vessel. It has been also observed that the volumetric flow rate is maintained during the CFVS operation, which is beneficial for pool scrubbing units. However, regarding the significant variations at the orifice downstream, careful design would be necessary.

  6. Analysis of Innovative Design of Energy Efficient Hydraulic Actuators

    Directory of Open Access Journals (Sweden)

    M Osman Abdalla

    2013-01-01

    Full Text Available Hydraulic cylinder actuators are used extensively in industrial, construction and agricultural works. The small sized outlet ports of the cylinders resist the flow of discharged oil; and as a result the piston motion is slowed down. This causes a lot of heat generation and energy loss within the actuators. The study investigates and analyzes the possibilities of reducing the hydraulic resistance and increasing efficiency of the hydraulic actuator. Conventional hydraulic cylinders are simulated in FLUENT. Results show that the small outlet ports are the sources of energy loss in hydraulic cylinders. A new hydraulic system was proposed as a solution to relieve the hydraulic resistance in the actuators. The proposed system is a four ports hydraulic cylinder fitted with a novel flow control valve. The proposed four ports cylinder was simulated and parameters such as ports sizes, loads and pressures are varied during the simulation. The hydraulic resisting forces, piston speed and mass flow rates are computed. Results show that the hydraulic resistance is significantly reduced in the proposed four ports actuators; and the proposed cylinders run faster than the conventional cylinders and a considerable amount of energyis saved as well.

  7. Hydraulically interconnected vehicle suspension: theoretical and experimental ride analysis

    Science.gov (United States)

    Smith, Wade A.; Zhang, Nong; Jeyakumaran, Jeku

    2010-01-01

    In this paper, a previously derived model for the frequency-domain analysis of vehicles with hydraulically interconnected suspension (HIS) systems is applied to the ride analysis of a four-degrees of freedom roll-plane, half-car under a rough road input. The entire road surface is assumed to be a realisation of a two-dimensional Gaussian homogenous and isotropic random process. The frequency responses of the half-car, in terms of bounce and roll acceleration, suspension deflection and dynamic tyre forces, are obtained under the road input of a single profile represented by its power spectral density function. Simulation results obtained for the roll-plane half-car fitted with an HIS and those with conventional suspensions are compared in detail. In addition, sensitivity analysis of key parameters of the HIS to the ride performance is carried out through simulations. The paper also presents the experimental validation of the analytical results of the free and forced vibrations of the roll-plane half-car. The hydraulic and mechanical system layouts, data acquisition system and the external force actuation mechanism of the test set-up are described in detail. The methodology for free and forced vibration tests and the application of mathematical models to account for the effective damper valve pressure loss are explained. Results are provided for the free and forced vibration testing of the half-car with different mean operating pressures. Comparisons are also given between the test results and those obtained from the system model with estimated damper valve loss coefficients. Furthermore, discussions on the deficiencies and practical implications of the proposed model and suggestions for future investigation are provided. Finally, the key findings of the investigation on the ride performance of the roll-plane half-car are summarised.

  8. Steady-state thermal-hydraulic analysis of SCWR assembly

    Institute of Scientific and Technical Information of China (English)

    Xiaojing LIU; Xu CHENG

    2008-01-01

    Among the six gen-Ⅳ reactor concepts recom-mended by the gen-Ⅳ international forum (GIF), super-critical water-cooled reactor (SCWR), the only reactor with water as coolant, achieves a high thermal efficiency and, subsequently, has economic advantages over the existing reactors due to its high outlet temperature. A thermal-hydraulic analysis of the SCWR assembly is per-formed in this paper using the modified COBRA-Ⅳ code. Two approaches to reduce the hot channel factor are investigated: decreasing the moderator mass flow and increasing the thermal resistance between moderator channel and its adjacent sub-channels. It is shown that heat transfer deterioration cannot be avoided in SCWR fuel assembly. It is, therefore, highly required to calculate the cladding temperature accurately and to preserve the fuel rod cladding integrity under heat transfer deteriora-tion conditions.

  9. Hydraulic analysis and optimization design in Guri rehabilitation project

    Science.gov (United States)

    Cheng, H.; Zhou, L. J.; Gong, L.; Wang, Z. N.; Wen, Q.; Zhao, Y. Z.; Wang, Y. L.

    2016-11-01

    Recently Dongfang was awarded the contract for rehabilitation of 6 units in Guri power plant, the biggest hydro power project in Venezuela. The rehabilitation includes, but not limited to, the extension of output capacity by about 50% and enhancement of efficiency level. To achieve the targets the runner and the guide vanes will be replaced by the newly optimized designs. In addition, the out-of-date stay vanes with straight plate shape will be modified into proper profiles after considering the application feasibility in field. The runner and vane profiles were optimized by using state-of-the-art flow simulation techniques. And the hydraulic performances were confirmed by the following model tests. This paper describes the flow analysis during the optimization procedure and the comparison between various technical concepts.

  10. Thermal hydraulic analysis of the annular flow helium heater design

    Science.gov (United States)

    Chen, N. C.; Sanders, J. P.

    1982-05-01

    Core support performance test (CSPT) by use of an existing facility, components flow test loop (CFTL), as part of the high temperature gas cooled reactor (HTGR) application program were conducted. A major objective of the CSPT is to study accelerated corrosion of the core graphite support structure in helium at reactor conditions. Concentration of impurities will be adjusted so that a 6 month test represents the 30 year reactor life. Thermal hydraulic and structural integrity of the graphite specimen, will be studied at high pressure of 7.24 MPa (1050 psi) and high temperature of 1000 deg C in a test vessel. To achieve the required high temperature at the test section, a heater bundle has to be specially designed and properly manufactured. Performance characteristics of the heater which were determined from an analysis based on this design are presented.

  11. Thermal hydraulic analysis of the JMTR improved LEU-core

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, Toshio; Nagao, Yoshiharu; Komukai, Bunsaku; Naka, Michihiro; Fujiki, Kazuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Takeda, Takashi [Radioactive Waste Management and Nuclear Facility Decommissioning Technology Center, Tokai, Ibaraki (Japan)

    2003-01-01

    After the investigation of the new core arrangement for the JMTR reactor in order to enhance the fuel burn-up and consequently extend the operation period, the ''improved LEU core'' that utilized 2 additional fuel elements instead of formerly installed reflector elements, was adopted. This report describes the results of the thermal-hydraulic analysis of the improved LEU core as a part of safety analysis for the licensing. The analysis covers steady state, abnormal operational transients and accidents, which were described in the annexes of the licensing documents as design bases events. Calculation conditions for the computer codes were conservatively determined based on the neutronic analysis results and others. The results of the analysis, that revealed the safety criteria were satisfied on the fuel temperature, DNBR and primary coolant temperature, were used in the licensing. The operation license of the JMTR with the improved LEU core was granted in March 2001, and the reactor operation with new core started in November 2001 as 142nd operation cycle. (author)

  12. Development of realistic thermal-hydraulic system analysis codes ; development of thermal hydraulic test requirements for multidimensional flow modeling

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Kune Yull; Yoon, Sang Hyuk; Noh, Sang Woo; Lee, Il Suk [Seoul National University, Seoul (Korea)

    2002-03-01

    This study is concerned with developing a multidimensional flow model required for the system analysis code MARS to more mechanistically simulate a variety of thermal hydraulic phenomena in the nuclear stem supply system. The capability of the MARS code as a thermal hydraulic analysis tool for optimized system design can be expanded by improving the current calculational methods and adding new models. In this study the relevant literature was surveyed on the multidimensional flow models that may potentially be applied to the multidimensional analysis code. Research items were critically reviewed and suggested to better predict the multidimensional thermal hydraulic behavior and to identify test requirements. A small-scale preliminary test was performed in the downcomer formed by two vertical plates to analyze multidimensional flow pattern in a simple geometry. The experimental result may be applied to the code for analysis of the fluid impingement to the reactor downcomer wall. Also, data were collected to find out the controlling parameters for the one-dimensional and multidimensional flow behavior. 22 refs., 40 figs., 7 tabs. (Author)

  13. A LiDAR based analysis of hydraulic hazard mapping

    Science.gov (United States)

    Cazorzi, F.; De Luca, A.; Checchinato, A.; Segna, F.; Dalla Fontana, G.

    2012-04-01

    Mapping hydraulic hazard is a ticklish procedure as it involves technical and socio-economic aspects. On the one hand no dangerous areas should be excluded, on the other hand it is important not to exceed, beyond the necessary, with the surface assigned to some use limitations. The availability of a high resolution topographic survey allows nowadays to face this task with innovative procedures, both in the planning (mapping) and in the map validation phases. The latter is the object of the present work. It should be stressed that the described procedure is proposed purely as a preliminary analysis based on topography only, and therefore does not intend in any way to replace more sophisticated analysis methods requiring based on hydraulic modelling. The reference elevation model is a combination of the digital terrain model and the digital building model (DTM+DBM). The option of using the standard surface model (DSM) is not viable, as the DSM represents the vegetation canopy as a solid volume. This has the consequence of unrealistically considering the vegetation as a geometric obstacle to water flow. In some cases the topographic model construction requires the identification and digitization of the principal breaklines, such as river banks, ditches and similar natural or artificial structures. The geometrical and topological procedure for the validation of the hydraulic hazard maps is made of two steps. In the first step the whole area is subdivided into fluvial segments, with length chosen as a reasonable trade-off between the need to keep the hydrographical unit as complete as possible, and the need to separate sections of the river bed with significantly different morphology. Each of these segments is made of a single elongated polygon, whose shape can be quite complex, especially for meandering river sections, where the flow direction (i.e. the potential energy gradient associated to the talweg) is often inverted. In the second step the segments are analysed

  14. ANALYSIS AND ESTIMATION OF HYDRAULIC STABILITY OF FRANCIS HYDRO TURBINE

    Institute of Scientific and Technical Information of China (English)

    LAI Xi-de

    2004-01-01

    With the development of large-capacity hydro turbines, the hydraulic instability of bydro turbines has become one of the most important problems that affect the stable operation of the hydro-electric units. The hydraulic vibration and unstable operation of Francis hydro turbines are primarily caused by the unsteady pressure pulsations inside draft tubes.The forced rotating vortex core at the runner exit and the channel vortices inside Francis turbine runners are origins of the unsteady pressure pulsations when operating at partial load. This paper briefly analyzes the hydraulic instability of operation caused by the vortex core and channel vortices at partial load, then, presents a way to estimate the hydraulic stability by calculation of the flow behavior at the runner exit.The validity of estimation is examined by comparison with experimental data. This will be helpful to evaluate the alternative design and predict the hydraulic stability for both the prototype and model hydro turbines.

  15. Disclosure of hydraulic fracturing fluid chemical additives: analysis of regulations.

    Science.gov (United States)

    Maule, Alexis L; Makey, Colleen M; Benson, Eugene B; Burrows, Isaac J; Scammell, Madeleine K

    2013-01-01

    Hydraulic fracturing is used to extract natural gas from shale formations. The process involves injecting into the ground fracturing fluids that contain thousands of gallons of chemical additives. Companies are not mandated by federal regulations to disclose the identities or quantities of chemicals used during hydraulic fracturing operations on private or public lands. States have begun to regulate hydraulic fracturing fluids by mandating chemical disclosure. These laws have shortcomings including nondisclosure of proprietary or "trade secret" mixtures, insufficient penalties for reporting inaccurate or incomplete information, and timelines that allow for after-the-fact reporting. These limitations leave lawmakers, regulators, public safety officers, and the public uninformed and ill-prepared to anticipate and respond to possible environmental and human health hazards associated with hydraulic fracturing fluids. We explore hydraulic fracturing exemptions from federal regulations, as well as current and future efforts to mandate chemical disclosure at the federal and state level.

  16. Analysis of an controller design for an electro-hydraulic servo pressure regulator

    DEFF Research Database (Denmark)

    Pedersen, Henrik C.; Andersen, Torben Ole; Madsen, A. M.;

    2009-01-01

    of the existing hydraulic components there are, however, still a need for being able to generate a hydraulic pilot pressure, as e.g. almost all open-circuit pumps are hydraulically controlled. The focus of the current paper is therefore on the analysis and controller design an electro-hydraulic servo pressure...... regulator, which generates a hydraulic LS-pressure based on an electrical reference, hereby synergistically integrating knowledge from all parts of the mechatronics area. The servo pressure regulator is used to generate the LS-signal for a variable displacement pump, and the paper rst presents...... to generate a controlled leakage  ow that aids in stabilising the system. The robustness of the system is then discussed in relation to dierent pilot line volumes and pump dynamics. Finally experimental results are presented, where the performance is compared to that of a similar hydraulic reference system...

  17. Addition to the method of dimensional analysis in hydraulic problems

    Directory of Open Access Journals (Sweden)

    A.M. Kalyakin

    2013-03-01

    Full Text Available The modern engineering design, structures, and especially machines running of new technologies set to engineers the problems that require immediate solution. Therefore, the importance of the method of dimensional analysis as a tool for ordinary engineer is increasing, allows developers to get quick and quite simple solution of even very complex tasks.The method of dimensional analysis is being applied to almost any field of physics and engineering, but it is especially effective at solving problems of mechanics and applied mechanics – hydraulics, fluid mechanics, structural mechanics, etc.Until now the main obstacle to the application of the method of dimensional analysis in its classic form was a multifactorial problem (with many arguments, the solution of which was rather difficult and sometimes impossible. In order to overcome these difficulties, the authors of this study proposed a simple method – application of the combined option avoiding these difficulties.The main result of the study is a simple algorithm which application will make it possible to solve a large class of previously unsolvable problems.

  18. Analysis of and H∞ Controller Design For An Electro-Hydraulic Servo Pressure Regulator

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole;

    2011-01-01

    -circuit pumps are still hydraulically controlled, there is however still a need for being able to generate a hydraulic pilot pressure. The focus of the current paper is on the analysis and controller design of an electrohydraulic servo pressure regulator, which generates a hydraulic LS-pressure for a variable......Currently mobile hydraulics is in a transition phase, where electronic sensors and digital signal processors are becoming standard on a high number of machines, hereby replacing hydraulic pilot lines and offering new possibilities with regard to both control and feasibility. As most open...... displacement pump based on an electrical reference. The paper first presents the considered system and an experimentally verified model of this. A linearized model and a stability analysis is then presented, based on which an H∞control strategy is selected. A nominal performance and a robustly stable...

  19. Thermal hydraulics analysis of the Advanced High Temperature Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dean, E-mail: Dean_Wang@uml.edu [University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854 (United States); Yoder, Graydon L.; Pointer, David W.; Holcomb, David E. [Oak Ridge National Laboratory, 1 Bethel Valley RD #6167, Oak Ridge, TN 37831 (United States)

    2015-12-01

    Highlights: • The TRACE AHTR model was developed and used to define and size the DRACS and the PHX. • A LOFF transient was simulated to evaluate the reactor performance during the transient. • Some recommendations for modifying FHR reactor system component designs are discussed. - Abstract: The Advanced High Temperature Reactor (AHTR) is a liquid salt-cooled nuclear reactor design concept, featuring low-pressure molten fluoride salt coolant, a carbon composite fuel form with embedded coated particle fuel, passively triggered negative reactivity insertion mechanisms, and fully passive decay heat rejection. This paper describes an AHTR system model developed using the Nuclear Regulatory Commission (NRC) thermal hydraulic transient code TRAC/RELAP Advanced Computational Engine (TRACE). The TRACE model includes all of the primary components: the core, downcomer, hot legs, cold legs, pumps, direct reactor auxiliary cooling system (DRACS), the primary heat exchangers (PHXs), etc. The TRACE model was used to help define and size systems such as the DRACS and the PHX. A loss of flow transient was also simulated to evaluate the performance of the reactor during an anticipated transient event. Some initial recommendations for modifying system component designs are also discussed. The TRACE model will be used as the basis for developing more detailed designs and ultimately will be used to perform transient safety analysis for the reactor.

  20. Analysis of CMX hydraulic data for the Mark 22

    Energy Technology Data Exchange (ETDEWEB)

    Koffman, L.D.

    1988-12-16

    The original CMX hydraulic data for the Mark 22 assembly, obtained by L.W. Ridenhour in 1972, is analyzed and documented. Comparisons are made to Ridenhour's working notebooks and summary document, and to the Mark 22 hydraulics manual. Several errors in these documents are corrected. Correlations are given in a form suitable for revisions to the hydraulics manual. The experimental setup and measurements are briefly described, and the original data is compiled in the appendix to this report. An error in the recorded length between channel pressure taps was found in Ridenhour's notebook. This error impacts the channel pressure drop correlations obtained by Ridenhour and used in the hydraulics manual. The hydraulics of the two purge channels are analyzed based on the geometry of the orifices and on the limited data available. The limited data is shown to be in reasonable agreement with accepted orifice correlations. Purge channel correlations are given, and the purge channel flow splits are shown to be about 1.5% of the total flow.

  1. Analysis of and H∞ Controller Design For An Electro-Hydraulic Servo Pressure Regulator

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole

    2011-01-01

    -circuit pumps are still hydraulically controlled, there is however still a need for being able to generate a hydraulic pilot pressure. The focus of the current paper is on the analysis and controller design of an electrohydraulic servo pressure regulator, which generates a hydraulic LS-pressure for a variable...... displacement pump based on an electrical reference. The paper first presents the considered system and an experimentally verified model of this. A linearized model and a stability analysis is then presented, based on which an H∞control strategy is selected. A nominal performance and a robustly stable...

  2. Thermo-hydraulic analysis for sub-module of Chinese HCSB TBM design

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhou; FENG Kai-ming; WANG Xiao-yu; YUAN Tao

    2006-01-01

    Thermo-hydraulic calculation and analysis for sub-module of Chinese HCSB TBM were carried out using FE code ANSYS. Results indicate that temperature distribution in materials used in sub-module is reasonable and acceptable.

  3. Progress of the DUPIC fuel compatibility analysis (II) - thermal-hydraulics

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joo Hwan; Choi, Hang Bok

    2005-03-01

    Thermal-hydraulic compatibility of the DUPIC fuel bundle with a 713 MWe Canada deuterium uranium (CANDU-6) reactor was studied by using both the single channel and sub-channel analysis methods. The single channel analysis provides the fuel channel flow rate, pressure drop, critical channel power, and the channel exit quality, which are assessed against the thermal-hydraulic design requirements of the CANDU-6 reactor. The single channel analysis by the NUCIRC code showed that the thermal-hydraulic performance of the DUPIC fuel is not different from that of the standard CANDU fuel. Regarding the local flow characteristics, the sub-channel analysis also showed that the uncertainty of the critical channel power calculation for the DUPIC fuel channel is very small. As a result, both the single and sub-channel analyses showed that the key thermal-hydraulic parameters of the DUPIC fuel channel do not deteriorate compared to the standard CANDU fuel channel.

  4. Dynamic Analysis & Characterization of Conventional Hydraulic Power Supply Units

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Liedhegener, Michael; Bech, Michael Møller

    2016-01-01

    Hydraulic power units operated as constant supply pres-sure systems remain to be widely used in the industry, to supply valve controlled hydraulic drives etc., where the hydraulic power units are constituted by variable pumps with mechanical outlet pressure control, driven by induction motors...... and drives will reduce the flow-to-pressure gain of the supply system, and hence increase the time constant of the sup-ply pressure dynamics. A consequence of this may be large vari-ations in the supply pressure, hence large variations in the pump shaft torque, and thereby the induction motor load torque......, with possible excitation of the induction motor dynamics as a result. In such cases, the coupled dynamics of the pressure controlled pump and induction motor may influence the supply pressure sig-nificantly, possibly affecting the dynamics of the supplied drives, especially in cases where pilot operated valves...

  5. Design Optimization of Hydraulic Press Plate using Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Akshay Vaishnav

    2016-05-01

    Full Text Available Metal forming is a process which is done by deforming metal work pieces to the desired shape and size using pressing or hammering action. Hydraulic presses are being used for forming and pressing operations with wide range of capacities. Hydraulic press machine works under continuous impact load. Because of this continuous load, tensile and compressive stresses are experienced in various parts of machine. These stresses cause permanent deformation in some parts of machine. This work is based on optimization of a 250-ton four pillar type hydraulic press considering constraints like design, weight and cost. The work is focused on design and optimization of top plate of the press machine. Top plate holds the hydraulic cylinder and is one of the most critical parts of the machine. The design is based on sizing optimization method and the results are validated by Finite Element method with proper boundary conditions. The CAD modelling has been carried out by PTC CREO and for FEA, ANSYS software is used.

  6. Verification of HYDRASTAR: Analysis of hydraulic conductivity fields and dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Morris, S.T.; Cliffe, K.A. [AEA Technology, Harwell (United Kingdom)

    1994-10-01

    HYDRASTAR is a code for the stochastic simulation of groundwater flow. It can be used to simulate both time-dependent and steady-state groundwater flow at constant density. Realizations of the hydraulic conductivity field are generated using the Turning Bands algorithm. The realizations can be conditioned on measured values of the hydraulic conductivity using Kriging. This report describes a series of verification studies that have been carried out on the code. The first study concerns the accuracy of the implementation of the Turning Bands algorithm in HYDRASTAR. The implementation has been examined by evaluating the ensemble mean and covariance of the generated fields analytically and comparing them with their prescribed values. Three other studies were carried out in which HYDRASTAR was used to solve problems of uniform mean flow and to calculate the transport and dispersion of fluid particles. In all three cases the hydraulic conductivity fields were unconditioned. The first two were two-dimensional: one at small values of the variance of the logarithm of the hydraulic conductivity for which there exists analytical results that the code can be compared with, and one at moderate variance where the results can only be compared with those obtained by another code. The third problem was three dimensional with a small variance and again analytical results are available for comparison. 14 refs, 24 figs.

  7. Comparative study of Thermal Hydraulic Analysis Codes for Pressurized Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yang Hoon; Jang, Mi Suk; Han, Kee Soo [Nuclear Engineering Service and Solution Co. Ltd., Daejeon (Korea, Republic of)

    2015-05-15

    Various codes are used for the thermal hydraulic analysis of nuclear reactors. The use of some codes among these is limited by user and some codes are not even open to general person. Thus, the use of alternative code is considered for some analysis. In this study, simple thermal hydraulic behaviors are analyzed using three codes to show that alternative codes are possible for the analysis of nuclear reactors. We established three models of the simple u-tube manometer using three different codes. RELAP5 (Reactor Excursion and Leak Analysis Program), SPACE (Safety and Performance Analysis CodE for nuclear power Plants), GOTHIC (Generation of Thermal Hydraulic Information for Containments) are selected for this analysis. RELAP5 is widely used codes for the analysis of system behavior of PWRs. SPACE has been developed based on RELAP5 for the analysis of system behavior of PWRs and licensing of the code is in progress. And GOTHIC code also has been widely used for the analysis of thermal hydraulic behavior in the containment system. The internal behavior of u-tube manometer was analyzed by RELAP5, SPACE and GOTHIC codes. The general transient behavior was similar among 3 codes. However, the stabilized status of the transient period analyzed by REPAP5 was different from the other codes. It would be resulted from the different physical models used in the other codes, which is specialized for the multi-phase thermal hydraulic behavior analysis.

  8. Status and subjects of thermal-hydraulic analysis for next-generation LWRs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The status and subjects on thermal-hydraulic analysis for next-generation light water reactors (LWRs) with passive safety systems were surveyed through about 5 years until March 1999 by subcommittee on improvement of reactor thermal-hydraulic analysis codes under the nuclear code committee in Japan Atomic Energy Research Institute. Based on the survey results and discussion, the status and subjects on system analysis for various types of proposed reactor were summarized in 1998 and those on multidimensional two-phase flow analysis were also reviewed, since the multidimensional analysis was recognized as one of the most important subjects through the investigation on system analysis. In this report, the status and subjects for the following were summarized from the survey results and discussion in 1998 and 1999; (1) BWR neutronic/thermal-hydraulic coupled analysis, (2) Evaluation of passive safety system performance and (3) Gas-liquid two-phase flow analysis. The contents in this report are the forefront of thermal-hydraulic analysis for LWRs including test results from several large-scale facilities. We expect that the contents can offer a guideline to improve reactor thermal-hydraulic analysis codes in future. (author)

  9. A quantitative analysis of hydraulic interaction processes in stream-aquifer systems.

    Science.gov (United States)

    Wang, Wenke; Dai, Zhenxue; Zhao, Yaqian; Li, Junting; Duan, Lei; Wang, Zhoufeng; Zhu, Lin

    2016-01-28

    The hydraulic relationship between the stream and aquifer can be altered from hydraulic connection to disconnection when the pumping rate exceeds the maximum seepage flux of the streambed. This study proposes to quantitatively analyze the physical processes of stream-aquifer systems from connection to disconnection. A free water table equation is adopted to clarify under what conditions a stream starts to separate hydraulically from an aquifer. Both the theoretical analysis and laboratory tests have demonstrated that the hydraulic connectedness of the stream-aquifer system can reach a critical disconnection state when the horizontal hydraulic gradient at the free water surface is equal to zero and the vertical is equal to 1. A boundary-value problem for movement of the critical point of disconnection is established for an analytical solution of the inverted water table movement beneath the stream. The result indicates that the maximum distance or thickness of the inverted water table is equal to the water depth in the stream, and at a steady state of disconnection, the maximum hydraulic gradient at the streambed center is 2. This study helps us to understand the hydraulic phenomena of water flow near streams and accurately assess surface water and groundwater resources.

  10. Unsteady flow analysis of a two-phase hydraulic coupling

    Science.gov (United States)

    Hur, N.; Kwak, M.; Lee, W. J.; Moshfeghi, M.; Chang, C.-S.; Kang, N.-W.

    2016-06-01

    Hydraulic couplings are being widely used for torque transmitting between separate shafts. A mechanism for controlling the transmitted torque of a hydraulic system is to change the amount of working fluid inside the system. This paper numerically investigates three-dimensional turbulent flow in a real hydraulic coupling with different ratios of charged working fluid. Working fluid is assumed to be water and the Realizable k-ɛ turbulence model together with the VOF method are used to investigate two-phase flow inside the wheels. Unsteady simulations are conducted using the sliding mesh technique. The primary wheel is rotating at a fixed speed of 1780 rpm and the secondary wheel rotates at different speeds for simulating different speed ratios. Results are investigated for different blade angles, speed ratios and also different water volume fractions, and are presented in the form of flow patterns, fluid average velocity and also torques values. According to the results, blade angle severely affects the velocity vector and the transmitted torque. Also in the partially-filled cases, air is accumulated in the center of the wheel forming a toroidal shape wrapped by water and the transmitted torque sensitively depends on the water volume fraction. In addition, in the fully-filled case the transmitted torque decreases as the speed ration increases and the average velocity associated with lower speed ratios are higher.

  11. Thermal-Hydraulic Analysis Tasks for ANAV NPPs in Support of Plant Operation and Control

    Directory of Open Access Journals (Sweden)

    F. Reventós

    2008-01-01

    Full Text Available Thermal-hydraulic analysis tasks aimed at supporting plant operation and control of nuclear power plants are an important issue for the Asociación Nuclear Ascó-Vandellòs (ANAV. ANAV is the consortium that runs the Ascó power plants (2 units and the Vandellòs-II power plant. The reactors are Westinghouse-design, 3-loop PWRs with an approximate electrical power of 1000 MW. The Technical University of Catalonia (UPC thermal-hydraulic analysis team has jointly worked together with ANAV engineers at different levels in the analysis and improvement of these reactors. This article is an illustration of the usefulness of computational analysis for operational support. The contents presented were operational between 1985 and 2001 and subsequently changed slightly following various organizational adjustments. The paper has two different parts. In the first part, it describes the specific aspects of thermal-hydraulic analysis tasks related to operation and control and, in the second part, it briefly presents the results of three examples of analyses that were performed. All the presented examples are related to actual situations in which the scenarios were studied by analysts using thermal-hydraulic codes and prepared nodalizations. The paper also includes a qualitative evaluation of the benefits obtained by ANAV through thermal-hydraulic analyses aimed at supporting operation and plant control.

  12. Thermal-hydraulic analysis of LTS cables for the DEMO TF coil using simplified models

    Directory of Open Access Journals (Sweden)

    Lewandowska Monika

    2017-03-01

    Full Text Available The conceptual design activities for the DEMOnstration reactor (DEMO – the prototype fusion power plant – are conducted in Europe by the EUROfusion Consortium. In 2015, three design concepts of the DEMO toroidal field (TF coil were proposed by Swiss Plasma Center (EPFL-SPC, PSI Villigen, Italian National Agency for New Technologies (ENEA Frascati, and Atomic Energy and Alternative Energies Commission (CEA Cadarache. The proposed conductor designs were subjected to complete mechanical, electromagnetic, and thermal-hydraulic analyses. The present study is focused on the thermal-hydraulic analysis of the candidate conductor designs using simplified models. It includes (a hydraulic analysis, (b heat removal analysis, and (c assessment of the maximum temperature and the maximum pressure in each conductor during quench. The performed analysis, aimed at verification whether the proposed design concepts fulfil the established acceptance criteria, provides the information for further improvements of the coil and conductors design.

  13. Steady thermal hydraulic analysis for a molten salt reactor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dalin; QIU Suizheng; LIU Changliang; SU Guanghui

    2008-01-01

    The Molten Salt Reactor (MSR) can meet the demand of transmutation and breeding. In this study, theoretical calculation of steady thermal hydraulic characteristics of a graphite-moderated channel type MSR is conducted. The DRAGON code is adopted to calculate the axial and radial power factor firstly. The flow and heat transfer model in the fuel salt and graphite are developed on basis of the fundamental mass, momentum and energy equations. The results show the detailed flow distribution in the core, and the temperature profiles of the fuel salt, inner and outer wall in the nine typical elements along the axial flow direction are also obtained.

  14. Mitigation method of thermal transient stress by a total analysis of thermal hydraulic and structural phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Kasahara, Naoto [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Jinbo, Masakazu [Toshiba Co., Tokyo (Japan); Hosogai, Hiromi [Joyo Industry Co., Ltd., Tokai, Ibaraki (Japan)

    2002-09-01

    This study proposes a mitigation method of thermal transient loads in fast reactor components by utilizing relationships among plant system parameters and resulting thermal stresses. Conventional design procedure against thermal transient loads has two independent steps: thermal hydraulic analysis to determine conservative thermal transient conditions considering variation of the system parameters and structural analysis to check structural integrity under given conditions. On the other hand, a total analysis procedure of thermal hydraulic and structural phenomena can grasp the relationship among system parameters and thermal stresses. It enables the mitigation of thermal transient loads by adjusting system parameters. (author)

  15. Application of computational fluid dynamics methods to improve thermal hydraulic code analysis

    Science.gov (United States)

    Sentell, Dennis Shannon, Jr.

    A computational fluid dynamics code is used to model the primary natural circulation loop of a proposed small modular reactor for comparison to experimental data and best-estimate thermal-hydraulic code results. Recent advances in computational fluid dynamics code modeling capabilities make them attractive alternatives to the current conservative approach of coupled best-estimate thermal hydraulic codes and uncertainty evaluations. The results from a computational fluid dynamics analysis are benchmarked against the experimental test results of a 1:3 length, 1:254 volume, full pressure and full temperature scale small modular reactor during steady-state power operations and during a depressurization transient. A comparative evaluation of the experimental data, the thermal hydraulic code results and the computational fluid dynamics code results provides an opportunity to validate the best-estimate thermal hydraulic code's treatment of a natural circulation loop and provide insights into expanded use of the computational fluid dynamics code in future designs and operations. Additionally, a sensitivity analysis is conducted to determine those physical phenomena most impactful on operations of the proposed reactor's natural circulation loop. The combination of the comparative evaluation and sensitivity analysis provides the resources for increased confidence in model developments for natural circulation loops and provides for reliability improvements of the thermal hydraulic code.

  16. Thermal-Hydraulic Analysis Tasks for ANAV NPPs in Support of Plant Operation and Control

    OpenAIRE

    2007-01-01

    Thermal-hydraulic analysis tasks aimed at supporting plant operation and control of nuclear power plants are an important issue for the Asociación Nuclear Ascó-Vandellòs (ANAV). ANAV is the consortium that runs the Ascó power plants (2 units) and the Vandellòs-II power plant. The reactors are Westinghouse-design, 3-loop PWRs with an approximate electrical power of 1000 MW. The Technical University of Catalonia (UPC) thermal-hydraulic analysis team has jointly worked togeth...

  17. In-depth analysis of bicycle hydraulic disc brakes

    Science.gov (United States)

    Maier, Oliver; Györfi, Benedikt; Wrede, Jürgen; Arnold, Timo; Moia, Alessandro

    2017-10-01

    Hydraulic Disc Brakes (HDBs) represent the most recent and innovative bicycle braking system. Especially Electric Bicycles (EBs), which are becoming more and more popular, are equipped with this powerful, unaffected by environmental influences, and low-wear type of brakes. As a consequence of the high braking performance, typical bicycle braking errors lead to more serious accidents. This is the starting point for the development of a Braking Dynamics Assistance system (BDA) to prevent front wheel lockup and nose-over (falling over the handlebars). One of the essential prerequisites for the system design is a better understanding of bicycle HDBs' characteristics. A physical simulation model and a test bench have been built for this purpose. The results of the virtual and real experiments conducted show a high correlation and allow valuable insights into HDBs on bicycles, which have not been studied scientifically in any depth so far.

  18. Development of two-phase pipeline hydraulic analysis model based on Beggs-Brill correlation

    Science.gov (United States)

    Waluyo, Joko; Hermawan, Achilleus; Indarto

    2016-06-01

    The hydraulic analysis is an important stage in a reliable pipeline design. In the implementation, fluid distribution from a source to the sinks often occurs on parallel pipeline networks. The solution to the problem is complicated because of the iterative technique requirement. Regarding its solution effectiveness, there is a need for analysis related to the model and the solution method. This study aims to investigate pipeline hydraulic analysis on distributing of two-phase fluids flow. The model uses Beggs-Brill correlation to converse mass flow rates into pressure drops. In the solution technique, the Newton-Raphson iterative method is utilized. The iterative technique is solved using a computer program. The study is carried out using a certain pipeline network. The model is validated by comparing between Beggs-Brill towards Mukherjee-Brill correlation. The result reveals that the computer program enables solving of iterative calculation on the parallel pipeline hydraulic analysis. Convergence iteration is achieved by 50 iterations. The main results of the model are mass flow rate and pressure drop. The mass flow rate is obtained in the deviation up to 2.06%, between Beggs-Brill and Mukherjee-Brill correlation. On the other hand, the pressure gradient deviation is achieved on a higher deviation due to the different approach of the two correlations. The model can be further developed in the hydraulic pipeline analysis for two-phase flow.

  19. Thermal Hydraulic Analysis of K-DEMO Single Blanket Module for Preliminary Accident Analysis using MELCOR

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Bo; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of)

    2016-05-15

    To develop the Korean fusion commercial reactor, preliminary design concept for K-DEMO (Korean fusion demonstration reactor) has been announced by NFRI (National Fusion Research Institute). This pre-conceptual study of K-DEMO has been introduced to identify technical details of a fusion power plant for the future commercialization of fusion reactor in Korea. Before this consideration, to build the K-DEMO, accident analysis is essential. Since the Fukushima accident, which is severe accident from unexpected disaster, safety analysis of nuclear power plant has become important. The safety analysis of both fission and fusion reactors is deemed crucial in demonstrating the low radiological effect of these reactors on the environment, during severe accidents. A risk analysis of K-DEMO should be performed, as a prerequisite for the construction of a fusion reactor. In this research, thermal-hydraulic analysis of single blanket module of K-DEMO is conducted for preliminary accident analysis for K-DEMO. Further study about effect of flow distributer is conducted. The normal K-DEMO operation condition is applied to the boundary condition and simulated to verify the material temperature limit using MELCOR. MELCOR is fully integrated, relatively fast-running code developed by Sandia National Laboratories. MELCOR had been used for Light Water Reactors and fusion reactor version of MELCOR was developed for ITER accident analysis. This study shows the result of thermal-hydraulic simulation of single blanket module with MELCOR which is severe accident code for nuclear fusion safety analysis. The difference of mass flow rate for each coolant channel with or without flow distributer is presented. With flow distributer, advantage of broadening temperature gradient in the K-DEMO blanket module and increase mass flow toward first wall is obtained. This can enhance the safety of K-DEMO blanket module. Most 13 .deg. C temperature difference in blanket module is obtained.

  20. Thermal APU/hydraulics analysis program. User's guide and programmer's manual

    Science.gov (United States)

    Deluna, T. A.

    1976-01-01

    The User's Guide information plus program description necessary to run and have a general understanding of the Thermal APU/Hydraulics Analysis Program (TAHAP) is described. This information consists of general descriptions of the APU/hydraulic system and the TAHAP model, input and output data descriptions, and specific subroutine requirements. Deck setups and input data formats are included and other necessary and/or helpful information for using TAHAP is given. The math model descriptions for the driver program and each of its supporting subroutines are outlined.

  1. SUPERENERGY-2: a multiassembly, steady-state computer code for LMFBR core thermal-hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Basehore, K.L.; Todreas, N.E.

    1980-08-01

    Core thermal-hydraulic design and performance analyses for Liquid Metal Fast Breeder Reactors (LMFBRs) require repeated detailed multiassembly calculations to determine radial temperature profiles and subchannel outlet temperatures for various core configurations and subassembly structural analyses. At steady-state, detailed core-wide temperature profiles are required for core restraint calculations and subassembly structural analysis. In addition, sodium outlet temperatures are routinely needed for each reactor operating cycle. The SUPERENERGY-2 thermal-hydraulic code was designed specifically to meet these designer needs. It is applicable only to steady-state, forced-convection flow in LMFBR core geometries.

  2. Analysis of load transfer stability control strategy in hydraulic synchronized continuous slippage

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-bo; WU Jian-zhong; ZHANG Xuan

    2006-01-01

    Hydraulic synchronized continuous slippage technique,which integrates mechanical,electrical and hydraulic control,is introduced in this paper for the practical requirements of some construction projects.The core of this technique (the stability of the load transfer) is illustrated in detail.Three speed control strategies to transfer the load-excessive,lower and same speed-are presented to accomplish the smoothness and stability in the process of slippage.An optimization of the speed control strategy (same speed) is deduced from the modeling analysis and its validity and maneuverability are tested by practical application,which provides evidence for similar engineering in theory and practice.

  3. Kinematic and Dynamic Simulation Analysis of Hydraulic Excavator’s Working Equipment based on ADAMS

    Directory of Open Access Journals (Sweden)

    Yu Hong Yan

    2016-01-01

    Full Text Available This paper establishes the 3D excavator model according to the actual size in UG firstly. Then based on the virtual simulation software ADAMS, the virtual prototype of the working device is built by adding interrelated constraints(kinematic pair and hydraulic cylinder driving function and load secondly. This paper gets the main parameters of the excavator working scope and the pressure situation change curves of point of each hydraulic cylinder by making kinematic and dynamic simulation analysis of hydraulic excavator’s working equipment at last. The conclusion providing design theory and improvement for the excavator’s working device, which also play an important role in improving the level of China’s excavator design, enhancing excavator’s performance and promoting the rapid development of excavator industry.

  4. RELIABILITY-BASED DESIGN AND ANALYSIS ON HYDRAULIC SYSTEM FOR SYNTHETIC RUBBER PRESS

    Institute of Scientific and Technical Information of China (English)

    Yao Chengyu; Zhao Jingyi

    2005-01-01

    To overcome the design limitations of traditional hydraulic control system for synthetic rubber press and such faults as high fault rate, low reliability, high energy-consuming and which always led to shutting down of post-treatment product line for synthetic rubber, brand-new hydraulic system combining with PC control and two-way cartridge valves for the press is developed, whose reliability is analyzed, reliability model of the hydraulic system for the press is established by analyzing processing steps, and reliability simulation of each step and the whole system is carried out by software MATLAB, which is verified through reliability test. The fixed time test has proved not that theory analysis is sound, but the system has characteristics of reasonable design and high reliability,and can lower the required power supply and operational energy cost.

  5. Analysis on the Pressure Fluctuation Law of a Hydraulic Exciting System with a Wave-exciter

    Institute of Scientific and Technical Information of China (English)

    WEI Xiu-ye; KOU Zi-ming; LU Zi-rong

    2011-01-01

    A hydraulic exciting system with a wave exciter has been constructed in order to study the hydraulic vibra- tion law. The system consists of an oil source, wave-exciter and oil cylinder, and is controlled by a wave-exciter. The working principle of the hydraulic exciting system and wave exciter has been analyzed, and its excitation process has been illustrated. The law of every pipe's pressure fluctuation of the system is obtained by experiment. The theo- retical analysis and experimental data prove that the pipeline pressure periodically changes and the pipeline pressure fluctuation frequency is independently controlled by the excitation frequency of the wave-exciter. Every pipelinc's pressure wave is produced by system flow fluctuation and water hammer coupling. The pressure fluctuation rules of the system provide a theoretical basis for the study of the associated liberation system.

  6. Advances in thermal hydraulic and neutronic simulation for reactor analysis and safety

    Energy Technology Data Exchange (ETDEWEB)

    Tentner, A.M.; Blomquist, R.N.; Canfield, T.R.; Ewing, T.F.; Garner, P.L.; Gelbard, E.M.; Gross, K.C.; Minkoff, M.; Valentin, R.A.

    1993-03-01

    This paper describes several large-scale computational models developed at Argonne National Laboratory for the simulation and analysis of thermal-hydraulic and neutronic events in nuclear reactors and nuclear power plants. The impact of advanced parallel computing technologies on these computational models is emphasized.

  7. HYDRAULICS, LOUISA COUNTY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydraulic analysis for estimating flood stages for a flood insurance study. It...

  8. Uncertainty analysis with reliability techniques of fluvial hydraulic simulations

    Science.gov (United States)

    Oubennaceur, K.; Chokmani, K.; Nastev, M.

    2016-12-01

    Flood inundation models are commonly used to simulate hydraulic and floodplain inundation processes, prerequisite to successful floodplain management and preparation of appropriate flood risk mitigation plans. Selecting statistically significant ranges of the variables involved in the inundation modelling is crucial for the model performance. This involves various levels of uncertainty, which due to the cumulative nature can lead to considerable uncertainty in the final results. Therefore, in addition to the validation of the model results, there is a need for clear understanding and identifying sources of uncertainty and for measuring the model uncertainty. A reliability approach called Point-Estimate Method is presented to quantify uncertainty effects of the input data and to calculate the propagation of uncertainty in the inundation modelling process. The Point Estimate Method is a special case of numerical quadrature based on orthogonal polynomials. It allows to evaluate the low order of performance functions of independent random variables such the water depth. The variables considered in the analyses include elevation data, flow rate and Manning's coefficient n given with their own probability distributions. The approach is applied to a 45 km reach of the Richelieu River, Canada, between Rouses point and Fryers Rapids. The finite element hydrodynamic model H2D2 was used to solve the shallow water equations (SWE) and provide maps of expected water depths associated spatial distributions of standard deviations as a measure of uncertainty. The results indicate that for the simulated flow rates of 1113, 1206, and 1282, the uncertainties in water depths have a range of 25 cm, 30cm, and 60 cm, respectively. This kind of information is useful information for decision-making framework risk management in the context flood risk assessment.

  9. Quantification of LOCA core damage frequency based on thermal-hydraulics analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jaehyun, E-mail: chojh@kaeri.re.kr; Park, Jin Hee; Kim, Dong-San; Lim, Ho-Gon

    2017-04-15

    Highlights: • We quantified the LOCA core damage frequency based on the best-estimated success criteria analysis. • The thermal-hydraulic analysis using MARS code has been applied to Korea Standard Nuclear Power Plants. • Five new event trees with new break size boundaries and new success criteria were developed. • The core damage frequency is 5.80E−07 (/y), which is 12% less than the conventional PSA event trees. - Abstract: A loss-of-coolant accident (LOCA) has always been significantly considered one of the most important initiating events. However, most probabilistic safety assessment models, up to now, have undoubtedly adopted the three groups of LOCA, and even an exact break size boundary that used in WASH-1400 reports was published in 1975. With an awareness of the importance of a realistic PSA for a risk-informed application, several studies have tried to find the realistic thermal-hydraulic behavior of a LOCA, and improve the PSA model. The purpose of this research is to obtain realistic results of the LOCA core damage frequency based on a success criteria analysis using the best-estimate thermal-hydraulics code. To do so, the Korea Standard Nuclear Power Plant (KSNP) was selected for this study. The MARS code was used for a thermal hydraulics analysis and the AIMS code was used for the core damage quantification. One of the major findings in the thermal hydraulics analysis was that the decay power is well removed by only a normal secondary cooling in LOCAs of below 1.4 in and by only a high pressure safety injection in LOCAs of 0.8–9.4 in. Based on the thermal hydraulics results regarding new break size boundaries and new success criteria, five new event trees (ETs) were developed. The core damage frequency of new LOCA ETs is 5.80E−07 (/y), which is 12% less than the conventional PSA ETs. In this research, we obtained not only thermal-hydraulics characteristics for the entire break size of a LOCA in view of the deterministic safety

  10. Thermal hydraulic similarity analysis of the integral effect test facility for main steam line break events

    Energy Technology Data Exchange (ETDEWEB)

    Choi, K.Y.; Park, H.S.; Euh, D.J.; Kwon, T.S.; Baek, W.P. [Thermal Hydraulic Safety Research Division Korea Atomic Energy Research Institute 150 Dukjin-Dong, Yusong-Gu, Daejeon 305-353 (Korea, Republic of)

    2005-07-01

    Full text of publication follows: A thermal-hydraulic integral effect test facility, ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation), is being constructed at Korea Atomic Energy Research Institute (KAERI). The ATLAS is a 1/2 reduced height and 1/288 volume scaled test facility based on the design features of the APR1400, an evolutionary pressurized water reactor developed by Korean industry. The ATLAS will be used to get more realistic understanding of the thermal hydraulic phenomena following postulated events and to carry out performance evaluation and safety analysis of the reference plants. The MSLB (Main Steam Line Break) event is one of the representative non-LOCA events and thermalhydraulic phenomena following the event are to be investigated in the ATLAS. In this paper, thermal hydraulic similarity for MSLB events between the ATLAS and the prototype plant, APR1400 is assessed by using the MARS code, which is a multi-dimensional best-estimate thermal hydraulic code being developed by KAERI. Several cases including SLBFPLOOP and SLBFP are taken into account for similarity analysis in this paper. The neutronic effects such as moderator temperature coefficients and doppler reactivity in APR1400 are not considered in this study. The same control logics for the major sequence of events such as reactor trip, turbine trip, valve opening and actuation of the emergency cooling system are applied to the ATLAS and the APR1400. The present investigation is focused on the scaling and the reduced power effects on thermal hydraulic similarity after initiation of MSLB events. It is found that the ATLAS facility has the similar thermal hydraulic responses against the MSLB events. However, the initial high secondary pressure before the MSLB initiation resulted in different primary pressure and temperature progression from the APR1400. The break flow from the main steam line is found to be one of the most dominating parameters governing the transient

  11. Spatial Prediction of Hydraulic Zones from Soil Properties and Secondary Data Using Factorial Kriging Analysis

    Science.gov (United States)

    Bevington, James; Morari, Francesco; Scudiero, Elia; Teatini, Pietro; Vellidis, George

    2015-04-01

    The development of pedotransfer functions (PTF) is an important topic in soil science research because there is a critical need for incorporation of vadose zone phenomena into large scale climate models. Soil measurements are inherently spatially dependent and therefore application of geospatial statistics provides an avenue for estimating soil properties. The aim of this study is to define management zones based on soil hydraulic properties. Samples were collected from 50 locations at 4 depths in a 20.8ha field located in the Po River delta in Italy. Water retention curves (WRC) and unsaturated hydraulic conductivity curves (UHC) and were determined via inversion of measurements taken using the Wind (Dane and Topp, 1994) method. This region is in known to have paleo-channel structures and highly heterogeneous soils. Factorial kriging analysis (FKA) was applied to hydraulic parameters in one data set and soil physical properties in another data set at 4 depths. The mapped principal components (PCs) were used in a fuzzy-c means algorithm to define zones of like properties. To examine the physical significance of these zones, curve parameters and hydraulic curves were investigated. Zones were able to distinguish between θ_s(saturated water content), n (shape parameter) and α (inverse of air entry) while θr (residual water content) and Ks (saturated conductivity) were not statistically different between the groups. For curve comparisons, WRC were found to be significantly different between zones at all tensions while effective saturation curves (Se) differ for the majority of tensions (except at 28cm), but UHC did not differ. The spatial relevance of the zones was examined by overlaying hydraulic zones with zones defined using the FKA and fuzzy-c means approach from soil physical properties such as texture and bulk density. The hydraulic zones overlaid with areal accuracy ranging from 46.66% to 92.41%. As there is much similarity between these sets of zones, there

  12. THERMAL HYDRAULIC ANALYSIS OF A LIQUID-METAL-COOLED NEUTRON SPALLATION TARGET

    Energy Technology Data Exchange (ETDEWEB)

    W. GREGORY; R. MARTIN; T. VALACHOVIC

    2000-07-01

    We have carried out numerical simulations of the thermal hydraulic behavior of a neutron spallation target where liquid metal lead-bismuth serves as both coolant and as a neutron spallation source. The target is one of three designs provided by the Institute of Physics and Power Engineering (IPPE) in Russia. This type of target is proposed for Accelerator-driven Transmutation of Waste (ATW) to eliminate plutonium from hazardous fission products. The thermal hydraulic behavior was simulated by use of a commercial CFD computer code called CFX. Maximum temperatures in the diaphragm window and in the liquid lead were determined. In addition the total pressure drop through the target was predicted. The results of the CFX analysis were close to those results predicted by IPPE in their preliminary analysis.

  13. Determination of minimum sample size for fault diagnosis of automobile hydraulic brake system using power analysis

    Directory of Open Access Journals (Sweden)

    V. Indira

    2015-03-01

    Full Text Available Hydraulic brake in automobile engineering is considered to be one of the important components. Condition monitoring and fault diagnosis of such a component is very essential for safety of passengers, vehicles and to minimize the unexpected maintenance time. Vibration based machine learning approach for condition monitoring of hydraulic brake system is gaining momentum. Training and testing the classifier are two important activities in the process of feature classification. This study proposes a systematic statistical method called power analysis to find the minimum number of samples required to train the classifier with statistical stability so as to get good classification accuracy. Descriptive statistical features have been used and the more contributing features have been selected by using C4.5 decision tree algorithm. The results of power analysis have also been verified using a decision tree algorithm namely, C4.5.

  14. Static Analysis of High-Performance Fixed Fluid Power Drive with a Single Positive-Displacement Hydraulic Motor

    Directory of Open Access Journals (Sweden)

    O. F. Nikitin

    2015-01-01

    Full Text Available The article deals with the static calculations in designing a high-performance fixed fluid power drive with a single positive-displacement hydraulic motor. Designing is aimed at using a drive that is under development and yet unavailable to find and record the minimum of calculations and maximum of existing hydraulic units that enable clear and unambiguous performance, taking into consideration an available assortment of hydraulic units of hydraulic drives, to have the best efficiency.The specified power (power, moment and kinematics (linear velocity or angular velocity of rotation parameters of the output element of hydraulic motor determine the main output parameters of the hydraulic drive and the useful power of the hydraulic drive under development. The value of the overall efficiency of the hydraulic drive enables us to judge the efficiency of high-performance fixed fluid power drive.The energy analysis of a diagram of the high-performance fixed fluid power drive shows that its high efficiency is achieved when the flow rate of fluid flowing into each cylinder and the magnitude of the feed pump unit (pump are as nearly as possible.The paper considers the ways of determining the geometric parameters of working hydromotors (effective working area or working volume, which allow a selection of the pumping unit parameters. It discusses the ways to improve hydraulic drive efficiency. Using the principle of holding constant conductivity allows us to specify the values of the pressure losses in the hydraulic units used in noncatalog modes. In case of no exact matching between the parameters of existing hydraulic power modes and a proposed characteristics of the pump unit, the nearest to the expected characteristics is taken as a working version.All of the steps allow us to create the high-performance fixed fluid power drive capable of operating at the required power and kinematic parameters with high efficiency.

  15. Thermal-hydraulic Analysis of New Zirconium Alloys Assembly Irradiated in CARR

    Institute of Scientific and Technical Information of China (English)

    YIN; Hao; ZHAO; Shou-zhi; LIU; Xing-min

    2013-01-01

    This article is mainly about the thermal-hydraulic analysis of the new zirconium alloys assembly on irradiation test of China Advanced Research Reactor(CARR),so as to provide security assessment throughout the design.CFD software was used for three-dimensional simulation.Firstly,the geometric model,mesh,specified boundary condition types and region types were constructed.Then importing the

  16. RELIABILITY ANALYSIS OF THE PRIMARY CYLINDER OF THE 10 MN HYDRAULIC PRESS

    Institute of Scientific and Technical Information of China (English)

    Zhao Jingyi; Zhuoru; Wang Yiqun

    2000-01-01

    According to the demand of high reliability of the primary cylinder of the hydraulic press,the reliability model of the primary cylinder is built after its reliability analysis.The stress of the primary cylinder is analyzed by finite element software-MARC,and the structure reliability of the cylinder based on stress-strength model is predicted,which would provide the reference to the design.

  17. Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. O' Brien; Andrew C. Klein; William T. Taitano; Justice Gibson; Brian Myers; Steven D. Howe

    2011-02-01

    Thermal-hydraulics analyses results produced using a combined suite of computational design and analysis codes are presented for the preliminary design of a concept Radioisotope Thermal Rocket (RTR) propulsion system. Modeling of the transient heating and steady state temperatures of the system is presented. Simulation results for propellant blow down during impulsive operation are also presented. The results from this study validate the feasibility of a practical thermally capacitive RTR propulsion system.

  18. Development of Regulatory Thermal-Hydraulic Analysis System (RETAS)

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Seung-Hoon; Kim, In-Goo; Kim, Hho-Jung; Cho, Yong Jin [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2007-10-15

    A review is provided of the reasons why the Korea Institute of Nuclear Safety needs improvement of the existing codes employed for a regulatory audit. The proposed new organization of the codes, developed or to be developed, is presented together with illustrative applications. Inspection of the quality assurance activities is planned to ensure the robustness of MARS (Multi-dimensional Analysis for Reactor Safety) code, served as a pivot of the organization.

  19. Numerical Flow Analysis of a Hydraulic Gear Pump

    Science.gov (United States)

    Panta, Yogendra M.; Kim, Hyun W.; Pierson, Hazel M.

    2007-11-01

    The pressure that exists at the outlet port of a gear pump is a result of system load that was created by a resistance to the fluid flow. However, the flow pattern created inside an external gear pump by the motion of two oppositely rotating gears is deceptively complex, despite the simple geometry of the gear pump. The flow cannot be analyzed, based on a steady-state assumption that is usually employed to analyze turbo-machinery although the flow is essentially steady. Only the time-dependent, transient analysis with moving dynamic meshing technique can predict the motion of the fluid flow against the very high adverse pressure distribution. Although the complexity of analysis is inherent in all positive displacement pumps, gear pumps pose an exceptional challenge in modeling due to the fact that there are two rotating components that are housed within a stationary casing and the gears must be in contact with each other all the time. Fluent, commercially available computational fluid dynamics (CFD) software was used to analyze the flow of the gear pump. The investigation done by CFD produced significant information on flow patterns, velocity and pressure fields, and flow rates.

  20. Effect of Dimensions of Crimped Portion upon Sealing Performance of Hydraulic Brake Hose by Applying Three-Dimensional FEM Analysis

    National Research Council Canada - National Science Library

    NODA, Nao-Aki; KIM, Bongkee; OTA, Kento; KAWAHARA, Hirofumi; SHINOZAKI, Takahiro

    2013-01-01

    .... In this study, three-dimensional FEM analysis has been applied to the crimped portion of hydraulic brake hose in order to investigate the effects of manufacturing errors upon the sealing performance...

  1. Particle Swarm Optimization for Hydraulic Analysis of Water Distribution Systems

    Directory of Open Access Journals (Sweden)

    Naser Moosavian

    2015-06-01

    Full Text Available The analysis of flow in water-distribution networks with several pumps by the Content Model may be turned into a non-convex optimization uncertain problem with multiple solutions. Newton-based methods such as GGA are not able to capture a global optimum in these situations. On the other hand, evolutionary methods designed to use the population of individuals may find a global solution even for such an uncertain problem. In the present paper, the Content Model is minimized using the particle-swarm optimization (PSO technique. This is a population-based iterative evolutionary algorithm, applied for non-linear and non-convex optimization problems. The penalty-function method is used to convert the constrained problem into an unconstrained one. Both the PSO and GGA algorithms are applied to analyse two sample examples. It is revealed that while GGA demonstrates better performance in convex problems, PSO is more successful in non-convex networks. By increasing the penalty-function coefficient the accuracy of the solution may be improved considerably.

  2. Combined Thermo-Hydraulic Analysis of a Cryogenic Jet

    CERN Document Server

    Chorowski, M

    1999-01-01

    A cryogenic jet is a phenomenon encountered in different fields like some technological processes and cryosurgery. It may also be a result of cryogenic equipment rupture or a cryogen discharge from the cryostats following resistive transition in superconducting magnets. Heat exchange between a cold jet and a warm steel element (e.g. a buffer tank wall or a transfer line vacuum vessel wall) may result in an excessive localisation of thermal strains and stresses. The objective of the analysis is to get a combined (analytical and experimental) one-dimensional model of a cryogenic jet that will enable estimation of heat transfer intensity between the jet and steel plate with a suitable accuracy for engineering applications. The jet diameter can only be determined experimentally. The mean velocity profile can be calculated from the fact that the total flux of momentum along the jet axis is conserved. The proposed model allows deriving the jet crown area with respect to the distance from the vent and the mean veloc...

  3. Numerical Methods for an Analysis of Hydrogen Behaviors Coupled with Thermal Hydraulics in a NPP Containment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongtae; Park, Rae-Joon; Hong, Seong-Wan; Kim, Gun-Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In a containment safety analysis, multi-dimensional characteristics in thermal hydraulics are very important because the flow paths are not confined in a large free volume of the containment. The analysis is difficult because of a difference in length scales between a characteristic length of the flow and representative length of the containment. In order to simulate hydrogen and steam behaviors in a containment during postulated severe accidents, the GASFLOW code as a multi-dimensional analysis tool for NPP containment has been used for years because of its computational efficiency. Though GASFLOW is well developed for a real NPP containment analysis, there exist shortcomings in nodalization, two-phase and turbulence models. It is based on a Cartesian or cylindrical coordinate mesh, so it is impractical to refine a mesh locally in a region with a physical or geometrical complication. In this paper, the importance of the hydrogen safety in an NPP containment and requirements of the analysis tool was described. And physical models necessary for the hydrogen safety analysis code were listed. As a member of international collaborative project HYMERES for containment thermal hydraulics, KAERI is actively participating in an analytic working group. As an analysis tool for blind benchmarkes, the analysis code described in this paper was used. From the blind benchmark analyses, it was found that the code is very promising for hydrogen safety analysis. Currently, it is proposed to develop the code collaboratively in a hydrogen safety community based on an open-source strategy.

  4. Development of best estimate auditing code for CANDU thermal hydraulic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. D.; Lee, W. J.; Lim, H. S. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-04-15

    The main purpose of this study is to develop a thermal hydraulic auditing code for the CANDU reactor, modifying the model of existing PWR auditing tool, i.e. RELAP5/MOD3. This scope of project is first step of the whole project, thus focus to the establishment of improvement area. The study was performed by reconsideration of the previous code assessment works and investigation of AECL design analysis tools. In order to identify the thermal hydraulic phenomena for events, the whole system of CANDU plant was divided into main functional systems and subcomponents. Each phenomena was addressed to the each subcomponent. FinaIly improvement areas of model development for auditing tool were established based on the identified phenomena.

  5. Development of best estimate auditing code for CANDU thermal hydraulic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. D.; Lee, W. J.; Lim, H. S. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    1998-04-01

    The main purpose of this study is to develop a thermal hydraulic auditing code for the CANDU reactor, modifying the model of existing PWR auditing tool, i.e. RELAP5/MOD3. This scope of project is first step of the whole project, thus focus to the establishment of improvement area. The study was performed by reconsideration of the previous code assessment works and investigation of AECL design analysis tools. In order to identify the thermal hydraulic phenomena for events, the whole system of CANDU plant was divided into main functional systems and subcomponents. Each phenomena was addressed to the each subcomponent. Finally improvement areas of model development for auditing tool were established based on the identified phenomena. 8 refs., 21 figs., 19 tabs. (Author)

  6. 3D thermal-hydraulic analysis of two irregular field joints for the ITER vacuum vessel

    Energy Technology Data Exchange (ETDEWEB)

    Savoldi, Laura, E-mail: laura.savoldi@polito.it [Dipartimento Energia, Politecnico di Torino, I-10129 Torino (Italy); Bonifetto, Roberto [Dipartimento Energia, Politecnico di Torino, I-10129 Torino (Italy); Izquierdo, Jesus [Fusion for Energy, ES-08019 Barcelona (Spain); Le Barbier, Robin; Utin, Yuri [ITER Organization, Route de Vinon sur Verdon, CS 90 046, 13067 Saint Paul Lez Durance Cedex (France); Zanino, Roberto [Dipartimento Energia, Politecnico di Torino, I-10129 Torino (Italy)

    2015-10-15

    Highlights: • ITER vacuum vessel irregular field joints analyzed with ANSYS-FLUENT. • Steady-state thermal-hydraulic performance evaluated with 3D analysis. • Pressure drop comparable to that of regular field joints. • Acceptable hot spots on the inner shell and ports. • Heat transfer coefficient above the target value of 500 W/m{sup 2} K on the inner shell. - Abstract: In ITER, so-called “Irregular” Field Joints (IFJs) are foreseen at the interface between irregular sectors of the Vacuum Vessel (VV), which is located inside the cryostat and houses the in-vessel components. In the IFJs, a peculiar design of the equatorial port, with respect to that adopted in the Regular Field Joints (RFJs), accommodates the irregularities of the adjacent VV sectors. The IFJs are subject to nuclear heating and actively cooled by sub-cooled pressurized water flowing in a dedicated hydraulic loop, which includes the space left open by the borated In-Wall Shielding (IWS). Here we perform the 3D steady state thermal-hydraulic analysis of two different IFJs using the Computational Fluid Dynamics (CFD) software ANSYS-FLUENT{sup ®}. The water flow field, the pressure drop and the temperature maps are computed. The thermal performance of the IFJs in nominal operation is compared to that of an RFJ and it is shown that also in this case enough cooling capability is available to avoid hot spots above the design limits, while the pressure drop remains acceptably low.

  7. Thermo-hydraulic analysis of the cool-down of the EDIPO test facility

    Science.gov (United States)

    Lewandowska, Monika; Bagnasco, Maurizio

    2011-09-01

    The first cool-down of the EDIPO (European DIPOle) test facility is foreseen to take place in 2011 by means of the existing 1.2 kW cryoplant at EPFL-CRPP Villigen. In this work, the thermo-hydraulic analysis of the EDIPO cool-down is performed in order both to assess the its duration and to optimize the procedure. The cool-down is driven by the helium flowing in both the outer cooling channel and in the windings connected hydraulically in parallel. We take into account limitations due to the pressure drop in the cooling circuit and the refrigerator capacity as well as heat conduction in the iron yoke. Two schemes of the hydraulic cooling circuit in the EDIPO windings are studied (coils connected in series and coils connected in parallel). The analysis is performed by means of an analytical model complemented by and numerical model. The results indicate that the cool-down to 5 K can be achieved in about 12 days.

  8. Development of numerical simulation system for thermal-hydraulic analysis in fuel assembly of sodium-cooled fast reactor

    Science.gov (United States)

    Ohshima, Hiroyuki; Uwaba, Tomoyuki; Hashimoto, Akihiko; Imai, Yasutomo; Ito, Masahiro

    2015-12-01

    A numerical simulation system, which consists of a deformation analysis program and three kinds of thermal-hydraulics analysis programs, is being developed in Japan Atomic Energy Agency in order to offer methodologies to clarify thermal-hydraulic phenomena in fuel assemblies of sodium-cooled fast reactors under various operating conditions. This paper gives the outline of the system and its applications to fuel assembly analyses as a validation study.

  9. Development of numerical simulation system for thermal-hydraulic analysis in fuel assembly of sodium-cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ohshima, Hiroyuki; Uwaba, Tomoyuki [Japan Atomic Energy Agency (4002 Narita, O-arai, Ibaraki 311-1393, Japan) (Japan); Hashimoto, Akihiko; Imai, Yasutomo [NDD Corporation (1-1-6 Jounan, Mito, Ibaraki 310-0803, Japan) (Japan); Ito, Masahiro [NESI Inc. (4002 Narita, O-arai, Ibaraki 311-1393, Japan) (Japan)

    2015-12-31

    A numerical simulation system, which consists of a deformation analysis program and three kinds of thermal-hydraulics analysis programs, is being developed in Japan Atomic Energy Agency in order to offer methodologies to clarify thermal-hydraulic phenomena in fuel assemblies of sodium-cooled fast reactors under various operating conditions. This paper gives the outline of the system and its applications to fuel assembly analyses as a validation study.

  10. A comprehensive numerical analysis of the hydraulic behavior of a permeable pavement

    Science.gov (United States)

    Brunetti, Giuseppe; Šimůnek, Jiří; Piro, Patrizia

    2016-09-01

    The increasing frequency of flooding events in urban catchments related to an increase in impervious surfaces highlights the inadequacy of traditional urban drainage systems. Low Impact Development (LID) techniques have proven to be a viable and effective alternative by reducing stormwater runoff and increasing the infiltration and evapotranspiration capacity of urban areas. However, the lack of adequate modeling tools represents a barrier in designing and constructing such systems. This paper investigates the suitability of a mechanistic model, HYDRUS-1D, to correctly describe the hydraulic behavior of permeable pavement installed at the University of Calabria. Two different scenarios of describing the hydraulic behavior of the permeable pavement system were analyzed: the first one uses a single-porosity model for all layers of the permeable pavement; the second one uses a dual-porosity model for the base and sub-base layers. Measured and modeled month-long hydrographs were compared using the Nash-Sutcliffe efficiency (NSE) index. A Global Sensitivity Analysis (GSA) followed by a Monte Carlo filtering highlighted the influence of the wear layer on the hydraulic behavior of the pavement and identified the ranges of parameters generating behavioral solutions. Reduced ranges were then used in the calibration procedure conducted with the metaheuristic Particle swarm optimization (PSO) algorithm for the estimation of hydraulic parameters. The best fit value for the first scenario was NSE = 0.43; for the second scenario, it was NSE = 0.81, indicating that the dual-porosity approach is more appropriate for describing the variably-saturated flow in the base and sub-base layers. Estimated parameters were validated using an independent, month-long set of measurements, resulting in NSE values of 0.43 and 0.86 for the first and second scenarios, respectively. The improvement in correspondence between measured and modeled hydrographs confirmed the reliability of the

  11. Thermal Hydraulic Analysis of 3 MW TRIGA Research Reactor of Bangladesh Considering Different Cycles of Burnup

    Directory of Open Access Journals (Sweden)

    M.H. Altaf

    2014-12-01

    Full Text Available Burnup dependent steady state thermal hydraulic analysis of TRIGA Mark-II research reactor has been carried out utilizing coupled point kinetics, neutronics and thermal hydraulics code EUREKA-2/RR. From the previous calculations of neutronics parameters including percentage burnup of individual fuel elements performed so far for 700 MWD burnt core of TRIGA reactor showed that the fuel rod predicted as hottest at the beginning of cycle (fresh core was found to remain as the hottest until 200 MWD of burn, but, with the progress of core burn, the hottest rod was found to be shifted and another rod in the core became the hottest. The present study intends to evaluate the thermal hydraulic parameters of these hottest fuel rods at different cycles of burnup, from beginning to 700 MWD core burnt considering reactor operates under steady state condition. Peak fuel centerline temperature, maximum cladding and coolant temperatures of the hottest channels were calculated. It revealed that maximum temperature reported for fuel clad and fuel centerline found to lie below their melting points which indicate that there is no chance of burnout on the fuel cladding surface and no blister in the fuel meat throughout the considered cycles of core burnt.

  12. Thermal-hydraulic Analysis in the Pool of PGSFR including the Shielding

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jung; Lee, Taeho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Various design issues relate to this region, and one of them is thermal-hydraulic behavior when shielding exists inside the reactor vessel. The shielding is used for the blockage of the radiation emitted by the reactor core. The shielding is installed at the Intermediate Heat eXchanger (IHX), core shroud, and redan region at the top of core. However, this structure disturbs the normal flow path and heat transfer of the primary heat transfer system. In this study, the multi-dimensional thermal-hydraulic characteristics in the pool of PGSFR including the shielding are analyzed. Also these results are compared to a case in which no shielding is installed. A thermal-hydraulic analysis in the pool of the PGSFR considering the shielding structure are performed using STAR-CCM+. The internal major components of the pool inside are modeled, and calculations are performed with a normal operation condition. Also, these results are compared to a no shielding case. The flow and temperature changes owing to the shielding structure at a redan inside are shown, but the overall flow and temperature distributions in both cases are substantially similar. Also the physical properties such as the flow rate, temperature, and static pressure at each major point are almost the same. These results are utilized in the arrangement of the reactor internal structure and design of the shielding structure.

  13. Lead Coolant Test Facility Systems Design, Thermal Hydraulic Analysis and Cost Estimate

    Energy Technology Data Exchange (ETDEWEB)

    Soli Khericha; Edwin Harvego; John Svoboda; Ryan Dalling

    2012-01-01

    The Idaho National Laboratory prepared a preliminary technical and functional requirements (T&FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic coolant. Based on review of current world lead or lead-bismuth test facilities and research needs listed in the Generation IV Roadmap, five broad areas of requirements were identified as listed: (1) Develop and Demonstrate Feasibility of Submerged Heat Exchanger; (2) Develop and Demonstrate Open-lattice Flow in Electrically Heated Core; (3) Develop and Demonstrate Chemistry Control; (4) Demonstrate Safe Operation; and (5) Provision for Future Testing. This paper discusses the preliminary design of systems, thermal hydraulic analysis, and simplified cost estimate. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 4200 C. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M (in 2006 $). It is also estimated that the facility will require two years to be constructed and ready for operation.

  14. Lead coolant test facility systems design, thermal hydraulic analysis and cost estimate

    Energy Technology Data Exchange (ETDEWEB)

    Khericha, Soli, E-mail: slk2@inel.gov [Battelle Energy Alliance, LLC, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Harvego, Edwin; Svoboda, John; Evans, Robert [Battelle Energy Alliance, LLC, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Dalling, Ryan [ExxonMobil Gas and Power Marketing, Houston, TX 77069 (United States)

    2012-01-15

    The Idaho National Laboratory prepared a preliminary technical and functional requirements (T and FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic coolant. Based on review of current world lead or lead-bismuth test facilities and research needs listed in the Generation IV Roadmap, five broad areas of requirements were identified as listed below: Bullet Develop and demonstrate feasibility of submerged heat exchanger. Bullet Develop and demonstrate open-lattice flow in electrically heated core. Bullet Develop and demonstrate chemistry control. Bullet Demonstrate safe operation. Bullet Provision for future testing. This paper discusses the preliminary design of systems, thermal hydraulic analysis, and simplified cost estimated. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 4200 Degree-Sign C. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M (in 2006 $). It is also estimated that the facility will require two years to be constructed and ready for operation.

  15. Error Analysis and Compensation Method on the Mechanical Structure of the Hydraulic Control System

    Directory of Open Access Journals (Sweden)

    Luo Yanyan

    2016-01-01

    Full Text Available Mechanical deformation of mechanical transmission part in hydraulic control system directly affects the loading accuracy of the system. For improving the mechanical properties of the system, The force analysis and motion analysis of mechanism are simulated based on the four-bar linkage structure (FLS, and kinematics simulation is designed by using Matlab program, then came to a system error bar graph. The system error was calculated accurately according to the results of the structural mechanics simulation made by Solidworks motion module. The structure of the system will be modified when systematic errors exceed the required limit values until it reach the required value.

  16. Thermal-hydraulic modeling and analysis of spool valve with sloping U-shape notch by bond graph

    Institute of Scientific and Technical Information of China (English)

    娄磊; 吴万荣; 王兆强; 梁向京

    2015-01-01

    To increase the efficiency and reliability of the thermodynamics analysis of the spool valve, the precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke and thermal-hydraulic bond graph based on the conservation of mass and energy were introduced. Subsequently, the connection rule for the bond graph elements and the method to construct the complete thermal-hydraulic system model were proposed. On the basis of heat transfer analysis of a typical hydraulic circuit containing the spool valve, the lumped parameter for mathematical model of the system was given. At last, the reliability of the mathematical model of the flow area and the thermal-hydraulic system for the sloping U-shape notch orifice on the spool were demonstrated by the test. The good agreement between the simulation results and experimental data demonstrates the validity of the modeling method.

  17. Comparative Analysis of CTF and Trace Thermal-Hydraulic Codes Using OECD/NRC PSBT Benchmark Void Distribution Database

    OpenAIRE

    2013-01-01

    The international OECD/NRC PSBT benchmark has been established to provide a test bed for assessing the capabilities of thermal-hydraulic codes and to encourage advancement in the analysis of fluid flow in rod bundles. The benchmark was based on one of the most valuable databases identified for the thermal-hydraulics modeling developed by NUPEC, Japan. The database includes void fraction and departure from nucleate boiling measurements in a representative PWR fuel assembly. On behalf of the be...

  18. Status and subjects of thermal-hydraulic analysis for next-generation LWRs with passive safety systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The present status and subjects on thermal-hydraulic analysis for next-generation light water reactors (LWRs) with passive safety systems were summarized based on survey results and discussion by subcommittee on improvement of reactor thermal-hydraulic analysis codes under nuclear code committee in Japan Atomic Energy Research Institute. This survey was performed to promote the research of improvement of reactor thermal-hydraulic analysis codes in future. In the first part of this report, the status and subjects on system analysis and those on evaluation of passive safety system performance are summarized for various types of reactor proposed before. In the second part, the status and subjects on multidimensional two-phase flow analysis are reviewed, since the multidimensional analysis was recognized as one of most important subjects through the investigation in the first part. Besides, databases for bubbly flow and annular dispersed flow were explored, those are needed to assess and verify each multidimensional analytical method. The contents in this report are the forefront of thermal-hydraulic analysis for LWRs and those include current findings for the development of multidimensional two-phase flow analytical method. Thus, we expect that the contents can offer various useful information against the improvement of reactor thermal-hydraulic analysis codes in future. (author)

  19. Status and subjects of thermal-hydraulic analysis for next-generation LWRs with passive safety systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The present status and subjects on thermal-hydraulic analysis for next-generation light water reactors (LWRs) with passive safety systems were summarized based on survey results and discussion by subcommittee on improvement of reactor thermal-hydraulic analysis codes under nuclear code committee in Japan Atomic Energy Research Institute. This survey was performed to promote the research of improvement of reactor thermal-hydraulic analysis codes in future. In the first part of this report, the status and subjects on system analysis and those on evaluation of passive safety system performance are summarized for various types of reactor proposed before. In the second part, the status and subjects on multidimensional two-phase flow analysis are reviewed, since the multidimensional analysis was recognized as one of most important subjects through the investigation in the first part. Besides, databases for bubbly flow and annular dispersed flow were explored, those are needed to assess and verify each multidimensional analytical method. The contents in this report are the forefront of thermal-hydraulic analysis for LWRs and those include current findings for the development of multidimensional two-phase flow analytical method. Thus, we expect that the contents can offer various useful information against the improvement of reactor thermal-hydraulic analysis codes in future. (author)

  20. Theory analysis and experimental research on on-line contamination detecting technology in hydraulic oil

    Institute of Scientific and Technical Information of China (English)

    YAO Cheng-yu; ZHAO Jing-yi; ZHANG Qi-sheng

    2006-01-01

    A system of on-line contamination detecting in hydraulic oil based on silting principle is accomplished, where, metal filter membrane as detector, solenoid as active force to propel piston to blotter and gain differential pressure, step motor drives the membrane to filtrate and counter-flush, LabVIEW as detecting software platform, oil's contamination detecting indirectly by gauging differential pressure. Based on theory analysis, accomplished is relation between contamination level and differential pressure, realizing polynomial curve fitting, and calibration experiment. Field experiment is simulated in the condition of experimental laboratory, has credible precision and real-time performance, which can popularize to the field of production.

  1. Software Tool for Automated Failure Modes and Effects Analysis (FMEA) of Hydraulic Systems

    DEFF Research Database (Denmark)

    Stecki, J. S.; Conrad, Finn; Oh, B.

    2002-01-01

    Offshore, marine,aircraft and other complex engineering systems operate in harsh environmental and operational conditions and must meet stringent requirements of reliability, safety and maintability. To reduce the hight costs of development of new systems in these fields improved the design...... management techniques and a vast array of computer aided techniques are applied during design and testing stages. The paper present and discusses the research and development of a software tool for automated failure mode and effects analysis - FMEA - of hydraulic systems. The paper explains the underlying...

  2. A new thermal hydraulics code coupled to agent for light water reactor analysis

    Science.gov (United States)

    Eklund, Matthew Deric

    A new numerical model for coupling a thermal hydraulics method based on the Drift Flux and Homogeneous Equilibrium Mixture (HEM) models, with a deterministic neutronics code system AGENT (Arbitrary Geometry Neutron Transport), is developed. Named the TH thermal hydraulics code, it is based on the mass continuity, momentum, and energy equations integrated with appropriate relations for liquid and vapor phasic velocities. The modified conservation equations are then evaluated in one-dimensional (1D) steady-state conditions for LWR coolant subchannel in the axial direction. This permits faster computation times without sacrificing significant accuracy, as compared to other three-dimensional (3D) codes such as RELAP5/TRACE. AGENT is a deterministic neutronics code system based on the Method of Characteristics to solve the 2D/3D neutron transport equation in current and future reactor systems. The coupling scheme between the TH and AGENT codes is accomplished by computing the normalized fission rate profile in the LWR fuel elements by AGENT. The normalized fission rate profile is then transferred to the TH thermal hydraulics code for computing the reactor coolant properties. In conjunction with the 1D axial TH code, a separate 1D radial heat transfer model within the TH code is used to determine the average fuel temperature at each node where coolant properties are calculated. These properties then are entered into Scale 6.1, a criticality analysis code, to recalculate fuel pin neutron interaction cross sections based on thermal feedback. With updated fuel neutron interaction cross sections, the fission rate profile is recalculated in AGENT, and the cycle continues until convergence is reached. The TH code and coupled AGENT-TH code are benchmarked against the TRACE reactor analysis software, showing required agreement in evaluating the basic reactor parameters.

  3. Scaling analysis of the thermal-hydraulic test facility for the large break LOCA of KNGR

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Byong Jo; Kwon, Tae Soon; Song, Chul Hwa; Euh, Dong Jin; Chu, In Cheol; Cho, Hyoung Kyu; Park, Jong Kyun

    2001-03-01

    Korea Next Generation Reactor(KNGR) adopts a Direct Vessel Injection (DVI) system instead of conventional Cold Leg Injection (CLI) system. In this report, a scaling analysis for the steam-water test facility of KNGR with DVI under reflood phase of Loss of Coolant Accident(LBLOCA) is carried out. The major objectives of the test facility are to clarify the thermal hydraulics phenomena in the upper downcomer region and to provide experimental data for evaluating or validating relevant thermal hydraulic models and correlations of the best estimate codes. The test facility should be designed based on the appropriate scaling law so that the same thermal hydraulics phenomena is happened as in the case of prototype. For these, the investigations of previous scaling laws are carried out. And, in the present study, a new scaling approach, named the modified linear scaling, is developed for the design of a scaled-down experimental facility. Its velocity is scaled by a Wallis-type parameter and an aspect ratio of experimental facility is preserved with that of a prototype. The test facility is designed primarily by a volume scaling law and the area ratio of test facility is set to be 1/24.3. However, additional DVI nozzles are also installed at the elevation which is determined by the modified linear scaling law. It is for the scaling analysis of ECC bypass fraction. The cold leg, hot leg and DVI nozzles are additionally attached in the upper annulus downcomer region so that the UPTF counterpart test is possible.

  4. Hydraulic analysis of river training cross-vanes as part of post-restoration monitoring

    Science.gov (United States)

    Endreny, T. A.; Soulman, M. M.

    2011-07-01

    River restoration design methods are incrementally improved by studying and learning from monitoring data in previous projects. In this paper we report post-restoration monitoring data and simulation analysis for a Natural Channel Design (NCD) restoration project along 1600 m of the Batavia Kill (14 km2 watershed) in the Catskill Mountains, NY. The restoration project was completed in 2002 with goals to reduce bank erosion and determine the efficacy of NCD approaches for restoring headwater streams in the Catskill Mountains, NY. The NCD approach used a reference-reach to determine channel form, empirical relations between the project site and reference site bankfull dimensions to size channel geometry, and hydraulic and sediment computations based on a bankfull (1.3 yr return interval) discharge to test channel capacity and sediment stability. The NCD project included 12 cross-vanes and 48 j-hook vanes as river training structures along 19 meander bends to protect against bank erosion and maintain scour pools for fish habitat. Monitoring data collected from 2002 to 2004 were used to identify aggradation of pools in meander bends and below some structures. Aggradation in pools was attributed to the meandering riffle-pool channel trending toward step-pool morphology and cross-vane arms not concentrating flow in the center of the channel. The aggradation subsequently caused flow splitting and 4 partial point bar avulsions during a spring 2005 flood with a 25-yr return interval. Processing the pre-flood monitoring data with hydraulic analysis software provided clues the reach was unstable and preventative maintenance was needed. River restoration and monitoring teams should be trained in robust hydraulic analytical methods that help them extend project restoration goals and structure stability.

  5. Hydraulic analysis of river training cross-vanes as part of post-restoration monitoring

    Directory of Open Access Journals (Sweden)

    T. A. Endreny

    2011-07-01

    Full Text Available River restoration design methods are incrementally improved by studying and learning from monitoring data in previous projects. In this paper we report post-restoration monitoring data and simulation analysis for a Natural Channel Design (NCD restoration project along 1600 m of the Batavia Kill (14 km2 watershed in the Catskill Mountains, NY. The restoration project was completed in 2002 with goals to reduce bank erosion and determine the efficacy of NCD approaches for restoring headwater streams in the Catskill Mountains, NY. The NCD approach used a reference-reach to determine channel form, empirical relations between the project site and reference site bankfull dimensions to size channel geometry, and hydraulic and sediment computations based on a bankfull (1.3 yr return interval discharge to test channel capacity and sediment stability. The NCD project included 12 cross-vanes and 48 j-hook vanes as river training structures along 19 meander bends to protect against bank erosion and maintain scour pools for fish habitat. Monitoring data collected from 2002 to 2004 were used to identify aggradation of pools in meander bends and below some structures. Aggradation in pools was attributed to the meandering riffle-pool channel trending toward step-pool morphology and cross-vane arms not concentrating flow in the center of the channel. The aggradation subsequently caused flow splitting and 4 partial point bar avulsions during a spring 2005 flood with a 25-yr return interval. Processing the pre-flood monitoring data with hydraulic analysis software provided clues the reach was unstable and preventative maintenance was needed. River restoration and monitoring teams should be trained in robust hydraulic analytical methods that help them extend project restoration goals and structure stability.

  6. Thermal Hydraulic Analysis Using GIS on Application of HTR to Thermal Recovery of Heavy Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Yangping Zhou

    2012-01-01

    Full Text Available At present, large water demand and carbon dioxide (CO2 emissions have emerged as challenges of steam injection for oil thermal recovery. This paper proposed a strategy of superheated steam injection by the high-temperature gas-cooled reactor (HTR for thermal recovery of heavy oil, which has less demand of water and emission of CO2. The paper outlines the problems of conventional steam injection and addresses the advantages of superheated steam injection by HTR from the aspects of technology, economy, and environment. A Geographic Information System (GIS embedded with a thermal hydraulic analysis function is designed and developed to analyze the strategy, which can make the analysis work more practical and credible. Thermal hydraulic analysis using this GIS is carried out by applying this strategy to a reference heavy oil field. Two kinds of injection are considered and compared: wet steam injection by conventional boilers and superheated steam injection by HTR. The heat loss, pressure drop, and possible phase transformation are calculated and analyzed when the steam flows through the pipeline and well tube and is finally injected into the oil reservoir. The result shows that the superheated steam injection from HTR is applicable and promising for thermal recovery of heavy oil reservoirs.

  7. Thermal-hydraulic performance analysis for the conceptual design of Korean HCCR TBMset

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Won; Jin, Hyung Gon; Lee, Eo Hwak; Yoon, Jae Sung; Kim, Suk Kwon [KAERI, Daejeon (Korea, Republic of); Shin, Kyu In [Gentec Co., Daejeon (Korea, Republic of); Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The purpose of this document is to provide the thermal-hydraulic (TH) analyses results of the Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM) including TBM-shield, which is called TBM-set. The analyses were performed for Electro- Magnetic Module (EM-TBM) and INTegral Module (INT-TBM) including TBM-shield, respectively, with the same model and meshes according to the ITER operation conditions of H/He and D-T phases, respectively. Thermal-hydraulic performance of the EM- and INTTBM- sets were analysed using the fixed CATIA model for CDR. Fine mesh with 15.9 million elements for solid and 44.7 million elements for fluid was used for ANSYS-CFX 14.5 simulation and coarse mesh with 7.6 million elements for solid is prepared for the thermomechanical analysis. The boundary conditions such as heat flux, nuclear heating, and coolant conditions were determined considering the ITER operation condition and designed cooling scheme. The analysis results and conclusions are as follows; (1) It is confirmed that both EM- and INT-TBM performance results meet the design requirements, which were determined by the material characteristics. (2) The temperature results with fine mesh of both EMand INT-TBM-sets were successfully transferred to those of coarse mesh for the thermo-mechanical analysis.

  8. Modeling and analysis of a meso-hydraulic climbing robot with artificial muscle actuation.

    Science.gov (United States)

    Chapman, Edward M; Jenkins, Tyler E; Bryant, Matthew

    2017-07-10

    This paper presents a fully coupled electro-hydraulic model of a bio-inspired climbing robot actuated by fluidic artificial muscles (FAMs). This analysis expands upon previous FAM literature by considering not only the force and contraction characteristics of the actuator, but the complete hydraulic and electromechanical circuits as well as the dynamics of the climbing robot. This analysis allows modeling of the time-varying applied pressure, electrical current, and actuator contraction for accurate prediction of the robot motion, energy consumption, and mechanical work output. The developed model is first validated against mechanical and electrical data collected from a proof-of-concept prototype robot. The model is then employed to study the system-level sensitivities of the robot locomotion efficiency and average climbing speed to several design and operating parameters. The results of this analysis demonstrate that considering only the transduction efficiency of the FAM actuators is insufficient to maximize the efficiency of the complete robot, and that a holistic approach can lead to significant improvements in performance. © 2017 IOP Publishing Ltd.

  9. Verification of combined thermal-hydraulic and heat conduction analysis code FLOWNET/TRUMP

    Science.gov (United States)

    Maruyama, Soh; Fujimoto, Nozomu; Kiso, Yoshihiro; Murakami, Tomoyuki; Sudo, Yukio

    1988-09-01

    This report presents the verification results of the combined thermal-hydraulic and heat conduction analysis code, FLOWNET/TRUMP which has been utilized for the core thermal hydraulic design, especially for the analysis of flow distribution among fuel block coolant channels, the determination of thermal boundary conditions for fuel block stress analysis and the estimation of fuel temperature in the case of fuel block coolant channel blockage accident in the design of the High Temperature Engineering Test Reactor(HTTR), which the Japan Atomic Energy Research Institute has been planning to construct in order to establish basic technologies for future advanced very high temperature gas-cooled reactors and to be served as an irradiation test reactor for promotion of innovative high temperature new frontier technologies. The verification of the code was done through the comparison between the analytical results and experimental results of the Helium Engineering Demonstration Loop Multi-channel Test Section(HENDEL T(sub 1-M)) with simulated fuel rods and fuel blocks.

  10. Fractal And Multi-fractal Analysis Of The Hydraulic Property Variations Of Karst Aquifers

    Science.gov (United States)

    Majone, B.; Bellin, A.; Borsato, A.

    Karst aquifers are very heterogeneous systems with hydraulic property variations acting at several continuous and discrete scales, as a result of the fact that macro- structural elements, such as faults and karst channels, and fractures are intertwined in a complex, and largely unknown, manner. Many experimental studies on karst springs showed that the recession limb of the typical storm hydrograph can be divided into several regions with different decreasing rate, suggesting that the discharge is com- posed of contributions experiencing different travel times. Despite the importance of karst aquifers as a source of fresh water for most Mediterranean countries fostered the attention of scientists and practitioners, the mechanisms controlling runoff production in such a complex subsurface environment need to be further explored. A detailed sur- vey, lasting for one year and conducted by the Museo Tridentino di Scienze Naturali of Trento, represents a unique opportunity to analyze the imprint of hydraulic prop- erty variations on the hydrological signal recorded at the spring of Prese Val, located in the Dolomiti group near Trento. Data include water discharge (Q), temperature (T) and electric conductivity of water (E). Analysis of the data revealed that the power spectrum of E scales as 1/f, with slightly, but significantly, smaller than 1. The scaling nature of the E-signal has been confirmed by rescaled range analysis of the time series. Since the electric conductivity is proportional to the concentration of ions in the spring water, which increases with the residence time, one may conclude that the fractal structure of the E signal is the consequence of a similar structure in the hydraulic property variations. This finding confirms previous results of Kirchner et al. (2000), who reported a similar behavior for chloride concentration in the streamflow of three small Welsh catchments. A more detailed analysis revealed that E and T are both multifractal signals

  11. Analysis of nonlinearities and effects in direct drive electro-hydraulic position servo system

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-jie; JI Tian-jing; MAO Xin-tao; LIU Quan-zhong

    2005-01-01

    The direct drive electro-hydraulic servo system is a new approach hydraulic system. It is much smaller and easier controlled than traditional systems and is a perfect energy saver. This paper will briefly introduce the popular nonlinearities in the electro-hydraulic system and analyse the effect of nonlinearities in direct drive electro-hydraulic position servo system by means of simulation research. Some valuable conclusions are given.

  12. Analysis of three-dimensional thermo-hydraulic phenomena in the reactor core of LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Hu, S.; Lee, Y. B.; Jang, W. P.; Ha, K. S.; Jung, H. Y. [KAERI, Taejon (Korea, Republic of)

    2004-07-01

    The mismatch between power and flow under the transient condition of LMFBR (Liquid Metal cooled Fast Breeder Reactor) core results in thermal stratification in hot pool. Since the fluid of hot pool enters IHXs, the temperature distribution of hot pool can alter the overall system response, therefore three-dimensional analysis of thermo-hydraulic phenomena is necessary. In this study, the thermo-hydraulic phenomena under normal operating condition and unprotected transient condition of LMFBR is investigated using which is the three-dimensional analysis code, COMMIX-1AR/P. The basic input data is based on the design data of KALIMER-600, which is sodium-cooled fast breeder reactor developed by KAERI. COMMIX-1AR/P code has not a reactivity model and the power and core flowrate must be supplied in the input data. In this study, results of SSC-K calculation is used. The temperature and velocity distributions are calculated and compared with those of SSC-K calculation results. The UTOF(Unprotected Loss Of Flow) accident is calculated using COMMIX-1AR/P and the temperature and velocity distributions in the total reactor core are calculated and the natural circulation mode under this transient condition is investigated.

  13. Fault detection of excavator's hydraulic system based on dynamic principal component analysis

    Institute of Scientific and Technical Information of China (English)

    HE Qing-hua; HE Xiang-yu; ZHU Jian-xin

    2008-01-01

    In order to improve reliability of the excavator's hydraulic system, a fault detection approach based on dynamic principal component analysis(PCA) was proposed. Dynamic PCA is an extension of PCA, which can effectively extract the dynamic relations among process variables. With this approach, normal samples were used as training data to develop a dynamic PCA model in the first step. Secondly, the dynamic PCA model decomposed the testing data into projections to the principal component subspace(PCS) and residual subspace(RS). Thirdly, T2 statistic and Q statistic performed as indexes of fault detection in PCS and RS, respectively.Several simulated faults were introduced to validate the approach. The results show that the dynamic PCA model developed is able to detect overall faults by using T2 statistic and Q statistic. By simulation analysis, the proposed approach achieves an accuracy of 95% for 20 test sample sets, which shows that the fault detection approach can be effectively applied to the excavator's hydraulic system.

  14. Development of a best estimate auditing code for CANDU thermal hydraulic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, M. K.; Lee, W. J. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-03-01

    The main purpose of this study is to develop a thermal hydraulic auditing code for the CANDU reactor, modifying the model of existing PWR auditing tool , i.e. RELAP5/MOD3. This scope of project is a fourth step of the whole project, applying the RELAP5/MOD3/CANDU+ version for the real CANDU plant LOCA Analysis and D2O leakage incident. There are three main models under investigation, i.e. Moody critical flow model, flow regime model of horizontal CANDU bundle, and fuel element heatup model when the stratification occurs, especially when CANDU LOCA is tested. Also, for Wolsung unit 1 D2O leakage incident analysis, the plant behavior is predicted with the newly developed version for the first 1000 seconds after onset of the incident, with the main interest aiming for system pressure, level control system, and thermal hydraulic transient behavior of the secondary system. The model applied for this particular application includes heat transfer model of nuclear fuel assembly, decay heat model, and MOV (Motor Operated Valve) model. Finally, the code maintenance work, mainly correcting the known errors, is presented. 12 refs., 26 figs., 3 tabs. (Author)

  15. The need for complementary hydraulic analysis in post-restoration monitoring of river restoration projects

    Science.gov (United States)

    Endreny, T. A.; Soulman, M. M.

    2011-03-01

    River restoration design methods are incrementally improved by studying and learning from monitoring data in previous projects. In this paper, we report post-restoration monitoring data for a Natural Channel Design (NCD) restoration project along 1600 m (10 channel wavelengths) of the Batavia Kill in the Catskill Mountains, NY, implemented in 2001 and 2002. The NCD project used a reference-reach to determine channel form, empirical relations between the project site and reference site bankfull dimensions to size channel geometry, and hydraulic and sediment computations to test channel capacity and sediment stability. In addition 12 cross-vanes and 48 j-hook vanes used in NCD for river training were installed to protect against bank erosion and maintain scour pools for fish habitat. Changes in pool depths were monitored with surveys from 2002-2004, and then after the channel-altering April 2005 flood. Aggradation in pools was attributed to cross-vane arms not concentrating flow in the center of the channel, which subsequently caused flow splitting and 4 partial point bar avulsions during the 2005 flood. Hydrodynamic simulation at the 18 m3s-1 bankfull flow suggested avulsions occurred where vanes allowed erosive bank scour to initiate the avulsion cut, and once the flow was split, the diminished in-channel flow caused more aggradation in the pools. In this project post-restoration monitoring had detected aggradation and considered it a problem. The lesson for the larger river restoration community is monitoring protocol should include complementary hydraulic and sediment analysis to comprehend potential consequences and develop preventative maintenance. River restoration and monitoring teams should be trained in robust hydraulic and sediment analytical methods that help them extend project restoration goals.

  16. The need for complementary hydraulic analysis in post-restoration monitoring of river restoration projects

    Directory of Open Access Journals (Sweden)

    T. A. Endreny

    2011-03-01

    Full Text Available River restoration design methods are incrementally improved by studying and learning from monitoring data in previous projects. In this paper, we report post-restoration monitoring data for a Natural Channel Design (NCD restoration project along 1600 m (10 channel wavelengths of the Batavia Kill in the Catskill Mountains, NY, implemented in 2001 and 2002. The NCD project used a reference-reach to determine channel form, empirical relations between the project site and reference site bankfull dimensions to size channel geometry, and hydraulic and sediment computations to test channel capacity and sediment stability. In addition 12 cross-vanes and 48 j-hook vanes used in NCD for river training were installed to protect against bank erosion and maintain scour pools for fish habitat. Changes in pool depths were monitored with surveys from 2002–2004, and then after the channel-altering April 2005 flood. Aggradation in pools was attributed to cross-vane arms not concentrating flow in the center of the channel, which subsequently caused flow splitting and 4 partial point bar avulsions during the 2005 flood. Hydrodynamic simulation at the 18 m3s−1 bankfull flow suggested avulsions occurred where vanes allowed erosive bank scour to initiate the avulsion cut, and once the flow was split, the diminished in-channel flow caused more aggradation in the pools. In this project post-restoration monitoring had detected aggradation and considered it a problem. The lesson for the larger river restoration community is monitoring protocol should include complementary hydraulic and sediment analysis to comprehend potential consequences and develop preventative maintenance. River restoration and monitoring teams should be trained in robust hydraulic and sediment analytical methods that help them extend project restoration goals.

  17. Development of best estimate auditing code for CANDU thermal hydraulic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. D.; Lee, W. J.; Lim, H. S. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2000-03-15

    The main purpose of this study is to develop a thermal hydraulic auditing code for the CANDU reactor, modifying the model if existing PWR auditing tool, i.e. RELAP5/MOD3. This scope of project is a third step of the whole project, and expand the RELAP5/MOD3/CANDU version for implementation of LOCA analysis. There are three main area of model development, i.e. moody critical flow model, flow regime model of horizontal CANDU bundle, and fuel element heatup model when the stratification occurs. Newly developed version, namely RELAP5/MOD3/CANDU+ is applicable to CANDU plant analysis with keeping the function of light water reactor analysis. The limited validations of model installation were performed. Assessment of CHF model using AECL separated effect test and calculation for Wolsong 2 plant were performed also for the applicability test of the developed version.

  18. Development of a best estimate auditing code for CANDU thermal hydraulic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B.D.; Lee, W.J.; Lim, H.S. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-03-01

    The main purpose of this study is to develop a thermal hydraulic auditing code for the CANDU reactor, modifying the model of existing PWR auditing tool , i.e. RELAP5/MOD3. This scope of project is a third step of the whole project, and expand the RELAP5/MOD3/CANDU version for implementation of LOCA Analysis. There are three main area of model development, i.e. Moody critical flow model, flow regime model of horizontal CANDU bundle, and fuel element heatup model when the stratification occurs. Newly developed version, namely RELAP5/MOD3/CANDU+ is applicable to CANDU plant analysis with keeping the function of light water reactor analysis. The limited validations of model installation were performed. Assessment of CHF model using AECL separated effect test and calculation for Wolsong 2 plant were performed also for the applicability test of the developed version. 15 refs., 37 figs., 8 tabs. (Author)

  19. Stress and Deformation Analysis of Cylinder-Crown Integrated Hydraulic Press with Large Capacity

    Institute of Scientific and Technical Information of China (English)

    Weiwei Zhang; Xiaosong Wang; Zhongren Wang

    2015-01-01

    Cylinder⁃crown integrated hydraulic press ( CCIHP ) is a new press structure. The hemispherical hydraulic cylinder also functions as a main portion of crown, which has lower weight and higher section modulus compared with the conventional hydraulic cylinder and press crown. In order to design cylinder⁃crown integrated hydraulic press with large capacity, the theoretical design of hemispherical hydraulic cylinder was first proposed, and the structural parameters of 150 MN CCIHP were listed. Then the simulation was carried out to analyze the stress and deformation of CCIHP , and weight comparison was conducted between CCIHP and conventional press. It is shown that the weight reduction for hydraulic cylinder and press crown is about 20%compared with that for conventional press, and the stress and deformation are both within the range of constraints including strength and stiffness conditions. It is possible to manufacture cylinder⁃crown integrated hydraulic press with large capacity.

  20. Flow-Log Analysis for Hydraulic Characterization of Selected Test Wells at the Indian Point Energy Center, Buchanan, New York

    Science.gov (United States)

    Williams, John H.

    2008-01-01

    Flow logs from 24 test wells were analyzed as part of the hydraulic characterization of the metamorphosed and fractured carbonate bedrock at the Indian Point Energy Center in Buchanan, New York. The flow logs were analyzed along with caliper, optical- and acoustic-televiewer, and fluid-resistivity and temperature logs to determine the character and distribution of fracture-flow zones and estimate their transmissivities and hydraulic heads. Many flow zones were associated with subhorizontal to shallow-dipping fractured zones, southeast-dipping bedding fractures, northwest-dipping conjugate fractures, or combinations of bedding and conjugate fractures. Flow-log analysis generally provided reasonable first-order estimates of flow-zone transmissivity and head differences compared with the results of conventional hydraulic-test analysis and measurements. Selected results of an aquifer test and a tracer test provided corroborating information in support of the flow-log analysis.

  1. Uncertainty analysis and validation of the estimation of effective hydraulic properties at the Darcy scale

    Science.gov (United States)

    Mesgouez, A.; Buis, S.; Ruy, S.; Lefeuve-Mesgouez, G.

    2014-05-01

    The determination of the hydraulic properties of heterogeneous soils or porous media remains challenging. In the present study, we focus on determining the effective properties of heterogeneous porous media at the Darcy scale with an analysis of their uncertainties. Preliminary, experimental measurements of the hydraulic properties of each component of the heterogeneous medium are obtained. The properties of the effective medium, representing an equivalent homogeneous material, are determined numerically by simulating a water flow in a three-dimensional representation of the heterogeneous medium, under steady-state scenarios and using its component properties. One of the major aspects of this study is to take into account the uncertainties of these properties in the computation and evaluation of the effective properties. This is done using a bootstrap method. Numerical evaporation experiments are conducted both on the heterogeneous and on the effective homogeneous materials to evaluate the effectiveness of the proposed approach. First, the impact of the uncertainties of the component properties on the simulated water matric potential is found to be high for the heterogeneous material configuration. Second, it is shown that the strategy developed herein leads to a reduction of this impact. Finally, the adequacy between the mean of the simulations for the two configurations confirms the suitability of the homogenization approach, even in the case of dynamic scenarios. Although it is applied to green roof substrates, a two-component media composed of bark compost and pozzolan used in the construction of buildings, the methodology proposed in this study is generic.

  2. Thermal-hydraulics and safety analysis of sectored compact reactor for lunar surface power

    Energy Technology Data Exchange (ETDEWEB)

    Schriener, T. M. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); El-Genk, M. S. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Mechanical Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States)

    2012-07-01

    The liquid NaK-cooled, fast-neutron spectrum, Sectored Compact Reactor (SCoRe-N 5) concept has been developed at the Univ. of New Mexico for lunar surface power applications. It is loaded with highly enriched UN fuel pins in a triangular lattice, and nominally operates at exit and inlet coolant temperatures of 850 K and 900 K. This long-life reactor generates up to 1 MWth continuously for {>=} 20 years. To avoid a single point failure in reactor cooling, the core is divided into 6 sectors that are neutronically and thermally coupled, but hydraulically independent. This paper performs a 3-D the thermal-hydraulic analysis of SCoRe--N 5 at nominal operation temperatures and a power level of 1 MWth. In addition, the paper investigates the potential of continuing reactor operation at a lower power in the unlikely event that one sector in the core experiences a loss of coolant (LOC). Redesigning the core with a contiguous steel matrix enhances the cooling of the sector experiencing a LOC. Results show that with a core sector experiencing a LOC, SCORE-N 5 could continue operating safely at a reduced power of 166.6 kWth. (authors)

  3. Shock Mechanism Analysis and Simulation of High-Power Hydraulic Shock Wave Simulator

    Directory of Open Access Journals (Sweden)

    Xiaoqiu Xu

    2017-01-01

    Full Text Available The simulation of regular shock wave (e.g., half-sine can be achieved by the traditional rubber shock simulator, but the practical high-power shock wave characterized by steep prepeak and gentle postpeak is hard to be realized by the same. To tackle this disadvantage, a novel high-power hydraulic shock wave simulator based on the live firing muzzle shock principle was proposed in the current work. The influence of the typical shock characteristic parameters on the shock force wave was investigated via both theoretical deduction and software simulation. According to the obtained data compared with the results, in fact, it can be concluded that the developed hydraulic shock wave simulator can be applied to simulate the real condition of the shocking system. Further, the similarity evaluation of shock wave simulation was achieved based on the curvature distance, and the results stated that the simulation method was reasonable and the structural optimization based on software simulation is also beneficial to the increase of efficiency. Finally, the combination of theoretical analysis and simulation for the development of artillery recoil tester is a comprehensive approach in the design and structure optimization of the recoil system.

  4. Reliability analysis of flood embankments taking into account a stochastic distribution of hydraulic loading

    Directory of Open Access Journals (Sweden)

    Amabile Alessia

    2016-01-01

    Full Text Available Flooding is a worldwide phenomenon. Over the last few decades the world has experienced a rising number of devastating flood events and the trend in such natural disasters is increasing. Furthermore, escalations in both the probability and magnitude of flood hazards are expected as a result of climate change. Flood defence embankments are one of the major flood defence measures and reliability assessment for these structures is therefore a very important process. Routine hydro-mechanical models for the stability of flood embankments are based on the assumptions of steady-state through-flow and zero pore-pressures above the phreatic surface, i.e. negative capillary pressure (suction is ignored. Despite common belief, these assumptions may not always lead to conservative design. In addition, hydraulic loading is stochastic in nature and flood embankment stability should therefore be assessed in probabilistic terms. This cannot be accommodated by steady-state flow models. The paper presents an approach for reliability analysis of flood embankment taking into account the transient water through-flow. The factor of safety of the embankment is assessed in probabilistic terms based on a stochastic distribution for the hydraulic loading. Two different probabilistic approaches are tested to compare and validate the results.

  5. Isotope supported recession analysis to assess hydraulic properties of karst aquifers across Austria

    Science.gov (United States)

    Hartmann, Andreas; Brielmann, Heike

    2017-04-01

    Austria obtains almost half of its drinking water from karst aquifers. To manage karst aquifers in a sustainable way, reliable estimations of available karst water resources, their renewal rates and their hydrodynamics are of utmost importance. Hydrological models, which are a common tool for water resources assessment and planning, are difficult to apply at karst aquifers as their strong heterogeneity of hydraulic properties requires detailed measurements that are mostly not available. Here, we present the preliminary results of the first attempt to assess karst aquifer hydraulic properties at a national scale. Our approach uses karst specific recession analysis that is supported by water isotope measurements. We show for a subset of test sites that isotopic information results in a more realistic description of recession properties. Through this combined approach, we can approximate the degree of karstification by comparing the recession of the slow and diffuse parts of the aquifer and the recession of the fast and concentrated parts of the karst aquifers. In the future, we will use a much larger set of water isotope measurements (>7,000 water samples) at a large number of karst springs across Austria and apply landscape descriptors, such as river network density, to upscale the approximated degree of karstification from the karst springs to all karst areas in Austria.

  6. Fundamental approaches for analysis thermal hydraulic parameter for Puspati Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Zaredah, E-mail: zaredah@nm.gov.my; Lanyau, Tonny Anak, E-mail: tonny@nm.gov.my; Farid, Mohamad Fairus Abdul; Kassim, Mohammad Suhaimi [Reactor Technology Centre, Technical Support Division, Malaysia Nuclear Agency, Ministry of Science, Technology and Innovation, Bangi, 43000, Kajang, Selangor Darul Ehsan (Malaysia); Azhar, Noraishah Syahirah [Universiti Teknologi Malaysia, 80350, Johor Bahru, Johor Darul Takzim (Malaysia)

    2016-01-22

    The 1-MW PUSPATI Research Reactor (RTP) is the one and only nuclear pool type research reactor developed by General Atomic (GA) in Malaysia. It was installed at Malaysian Nuclear Agency and has reached the first criticality on 8 June 1982. Based on the initial core which comprised of 80 standard TRIGA fuel elements, the very fundamental thermal hydraulic model was investigated during steady state operation using the PARET-code. The main objective of this paper is to determine the variation of temperature profiles and Departure of Nucleate Boiling Ratio (DNBR) of RTP at full power operation. The second objective is to confirm that the values obtained from PARET-code are in agreement with Safety Analysis Report (SAR) for RTP. The code was employed for the hot and average channels in the core in order to calculate of fuel’s center and surface, cladding, coolant temperatures as well as DNBR’s values. In this study, it was found that the results obtained from the PARET-code showed that the thermal hydraulic parameters related to safety for initial core which was cooled by natural convection was in agreement with the designed values and safety limit in SAR.

  7. Development of a steady thermal-hydraulic analysis code for the China Advanced Research Reactor

    Institute of Scientific and Technical Information of China (English)

    TIAN Wenxi; QIU Suizheng; GUO Yun; SU Guanghui; JIA Dounan; LIU Tiancai; ZHANG Jianwei

    2007-01-01

    A multi-channel model steady-state thermalhydraulic analysis code was developed for the China Advanced Research Reactor (CARR). By simulating the whole reactor core, the detailed mass flow distribution in the core was obtained. The result shows that structure size plays the most important role in mass flow distribution, and the influence of core power could be neglected under singlephase flow. The temperature field of the fuel element under unsymmetrical cooling condition was also obtained, which is necessary for further study such as stress analysis, etc. Of the fuel element. At the same time, considering the hot channel effect including engineering factor and nuclear factor, calculation of the mean and hot channel was carried out and it is proved that all thermal-hydraulic parameters satisfy the "Safety design regulation of CARR".

  8. Apu/hydraulic/actuator Subsystem Computer Simulation. Space Shuttle Engineering and Operation Support, Engineering Systems Analysis. [for the space shuttle

    Science.gov (United States)

    1975-01-01

    Major developments are examined which have taken place to date in the analysis of the power and energy demands on the APU/Hydraulic/Actuator Subsystem for space shuttle during the entry-to-touchdown (not including rollout) flight regime. These developments are given in the form of two subroutines which were written for use with the Space Shuttle Functional Simulator. The first subroutine calculates the power and energy demand on each of the three hydraulic systems due to control surface (inboard/outboard elevons, rudder, speedbrake, and body flap) activity. The second subroutine incorporates the R. I. priority rate limiting logic which limits control surface deflection rates as a function of the number of failed hydraulic. Typical results of this analysis are included, and listings of the subroutines are presented in appendicies.

  9. Neutronic and thermal-hydraulic analysis of fission molybdenum-99 production at Tehran Research Reactor using LEU plate targets.

    Science.gov (United States)

    Abedi, Ebrahim; Ebrahimkhani, Marzieh; Davari, Amin; Mirvakili, Seyed Mohammad; Tabasi, Mohsen; Maragheh, Mohammad Ghannadi

    2016-12-01

    Efficient and safe production of molybdenum-99 ((99)Mo) radiopharmaceutical at Tehran Research Reactor (TRR) via fission of LEU targets is studied. Neutronic calculations are performed to evaluate produced (99)Mo activity, core neutronic safety parameters and also the power deposition values in target plates during a 7 days irradiation interval. Thermal-hydraulic analysis has been also carried out to obtain thermal behavior of these plates. Using Thermal-hydraulic analysis, it can be concluded that the safety parameters are satisfied in the current study. Consequently, the present neutronic and thermal-hydraulic calculations show efficient (99)Mo production is accessible at significant activity values in TRR current core configuration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  11. Sensitivity and uncertainty analysis of estimated soil hydraulic parameters for simulating soil water content

    Science.gov (United States)

    Gupta, Manika; Garg, Naveen Kumar; Srivastava, Prashant K.

    2014-05-01

    The sensitivity and uncertainty analysis has been carried out for the scalar parameters (soil hydraulic parameters (SHPs)), which govern the simulation of soil water content in the unsaturated soil zone. The study involves field experiments, which were conducted in real field conditions for wheat crop in Roorkee, India under irrigated conditions. Soil samples were taken for the soil profile of 60 cm depth at an interval of 15 cm in the experimental field to determine soil water retention curves (SWRCs). These experimentally determined SWRCs were used to estimate the SHPs by least square optimization under constrained conditions. Sensitivity of the SHPs estimated by various pedotransfer functions (PTFs), that relate various easily measurable soil properties like soil texture, bulk density and organic carbon content, is compared with lab derived parameters to simulate respective soil water retention curves. Sensitivity analysis was carried out using the monte carlo simulations and the one factor at a time approach. The different sets of SHPs, along with experimentally determined saturated permeability, are then used as input parameters in physically based, root water uptake model to ascertain the uncertainties in simulating soil water content. The generalised likelihood uncertainty estimation procedure (GLUE) was subsequently used to estimate the uncertainty bounds (UB) on the model predictions. It was found that the experimentally obtained SHPs were able to simulate the soil water contents with efficiencies of 70-80% at all the depths for the three irrigation treatments. The SHPs obtained from the PTFs, performed with varying uncertainties in simulating the soil water contents. Keywords: Sensitivity analysis, Uncertainty estimation, Pedotransfer functions, Soil hydraulic parameters, Hydrological modelling

  12. 基于有限元分析的2MN四柱液压机液压缸设计%Design of Hydraulic Cylinder for 2 MN Four-column Hydraulic Press Based on FEM Analysis

    Institute of Scientific and Technical Information of China (English)

    卜匀; 王会刚; 刘晓雯

    2014-01-01

    The hydraulic cylinder is a widely used actuators.Based on the design theory for hydraulic press,the structure design method of four-column hydraulic press hydraulic cylinder was introduced.Static finite element analysis of cylinder part was done.Then optimization scheme was proposed.The finite element analysis results show that the improvement design is reasonable.%液压缸是一种应用广泛的执行元件。依据液压机设计理论,介绍四柱式液压机液压缸结构设计方法,对缸筒部件进行静态有限元分析,提出优化改进方案,有限元分析结果表明改进设计合理。

  13. Analysis of a hydraulic a scaled asymmetric labyrinth weir with Ansys-Fluent

    Science.gov (United States)

    Otálora Carmona, Andrés Humberto; Santos Granados, Germán Ricardo

    2017-04-01

    This document presents the three dimensional computational modeling of a labyrinth weir, using the version 17.0 of the Computational Fluid Dynamics (CFD) software ANSYS - FLUENT. The computational characteristics of the model such as the geometry consideration, the mesh sensitivity, the numerical scheme, and the turbulence modeling parameters. The volume fraction of the water mixture - air, the velocity profile, the jet trajectory, the discharge coefficient and the velocity field are analyzed. With the purpose of evaluating the hydraulic behavior of the labyrinth weir of the Naveta's hydroelectric, in Apulo - Cundinamarca, was development a 1:21 scale model of the original structure, which was tested in the laboratory of the hydraulic studies in the Escuela Colombiana de Ingeniería Julio Garavito. The scale model of the structure was initially developed to determine the variability of the discharge coefficient with respect to the flow rate and their influence on the water level. It was elaborate because the original weir (labyrinth weir with not symmetrical rectangular section), did not have the capacity to work with the design flow of 31 m3/s, because over 15 m3/s, there were overflows in the adduction channel. This variation of efficiency was due to the thickening of the lateral walls by structural requirements. During the physical modeling doing by Rodríguez, H. and Matamoros H. (2015) in the test channel, it was found that, with the increase in the width of the side walls, the discharge coefficient is reduced an average by 34%, generating an increase of the water level by 0.26 m above the structure. This document aims to develop a splicing methodology between the physical models of a labyrinth weir and numerical modeling, using concepts of computational fluid dynamics and finite volume theories. For this, was carried out a detailed analysis of the variations in the different directions of the main hydraulic variables involved in the behavior, such as, the

  14. The application of Global Sensitivity Analysis to quantify the dominant input factors for hydraulic model simulations

    Science.gov (United States)

    Savage, James; Pianosi, Francesca; Bates, Paul; Freer, Jim; Wagener, Thorsten

    2015-04-01

    Predicting flood inundation extents using hydraulic models is subject to a number of critical uncertainties. For a specific event, these uncertainties are known to have a large influence on model outputs and any subsequent analyses made by risk managers. Hydraulic modellers often approach such problems by applying uncertainty analysis techniques such as the Generalised Likelihood Uncertainty Estimation (GLUE) methodology. However, these methods do not allow one to attribute which source of uncertainty has the most influence on the various model outputs that inform flood risk decision making. Another issue facing modellers is the amount of computational resource that is available to spend on modelling flood inundations that are 'fit for purpose' to the modelling objectives. Therefore a balance needs to be struck between computation time, realism and spatial resolution, and effectively characterising the uncertainty spread of predictions (for example from boundary conditions and model parameterisations). However, it is not fully understood how much of an impact each factor has on model performance, for example how much influence changing the spatial resolution of a model has on inundation predictions in comparison to other uncertainties inherent in the modelling process. Furthermore, when resampling fine scale topographic data in the form of a Digital Elevation Model (DEM) to coarser resolutions, there are a number of possible coarser DEMs that can be produced. Deciding which DEM is then chosen to represent the surface elevations in the model could also influence model performance. In this study we model a flood event using the hydraulic model LISFLOOD-FP and apply Sobol' Sensitivity Analysis to estimate which input factor, among the uncertainty in model boundary conditions, uncertain model parameters, the spatial resolution of the DEM and the choice of resampled DEM, have the most influence on a range of model outputs. These outputs include whole domain maximum

  15. Analysis of Proppant Hydraulic Fracturing in a Sand Oil Reservoir in Southwest of Iran

    OpenAIRE

    Reza Masoomi; Iniko Bassey; Dolgow Sergie Viktorovich; Hosein Dehghani

    2015-01-01

    Hydraulic fracturing is one way to increase the productivity of oil and gas wells. One of the most fundamental successes of hydraulic fracturing operation is selecting the proper size and type of proppants which are used during the process. The aim of this study is optimizing the type and size of used propant in hydraulic fracturing operation in a sand oil reservoir in southwest of Iran. In this study sand and ceramic (sintered bauxite) have been considered as proppant type. Also the various ...

  16. A solenoid-based active hydraulic engine mount: modelling, analysis, and verification

    OpenAIRE

    Hosseini, Ali

    2010-01-01

    The focus of this thesis is on the design, modelling, identification, simulation, and experimental verification of a low-cost solenoid-based active hydraulic engine mount. To build an active engine mount, a commercial On-Off solenoid is modified to be used as an actuator and it is embedded inside a hydraulic engine mount. The hydraulic engine mount is modelled and tested, solenoid actuator is modelled and identified, and finally the models were integrated to obtain the analytical model of the...

  17. Structure Analysis for a New Type of Vane Hydraulic Damper Using Magneto-rheological Fluid

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jin-qiu; FENG Zhan-zong; WANG Hong-tao

    2008-01-01

    Over recent years the progress in actuator and microelectronics technology has made intelligent suspension systems feasible. Based on conventional vane hydraulic damper, a new vane magneto-rheological fluid (MRF) damper with fail-safe capability is designed. Firstly, the mathematical model of damping moment is deduced based on the parallel-plate model and Bingham model of MR fluids. Secondly, some influence factors of damping adjustable multiple are analyzed to provide some ways for augmenting the damping adjustable multiple under the condition of keeping initial damping moment invariable. Finally, the magnetic circuit is designed, and magnetic field distribution is simulated with the magnetic finite element analysis software-AN,SOFT. The theory and simulation results confirm that the damping adjustable range of vane MRF damper can meet the requirement of heavy vehiele semi-active suspension system.

  18. Energy-saving analysis of hydraulic hybrid excavator based on common pressure rail.

    Science.gov (United States)

    Shen, Wei; Jiang, Jihai; Su, Xiaoyu; Karimi, Hamid Reza

    2013-01-01

    Energy-saving research of excavators is becoming one hot topic due to the increasing energy crisis and environmental deterioration recently. Hydraulic hybrid excavator based on common pressure rail (HHEC) provides an alternative with electric hybrid excavator because it has high power density and environment friendly and easy to modify based on the existing manufacture process. This paper is focused on the fuel consumption of HHEC and the actuator dynamic response to assure that the new system can save energy without sacrificing performance. Firstly, we introduce the basic principle of HHEC; then, the sizing process is presented; furthermore, the modeling period which combined mathematical analysis and experiment identification is listed. Finally, simulation results show that HHEC has a fast dynamic response which can be accepted in engineering and the fuel consumption can be reduced 21% to compare the original LS excavator and even 32% after adopting another smaller engine.

  19. Nonlinear Dynamical Analysis of Hydraulic Turbine Governing Systems with Nonelastic Water Hammer Effect

    Directory of Open Access Journals (Sweden)

    Junyi Li

    2014-01-01

    Full Text Available A nonlinear mathematical model for hydroturbine governing system (HTGS has been proposed. All essential components of HTGS, that is, conduit system, turbine, generator, and hydraulic servo system, are considered in the model. Using the proposed model, the existence and stability of Hopf bifurcation of an example HTGS are investigated. In addition, chaotic characteristics of the system with different system parameters are studied extensively and presented in the form of bifurcation diagrams, time waveforms, phase space trajectories, Lyapunov exponent, chaotic attractors, and Poincare maps. Good correlation can be found between the model predictions and theoretical analysis. The simulation results provide a reasonable explanation for the sustained oscillation phenomenon commonly seen in operation of hydroelectric generating set.

  20. Hydraulic design and analysis of the saxo-type vertical axial turbine

    Energy Technology Data Exchange (ETDEWEB)

    Hofler, Edvard; Gale, Janez; Bergant, Anton

    2010-07-01

    The design of the blade geometry of a wind turbine is highly important as it influences the power generation. The aim of this study is to introduce a method for hydraulic design and analysis of the blade geometry of a highly specific speed runner of the Saxo-type double-regulated vertical axial turbine. The streamline curvature method (SCM) was used to develop four blade shapes which were analyzed with computational fluid dynamics (CFD) tools and the best one chosen in term of turbine efficiency and cavitational characteristics. Results demonstrated that the physical shape of the blade can be found for the design duty point in a rapid and transparent way by using the SCM method with no adjustments required to use the CFD methods. This study proved that the SCM design procedure developed herein can be used to accurately design runner blades.

  1. Development of system analysis code for thermal-hydraulic simulation of integral reactor, Rex-10

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    Rex-10 is an environment-friendly and economical small-scale nuclear reactor to provide the energy for district heating as well as the electric power in micro-grid. This integral reactor comprises several innovative concepts supported by advanced primary circuit components, low coolant parameters and natural circulation cooling. To evaluate the system performance and thermal-hydraulic behavior of the reactor, a system analysis code is being developed so that the new designs and technologies adopted in Rex-10 can be reflected. The research efforts are absorbed in programming the simple and fast-running thermal-hydraulic analysis software. The details of hydrodynamic governing equations component models and numerical solution scheme used in this code are presented in this paper. On the basis of one-dimensional momentum integral model, the models of point reactor neutron kinetics for thorium-fueled core, physical processes in the steam-gas pressurizer, and heat transfers in helically coiled steam generator are implemented to the system code. Implicit numerical scheme is employed to momentum and energy equations to assure the numerical stability. The accuracy of simulation is validated by applying the solution method to the Rex-10 test facility. Calculated natural circulation flow rate and coolant temperature at steady-state are compared to the experimental data. The validation is also carried out for the transients in which the sudden reduction in the core power or the feedwater flow takes place. The code's capability to predict the steady-state flow by natural convection and the qualitative behaviour of the primary system in the transients is confirmed. (Author)

  2. KUGEL: a thermal, hydraulic, fuel performance, and gaseous fission product release code for pebble bed reactor core analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shamasundar, B.I.; Fehrenbach, M.E.

    1981-05-01

    The KUGEL computer code is designed to perform thermal/hydraulic analysis and coated-fuel particle performance calculations for axisymmetric pebble bed reactor (PBR) cores. This computer code was developed as part of a Department of Energy (DOE)-funded study designed to verify the published core performance data on PBRs. The KUGEL code is designed to interface directly with the 2DB code, a two-dimensional neutron diffusion code, to obtain distributions of thermal power, fission rate, fuel burnup, and fast neutron fluence, which are needed for thermal/hydraulic and fuel performance calculations. The code is variably dimensioned so that problem size can be easily varied. An interpolation routine allows variable mesh size to be used between the 2DB output and the two-dimensional thermal/hydraulic calculations.

  3. Analysis of the Thermal and Hydraulic Stimulation Program at Raft River, Idaho

    Science.gov (United States)

    Bradford, Jacob; McLennan, John; Moore, Joseph; Podgorney, Robert; Plummer, Mitchell; Nash, Greg

    2017-05-01

    Laboratory is being used to simulate and visualize the effects of the injection. The simulation model uses a discrete fracture network generated for RRG-9 using acoustic borehole imaging and analysis of microseismic activity. By adjusting the permeability of the fractures, a pressure history match for the first part of the stimulation program was obtained. The results of this model indicate that hydraulic fracturing is the dominant mechanism for permeability improvement for this part of the stimulation program.

  4. 75 FR 69140 - NUREG-1953, Confirmatory Thermal-Hydraulic Analysis To Support Specific Success Criteria in the...

    Science.gov (United States)

    2010-11-10

    ... COMMISSION NUREG-1953, Confirmatory Thermal-Hydraulic Analysis To Support Specific Success Criteria in the... Regulatory Commission has issued for public comment a document entitled: NUREG-1953, ``Confirmatory Thermal...-4209, 301-415-4737, or by e-mail to pdr.resource@nrc.gov . NUREG-1953 is available electronically...

  5. 75 FR 80544 - NUREG-1953, Confirmatory Thermal-Hydraulic Analysis To Support Specific Success Criteria in the...

    Science.gov (United States)

    2010-12-22

    ... COMMISSION NUREG-1953, Confirmatory Thermal-Hydraulic Analysis To Support Specific Success Criteria in the... Regulatory Commission is re-opening the public comment period for the document entitled: NUREG-1953....gov . NUREG-1953 is available electronically under ADAMS Accession Number ML102940233....

  6. Solving thermal-hydraulic tasks in the context of structure-mechanical analysis; Loesung thermohydraulischer Aufgaben im Rahmen strukturmechanischer Analysen

    Energy Technology Data Exchange (ETDEWEB)

    Hermsmeyer, S.

    1999-06-01

    The thermomechanical analysis of fluid-cooled structures depends critically on local coolant temperatures. This is particularly true for transient analyses of fusion reactor blankets that are exposed to large radial and temporal power gradients in power cycling reactors and see large thermal-mechanical loads. This report is concerned with the issue of thermal-hydraulic modelling and analysis that is an integral part of structure-mechanical analyses yet has to be treated separately because of differing needs regarding the finite element code and structure discretisation. This report presents a simplified thermal no-momentum fluid model that poses acceptable icomputational cost even for extended and branched cooling systems. The implementation of this model in the finite element codes FIDAP and ABAQUS is described. A comparison of the codes finds advantages for thermal-hydraulic modelling in FIDAP, stressing however, that unified computer-aided-design-based grid generation would be desirable. Two examples serve the purpose of demonstrating the methodology of the thermal-hydraulic analysis. Key parts of this methodology are the use of symmetry conditions when modelling a representative blanket section, the partitioning into submodels, the simplification of geometrical model features and the feeding thermal-hydraulic results into the structure-mechanic analysis. Part of the appendix is a description and manual for a computer code that has been written to simplify the design of three-dimensional FIDAP models. The code automates the successive rotation and/or translation of surfaces defined in FIDAP.

  7. 4C code analysis of thermal-hydraulic transients in the KSTAR PF1 superconducting coil

    Science.gov (United States)

    Savoldi Richard, L.; Bonifetto, R.; Chu, Y.; Kholia, A.; Park, S. H.; Lee, H. J.; Zanino, R.

    2013-01-01

    The KSTAR tokamak, in operation since 2008 at the National Fusion Research Institute in Korea, is equipped with a full superconducting magnet system including the central solenoid (CS), which is made of four symmetric pairs of coils PF1L/U-PF4L/U. Each of the CS coils is pancake wound using Nb3Sn cable-in-conduit conductors with a square Incoloy jacket. The coils are cooled with supercritical He in forced circulation at nominal 4.5 K and 5.5 bar inlet conditions. During different test campaigns the measured temperature increase due to AC losses turned out to be higher than expected, which motivates the present study. The 4C code, already validated against and applied to different types of thermal-hydraulic transients in different superconducting coils, is applied here to the thermal-hydraulic analysis of a full set of trapezoidal current pulses in the PF1 coils, with different ramp rates. We find the value of the coupling time constant nτ that best fits, at each current ramp rate, the temperature increase up to the end of the heating at the coil outlet. The agreement between computed results and the whole set of measured data, including temperatures, pressures and mass flow rates, is then shown to be very good both at the inlet and at the outlet of the coil. The nτ values needed to explain the experimental results decrease at increasing current ramp rates, consistently with the results found in the literature.

  8. Evaluating the feasibility of hydraulic and physical barriers at contaminated sites by means of multicriteria analysis

    Directory of Open Access Journals (Sweden)

    Andrea Gigliuto

    2014-06-01

    Full Text Available Controlling contaminant plumes in groundwater using pump and treat or hydraulic and physical barriers is a common practice to contain and reduce solute contaminants in remediation activities. Recent evolution in engineering techniques also allowed to extend the number of solutions that can be designed and set in practice. As such, the decision-making process assumes great importance in leading the selection of the best suitable technology for a certain case study. This process has to take into account technical, environmental and socioeconomic factors. This paper presents the results of a research project aimed at defining a multi-criteria procedure analysis to support the decision-making process in the barrier technology selection, taking into account technical, economic, social and environmental factors. A multi-criteria analysis methodology has been defined to provide a quantitative tool to guide the selection of the best suitable technology concerning a specific case. The methodology was applied to a real case, selected from many case studies based on data availability and quality, in order to verify the effectiveness of the procedure in evaluating the alternative selections and to highlight the differences between the results of the multi-criteria analysis and the real engineers choices. A sensitivity analysis was performed to analyze the influence of each criterion on the final result of the study. With this paper we aim to start a discussion to deepen the decision making process, in order to develop methodologies allowing to chose the best solution without subjective evaluations.

  9. Baseflow recession analysis in a large shale play: Climate variability and anthropogenic alterations mask effects of hydraulic fracturing

    Science.gov (United States)

    Arciniega-Esparza, Saúl; Breña-Naranjo, Jose Agustín; Hernández-Espriú, Antonio; Pedrozo-Acuña, Adrián; Scanlon, Bridget R.; Nicot, Jean Philippe; Young, Michael H.; Wolaver, Brad D.; Alcocer-Yamanaka, Victor Hugo

    2017-10-01

    Water resources development and landscape alteration exert marked impacts on water-cycle dynamics, including areas subjected to hydraulic fracturing (HF) for exploitation of unconventional oil and gas resources found in shale or tight sandstones. Here we apply a conceptual framework for linking baseflow analysis to changes in water demands from different sectors (e.g. oil/gas extraction, irrigation, and municipal consumption) and climatic variability in the semiarid Eagle Ford play in Texas, USA. We hypothesize that, in water-limited regions, baseflow (Qb) changes are partly due (along with climate variability) to groundwater abstraction. For a more realistic assessment, the analysis was conducted in two different sets of unregulated catchments, located outside and inside the Eagle Ford play. Three periods were considered in the analysis related to HF activities: pre-development (1980-2000), moderate (2001-2008) and intensive (2009-2015) periods. Results indicate that in the Eagle Ford play region, temporal changes in baseflow cannot be directly related to the increase in hydraulic fracturing. Instead, substantial baseflow declines during the intensive period of hydraulic fracturing represent the aggregated effects from the combination of: (1) a historical exceptional drought during 2011-2012; (2) increased groundwater-based irrigation; and (3) an intensive hydraulic fracturing activity.

  10. THE THERMAL-HYDRAULICS ANALYSIS ON RADIAL AND AXIAL POWER FLUCTUATION FOR AP1000 REACTOR

    Directory of Open Access Journals (Sweden)

    Muh. Darwis Isnaini

    2015-06-01

    Full Text Available ABSTRACT THE THERMAL-HYDRAULICS ANALYSIS ON RADIAL AND AXIAL POWER FLUCTUATION FOR AP1000 REACTOR. The reduction of fissile material during reactor operation affects reactivity reduction. Therefore, in order to keep the reactor operating at fixed power, it must be compensated by slowly withdrawing the control-rod up. However, it will change the shape of the horizontal/axial power distribution and safety margin as well. The research carries out the calculations of the core thermal-hydraulics to determine the effect of the fluctuations of the power distribution on the thermal-hydraulic AP1000’s parameters and study their impacts on the safety margin. The calculation is done using the COBRA-EN code and the result shows that the maximum heat flux at the Beginning of Cycle (BOC is 1624.02 kW/m2. This heat flux will then decrease by 22.75% at the Middle of Cycle (MOC and by 0.29% at the End of Cycle (EOC. The peak fuel centerline temperature at the BOC, MOC and EOC, are 1608.15°C, 1232.15°C, and 1301.75°C, respectively. These temperature differences are caused by the heat flux effects on sub-cooled boiling regions in the cladding surface. Moreover, the value of MDNBRs at the MOC and EOC are 3.23 and 3.00, which are higher than the MDNBR at the BOC of 2.49. It could be concluded that the operating cycle of the AP1000 reactor should be operated in the MOC and the EOC, which will be more safely than be operated in the BOC. Keywords: Core thermal-hydraulics, AP1000, fluctuation of power distribution, COBRA-EN.   ABSTRAK ANALISIS TERMOHIDRAULIKA PADA FLUKTUASI DAYA AXIAL DAN RADIAL UNTUK REAKTOR AP1000. Berkurangnya material fisil selama operasi reaktor, mengakibatkan reaktivitas berkurang. Oleh karena itu, agar reaktor tetap beroperasi pada daya yang tetap, maka harus dikompensasi dengan menarik batang kendali ke atas sedikit demi sedikit. Akan tetapi, hal ini akan berakibat pada berubahnya bentuk distribusi daya ke arah horisontal/aksial dan

  11. Hydraulic structures

    CERN Document Server

    Chen, Sheng-Hong

    2015-01-01

    This book discusses in detail the planning, design, construction and management of hydraulic structures, covering dams, spillways, tunnels, cut slopes, sluices, water intake and measuring works, ship locks and lifts, as well as fish ways. Particular attention is paid to considerations concerning the environment, hydrology, geology and materials etc. in the planning and design of hydraulic projects. It also considers the type selection, profile configuration, stress/stability calibration and engineering countermeasures, flood releasing arrangements and scouring protection, operation and maintenance etc. for a variety of specific hydraulic structures. The book is primarily intended for engineers, undergraduate and graduate students in the field of civil and hydraulic engineering who are faced with the challenges of extending our understanding of hydraulic structures ranging from traditional to groundbreaking, as well as designing, constructing and managing safe, durable hydraulic structures that are economical ...

  12. Development of best estimate auditing code for CANDU thermal-hydraulic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Bub Dong; Lee, Won Jae; Hwang, Moon Kyu; Lim, Hong Sik [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-04-01

    The main purpose of this study is to develop a thermal hydraulic auditing code for the CANDU reactor, modifying the model of existing PWR auditing tool, i.e. RELAP5/MOD3.The study was performed by reconsideration of the previous code assessment works and phenomena identification for essential accident scenario. Improvement areas of model development for auditing tool were identified based on the code comparison and PIRT results. Nine models have been improved significantly for the analysis of LOCA and Mon LOCA event. Conceptual problem or separate effect assessment have been performed to verify the model improvement. The linking calculation with CONTAIN 2.0 has been also enabled to establish the unified auditing code system. Analysis for the CANDU plant real transient and hypothetical LOCA bas been performed using the improved version. It has been concluded that the developed version can be utilized for the auditing analysis of LOCA and non-LOCA event for the CANDU reactor. 25 refs., 84 figs., 36 tabs. (Author)

  13. CFD analysis of the ITER first wall 06 panel. Part II: Thermal-hydraulics

    Energy Technology Data Exchange (ETDEWEB)

    Zanino, R.; Bonifetto, R. [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); Cau, F.; Portone, A. [Fusion for Energy, 08019 Barcelona (Spain); Savoldi Richard, L., E-mail: laura.savoldi@polito.it [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy)

    2014-04-15

    The computational fluid dynamics (CFD) analysis of the FW06 panel of the ITER shielding blanket is presented in two companion papers. In this Part II we concentrate on the thermal-hydraulics of the water coolant, driven by the nuclear volumetric and plasma surface heat loads discussed in Part I. Both the detailed steady state analysis of a single cooling channel and the coarse transient analysis of the whole panel are considered. The compatibility of the hot spots with the maximum recommended temperatures for the different materials is confirmed. The heat transfer coefficient between coolant and walls is obtained post-processing the results of the simulation and compared with the results of available correlations, which may be used for simpler analyses: in the fully developed flow regions of the cooling pipes, it turns out to be well approximated by the Sieder–Tate correlation. The operation margin with respect to the critical heat flux is also computed and turns out to be sufficiently large compared with the design limit.

  14. Dispersion analysis of passive surface-wave noise generated during hydraulic-fracturing operations

    Science.gov (United States)

    Forghani-Arani, Farnoush; Willis, Mark; Snieder, Roel; Haines, Seth S.; Behura, Jyoti; Batzle, Mike; Davidson, Michael

    2014-01-01

    Surface-wave dispersion analysis is useful for estimating near-surface shear-wave velocity models, designing receiver arrays, and suppressing surface waves. Here, we analyze whether passive seismic noise generated during hydraulic-fracturing operations can be used to extract surface-wave dispersion characteristics. Applying seismic interferometry to noise measurements, we extract surface waves by cross-correlating several minutes of passive records; this approach is distinct from previous studies that used hours or days of passive records for cross-correlation. For comparison, we also perform dispersion analysis for an active-source array that has some receivers in common with the passive array. The active and passive data show good agreement in the dispersive character of the fundamental-mode surface-waves. For the higher mode surface waves, however, active and passive data resolve the dispersive properties at different frequency ranges. To demonstrate an application of dispersion analysis, we invert the observed surface-wave dispersion characteristics to determine the near-surface, one-dimensional shear-wave velocity.

  15. Steady state thermal hydraulic analysis of LMR core using COBRA-K code

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eui Kwang; Kim, Young Gyun; Kim Young In; Kim Young Cheol

    1997-02-01

    A thermal hydraulics analysis code COBRA-K is being developed by the KAERI LMR core design technology development team. COBRA-K is a part of the integrated computation system for LMR core design and analysis, the K-CORE system. COBRA-K is supposed to predict the flow and temperature distributions in LMR core. COBRA-K is an extension of the previously published COBRA-IV-I code with several functional improvements. Specially COBRA-K has been improved to analyze single and multi-assembly, and whole-core in the transient condition. This report describes the overall features of COBRA-K and gives general input descriptions. The 19 pin assembly experimental data of ORNL were used to verify the accuracy of this code for the steady state analysis. The comparative results show good agreements between the calculated and the measured data. And COBRA-K can be used to predict flow and temperature distributions for the LMR core design. (author). 7 refs., 6 tabs., 13 figs.

  16. FE Analysis of Rock with Hydraulic-Mechanical Coupling Based on Continuum Damage Evolution

    Directory of Open Access Journals (Sweden)

    Yongliang Wang

    2016-01-01

    Full Text Available A numerical finite element (FE analysis technology is presented for efficient and reliable solutions of rock with hydraulic-mechanical (HM coupling, researching the seepage characteristics and simulating the damage evolution of rock. To be in accord with the actual situation, the rock is naturally viewed as heterogeneous material, in which Young’s modulus, permeability, and strength property obey the typical Weibull distribution function. The classic Biot constitutive relation for rock as porous medium is introduced to establish a set of equations coupling with elastic solid deformation and seepage flow. The rock is subsequently developed into a novel conceptual and practical model considering the damage evolution of Young’s modulus and permeability, in which comprehensive utilization of several other auxiliary technologies, for example, the Drucker-Prager strength criterion, the statistical strength theory, and the continuum damage evolution, yields the damage variable calculating technology. To this end, an effective and reliable numerical FE analysis strategy is established. Numerical examples are given to show that the proposed method can establish heterogeneous rock model and be suitable for different load conditions and furthermore to demonstrate the effectiveness and reliability in the seepage and damage characteristics analysis for rock.

  17. A decision analysis framework for estimating the potential hazards for drinking water resources of chemicals used in hydraulic fracturing fluids.

    Science.gov (United States)

    Yost, Erin E; Stanek, John; Burgoon, Lyle D

    2017-01-01

    Despite growing concerns over the potential for hydraulic fracturing to impact drinking water resources, there are limited data available to identify chemicals used in hydraulic fracturing fluids that may pose public health concerns. In an effort to explore these potential hazards, a multi-criteria decision analysis (MCDA) framework was employed to analyze and rank selected subsets of these chemicals by integrating data on toxicity, frequency of use, and physicochemical properties that describe transport in water. Data used in this analysis were obtained from publicly available databases compiled by the United States Environmental Protection Agency (EPA) as part of a larger study on the potential impacts of hydraulic fracturing on drinking water. Starting with nationwide hydraulic fracturing chemical usage data from EPA's analysis of the FracFocus Chemical Disclosure Registry 1.0, MCDAs were performed on chemicals that had either noncancer toxicity values (n=37) or cancer-specific toxicity values (n=10). The noncancer MCDA was then repeated for subsets of chemicals reported in three representative states (Texas, n=31; Pennsylvania, n=18; and North Dakota, n=20). Within each MCDA, chemicals received scores based on relative toxicity, relative frequency of use, and physicochemical properties (mobility in water, volatility, persistence). Results show a relative ranking of these chemicals based on hazard potential, and provide preliminary insight into chemicals that may be more likely than others to impact drinking water resources. Comparison of nationwide versus state-specific analyses indicates regional differences in the chemicals that may be of more concern to drinking water resources, although many chemicals were commonly used and received similar overall hazard rankings. Several chemicals highlighted by these MCDAs have been reported in groundwater near areas of hydraulic fracturing activity. This approach is intended as a preliminary analysis, and represents one

  18. HYDRAULIC SERVO

    Science.gov (United States)

    Wiegand, D.E.

    1962-05-01

    A hydraulic servo is designed in which a small pressure difference produced at two orifices by an electrically operated flapper arm in a constantly flowing hydraulic loop is hydraulically amplified by two constant flow pumps, two additional orifices, and three unconnected ball pistons. Two of the pistons are of one size and operate against the additional orifices, and the third piston is of a different size and operates between and against the first two pistons. (AEC)

  19. Near-saturated hydraulic conductivity: database development, meta-analysis and pedotransfer functions

    Science.gov (United States)

    Jarvis, Nicholas; Koestel, John; Messing, Ingmar; Lindahl, Anna

    2013-04-01

    Near-saturated hydraulic conductivity exerts a critical control on water flow and solute transport through the vadose zone, yet very little is known concerning how it is influenced by various soil properties and site factors and attributes. Starting from the 1980's, tension infiltrometers or disc permeameters have become an increasingly popular method to measure near-saturated hydraulic conductivity in undisturbed soil. In this presentation, we describe the development and organization of a large database of tension infiltrometer measurements (n>700) collated from the published literature. The raw datasets were standardized and summarized using a modified Kozeny-Carman model of near-saturated hydraulic conductivity (Jarvis, N.J. 2008. Near-saturated hydraulic properties of macroporous soils. Vadose Zone Journal, 7, 1302-1310). This model was found to accurately describe near-saturated conductivity for this large dataset (92% of cases had R2 values larger than 0.9). We will show the results of some initial analyses of the dataset, which show how hydraulic conductivity at pressure heads of -1 and -10 cm, as well as the slope of the near-saturated conductivity function, are affected by: i.) the choice of method to convert unconfined 3D infiltration to hydraulic conductivity, and ii.) interactions between soil properties such as texture and bulk density and site attributes such as land use and climate. We will also present some initial attempts to develop pedotransfer functions for parameters describing near-saturated hydraulic conductivity using the technique of random forests.

  20. Establishment of digital model for dynamic simulation analysis on hydraulic impact perforator

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Hydraulic impact perforator is powerful tools for trenchless project. It has advantages in cabinet structure, low cost, long life and easy protected. Compared with pneumatic DTH, the hydraulic impact spear worked under high pressure and using uncompressible fluid thusgreater impact energy and higher efficiency can be supported. The authors founded the dynamic simulation model of HDI-146 hydraulic impact spear. The project for solving the differential equation was suggested also. By means of virtual machine technology, the dynamic mechanism of HDI-146 can be explored and tutoring us to optimize the structural parameters can be made.

  1. Simplified thermal-hydraulic analysis of single phase natural circulation circuit with two heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Larissa Cunha; Su, Jian, E-mail: larissa@lasme.coppe.ufrj.br, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenhraria Nuclear; Cotta, Renato Machado, E-mail: cotta@mecanica.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (POLI/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica

    2015-07-01

    Single phase natural circulation circuits composed of two convective heat exchangers and connecting tubes are important for the passive heat removal from spent fuel pools (SFP). To keep the structural integrity of the stored spent fuel assemblies, continuously cooling has to be provided in order to avoid increase at the pool temperature and subsequent uncovering of the fuel and enhanced reaction between water and metal releasing hydrogen. Decay heat can achieve considerably high amounts of energy e.g. in the AP1000, considering the emergency fuel assemblies, the maximum heat decay will reach 13 MW in the 15th day (Westinghouse Electric Company, 2010). A highly efficient alternative to do so is by means of natural circulation, which is cost-effective compared to active cooling systems and is inherently safer since presents less associated devices and no external work is required. Many researchers have investigated safety and stability aspects of natural circulation loops (NCL). However, there is a lack of literature concerning the improvement of NCL through a standard unified methodology, especially for natural circulation circuits with two heat exchangers. In the present study, a simplified thermal-hydraulic analysis of single phase natural circulation circuit with two heat exchanges is presented. Relevant dimensionless key groups were proposed to for the design and safety analysis of a scaled NCL for the cooling of spent fuel storage pool with convective cooling and heating. (author)

  2. Analysis of Proppant Hydraulic Fracturing in a Sand Oil Reservoir in Southwest of Iran

    Directory of Open Access Journals (Sweden)

    Reza Masoomi

    2015-10-01

    Full Text Available Hydraulic fracturing is one way to increase the productivity of oil and gas wells. One of the most fundamental successes of hydraulic fracturing operation is selecting the proper size and type of proppants which are used during the process. The aim of this study is optimizing the type and size of used propant in hydraulic fracturing operation in a sand oil reservoir in southwest of Iran. In this study sand and ceramic (sintered bauxite have been considered as proppant type. Also the various types of resin-coated sand and resin-coated ceramic have been considered. Then the various scenarios have been designed to optimize the size and type of proppant used in hydraulic fracturing in a sand oil reservoir in southwest of Iran. Also in this study increasing the cumulative oil recovery in fractured and Non-fractured wells in a sand oil reservoir in southwest of Iran have been investigated.

  3. Design and performance characteristic analysis of servo valve-type water hydraulic poppet valve

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Hwan [Pusan National University, Busan (Korea, Republic of)

    2009-09-15

    For water hydraulic system control, the flow or pressure control using high-speed solenoid valve controlled by PWM control method could be a good solution for prevention of internal leakage. However, since the PWM control of on-off valves cause extensive flow and pressure fluctuation, it is difficult to control the water hydraulic actuators precisely. In this study, the servo valve-type water hydraulic valve using proportional poppet as the main valve is designed and the performance characteristics of the servo valve-type water hydraulic valve are analyzed. Furthermore, it is demonstrated through experiments that a decline in control chamber pressure that follows the change of pilot flow is caused by the occurrence of cavitation around the proportional poppet, and that fundamental characteristics of the developed valve remain unaffected by the occurrence of cavitation

  4. Numerical analysis of fracture propagation during hydraulic fracturing operations in shale gas systems

    Science.gov (United States)

    Researchers used the TOUGH+ geomechanics computational software and simulation system to examine the likelihood of hydraulic fracture propagation (the spread of fractures) traveling long distances to connect with drinking water aquifers.

  5. Reliability and safety of the K Reactor cooling system: Part 2, Engineering analysis of hydraulic and mechanical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Shoemaker, R.H.

    1960-04-04

    Subsequent to the recent formulation and adoption of safety criteria for reactor cooling systems, there appeared the need for an independent evaluation of the safety and reliability of the K-Reactor cooling system in terms of these criteria. The primary, secondary and last-ditch cooling systems of this reactor involve a strong inter-dependence between electrical and hydraulic components of the water plant. Because of the complexity of inter-relationships between these components, the analysis was divided into two parallel studies which were accomplished during the simmer of 1959. F. D. Robbins has presented his analysis of the electrical power and control system in HW-61887. This report deals with an engineering analysis of the hydraulic and mechanical aspects of the reliability and safety of the K-Reactor Cooling System. The system, as described in this report, is that which existed during the simmer of 1959, prior to modification under Project CG-775 (now Project CG-883).

  6. Comparative Analysis of CTF and Trace Thermal-Hydraulic Codes Using OECD/NRC PSBT Benchmark Void Distribution Database

    Directory of Open Access Journals (Sweden)

    M. Avramova

    2013-01-01

    Full Text Available The international OECD/NRC PSBT benchmark has been established to provide a test bed for assessing the capabilities of thermal-hydraulic codes and to encourage advancement in the analysis of fluid flow in rod bundles. The benchmark was based on one of the most valuable databases identified for the thermal-hydraulics modeling developed by NUPEC, Japan. The database includes void fraction and departure from nucleate boiling measurements in a representative PWR fuel assembly. On behalf of the benchmark team, PSU in collaboration with US NRC has performed supporting calculations using the PSU in-house advanced thermal-hydraulic subchannel code CTF and the US NRC system code TRACE. CTF is a version of COBRA-TF whose models have been continuously improved and validated by the RDFMG group at PSU. TRACE is a reactor systems code developed by US NRC to analyze transient and steady-state thermal-hydraulic behavior in LWRs and it has been designed to perform best-estimate analyses of LOCA, operational transients, and other accident scenarios in PWRs and BWRs. The paper presents CTF and TRACE models for the PSBT void distribution exercises. Code-to-code and code-to-data comparisons are provided along with a discussion of the void generation and void distribution models available in the two codes.

  7. Mechanical Analysis of Dead Load Crown and Structure Parameter of Hydraulic Elastic Bulging Roll

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chang-cai; LI Wei-min; LIU Zhu-bai

    2003-01-01

    The dead load crown of hydraulic elastic bulging roll was discussed using the theory of elastically supported beam, and the dead load experiment was carried out. The theoretical calculation is consistent with the experimental result. The structure parameters for the thickness of roll sleeve, the length of the oil groove and the crown of roll were discussed. The fundamental principle of determining the parameters was put forward. The theoretical basis of the application of the hydraulic elastic bulging roll was established.

  8. Design and Analysis of High Pressure Hydraulic Filter for Marine Application

    Science.gov (United States)

    Momin, Toshin; Chandrasekar, RP; Balasubramanian, S.; Junaid Basha, AM, Dr.

    2017-05-01

    Filter is a critical component in ahydraulic system for maintaining the cleanliness of the fluid to required class level. InMarine applications very high reliable filter is required to operate continuously in saline environment. Design anddevelopment of high pressure hydraulic filter for Marine application is a challenging task. The design involves selection of special materialsandstringent qualification tests as per International standards. The present paper describes various stages of design and development of high pressure hydraulic filter for Marine application.

  9. Thermal-hydraulic analysis for changing feedwater check valve leakage rate testing methodology

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, R.; Harrell, J.

    1996-12-01

    The current design and testing requirements for the feedwater check valves (FWCVs) at the Grand Gulf Nuclear Station are established from original licensing requirements that necessitate extremely restrictive air testing with tight allowable leakage limits. As a direct result of these requirements, the original high endurance hard seats in the FWCVs were modified with elastomeric seals to provide a sealing surface capable of meeting the stringent air leakage limits. However, due to the relatively short functional life of the elastomeric seals compared to the hard seats, the overall reliability of the sealing function actually decreased. This degraded performance was exhibited by frequent seal failures and subsequent valve repairs. The original requirements were based on limited analysis and the belief that all of the high energy feedwater vaporized during the LOCA blowdown. These phenomena would have resulted in completely voided feedwater lines and thus a steam environment within the feedwater leak pathway. To challenge these criteria, a comprehensive design basis accident analysis was developed using the RELAP5/MOD3.1 thermal-hydraulic code. Realistic assumptions were used to more accurately model the post-accident fluid conditions within the feedwater system. The results of this analysis demonstrated that no leak path exists through the feedwater lines during the reactor blowdown phase and that sufficient subcooled water remains in various portions of the feedwater piping to form liquid water loop seals that effectively isolate this leak path. These results provided the bases for changing the leak testing requirements of the FWCVs from air to water. The analysis results also established more accurate allowable leakage limits, determined the real effective margins associated with the FWCV safety functions, and led to design changes that improved the overall functional performance of the valves.

  10. Hydraulic Self Servo Swing Cylinder Structure Optimization and Dynamic Characteristics Analysis Based on Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    Lin Jiang; Ruolin Wu∗and Zhichao Zhu

    2015-01-01

    The dynamic characteristics of hydraulic self servo swing cylinder were analyzed according to the hydraulic system natural frequency formula. Based on that, a method of the hydraulic self servo swing cylinder structure optimization based on genetic algorithm was proposed in this paper. By analyzing the four parameters that affect the dynamic characteristics, we had to optimize the structure to obtain as larger the Dm ( displacement) as possible under the condition with the purpose of improving the dynamic characteristics of hydraulic self servo swing cylinder. So three state equations were established in this paper. The paper analyzed the effect of the four parameters in hydraulic self servo swing cylinder natural frequency equation and used the genetic algorithm to obtain the optimal solution of structure parameters. The model was simulated by substituting the parameters and initial value to the simulink model. Simulation results show that: using self servo hydraulic swing cylinder natural frequency equation to study its dynamic response characteristics is very effective. Compared with no optimization, the overall system dynamic response speed is significantly improved.

  11. The detection of cavitation in hydraulic machines by use of ultrasonic signal analysis

    Science.gov (United States)

    Gruber, P.; Odermatt, P.; Etterlin, M.; Lerch, T.; Frei, M.; Farhat, M.

    2014-03-01

    This presentation describes an experimental approach for the detection of cavitation in hydraulic machines by use of ultrasonic signal analysis. Instead of using the high frequency pulses (typically 1MHz) only for transit time measurement different other signal characteristics are extracted from the individual signals and its correlation function with reference signals in order to gain knowledge of the water conditions. As the pulse repetition rate is high (typically 100Hz), statistical parameters can be extracted of the signals. The idea is to find patterns in the parameters by a classifier that can distinguish between the different water states. This classification scheme has been applied to different cavitation sections: a sphere in a water flow in circular tube at the HSLU in Lucerne, a NACA profile in a cavitation tunnel and a Francis model test turbine both at LMH in Lausanne. From the signal raw data several statistical parameters in the time and frequency domain as well as from the correlation function with reference signals have been determined. As classifiers two methods were used: neural feed forward networks and decision trees. For both classification methods realizations with lowest complexity as possible are of special interest. It is shown that three signal characteristics, two from the signal itself and one from the correlation function are in many cases sufficient for the detection capability. The final goal is to combine these results with operating point, vibration, acoustic emission and dynamic pressure information such that a distinction between dangerous and not dangerous cavitation is possible.

  12. Application of entropy production theory to hydro-turbine hydraulic analysis

    Institute of Scientific and Technical Information of China (English)

    GONG; RuZhi; WANG; HongJie; CHEN; LiXia; LI; DeYou; ZHANG; HaoChun; WEI; XianZhu

    2013-01-01

    The understanding of hydraulic behavior in the hydro turbine requires the detailed study of fluid flow in the turbine. Previous methods of analyzing the numerical simulation results on the fluid machinery are short of intuitiveness on energy dissipation.In this paper, the energy dissipation was analyzed based on the entropy production theory. 3-D steady flow simulations and entropy production calculations of the reduced hydro turbine were carried out. The results indicated that the entropy production theory was suitable for evaluating the performance of the hydro turbine. The energy dissipation in the guide vanes area weighted nearly 25% of the whole flow passage, and mainly happened at the head and tail areas of the vanes. However, more than half the energy dissipation occurred in the runner, mostly at the leading edge of runner blade and the trailing edge of run-ner blade. Meanwhile, close to 20% of the energy dissipation occurred in the elbow. And it can be concluded that the method of entropy production analysis has the advantages of determining the quantity of energy dissipation and where the dissipation happens.

  13. Design, Modeling, and Analysis of a Novel Hydraulic Energy-Regenerative Shock Absorber for Vehicle Suspension

    Directory of Open Access Journals (Sweden)

    Junyi Zou

    2017-01-01

    Full Text Available To reduce energy consumption or improve energy efficiency, the regenerative devices recently have drawn the public’s eyes. In this paper, a novel hydraulic energy-regenerative shock absorber (HERSA is developed for vehicle suspension to regenerate the vibration energy which is dissipated by conventional viscous dampers into heat waste. At first, the schematic of HERSA is presented and a mathematic model is developed to describe the characteristic of HERSA. Then the parametric sensitivity analysis of the vibration energy is expounded, and the ranking of their influences is k1≫m2>m1>k2≈cs. Besides, a parametric study of HERSA is adopted to research the influences of the key parameters on the characteristic of HERSA. Moreover, an optimization of HERSA is carried out to regenerate more power as far as possible without devitalizing the damping characteristic. To make the optimization results more close to the actual condition, the displacement data of the shock absorber in the road test is selected as the excitation in the optimization. The results show that the RMS of regenerated energy is up to 107.94 W under the actual excitation. Moreover it indicates that the HERSA can improve its performance through the damping control.

  14. Thermal Hydraulic Analysis of a Passive Residual Heat Removal System for an Integral Pressurized Water Reactor

    Directory of Open Access Journals (Sweden)

    Junli Gou

    2009-01-01

    Full Text Available A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS, which is connected to the reactor coolant system via the secondary side of the steam generator, for an integral pressurized water reactor is presented in this paper. Three-interknited natural circulation loops are adopted by this PRHRS to remove the residual heat of the reactor core after a reactor trip. Based on the one-dimensional model and a simulation code (SCPRHRS, the transient behaviors of the PRHRS as well as the effects of the height difference between the steam generator and the heat exchanger and the heat transfer area of the heat exchanger are studied in detail. Through the calculation analysis, it is found that the calculated parameter variation trends are reasonable. The higher height difference between the steam generator and the residual heat exchanger and the larger heat transfer area of the residual heat exchanger are favorable to the passive residual heat removal system.

  15. Numerical analysis on the cavitation and unsteady flow in a scroll hydraulic pump

    Science.gov (United States)

    Sun, S. H.; Guo, P. C.; Huang, Y.; Zuo, J. L.; Luo, X. Q.

    2016-05-01

    This paper presents numerical analysis of unsteady flow in a scroll hydraulic pump to discover its flow mechanism. The dynamic mesh model has to be used to simulate the flow field unsteadily. The unsteady flow patterns and pressure distributions in the suction, squeezing and discharge chamber are analysed. The suction process continues until the crank angle reaches the 320 degree. Then the pressure in the chamber rises instantaneously, and the fluid begins to flow out from the chamber. Because of the high pressure difference at the clearance, the jet flow and the vortex appear, and the large flow losses generates with them. In addition, the velocity and static pressure distribution in the two symmetry crescent suction chamber is different remarkably. One reason is that the location of suction port cannot be set symmetrically for the simplification of the pump structure. Another reason for that is the fluid is impelled by different part of the orbiting scroll. The asymmetric pressure distribution will result in the extra force on the scroll. The cavitation generates at the negative pressure region. Therefore, the unsteady simulation shows some important phenomena. The structure of the scroll pump need to be optimized to reduce the maximum pressure, weaken the jet flow, vortex and the uneven pressure distribution to ensure the pump working safely and efficiently.

  16. Multidimensional Thermal-Hydraulic Analysis for Decay Heat Exchanger of PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jonggan; Yoon, Jung; Kim, Dehee; Lee, Tae-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The decay heat exchanger (DHX) of PGSFR is a shell-and-tube type counter-current flow sodium heat exchanger, and each unit is designed for the rated thermal power of 1.0 MWt, which is corresponding to the nominal design capacity of a single passive decay heat removal system (PDHRS) and active decay heat removal system (ADHRS) loops. The DHX unit is fully immersed in the cold sodium pool region and removes the system heat load sufficiently and reliably during the temperature transient. In this work, a multidimensional thermal-hydraulic analysis for the DHX was carried out numerically and the numerical results were compared with the calculated results of the 1-D DHX design code to verify the reliability of the design code. In addition, an influence of the cold pool sodium which flows into the shell-side of the DHX through the shell outlet was evaluated. The SHXSA code was conservative in calculating the pressure drop of the shell-side which is our major concern in designing the natural circulation of the decay heat removal system. It was revealed that the buffer region is needed to reduce the thermal stress in the lower tubesheet by the inflow of the cold pool sodium.

  17. TRAC analysis of upper plenum thermal-hydraulic phenomena in the slab core test facility

    Energy Technology Data Exchange (ETDEWEB)

    Shire, P.; Boyack, B.

    1986-01-01

    The Transient Reactor Analysis Code, TRAC-PF1/MOD1, was used to analyze an upper-plenum model of the Slab Core Test Facility (SCTF). The SCTF is a two-dimensional thermal-hydraulic model of a pressurized water reactor used for core-reflood simulations by the Japan Atomic Energy Research Institute. The purpose of this study was to evaluate the effects of code input-model refinements on the comparison between TRAC calculations and test data. Of particular interest were the comparisons of upper-plenum liquid levels and of the distributions of liquid radially across the upper-plenum. The upper-plenum region was selected for study. The test data indicated that the liquid level responded to the onset of emergency core cooling (ECC) by rising in the upper-plenum immediately when injection occurred. However, the early TRAC results indicated no significant liquid level increase until approx.300 s after the injection. Test data also indicated a liquid gradient rising toward the hot-leg entrance, but none was observed with TRAC.

  18. Investigation of Correlations for the Thermal-hydraulic Analysis of Liquid Metal Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Won Pyo; Jeong, Hae Yong; Lee, Yong Bum

    2007-08-15

    The present investigation is aimed at reducing favorable constitutive correlations from those developed for the thermal-hydraulic analysis of Liquid Metal Reactors (LMR), for reliable safety analyses of KALIMER. It is achieved by analyzing them in a point of their accuracies. The study is particularly important because its outcomes can provide an essential knowledge on their relative errors including their conservatisms to be analyzed in the future KALIMER licensing stage. The predictions of the correlations have been compared with available experimental data on both friction factors for the wired-wrapped rod bundles in the core and the heat transfer coefficients in the system. As a result, the heat transfer coefficient inside pipe currently featured in SSC-K has been found acceptable. It, however, has shown a discrepancy of about 60 % and thus an alternative one has been proposed for improvement. Meanwhile, the friction factor model in the current SSC-K has not shown a prominent discrepancy in prediction trend but it has not backed an enough theoretical basis so that another model has been proposed. A systematic assessment for effects of those factors to the conservatism must be fully understood for the future licensing stage, and systematic calculations must be followed by designing an assessment matrix. Besides, it is essential to conduct experiments under similar conditions for constitutive parts of geometries which represent the KALIMER design.

  19. Thermal-hydraulic analysis of a heavy-water reactor moderator tank using the CUPID Code

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Su Ryong; Jeong, Jae Jun [Pusan National Univ., Busan (Korea, Republic of); Kim, Hyoung Tae; Yoon, Han Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this study, a preliminary analysis is performed for the CANDU moderator tank. The calculation results using the basic case input showed a unrealistic, thermal stratification in the upper region, which was caused by the lack of the momentum of the cooling water from the inlet nozzle. To increase the flow momentum from the inlet nozzle, the cross-section area of each inlet nozzle was reduced by half and, then, the calculation showed very realistic results. It is clear that the modeling of the inlet nozzle affects the calculation result significantly. Further studies are needed for a realistic and efficient simulation of the flow in the Calandria tank. When the core cooling system fails to remove the decay heat from the fuel channels during a loss of coolant accident (LOCA), the pressure tube (PT) could strain to contact its surrounding Calandria tube (CT), which leads to sustained CTs dry out, finally resulting in damages to nuclear fuel. This situation can occur when the degree of the subcooling of the moderator inside the Calandria vessel is insufficient. In this regard, to estimate the local subcooling of the moderator inside the Calandria vessel is very important. However, the local temperature is measured at the inlet and outlet of the vessel only. Therefore, we need to accurately predict the local temperature inside the Calandria vessel.In this study, the thermal-hydraulic analysis of the real-scale heavy-water reactor moderator is carried out using the CUPID code. The applicability of the CUPID code to the analysis of the flow in the Calandria vessel has been assessed in the previous studies.

  20. Estimation of changes in dynamic hydraulic force in a magnetically suspended centrifugal blood pump with transient computational fluid dynamics analysis.

    Science.gov (United States)

    Masuzawa, Toru; Ohta, Akiko; Tanaka, Nobuatu; Qian, Yi; Tsukiya, Tomonori

    2009-01-01

    The effect of the hydraulic force on magnetically levitated (maglev) pumps should be studied carefully to improve the suspension performance and the reliability of the pumps. A maglev centrifugal pump, developed at Ibaraki University, was modeled with 926 376 hexahedral elements for computational fluid dynamics (CFD) analyses. The pump has a fully open six-vane impeller with a diameter of 72.5 mm. A self-bearing motor suspends the impeller in the radial direction. The maximum pressure head and flow rate were 250 mmHg and 14 l/min, respectively. First, a steady-state analysis was performed using commercial code STAR-CD to confirm the model's suitability by comparing the results with the real pump performance. Second, transient analysis was performed to estimate the hydraulic force on the levitated impeller. The impeller was rotated in steps of 1 degrees using a sliding mesh. The force around the impeller was integrated at every step. The transient analysis revealed that the direction of the radial force changed dynamically as the vane's position changed relative to the outlet port during one circulation, and the magnitude of this force was about 1 N. The current maglev pump has sufficient performance to counteract this hydraulic force. Transient CFD analysis is not only useful for observing dynamic flow conditions in a centrifugal pump but is also effective for obtaining information about the levitation dynamics of a maglev pump.

  1. Program ELM: A tool for rapid thermal-hydraulic analysis of solid-core nuclear rocket fuel elements

    Science.gov (United States)

    Walton, James T.

    1992-01-01

    This report reviews the state of the art of thermal-hydraulic analysis codes and presents a new code, Program ELM, for analysis of fuel elements. ELM is a concise computational tool for modeling the steady-state thermal-hydraulics of propellant flow through fuel element coolant channels in a nuclear thermal rocket reactor with axial coolant passages. The program was developed as a tool to swiftly evaluate various heat transfer coefficient and friction factor correlations generated for turbulent pipe flow with heat addition which have been used in previous programs. Thus, a consistent comparison of these correlations was performed, as well as a comparison with data from the NRX reactor experiments from the Nuclear Engine for Rocket Vehicle Applications (NERVA) project. This report describes the ELM Program algorithm, input/output, and validation efforts and provides a listing of the code.

  2. Screening of Gas-Cooled Reactor Thermal-Hydraulic and Safety Analysis Tools and Experimental Database

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Kim, Min Hwan; Lee, Seung Wook (and others)

    2007-08-15

    This report is a final report of I-NERI Project, 'Screening of Gas-cooled Reactor Thermal Hydraulic and Safety Analysis Tools and Experimental Database 'jointly carried out by KAERI, ANL and INL. In this study, we developed the basic technologies required to develop and validate the VHTR TH/safety analysis tools and evaluated the TH/safety database information. The research tasks consist of; 1) code qualification methodology (INL), 2) high-level PIRTs for major nucleus set of events (KAERI, ANL, INL), 3) initial scaling and scoping analysis (ANL, KAERI, INL), 4) filtering of TH/safety tools (KAERI, INL), 5) evaluation of TH/safety database information (KAERI, INL, ANL) and 6) key scoping analysis (KAERI). The code qualification methodology identifies the role of PIRTs in the R and D process and the bottom-up and top-down code validation methods. Since the design of VHTR is still evolving, we generated the high-level PIRTs referencing 600MWth block-type GT-MHR and 400MWth pebble-type PBMR. Nucleus set of events that represents the VHTR safety and operational transients consists of the enveloping scenarios of HPCC (high pressure conduction cooling: loss of primary flow), LPCC/Air-Ingress (low pressure conduction cooling: loss of coolant), LC (load changes: power maneuvering), ATWS (anticipated transients without scram: reactivity insertion), WS (water ingress: water-interfacing system break) and HU (hydrogen-side upset: loss of heat sink). The initial scaling analysis defines dimensionless parameters that need to be reflected in mixed convection modeling and the initial scoping analysis provided the reference system transients used in the PIRTs generation. For the PIRTs phenomena, we evaluated the modeling capability of the candidate TH/safety tools and derived a model improvement need. By surveying and evaluating the TH/safety database information, a tools V and V matrix has been developed. Through the key scoping analysis using available database, the

  3. FINITE ELEMENT METHOD ANALYSIS OF PIPE MATERIAL TEMPERATURE CHANGES INFLUENCE ON LINE EXPANSION LOOPS IN HYDRAULIC INSTALLATIONS ON MODERN TANKERS

    OpenAIRE

    2011-01-01

    Finite element method analysis of main lines of hydraulic central loading system installation expansion loops mounted on product and chemical tankers has been presented in the paper. The axial forces problem in installations mounted along the ship's open decks executed from hull deformations on waves and thermal stresses is given. Use of "U" type expansion loops is described. Results of forces in anchor points and stresses of Mises due to expansion loop deformations are shown. Calculations we...

  4. Basic hydraulics

    CERN Document Server

    Smith, P D

    1982-01-01

    BASIC Hydraulics aims to help students both to become proficient in the BASIC programming language by actually using the language in an important field of engineering and to use computing as a means of mastering the subject of hydraulics. The book begins with a summary of the technique of computing in BASIC together with comments and listing of the main commands and statements. Subsequent chapters introduce the fundamental concepts and appropriate governing equations. Topics covered include principles of fluid mechanics; flow in pipes, pipe networks and open channels; hydraulic machinery;

  5. Thermal-hydraulic analysis of SWAMUP facility using ATHLET-SC code

    Directory of Open Access Journals (Sweden)

    Zidi eWang

    2015-03-01

    Full Text Available During the loss of coolant accident (LOCA of supercritical water cooled reactor (SCWR, the pressure in the reactor system will undergo a rapid decrease from the supercritical pressure to the subcritical condition. This process is called trans-critical transients, which is of crucial importance for the LOCA analysis of SCWR. In order to simulate the trans-critical transient, a number of system codes for SCWR have been developed up to date. However, the validation work for the trans-critical models in these codes is still missing. The test facility Supercritical WAter MUltiPurpose loop (SWAMUP with 2×2 rod bundle in Shanghai Jiao Tong University (SJTU will be applied to provide test data for code validation. Some pre-test calculations are important and necessary to show the feasibility of the experiment. In this study, trans-critical transient analysis is performed for the SWAMUP facility with the system code ATHLET-SC, which is modified in SJTU, for supercritical water system. This paper presents the system behavior e.g. system pressure, coolant mass flow, cladding temperature during the depressurization. The effects of some important parameters such as heating power, depressurization rate on the system characteristics are also investigated in this paper. Additionally, some sensitivities study of the code models, e.g. heat transfer coefficient, CHF correlation, are analyzed and discussed. The results indicate that the revised system code ATHLET-SC is capable of simulating thermal hydraulic behavior during the trans-critical transient. According to the results, the cladding temperature during the transient is kept at a low value. However, the pressure difference of the heat exchanger after depressurization could reach 6 MPa, which should be considered in the experiment.

  6. Spatial Risk Analysis of Hydraulic Fracturing near Abandoned and Converted Oil and Gas Wells.

    Science.gov (United States)

    Brownlow, Joshua W; Yelderman, Joe C; James, Scott C

    2017-03-01

    Interaction between hydraulically generated fractures and existing wells (frac hits) could represent a potential risk to groundwater. In particular, frac hits on abandoned oil and gas wells could lead to upward leakage into overlying aquifers, provided migration pathways are present along the abandoned well. However, potential risk to groundwater is relatively unknown because few studies have investigated the probability of frac hits on abandoned wells. In this study, actual numbers of frac hits were not determined. Rather, the probability for abandoned wells to intersect hypothetical stimulated reservoir sizes of horizontal wells was investigated. Well data were compiled and analyzed for location and reservoir information, and sensitivity analyses were conducted by varying assumed sizes of stimulated reservoirs. This study used public and industry data for the Eagle Ford Shale play in south Texas, with specific attention paid to abandoned oil and gas wells converted into water wells (converted wells). In counties with Eagle Ford Shale activity, well-data analysis identified 55,720 abandoned wells with a median age of 1983, and 2400 converted wells with a median age of 1954. The most aggressive scenario resulted in 823 abandoned wells and 184 converted wells intersecting the largest assumed stimulated reservoir size. Analysis showed abandoned wells have the potential to be intersected by multiple stimulated reservoirs, and risks for intersection would increase if currently permitted horizontal wells in the Eagle Ford Shale are actually completed. Results underscore the need to evaluate historical oil and gas activities in areas with modern unconventional oil and gas activities. © 2016, National Ground Water Association.

  7. STOCHASTIC ANALYSIS OF UNSATURATED FLOW WITH THE NORMAL DISTRIBUTION OF SOIL HYDRAULIC CONDUCTIVITY

    Institute of Scientific and Technical Information of China (English)

    Huang Guan-hua; Zhang Ren-duo

    2003-01-01

    Stochastic approaches are useful to quantitatively describe transport behavior over large temporal and spatial scales while accounting for the influence of small-scale variabilities. Numerous solutions have been developed for unsaturated soil water flow based on the lognormal distribution of soil hydraulic conductivity. To our knowledge, no available stochastic solutions for unsaturated flow have been derived on the basis of the normal distribution of hydraulic conductivity. In this paper, stochastic solutions were developed for unsaturated flow by assuming the normal distribution of saturated hydraulic conductivity (Ks). Under the assumption that soil hydraulic properties are second-order stationary, analytical expressions for capillary tension head variance (σ2h) and effective hydraulic conductivity (K*ii) in stratified soils were derived using the perturbation method. The dependence of σ2h and K*ii on soil variability and mean flow variables (the mean capillary tension head and its temporal and spatial gradients) and mean flow conditions (wetting and drying) were systematically analyzed. The calculated variance of capillary tension head with the analytical solution derived in this paper was compared with field experimental data. The good agreement indicates that the analytical solution is applicable to evaluate the variance of capillary tension head of field soils with moderate variability.

  8. Fault degradation assessment of water hydraulic motor by impulse vibration signal with Wavelet Packet Analysis and Kolmogorov Smirnov Test

    Science.gov (United States)

    Chen, H. X.; Chua, Patrick S. K.; Lim, G. H.

    2008-10-01

    The machinery fault diagnosis is important for improving reliability and performance of systems. Many methods such as Time Synchronous Average (TSA), Fast Fourier Transform (FFT)-based spectrum analysis and short-time Fourier transform (STFT) have been applied in fault diagnosis and condition monitoring of mechanical system. The above methods analyze the signal in frequency domain with low resolution, which is not suitable for non-stationary vibration signal. The Kolmogorov-Smirnov (KS) test is a simple and precise technique in vibration signal analysis for machinery fault diagnosis. It has limited use and advantage to analyze the vibration signal with higher noise directly. In this paper, a new method for the fault degradation assessment of the water hydraulic motor is proposed based on Wavelet Packet Analysis (WPA) and KS test to analyze the impulsive energy of the vibration signal, which is used to detect the piston condition of water hydraulic motor. WPA is used to analyze the impulsive vibration signal from the casing of the water hydraulic motor to obtain the impulsive energy. The impulsive energy of the vibration signal can be obtained by the multi-decomposition based on Wavelet Packet Transform (WPT) and used as feature values to assess the fault degradation of the pistons. The kurtosis of the impulsive energy in the reconstructed signal from the Wavelet Packet coefficients is used to extract the feature values of the impulse energy by calculating the coefficients of the WPT multi-decomposition. The KS test is used to compare the kurtosis of the impulse energy of the vibration signal statistically under the different piston conditions. The results show the applicability and effectiveness of the proposed method to assess the fault degradation of the pistons in the water hydraulic motor.

  9. IAEA Coordinated Research Project on HTGR Reactor Physics, Thermal-hydraulics and Depletion Uncertainty Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Strydom, Gerhard [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bostelmann, F. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The continued development of High Temperature Gas Cooled Reactors (HTGRs) requires verification of HTGR design and safety features with reliable high fidelity physics models and robust, efficient, and accurate codes. The predictive capability of coupled neutronics/thermal-hydraulics and depletion simulations for reactor design and safety analysis can be assessed with sensitivity analysis (SA) and uncertainty analysis (UA) methods. Uncertainty originates from errors in physical data, manufacturing uncertainties, modelling and computational algorithms. (The interested reader is referred to the large body of published SA and UA literature for a more complete overview of the various types of uncertainties, methodologies and results obtained). SA is helpful for ranking the various sources of uncertainty and error in the results of core analyses. SA and UA are required to address cost, safety, and licensing needs and should be applied to all aspects of reactor multi-physics simulation. SA and UA can guide experimental, modelling, and algorithm research and development. Current SA and UA rely either on derivative-based methods such as stochastic sampling methods or on generalized perturbation theory to obtain sensitivity coefficients. Neither approach addresses all needs. In order to benefit from recent advances in modelling and simulation and the availability of new covariance data (nuclear data uncertainties) extensive sensitivity and uncertainty studies are needed for quantification of the impact of different sources of uncertainties on the design and safety parameters of HTGRs. Only a parallel effort in advanced simulation and in nuclear data improvement will be able to provide designers with more robust and well validated calculation tools to meet design target accuracies. In February 2009, the Technical Working Group on Gas-Cooled Reactors (TWG-GCR) of the International Atomic Energy Agency (IAEA) recommended that the proposed Coordinated Research Program (CRP) on

  10. Hydraulic manipulator research at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-03-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

  11. Design, Optimization and Analysis of Hydraulic Soft Yaw System for 5 MW Wind Turbine

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.

    2011-01-01

    presents work previous done on this subject with focus on hydraulic yaw systems. By utilizing the HAWC2 aeroelastic code and an extended model of the NREL 5MW turbine combined with a simplified linear model of the turbine, the parameters of the soft yaw system are optimized. Results show that a significant...... reduction in fatigue and extreme loads to the yaw system and rotor shaft are possible, when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. The duty cycles, based...... on the extrapolated loads, show that it is possible to construct a hydraulic soft yaw system, which is able to reduce the loads on the wind turbine significantly....

  12. Design of a New Type of Distribution Valve for Hydraulic Breaker and Analysis of Energy Consumption

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Energy consumed by distribution valves causes an energy loss for the output energy of hydraulic breakers, which has a significant influence on its efficiency. A new type of distribution valve used for hydraulic breakers, designed to reduce energy consumption, is analyzed on the basis of the operating principle and energy loss of the current distribution valve. The new distribution valve adopts a cone valve and the optimization technique of unequal open degree for the valve port. Theoretical calculations and analyses have proven that the new distribution valve can reduce energy loss by 9.0127J, or energy consumption by 31%, during an impact cycle and the efficiency of the hydraulic breaker can be raised by 4.5%. It has the following characteristics: little leakage, little pressure loss and low energy consumption.

  13. Hydraulic Structures

    Data.gov (United States)

    Department of Homeland Security — This table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the FIRM, channels containing the...

  14. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on......-going research projects on fluid power and mechatronics based on tap water hydraulic servovalves and linear servo actuators and rotary vane actuators for motion control and power transmission. Development and design a novel water hydraulic rotary vane actuator for robot manipulators. Proposed mathematical...... modelling, control and simulation of a water hydraulic rotary vane actuator applied to power and control a two-links manipulator and evaluate performance. The results include engineering design and test of the proposed simulation models compared with IHA Tampere University’s presentation of research...

  15. Analysis of the steady state hydraulic behaviour of the ITER blanket cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Di Maio, P.A., E-mail: pietroalessandro.dimaio@unipa.it [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Dell’Orco, G.; Furmanek, A. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Garitta, S. [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Merola, M.; Mitteau, R.; Raffray, R. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Spagnuolo, G.A.; Vallone, E. [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy)

    2015-10-15

    Highlights: • Nominal steady state hydraulic behaviour of ITER blanket standard sector cooling system has been investigated. • Numerical simulations have been run adopting a qualified thermal-hydraulic system code. • Hydraulic characteristic functions and coolant mass flow rates, velocities and pressure drops have been assessed. • Most of the considered circuits are able to effectively cool blanket modules, meeting ITER requirements. - Abstract: The blanket system is the ITER reactor component devoted to providing a physical boundary for plasma transients and contributing to thermal and nuclear shielding of vacuum vessel, magnets and external components. It is expected to be subjected to significant heat loads under nominal conditions and its cooling system has to ensure an adequate cooling, preventing any risk of critical heat flux occurrence while complying with pressure drop limits. At the University of Palermo a study has been performed, in cooperation with the ITER Organization, to investigate the steady state hydraulic behaviour of the ITER blanket standard sector cooling system. A theoretical–computational approach based on the finite volume method has been followed, adopting the RELAP5 system code. Finite volume models of the most critical blanket cooling circuits have been set-up, realistically simulating the coolant flow domain. The steady state hydraulic behaviour of each cooling circuit has been investigated, determining its hydraulic characteristic function and assessing the spatial distribution of coolant mass flow rates, velocities and pressure drops under reference nominal conditions. Results obtained have indicated that the investigated cooling circuits are able to provide an effective cooling to blanket modules, generally meeting ITER requirements in term of pressure drop and velocity distribution, except for a couple of circuits that are being revised.

  16. Comparison Study on Thermal-Hydraulic Analysis Depending on Liquid Relief Valve Response for an Station Blackout in CANDU-6

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. M.; Kho, D. W. [KHNP-CRI, Daejeon (Korea, Republic of); Choi, S. H.; Moon, B. J.; Kim, S. R. [Nuclear Engineering Service and Solution Co., Daejeon (Korea, Republic of)

    2014-10-15

    The purpose of this analysis is to compare the results of thermal-hydraulic analysis depending on liquid relief valve response during a station black out (SBO) events in CANDU-6. The primary heat transport system (PHTS) behavior following the postulated SBO is analyzed using CATHENA code. In the paper, analysis was performed to evaluate the effect on coolant system where LRVs are assumed to be opened or opened according to normal open characteristics in the condition of SBO. The result showed that the primary pressure boundary is extended from LRV to DCT and the effects on primary system behavior were neglectable.

  17. Stability analysis of the governor-turbine-hydraulic system of pumped storage plant during small load variation

    Science.gov (United States)

    Yu, X. D.; Zhang, J.; Chen, S.; Liu, J. C.

    2016-11-01

    Governor-turbine-hydraulic (GTH) system is complex because of strong couplings of hydraulic, mechanical and electrical system. This paper presents a convenient mathematical model of the GTH system of a pumped storage plant (PSP) during small load variation. By using state space method and eigenvalue method, the stability of the GTH system is analyzed and the stable regions of the system can be given as well, which would help to optimize system design or the turning of governors. The proposed method is used to analyze the stability of a practical pumped storage plant during small load variation, which is also simulated in time domain on the basis of characteristics method. The theoretical analysis is in good agreement with numerical simulations. Based on the proposed method, the effect of the system parameters and operating conditions on the stable regions is investigated. These results are useful for the design of the GTH system of pumped storage plants.

  18. Thermal Hydraulic Design and Analysis of a Water-Cooled Ceramic Breeder Blanket with Superheated Steam for CFETR

    Science.gov (United States)

    Cheng, Xiaoman; Ma, Xuebin; Jiang, Kecheng; Chen, Lei; Huang, Kai; Liu, Songlin

    2015-09-01

    The water-cooled ceramic breeder blanket (WCCB) is one of the blanket candidates for China fusion engineering test reactor (CFETR). In order to improve power generation efficiency and tritium breeding ratio, WCCB with superheated steam is under development. The thermal-hydraulic design is the key to achieve the purpose of safe heat removal and efficient power generation under normal and partial loading operation conditions. In this paper, the coolant flow scheme was designed and one self-developed analytical program was developed, based on a theoretical heat transfer model and empirical correlations. Employing this program, the design and analysis of related thermal-hydraulic parameters were performed under different fusion power conditions. The results indicated that the superheated steam water-cooled blanket is feasible. supported by the National Special Project for Magnetic Confined Nuclear Fusion Energy of China (Nos. 2013GB108004, 2014GB122000 and 2014GB119000), and National Natural Science Foundation of China (No. 11175207)

  19. Overview of the use of ATHENA for thermal-hydraulic analysis of systems with lead-bismuth coolant

    Energy Technology Data Exchange (ETDEWEB)

    C. B. Davis; A. S. Shieh

    2000-04-02

    The INEEL and MIT are investigating the suitability of lead-bismuth cooled fast reactor for producing low-cost electricity as well as for actinide burning. This paper is concerned with the general area of thermal-hydraulics of lead-bismuth cooled reactors. The ATHENA code is being used in the thermal-hydraulic design and analysis of lead-bismuth cooled reactors. The ATHENA code was reviewed to determine its applicability for simulating lead-bismuth cooled reactors. Two modifications were made to the code as a result of this review. Specifically, a correlation to represent heat transfer from rod bundles to a liquid metal and a void correlation based on data taken in a mixture of lead-bismuth and steam were added the code. The paper also summarizes the analytical work that is being performed with the code and plans for future analytical work.

  20. Overview of the Use of ATHENA for Thermal-Hydraulic Analysis of Systems with Lead-Bismuth Coolant

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Cliff Bybee; Shieh, Arthur Shan Luk

    2000-04-01

    The INEEL and MIT are investigating the suitability of lead-bismuth cooled fast reactor for producing low-cost electricity as well as for actinide burning. This paper is concerned with the general area of thermal-hydraulics of lead-bismuth cooled reactors. The ATHENA code is being used in the thermal-hydraulic design and analysis of lead-bismuth cooled reactors. The ATHENA code was reviewed to determine its applicability for simulating lead-bismuth cooled reactors. Two modifications were made to the code as a result of this review. Specifically, a correlation to represent heat transfer from rod bundles to a liquid metal and a void correlation based on data taken in a mixture of lead-bismuth and steam were added the code. The paper also summarizes the analytical work that is being performed with the code and plans for future analytical work.

  1. Numerical analysis of thermal-hydraulic behavior of supercritical water in vertical upward/downward flow channels

    Institute of Scientific and Technical Information of China (English)

    GU Hanyang; YU Yiqi; CHENG Xu; LIU Xiaojing

    2008-01-01

    Investigations on the thermal-hydraulic behavior in the SCWR fuel assembly have obtained a significant attention in the international SCWR community. However, there is still a lack of understanding of the heat transfer behavior of supercritical fluids. In this paper, the numerical analysis is carried out to study the thermal-hydraulic behaviour in vertical sub-channels cooled by supercritical water. Remarkable differences in characteristics of secondary flow are found, especially in square lattice, between the upward flow and downward flow. The turbulence mixing across sub-channel gap for downward flow is much stronger than that for upward flow in wide lattice when the bulk temperature is lower than pseudo-critical point temperature. For downward flow, heat transfer deterioration phenomenon is suppressed with respect to the case of upward flow at the same conditions.

  2. Neutronics and thermal hydraulic analysis of TRIGA Mark II reactor using MCNPX and COOLOD-N2 computer code

    Science.gov (United States)

    Tiyapun, K.; Wetchagarun, S.

    2017-06-01

    The neutronic analysis of TRIGA Mark II reactor has been performed. A detailed model of the reactor core was conducted including standard fuel elements, fuel follower control rods, and irradiation devices. As the approach to safety nuclear design are based on determining the criticality (keff), reactivity worth, reactivity excess, hot rod power factor and power peaking of the reactor, the MCNPX code had been used to calculate the nuclear parameters for different core configuration designs. The thermal-hydraulic model has been developed using COOLOD-N2 for steady state, using the nuclear parameters and power distribution results from MCNPX calculation. The objective of the thermal-hydraulic model is to determine the thermal safety margin and to ensure that the fuel integrity is maintained during steady state as well as during abnormal condition at full power. The hot channel fuel centerline temperature, fuel surface temperature, cladding surface temperature, the departure from nucleate boiling (DNB) and DNB ratio were determined. The good agreement between experimental data and simulation concerning reactor criticality proves the reliability of the methodology of analysis from neutronic and thermal hydraulic perspective.

  3. Hydraulic analysis of water supply networks and controlling the leak using WATER GEMS model

    Directory of Open Access Journals (Sweden)

    Mahmood Motevalizadeh

    2016-03-01

    Full Text Available Given that the discussion on water is strategic in terms of economic and social aspects as well as environmental impact, water leak in urban water-supply systems is very important, so, dealing with it is necessary and inevitable. Controlling and reducing water leak are of the main goals of water supplier organization due to limitations in terms of water resources, especially in dry lands which have few water resources. Pressure management is an efficient tool to reduce costs, enhance the operation of the network and therefore, it reduces the leak and increases the life of facilities and equipment and reduces the number of accidents. Smart pressure containment is a good way to prevent excess pressure in network to control undesirable phenomenon of leak which is directly related to pressure. In this study, Badamuiyeh water supply complex in Kerman City was selected to study on adjusting the pressure to control the leak of water and the hydraulic analysis was performed with demand-based method (DDSM, which is common technique and demand is constant, by Water GEMS software. For this end, the pressure reducing valves (prv were installed in critical point and they were timed to provide standard pressure in all nodes of the network and then, the impact of smart pressure management on water supply system has been investigated. Then its impact on the leak was examined and the results show that smart pressure control through pressure-reducing valve is a proper method for optimal management of water and reducing the leak significantly that with 45.15% reduction in average pressure, one can reduce the leak as much as 25.67% that as its result, 15380 m3 of water is annually saved in this region which is equal to 27.18% of consuming water.

  4. Meta-analysis: abundance, behavior, and hydraulic energy shape biotic effects on sediment transport in streams.

    Science.gov (United States)

    Albertson, L K; Allen, D C

    2015-05-01

    An increasing number of studies have emphasized the need to bridge the disciplines of ecology and geomorphology. A large number of case studies show that organisms can affect erosion, but a comprehensive understanding of biological impacts on sediment transport conditions is still lacking. We use meta-analysis to synthesize published data to quantify the effects of the abundance, body size, and behavior of organisms on erosion in streams. We also explore the influence of current velocity, discharge, and sediment grain size on the strength of biotic effects on erosion. We found that species that both increase erosion (destabilizers) and decrease erosion (stabilizers) can alter incipient sediment motion, sediment suspension, and sediment deposition above control conditions in which the organisms were not present. When abundance was directly manipulated, these biotic effects were consistently stronger in the higher abundance treatment, increasing effect sizes by 66%. Per capita effect size and per capita biomass were also consistently positively correlated. Fish and crustaceans were the most studied organisms, but aquatic insects increased the effect size by 550 x compared to other types of organisms after accounting for biomass. In streams with lower discharge and smaller grain sizes, we consistently found stronger biotic effects. Taken collectively, these findings provide synthetic evidence that biology can affect physical processes in streams, and these effects can be mediated by hydraulic energy. We suggest that future studies focus on understudied organisms, such as biofilms, conducting experiments under realistic field conditions, and developing hypotheses for the effect of biology on erosion and velocity currents in the context of restoration to better understand the forces that mediate physical disturbances in stream ecosystems.

  5. Sensitivity analysis of hydraulic model to morphological changes and changes in flood inundation extent

    Science.gov (United States)

    Wong, J. S.; Freer, J.; Bates, P. D.; Sear, D. A.

    2012-04-01

    Recent research into modelling floodplain inundation processes is primarily concentrated on the simulation of inundation flow without considering the influences of channel morphology and sediment delivery from upstream. River channels are often represented by simplified geometry and implicitly assumed to remain unchanged. However, during and after flood episodes the river bed elevation can change quickly and in some cases drastically. Despite this, the effect of channel geometry and topographic complexity on model results has been largely unexplored. To address this issue, the impact of channel cross-section geometry, and channel long-profile variability on flood inundation extent are examined using a simplified 1D-2D hydraulic model (LISFLOOD-FP) of the Cockermouth floods of November 2009 within an uncertainty analysis framework. The Cockermouth region provides a useful test site for such study because of the availability of channel and floodplain data, the collection of post-event water and wrack marks and the presence of pre-and post-event morphological surveyed data. More importantly, in some areas the river has undergone significant course change and additionally the deposition of stones and debris on the floodplain. The use of relatively simple formulations of critical velocities in the initiation of motion formula enables the construction of a series of hypothetical bedform scenarios among cross-sections. These scenarios can be used as input to LISFLOOD-FP. Slope gradient, Manning roughness coefficients, grain size characteristic, and critical shear stress will be considered in a Monte Carlo simulation framework. The November 2009 Cockermouth flood is simulated and the results are analysed to quantify the accuracy associated with each bedform scenario and to assess how different channel long-profiles affects the performance of LISFLOOD-FP. The study will further analyse and quantify the variability and uncertainty of flood inundation extent resulting from

  6. ANTEO+: A subchannel code for thermal-hydraulic analysis of liquid metal cooled systems

    Energy Technology Data Exchange (ETDEWEB)

    Lodi, F., E-mail: francesco.lodi5@unibo.it [DIN – Laboratory of Montecuccolino, University of Bologna, Via dei Colli 16, 40136 Bologna (Italy); Grasso, G., E-mail: giacomo.grasso@enea.it [ENEA (Italian National Agency for New Technologies, Energy and Sustainable Economic Development), via Martiri di Monte Sole, 4, 40129 Bologna (Italy); Mattioli, D., E-mail: davide.mattioli@enea.it [ENEA (Italian National Agency for New Technologies, Energy and Sustainable Economic Development), via Martiri di Monte Sole, 4, 40129 Bologna (Italy); Sumini, M., E-mail: marco.sumini@unibo.it [DIN – Laboratory of Montecuccolino, University of Bologna, Via dei Colli 16, 40136 Bologna (Italy)

    2016-05-15

    Highlights: • The code structure is presented in detail. • The performed validation is outlined. • Results are critically discussed assessing code accuracy. • Conclusions are drawn and ground for future work identified. - Abstract: Liquid metal cooled fast reactors are promising options for achieving the high degrees of safety and sustainability demanded by the Generation IV paradigm. Among the critical aspects to be addressed in the design process, thermal-hydraulics is one of the most challenging; in order to embed safety in the core conceptualization, these aspects are to be considered at the very beginning of the design process, and translated in a design perspective. For achieving these objectives the subchannel code ANTEO+ has been conceived, able to simulate pin bundle arrangements cooled by liquid metals. The main purposes of ANTEO+ are simplifying the problem description maintaining the required accuracy, enabling a more transparent interface with the user, and having a clear and identifiable application domain, in order to help the user interpreting the results and, mostly, defining their confidence. Since ANTEO+ relies on empirical correlations, the validation phase is of paramount importance along with a clear discussion on the simplifications adopted in modeling the conservation equations. In the present work a detailed description of ANTEO+ structure is given along with a thorough validation of the main models implemented for flow split, pressure drops and subchannel temperatures. The analysis confirmed the ability of ANTEO+ in reproducing experimental data in its anticipated validity domain, with a relatively high degree of accuracy when compared to other classical subchannel tools like ENERGY-II, COBRA-IV-I-MIT and BRS-TVS.

  7. Novel wave power analysis linking pressure-flow waves, wave potential, and the forward and backward components of hydraulic power.

    Science.gov (United States)

    Mynard, Jonathan P; Smolich, Joseph J

    2016-04-15

    Wave intensity analysis provides detailed insights into factors influencing hemodynamics. However, wave intensity is not a conserved quantity, so it is sensitive to diameter variations and is not distributed among branches of a junction. Moreover, the fundamental relation between waves and hydraulic power is unclear. We, therefore, propose an alternative to wave intensity called "wave power," calculated via incremental changes in pressure and flow (dPdQ) and a novel time-domain separation of hydraulic pressure power and kinetic power into forward and backward wave-related components (ΠP±and ΠQ±). Wave power has several useful properties:1) it is obtained directly from flow measurements, without requiring further calculation of velocity;2) it is a quasi-conserved quantity that may be used to study the relative distribution of waves at junctions; and3) it has the units of power (Watts). We also uncover a simple relationship between wave power and changes in ΠP±and show that wave reflection reduces transmitted power. Absolute values of ΠP±represent wave potential, a recently introduced concept that unifies steady and pulsatile aspects of hemodynamics. We show that wave potential represents the hydraulic energy potential stored in a compliant pressurized vessel, with spatial gradients producing waves that transfer this energy. These techniques and principles are verified numerically and also experimentally with pressure/flow measurements in all branches of a central bifurcation in sheep, under a wide range of hemodynamic conditions. The proposed "wave power analysis," encompassing wave power, wave potential, and wave separation of hydraulic power provides a potent time-domain approach for analyzing hemodynamics.

  8. Analysis of Responses From Hydraulic Testing of the Lower Carbonate Aquifer at Yucca Flat, Nevada Test Site, Nye County, Nevada

    Science.gov (United States)

    Bhark, E. W.; Ruskauff, G.

    2005-12-01

    The Yucca Flat corrective action unit extends over an approximately 120 square-mile basin at the Nevada Test Site (NTS), southern Nevada, and was the site for over 650 historical underground nuclear tests. The lower carbonate aquifer (LCA), roughly 1,800 feet below ground surface at Yucca Flat and with a confined thickness of several thousand feet, is the primary aquifer for much of southern Nevada and underlies the full extent of Yucca Flat. Within the last decade, long-term (multiple-day) single- and multiple-well hydraulic tests have been performed to better define aquifer properties over larger scales. The LCA is highly heterogeneous, both laterally and vertically across Yucca Flat, reflecting differences in fracturing and fault density. As such, analysis of the recent testing data requires the consideration of heterogeneous hydraulic properties at multiple spatial scales. Three individual hydraulic tests are presented that portray the marked spatial variability of hydraulic properties related to both local fracturing and basin-scale faulting across Yucca Flat. Two ten-day single-well tests (wells ER-7-1, ER-6-2) and one ninety-day multiple-well test (well cluster ER-6-1) are considered. Interpretive and numerical analyses are based upon the log-log diagnostic plots of drawdown and recovery from pumping, utilizing both the head change and derivative. Heterogeneity is considered using the flow dimension, which represents a variable formation area of flow away from the well, and proves to be a fundamental analytical tool. All hydraulic parameter estimates, including flow dimension, are complete with a measure of uncertainty. The composite interpretation of all data results in a conceptual flow model representative of two spatially continuous scales. At the larger basin (km) scale, the data indicate a fracture- or high permeability strip-dominated flow regime created by fault-related features. Ubiquitous north-south trending faults throughout Yucca Flat appear to

  9. Thermal Equilibrium Analysis of Hydraulic System%液压系统热平衡分析

    Institute of Scientific and Technical Information of China (English)

    李永衡

    2016-01-01

    For hydraulic system due to the ageing of the equipment caused to the system temperature is too high,don’t adopt the traditional method,for the heat generated by the power loss and heat coming from the system to calculate,but only for the Newly added heat of the hydraulic system for testing,calculation.Select the corre-sponding cooling mode,the hydraulic system is maintained at the set temperature range.When QAbsorption is equal to QRelease ,the new thermal balance of hydraulic system is realized.%针对液压系统因设备老化而造成的系统温度过高,传统的方法采用对功率损耗产生的热量与系统散发的热量进行计算,而本文是仅对液压系统的新增热量进行测试、计算。选择相对应的冷却方式,使液压系统保持在设定的温度范围内,当Q吸=Q放时,即实现了液压系统新的热平衡。

  10. Statistical Analysis of Seismicity Associated with Hydraulic Fracturing in Western Canada

    Science.gov (United States)

    Shcherbakov, R.; Ghofrani, H.; Kothari, S.; Atkinson, G. M.; Cheadle, B.; Eaton, D. W. S.; Tiampo, K. F.

    2015-12-01

    The unconventional extraction of shale oil or gas is typically carried out by the subsurface injection of large volumes of fluids. The fluids are used in the process of hydraulic fracturing and subsequent wastewater injection into high volume disposal wells. These operations are usually accompanied by various levels of seismic activity and sometimes result in the occurrence of moderate to large earthquakes. It is suggested that the increase in seismic activity within the central U.S. in the last decade or so is primely associated with large-scale disposal of wastewater. The Western Canada Sedimentary Basin (WCSB) is an active exploration area for the extraction of oil and gas. The average rate of seismicity is lower than in the central U.S., however, there are several active clusters, where in the last 8-10 years, there has been an increase in the occurrence of moderate earthquakes. In this study, we analyze the statistical properties of seismicity associated with the WCSB. We find that the increase in seismicity rate is mostly associated with the hydraulic fracturing operations in several well defined spatial zones. Hydraulic fracturing involves high-pressure injections of fluids and is performed in multiple stages. This is done along horizontal wells which are drilled at average depths of 2 to 3 km. The triggering of large earthquakes is mostly due to injection of fluids into nearby tectonic faults which are close to failure. To model the rate of the occurrence of earthquakes we introduce a modified version of the Epidemic Type Aftershock Sequence model. The earthquake occurrence rate associated with several prominent clusters is characterized by bursts of activity associated with specifics of hydraulic fracturing operations. The proposed model can be used in the probabilistic assessment and mitigation of the risks associated with hydraulic fracturing.

  11. Development of a multi-dimensional realistic thermal-hydraulic system analysis code, MARS 1.3 and its verification

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Chung, Bub Dong; Jeong, Jae Jun; Ha, Kwi Seok [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-06-01

    A multi-dimensional realistic thermal-hydraulic system analysis code, MARS version 1.3 has been developed. Main purpose of MARS 1.3 development is to have the realistic analysis capability of transient two-phase thermal-hydraulics of Pressurized Water Reactors (PWRs) especially during Large Break Loss of Coolant Accidents (LBLOCAs) where the multi-dimensional phenomena domain the transients. MARS code is a unified version of USNRC developed COBRA-TF, domain the transients. MARS code is a unified version of USNRC developed COBRA-TF, three-dimensional (3D) reactor vessel analysis code, and RELAP5/MOD3.2.1.2, one-dimensional (1D) reactor system analysis code., Developmental requirements for MARS are chosen not only to best utilize the existing capability of the codes but also to have the enhanced capability in code maintenance, user accessibility, user friendliness, code portability, code readability, and code flexibility. For the maintenance of existing codes capability and the enhancement of code maintenance capability, user accessibility and user friendliness, MARS has been unified to be a single code consisting of 1D module (RELAP5) and 3D module (COBRA-TF). This is realized by implicitly integrating the system pressure matrix equations of hydrodynamic models and solving them simultaneously, by modifying the 1D/3D calculation sequence operable under a single Central Processor Unit (CPU) and by unifying the input structure and the light water property routines of both modules. In addition, the code structure of 1D module is completely restructured using the modular data structure of standard FORTRAN 90, which greatly improves the code maintenance capability, readability and portability. For the code flexibility, a dynamic memory management scheme is applied in both modules. MARS 1.3 now runs on PC/Windows and HP/UNIX platforms having a single CPU, and users have the options to select the 3D module to model the 3D thermal-hydraulics in the reactor vessel or other

  12. Modelling of a hydraulic engine mount with fluid-structure interaction finite element analysis

    Science.gov (United States)

    Shangguan, Wen-Bin; Lu, Zhen-Hua

    2004-08-01

    Hydraulic engine mount (HEM) is now widely used as a highly effective vibration isolator in automotive powertrain. A lumped parameter (LP) model is a traditional model for modelling the dynamic characteristics of HEM, in which the system parameters are usually obtained by experiments. In this paper, a fluid-structure interaction (FSI) finite element analysis (FEA) method and a non-linear FEA technology are used to determine the system parameters, and a fully coupled FSI model is developed for modelling the static and lower-frequency performance of an HEM. A FSI FEA technique is used to estimate the parameters of volumetric compliances, equivalent piston area, inertia and resistance of the fluid in the inertia track and the decoupler of an HEM. A non-linear FEA method is applied to determine the dynamic stiffness of rubber spring of the HEM. The system parameters predicated by FEA are compared favorably with experimental data and/or analytical solutions. A numerical simulation for an HEM with an inertia track and a free decoupler is performed based on the FSI model and the LP model along with the estimated system parameters, and again the simulation results are compared with experimental data. The calculated time histories of some variables in the model, such as the pressure in the upper chamber, the displacement of the free decoupler and the volume flow through the inertia track and the decoupler, under different excitations, elucidate the working mechanism of the HEM. The pressure distribution calculated with the FSI model in the chambers of the HEM validates the assumption that the pressure distribution in the upper and lower chamber is uniform in the LP model. The work conducted in the paper demonstrates that the methods for estimating the system parameters in the LP model and the FSI model for modelling HEM are effective, with which the dynamic characteristic analysis and design optimization of an HEM can be performed before its prototype development, and this

  13. Improvement of auditing technology of safety analysis through thermal-hydraulic separate effect tests

    Energy Technology Data Exchange (ETDEWEB)

    No, Hee Cheon; Moon, Young Min; Lee, Dong Won; Lee, Sang Ik; Kim, Eung Soo; Yeom, Keum Soo [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2002-03-15

    The objective of the present research is to perform the separate effect tests and to assess the RELAP5/MOD3.2 code for the analysis of thermal-hydraulic behavior in the reactor coolant system and the improvement of the auditing technology of safety analysis. Three Separate Effect Tests (SETs) are the reflux condensation in the U-tube, the direct contact condensation in the hot-leg and the mixture level buildup in the pressurizer. The experimental data and the empirical correlations are obtained through SETs. On the ases of the three SET works, models in RELAP5 are modified and improved, which are compared with the data. The Korea Standard Nuclear Power Plant (KSNP) are assessed using the modified RELAP5. In the reflux condensation test, the data of heat transfer coefficients and flooding are obtained and the condensation models are modified using the non-iterative model, as results, modified code better predicts the data. In the direct contact condensation test, the data of heat transfer coefficients are obtained for the cocurrent and countercurrent flow between the mixture gas and the water in condition of horizontal stratified flow. Several condensation and friction models are modified, which well predict the present data. In the mixture level test, the data for the mixture level and the onset of water draining into the surge line are obtained. The standard RELAP5 over-predicts the mixture level and the void fraction in the pressurizer. Simple modification of model related to the pool void fraction is suggested. The KSNP is assessed using the standard and the modified RELAP5 resulting from the experimental and code works for the SETs. In case of the pressurizer manway opening with available secondary side of the steam generators, the modified code predicts that the collapsed level in the pressurizer is little accumulated. The presence and location of the opening and the secondary condition of the steam generators have an effect on the coolant inventory. The

  14. Development of a 1D thermal-hydraulic analysis code for once-through steam generator in SMRs using straight tubes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Youngjae; Kim, Iljin; Kim, Hyungdae [Kyung Hee University, Yongin (Korea, Republic of)

    2015-10-15

    Diverse integral/small-modular reactors (SMRs) have been developed. Once-through steam generator (OTSG) which generates superheated steam without steam separator and dryer was used in the SMRs to reduce volume of steam generator. It would be possible to design a new steam generator with best estimate thermal-hydraulic codes such as RELAP and MARS. However, it is not convenience to use the general purpose thermal-hydraulic analysis code to design a specific component of nuclear power plants. A widely used simulation tool for thermal-hydraulic analysis of drum-type steam generators is ATHOS, which allows 3D analysis. On the other hand, a simple 1D thermal-hydraulic analysis code might be accurate enough for the conceptual design of OTSG. In this study, thermal-hydraulic analysis code for conceptual design of OTSG was developed using 1D homogeneous equilibrium model (HEM). A benchmark calculation was also conducted to verify and validate the prediction accuracy of the developed code by comparing with the analysis results with MARS. Finally, conceptual design of OTSG was conducted by the developed code. A simple 1D thermal-hydraulic analysis code was developed for the purpose of conceptual design OTSG for SMRs. A set of benchmark calculations was conducted to verify and validate the analysis accuracy of the developed code by comparing results obtained with a best-estimated thermal-hydraulic analysis code, MARS. Finally, analysis of two different OTSG design concepts with superheating and recirculation was demonstrated using the developed code.

  15. Nuclear-coupled thermal-hydraulic stability analysis of boiling water reactors

    Science.gov (United States)

    Karve, Atul A.

    We have studied the nuclear-coupled thermal-hydraulic stability of boiling water reactors (BWRs) using a model we developed from: the space-time modal neutron kinetics equations based on spatial omega-modes, the equations for two-phase flow in parallel boiling channels, the fuel rod heat conduction equations, and a simple model for the recirculation loop. The model is represented as a dynamical system comprised of time-dependent nonlinear ordinary differential equations, and it is studied using stability analysis, modern bifurcation theory, and numerical simulations. We first determine the stability boundary (SB) in the most relevant parameter plane, the inlet-subcooling-number/external-pressure-drop plane, for a fixed control rod induced external reactivity equal to the 100% rod line value and then transform the SB to the practical power-flow map. Using this SB, we show that the normal operating point at 100% power is very stable, stability of points on the 100% rod line decreases as the flow rate is reduced, and that points are least stable in the low-flow/high-power region. We also determine the SB when the modal kinetics is replaced by simple point reactor kinetics and show that the first harmonic mode has no significant effect on the SB. Later we carry out the relevant numerical simulations where we first show that the Hopf bifurcation, that occurs as a parameter is varied across the SB is subcritical, and that, in the important low-flow/high-power region, growing oscillations can result following small finite perturbations of stable steady-states on the 100% rod line. Hence, a point on the 100% rod line in the low-flow/high-power region, although stable, may nevertheless be a point at which a BWR should not be operated. Numerical simulations are then done to calculate the decay ratios (DRs) and frequencies of oscillations for various points on the 100% rod line. It is determined that the NRC requirement of DR loop model that we develop is studied by carrying

  16. Improvement of auditing technology of safety analysis through thermal-hydraulic separate effect tests

    Energy Technology Data Exchange (ETDEWEB)

    No, Hee Cheon; Park, Hyun Sik; Kim, Hyoung Tae; Moon, Young Min; Choi, Sung Won; Hwang, Do Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2000-03-15

    The direct-contact condensation hear transfer coefficients are experimentally obtained in the following conditions : pure steam/steam in the presence of noncondensible gas, horizontal/slightly inclined pipe, cocurrent/countercurrent stratified flow with water. The empirical correlation for liquid Nusselt number is developed in conditions of the slightly inclined pipe and the cocurrent stratified flow. The several models - the wall friction coefficient, the interfacial friction coefficient, the correlation of direct-contact condensation with noncondensible gases, and the correlation of wall film condensation - in the RELAP5/MOD3.2 code are modified, As results, RELAP5/MOD3.2 is improved. The present experimental data is used for evaluating the improved code. The standard RELAP5/MOD3.2 code is modified using the non-iterative modeling, which is a mechanistic model and does not require any interfacial information such as the interfacial temperature, The modified RELAP5/MOD3.2 code os used to simulate the horizontally stratified in-tube condensation experiment which represents the direct-contact condensation phenomena in a hot leg of a nuclear reactor. The modeling capabilities of the modified code as well as the standard code are assessed using several hot-leg condensation experiments. The modified code gives better prediction over local experimental data of liquid void fraction and interfacial heat transfer coefficient than the standard code. For the separate effect test of the thermal-hydraulic phenomena in the pressurizer, the scaling analysis is performed to obtain a similarity of the phenomena between the Korea Standard Nuclear Power Plant(KSNPP) and the present experimental facility. The diameters and lengths of the hot-leg, the surge line and the pressurizer are scaled down with the similitude of CCFL and velocity. The ratio of gas flow rate is 1/25. The experimental facility is composed of the air-water supply tank, the horizontal pipe, the surge line and the

  17. Estimating saturated hydraulic conductivity and air permeability from soil physical properties using state-space analysis

    DEFF Research Database (Denmark)

    Poulsen, Tjalfe; Møldrup, Per; Nielsen, Don

    2003-01-01

    field were used. Multiple regression and ARIMA models yielded similar prediction accuracy, whereas state-space models generally gave significantly higher accuracy. State-space modeling suggested K-S at a given location could be predicted using nearby values of K-S, k(a100) and air-filled porosity......Estimates of soil hydraulic conductivity (K) and air permeability (k(a)) at given soil-water potentials are often used as reference points in constitutive models for K and k(a) as functions of moisture content and are, therefore, a prerequisite for predicting migration of water, air, and dissolved...... and gaseous chemicals in the vadose zone. In this study, three modeling approaches were used to identify the dependence of saturated hydraulic conductivity (K-S) and air permeability at -100 cm H2O soil-water potential (k(a100)) on soil physical properties in undisturbed soil: (i) Multiple regression, (ii...

  18. CFX Analysis of the CANDU Moderator Thermal-Hydraulics in the Stern Lab. Test Facility

    Science.gov (United States)

    Kim, Hyoung Tae

    2014-06-01

    A numerical calculation with the commercial CFD code CFX is conducted for a test facility simulating the CANDU moderator thermal-hydraulics. Two kinds of moderator thermal-hydraulic tests at Stern Laboratories Inc. were performed in the full geometric configuration of the CANDU moderator circulating vessel, which is called a Calandria, housing a matrix of horizontal rod bundles simulating the Calandria tubes. The first of these tests is the pressure drop measurement of a cross flow in the horizontal rod bundles. The other is the local temperature measurement on the cross section of the horizontal cylinder vessel simulating the Calandria. In the present study the full geometric details of the Calandria are incorporated in the grid generation of the computational domain to which the boundary conditions for each experiment are applied. The numerical solutions are reviewed and compared with the available test data.

  19. The Kinematics Analysis of the Hydraulic Mine-clearing Mechanical Manipulator

    Institute of Scientific and Technical Information of China (English)

    XIE Qing-hua; DUAN Hong

    2005-01-01

    Through analyzing the kinematics of the hydraulic manipulator operating system, according to the rules for seting up the D-H coordinate system, the generalized coordinate of the manipulator system is established. The rotating and moving joints are selected from the mechanism as joint variables. Each generalized transformation matrix of joints is worked out. The kinematics equation at the finger end of the manipulator is calculated. The obverse solution for the manipulator is gained. The geometrical operating parameters and primary technical specification of the manipulator system are simulated through the computer. The simulative result has shown that the manipulator operating system meets the working task requirements. This research provides theoretical basis for optimizing structural parameters of the manipulator operating. So it also is justified the feasibility for mechanical manipulators to be used in the engineering equipment platform of the hydraulic excavator.

  20. The Analysis Regarding the Building of a Hydraulic Power Plant on the Black Sea Shore

    Directory of Open Access Journals (Sweden)

    Gheorghe Samoilescu

    2013-09-01

    Full Text Available The present paper represents the result of a research project regarding the construction of a wave driven hydraulic plant that is going to be installed on the Black Sea shore in the area of the city of Constanta. Several phases were analyzed: numerical simulations for the micro plant – wave energy theory; finite element simulation – results and conclusions; generating the blueprint for the construction of the plant.

  1. Thermal Hydraulic Analysis of a Passive Residual Heat Removal System for an Integral Pressurized Water Reactor

    OpenAIRE

    2009-01-01

    A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS), which is connected to the reactor coolant system via the secondary side of the steam generator, for an integral pressurized water reactor is presented in this paper. Three-interknited natural circulation loops are adopted by this PRHRS to remove the residual heat of the reactor core after a reactor trip. Based on the one-dimensional model and a simulation code (S...

  2. FINITE ELEMENT METHOD ANALYSIS OF PIPE MATERIAL TEMPERATURE CHANGES INFLUENCE ON LINE EXPANSION LOOPS IN HYDRAULIC INSTALLATIONS ON MODERN TANKERS

    Directory of Open Access Journals (Sweden)

    Bartlomiej Zylinski

    2011-01-01

    Full Text Available Finite element method analysis of main lines of hydraulic central loading system installation expansion loops mounted on product and chemical tankers has been presented in the paper. The axial forces problem in installations mounted along the ship's open decks executed from hull deformations on waves and thermal stresses is given. Use of "U" type expansion loops is described. Results of forces in anchor points and stresses of Mises due to expansion loop deformations are shown. Calculations were made by ABAQUS Ver.6.7 FEM computer program.

  3. Force Balance Analysis Calculation of Downhole Hydraulic Piston Pump%井下水力活塞泵力平衡分析计算

    Institute of Scientific and Technical Information of China (English)

    刘乾义; 郭庆平

    2012-01-01

    The structure and working principle of hydraulic piston pumps is introduced* analysis and calculation of its effective displacement pump and hydraulic motor displacement, and the actual displacement and rated discharge capacity were made. The force balance equation for hydraulic piston pump was established. The P/E values were computed to obtain friction losses, which provided a basis for design and application of hydraulic piston pumps.%介绍了水力活塞泵的结构及工作原理,分析计算了其液马达排量和泵的有效排量、实际排量及额定排量,建立了水力活塞泵力平衡方程,计算得到摩阻损失和P/E值,为水力活塞泵的设计应用提供依据.

  4. Characteristics and performance analysis report of the major thermal hydraulic components in the high temperature/high pressure thermal hydraulic test facility (VISTA)

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ki Yong; Park, Hyun Sik; Cho, Seok; Lee, Sung Jae; Song, Chul Hwa; Park, Chun Kyong; Chung, Moon Ki

    2003-12-01

    The VISTA (Experimental Verification by Integral Simulation of Transients and Accidents) is an experimental facility to verify the performance and safety issues of the SMART-P (Pilot plant of the System-integrated Modular Advanced Reactor). The basic design of the SMART-P has been completed by KAERI. The present report describes the characteristics and performance of the major thermal hydraulic components in the VISTA Facility.

  5. Thermal-hydraulic analysis of an innovative decay heat removal system for lead-cooled fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Giannetti, Fabio; Vitale Di Maio, Damiano; Naviglio, Antonio; Caruso, Gianfranco, E-mail: gianfranco.caruso@uniroma1.it

    2016-08-15

    Highlights: • LOOP thermal-hydraulic transient analysis for lead-cooled fast reactors. • Passive decay heat removal system concept to avoid lead freezing. • Solution developed for the diversification of the decay heat removal functions. • RELAP5 vs. RELAP5-3D comparison for lead applications. - Abstract: Improvement of safety requirements in GEN IV reactors needs more reliable safety systems, among which the decay heat removal system (DHR) is one of the most important. Complying with the diversification criteria and based on pure passive and very reliable components, an additional DHR for the ALFRED reactor (Advanced Lead Fast Reactor European Demonstrator) has been proposed and its thermal-hydraulic performances are analyzed. It consists in a coupling of two innovative subsystems: the radiative-based direct heat exchanger (DHX), and the pool heat exchanger (PHX). Preliminary thermal-hydraulic analyses, by using RELAP5 and RELAP5-3D© computer programs, have been carried out showing that the whole system can safely operate, in natural circulation, for a long term. Sensitivity analyses for: the emissivity of the DHX surfaces, the PHX water heat transfer coefficient (HTC) and the lead HTC have been carried out. In addition, the effects of the density variation uncertainty on the results has been analyzed and compared. It allowed to assess the feasibility of the system and to evaluate the acceptable range of the studied parameters. A comparison of the results obtained with RELAP5 and RELAP5-3D© has been carried out and the analysis of the differences of the two codes for lead is presented. The features of the innovative DHR allow to match the decay heat removal performance with the trend of the reactor decay heat power after shutdown, minimizing at the same time the risk of lead freezing. This system, proposed for the diversification of the DHR in the LFRs, could be applicable in the other pool-type liquid metal fast reactors.

  6. Multi-elemental analysis of jet engine lubricating oils and hydraulic fluids and their implication in aircraft air quality incidents.

    Science.gov (United States)

    van Netten, C

    1999-05-07

    The flight crews of aircraft often report symptoms including dizziness, nausea, disorientation, blurred vision and tingling in legs and arms. Many of these incidents have been traced to contamination of cabin air with lubricating oil, as well as hydraulic fluid, constituents. Considering that these air contaminants are often subjected to temperatures in excess of 500 degrees C, a large number of different exposures can be expected. Although the reported symptoms are most consistent with exposures to volatile organic compounds, carbon monoxide, and the organophosphate constituents in these oils and fluids, the involvement of these agents has not been clearly demonstrated. Possible exposure to toxic elements, such as lead, mercury, thallium and others, have not been ruled out. In order to assess the potential of exposure to toxic elements a multi-elemental analysis was done on two hydraulic fluids and three lubricating oils which have been implicated in a number of air quality incidents. A secondary objective was to establish if the multi-elemental concentrations of the fluids tested are different enough to allow such an analysis to be used as a possible method of identifying the source of exposure that might have been present during aircraft air quality incidents. No significant concentrations of toxic elements were identified in any of the oils or hydraulic fluids. The elemental compositions of the samples were different enough to be used for identification purposes and the measurement of only three elements was able to achieve this. Whether these findings have an application, in aircraft air quality incident investigations, needs to be established with further studies.

  7. Dynamic Coupling Analysis of a Spatial 6-DOF Electro-Hydraulic Parallel Manipulator Using a Modal Decoupling Method

    Directory of Open Access Journals (Sweden)

    Chifu Yang

    2013-02-01

    Full Text Available The workspace of a spatial 6‐DOF electro‐hydraulic parallel manipulator is strongly coupled, due to its multi‐closed‐loop kinematic structure and the coupling complicates motion planning and control of the parallel manipulator. This paper clearly analyses the strong dynamic coupling property in the workspace of a spatial 6‐DOF parallel manipulator, using modal decoupling theory and a frequency responses characteristics analysis method. The dynamic model of a spatial 6‐DOF electro‐hydraulic parallel manipulator is expressed with the Kane method and hydromechanics principles. The modal analysis method is used to establish the map between strong coupling workspace and decoupled modal space and the dynamic coupling relationship and coupling strength between workspaces are exactly revealed. The quantitative evaluation index of dynamic coupling is presented. Moreover, the relationship between dynamic coupling effects and input is discussed through applying frequency characteristics analysis. Experimental results show the workspace of the parallel manipulator is strongly coupled and the coupling property is coincident with theoretical results.

  8. Thermal-hydraulic analysis of the semiscale Mod-1 blowdown heat transfer test series. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Cozzuol, J.M.

    1976-06-01

    Selected experimental thermal-hydraulic data from the recent Semiscale Mod-1 blowdown heat transfer test series are analyzed from an experimental viewpoint with emphasis on explaining those phenomena which influence core fluid behavior. Comparisons are made between the trends measured by the system instrumentation and the trends predicted by the RELAP4 computer code to aid in obtaining an understanding of the interactions between phenomena occurring in different parts of the system. The analyses presented in this report are valuable for evaluating the adequacy and improving the predictive capability of analytical models developed to predict the system response of a pressurized water reactor during a postulated loss-of-coolant accident (LOCA).

  9. THEORETICAL ANALYSIS ON HYDRAULIC TRANSIENT RESULTED BY SUDDEN INCREASE OF INLET PRESSURE FOR LAMINAR PIPELINE FLOW

    Institute of Scientific and Technical Information of China (English)

    邓松圣; 周绍骑; 廖振方; 邱正阳; 曾顺鹏

    2004-01-01

    Hydraulic transient,which is resulted from sudden increase of inlet pressure for laminar pipeline flow,is studied.The partial differential equation,initial and boundary conditions for transient pressure were constructed,and the theoretical solution was obtained by variable-separation method.The partial differential equation,initial and boundary conditions for flow rate were obtained in accordance with the constraint correlation between flow rate and pressure while the transient flow rate distribution was also solved by variable-separation method.The theoretical solution conforms to numerical solution obtained by method of characteristics(MOC)very well.

  10. Design, analysis and control of hydraulic soft yaw system for 5MW wind turbine

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole

    2012-01-01

    by active control of a hydraulic yaw system. The control is based on a non-linear and linear model derived based on a concept yaw system for the NREL 5MW wind turbine. The control strategies show a reduction in pressure pulsations under load and it is concluded that the strategie including high......As wind turbines increase in size and the demands for lifetime also increases, new methods of load reduction needs to be examined. One method is to make the yaw system of the turbine soft/flexible and wereby dampen the loads to the system. This paper presents work done on dampening of these loads...

  11. Sensitivity analysis of hydraulic and thermal parameters inducing anomalous heat flow in the Lower Yarmouk Gorge

    Science.gov (United States)

    Goretzki, Nora; Inbar, Nimrod; Kühn, Michael; Möller, Peter; Rosenthal, Eliyahu; Schneider, Michael; Siebert, Christian; Magri, Fabien

    2016-04-01

    The Lower Yarmouk Gorge, at the border between Israel and Jordan, is characterized by an anomalous temperature gradient of 46 °C/km. Numerical simulations of thermally-driven flow show that ascending thermal waters are the result of mixed convection, i.e. the interaction between the regional flow from the surrounding heights and buoyant flow within permeable faults [1]. Those models were calibrated against available temperature logs by running several forward problems (FP), with a classic "trial and error" method. In the present study, inverse problems (IP) are applied to find alternative parameter distributions that also lead to the observed thermal anomalies. The investigated physical parameters are hydraulic conductivity and thermal conductivity. To solve the IP, the PEST® code [2] is applied via the graphical interface FEPEST® in FEFLOW® [3]. The results show that both hydraulic and thermal conductivity are consistent with the values determined with the trial and error calibrations, which precede this study. However, the IP indicates that the hydraulic conductivity of the Senonian Paleocene aquitard can be 8.54*10-3 m/d, which is three times lower than the originally estimated value in [1]. Moreover, the IP suggests that the hydraulic conductivity in the faults can increase locally up to 0.17 m/d. These highly permeable areas can be interpreted as local damage zones at the faults/units intersections. They can act as lateral pathways in the deep aquifers that allow deep outflow of thermal water. This presentation provides an example about the application of FP and IP to infer a wide range of parameter values that reproduce observed environmental issues. [1] Magri F, Inbar N, Siebert C, Rosenthal E, Guttman J, Möller P (2015) Transient simulations of large-scale hydrogeological processes causing temperature and salinity anomalies in the Tiberias Basin. Journal of Hydrology, 520, 342-355 [2] Doherty J (2010) PEST: Model-Independent Parameter Estimation. user

  12. Comparison of dynamic analysis of a Schilling hydraulic manipulator with experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Baker, C.P.; Lew, J.Y.; Evans, M.S. [Pacific Northwest Lab., Richland, WA (United States); Magee, D.P. [Georgia Inst. of Technology, Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

    1993-07-01

    Two independent models of the dynamics of a Schilling Titan II hydraulic manipulator were developed and compared in order to obtain an accurate model of the manipulator dynamics. These models will be used in the development of feedback control laws and active damping algorithms. One of the model is an analytical model which was developed {open_quotes}by hand{close_quotes} with the assistance of computer symbolic manipulation. The other is a numerical model developed using a commercially available dynamics code. The data from these models were then compared with experimental data from an actual Titan II manipulator.

  13. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on-going...

  14. Modelling, Testing and Analysis of a Regenerative Hydraulic Shock Absorber System

    Directory of Open Access Journals (Sweden)

    Ruichen Wang

    2016-05-01

    Full Text Available To improve vehicle fuel economy whilst enhancing road handling and ride comfort, power generating suspension systems have recently attracted increased attention in automotive engineering. This paper presents our study of a regenerative hydraulic shock absorber system which converts the oscillatory motion of a vehicle suspension into unidirectional rotary motion of a generator. Firstly a model which takes into account the influences of the dynamics of hydraulic flow, rotational motion and power regeneration is developed. Thereafter the model parameters of fluid bulk modulus, motor efficiencies, viscous friction torque, and voltage and torque constant coefficients are determined based on modelling and experimental studies of a prototype system. The model is then validated under different input excitations and load resistances, obtaining results which show good agreement between prediction and measurement. In particular, the system using piston-rod dimensions of 50–30 mm achieves recoverable power of 260 W with an efficiency of around 40% under sinusoidal excitation of 1 Hz frequency and 25 mm amplitude when the accumulator capacity is set to 0.32 L with the load resistance 20 Ω. It is then shown that the appropriate damping characteristics required from a shock absorber in a heavy-haulage vehicle can be met by using variable load resistances and accumulator capacities in a device akin to the prototype. The validated model paves the way for further system optimisation towards maximising the performance of regeneration, ride comfort and handling.

  15. Thermal-Hydraulic Issues in the ITER Toroidal Field Model Coil (TFMC) Test and Analysis

    Science.gov (United States)

    Zanino, R.; Bagnasco, M.; Fillunger, H.; Heller, R.; Savoldi Richard, L.; Suesser, M.; Zahn, G.

    2004-06-01

    The International Thermonuclear Experimental Reactor (ITER) Toroidal Field Model Coil (TFMC) was tested in the Toska facility of Forschungszentrum Karlsruhe during 2001 (standalone) and 2002 (in the background magnetic field of the LCT coil). The TFMC is a racetrack coil wound in five double pancakes on stainless steel radial plates using Nb3Sn dual-channel cable-in-conduit conductor (CICC) with a thin circular SS jacket. The coil was cooled by supercritical helium in forced convection at nominal 4.5 K and 0.5 MPa. Instrumentation, all outside the coil, included voltage taps, pressure and temperature sensors, as well as flow meters. Additionally, differential pressure drop measurement was available on the two pancakes DP1.1 and DP1.2, equipped with heaters. Two major thermal-hydraulic issues in the TFMC tests will be addressed here: 1) the pressure drop along heated pancakes and the comparison with friction factor correlations; 2) the quench initiation and propagation. Other thermal-hydraulic issues like heat generation and exchange in joints, radial plates, coil case, or the effects of the resistive heaters on the helium dynamics, have been already addressed elsewhere.

  16. Analysis of Thermal-Hydraulic Behavior of CMT in the SMART-ITL Facility

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Byong Guk; Bae, Hwang; Ryu, Sung-Uk; Ryu, Hyobong; Byun, Sun-Joon; Yi, Sung-Jae; Park, Hyun-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    SMART, an integral small modular reactor, received a standard design approval in 2012 and now extends its safety features through replacing active safety injection pumps by passive safety injection systems: core makeup tanks (CMT) and safety injection tanks (SIT). SMART-ITL has been built in a full height scale and 1/49 area and power scale. One train of CMT and SIT has been installed and their thermal-hydraulic behaviors have been identified through a series of tests. In this paper, initial condensation characteristics as well as force balance around the CMT will be discussed for a representative test. PSIS are added into SMART for better treatment of accidents with prolonged station blackout. In the SMART-ITL, the CMT and SIT are installed to evaluate their performance and a series of tests have been conducted. In this paper, the thermal-hydraulic behavior of CMT is addressed based on the experimental data, especially focusing on the issues of fierce condensation after opening of the isolation valve and driving force balance around the CMT.

  17. The Dynamic Analysis of Hydropower House and Unit System in Coupled Hydraulic-mechanical-electric Factors

    Science.gov (United States)

    MA, Z. Y.; Wu, Q. Q.

    2016-11-01

    A hydraulic-mechanical-electric and structures coupled model of hydropower station system including subsystem models of the penstock, hydro-turbine model, speed governor, synchronous generator as well as grid, rotor-bearing system and powerhouse structure is established. This model is used to simulate the small fluctuation transient process of 10% load-up in the part load condition for hydropower station. Mechanical eccentric force, unbalanced magnetic pull and vortex pressure fluctuation at inlet of draft tube are considered in the numerical calculation. The interaction between hydraulic-mechanical-electric coupled factors and structural vibration properties during the small fluctuation transient process is studied. The results indicate that the speed regulation for turbine has very litter impact on the transient process of generator. In the process of small fluctuation with loading method in this paper, structure of powerhouse is greatly influenced by vortex pressure pulse in the draft tube, and the vibration of unit is excited by loads which caused by itself rotating.

  18. Design and Optimization of the Slide Guide System of Hydraulic Press Based on Energy Loss Analysis

    Directory of Open Access Journals (Sweden)

    Mengdi Gao

    2016-06-01

    Full Text Available The clearances in the slide guide system of a hydraulic press are one of the significant factors affecting its accuracy. These clearances also affect the energy consumption of the press. An energy loss model that considers the oil leaks and friction associated with these clearances was proposed, and the size of clearances was optimized based on the model. The maximum allowable eccentric load and the energy loss on the wedge clearance condition were calculated to ensure the slide and guide pillars function properly. The stiffness of pillars and wear of guide rails were checked under an eccentric load condition. A case for rapid sheet metal forming with a 20 MN hydraulic press was examined. For this case, the optimum fit clearances were found to be approximately 0.4 mm. The energy loss under an eccentric load condition was increased by approximately 83% compared to a non-eccentric load condition. The pillars were optimized by reducing excessive stiffness, which served to decrease the pillar weight by nearly 20%.

  19. Dynamic Analysis and Design Optimization of Series Hydraulic Hybrid System through Power Bond Graph Approach

    Directory of Open Access Journals (Sweden)

    R. Ramakrishnan

    2014-01-01

    Full Text Available The availability of natural gas and crude oil resources has been declining over the years. In automobile sector, the consumption of crude oil is 63% of total crude oil production in the world. Hence, automobile industries are placing more emphasis on energy efficient hydraulic hybrid systems, which can replace their conventional transmission systems. Series hydraulic hybrid system (SHHS is a multidomain mechatronics system with two distinct power sources that includes prime mover and hydropneumatic accumulator. It replaces the conventional transmission system to drive the vehicle. The sizing of the subsystems in SHHS plays a major role in improving the energy efficiency of the vehicle. In this paper, a power bond graph approach is used to model the dynamics of the SHHS. The obtained simulation results indicate the energy flow during various modes of operations. It also includes the dynamic response of hydropneumatic accumulator, prime mover, and system output speed. Further, design optimization of the system is carried out to optimize the process parameters for maximizing the system energy efficiency. This leads to increase in fuel economy and environmentally friendly vehicle.

  20. Analysis of Grain Size Distribution and Hydraulic Conductivity for a Variety of Sediment Types with Application to Wadi Sediments

    KAUST Repository

    Rosas Aguilar, Jorge

    2013-05-01

    Grain size distribution, porosity, and hydraulic conductivity from over 400 unlithified sediment samples were analized. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations commonly used to estimate hydraulic conductivity from grain size analyses. It was found that most of the hydraulic conductivity values estimated from the empirical equations correlated very poorly to the measured hydraulic conductivity values. Modifications of the empirical equations, including changes to special coefficients and statistical off sets, were made to produce modified equations that considerably improve the hydraulic conductivity estimates from grain size data for beach, dune, off shore marine, and wadi sediments. Expected hydraulic conductivity estimation errors were reduced. Correction factors were proposed for wadi sediments, taking mud percentage and the standard deviation (in phi units) into account.

  1. Development of thermal-hydraulic analysis methodology for multiple modules of water-cooled breeder blanket in fusion DEMO reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geon-Woo; Lee, Jeong-Hun [Department of Nuclear Engineering, Seoul National University 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Cho, Hyoung-Kyu, E-mail: chohk@snu.ac.kr [Department of Nuclear Engineering, Seoul National University 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Park, Goon-Cherl [Department of Nuclear Engineering, Seoul National University 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Im, Kihak [National Fusion Research Institute, 169-148, Yuseong-gu, Daejeon 305-806 (Korea, Republic of)

    2016-02-15

    Highlights: • A methodology to simulate the K-DEMO blanket system was proposed. • The results were compared with the CFD, to verify the prediction capability of MARS. • 46 Blankets in a single sector in K-DEMO were simulated using MARS-KS. • Supervisor program was devised to handle each blanket module individually. • The calculation results showed the flow rates, pressure drops, and temperatures. - Abstract: According to the conceptual design of the fusion DEMO reactor proposed by the National Fusion Research Institute of Korea, the water-cooled breeding blanket system incorporates a total of 736 blanket modules. The heat flux and neutron wall loading to each blanket module vary along their poloidal direction, and hence, thermal analysis for at least one blanket sector is required to confirm that the temperature limitations of the materials are satisfied in all the blanket modules. The present paper proposes a methodology of thermal analysis for multiple modules of the blanket system using a nuclear reactor thermal-hydraulic analysis code, MARS-KS. In order to overcome the limitations of the code, caused by the restriction on the number of computational nodes, a supervisor program was devised, which handles each blanket module separately at first, and then corrects the flow rate, considering pressure drops that occur in each module. For a feasibility test of the proposed methodology, 46 blankets in a single sector were simulated; the calculation results of the parameters, such as mass flow, pressure drops, and temperature distribution in the multiple blanket modules showed that the multi-module analysis method can be used for efficient thermal-hydraulic analysis of the fusion DEMO reactor.

  2. Thermodynamic Analysis and Calculation on Hydraulic Steering Units of Aircraft Hydraulic System%飞机液压系统伺服舵机热力学分析与计算

    Institute of Scientific and Technical Information of China (English)

    李晶; 汤贵春; 曹骏飞; 是贤珠

    2015-01-01

    A thermodynamic analysis method was adopted to hydraulic servo steering units in temG perature controlling for reducing aircraft hydraulic systems failure.A hydraulic servo steering units can be simplified to a servo valve and an actuator cylinder.Based on the first law of thermodynamics, the thermodynamic model of hydraulic steering units for aircraft was established.And the thermodyG namic differential equations set of the model were derived with lumped parameter method,and solved by RungeKutta method.Simulations of hydraulic servo steering thermodynamics model were carried out by employing MATLAB software.And the calculation results coincide with the experimental data. The model presented herein can be used to calculate the dynamic temperature of aircraft hydraulic sysG tems.%为减少飞机液压系统故障,从温度控制层面对飞机液压伺服舵机进行热力学分析。将液压伺服舵机的物理模型简化为伺服阀控制作动筒的形式,建立液压伺服舵机热力学模型。根据热力学第一定律,采用集中参数法建立热力学方程。基于 MATLAB 平台,采用龙格库塔法对舵机热力学模型进行编程仿真计算,得出舵机各节点温度分布曲线。将仿真结果与实验数据进行了对比,对比结果验证了飞机液压伺服舵机热力学模型的正确性,该模型可应用于飞机液压系统动态温度计算。

  3. TAPINS: A THERMAL-HYDRAULIC SYSTEM CODE FOR TRANSIENT ANALYSIS OF A FULLY-PASSIVE INTEGRAL PWR

    Directory of Open Access Journals (Sweden)

    YEON-GUN LEE

    2013-08-01

    Full Text Available REX-10 is a fully-passive small modular reactor in which the coolant flow is driven by natural circulation, the RCS is pressurized by a steam-gas pressurizer, and the decay heat is removed by the PRHRS. To confirm design decisions and analyze the transient responses of an integral PWR such as REX-10, a thermal-hydraulic system code named TAPINS (Thermal-hydraulic Analysis Program for INtegral reactor System is developed in this study. Based on a one-dimensional four-equation drift-flux model, TAPINS incorporates mathematical models for the core, the helical-coil steam generator, and the steam-gas pressurizer. The system of difference equations derived from the semi-implicit finite-difference scheme is numerically solved by the Newton Block Gauss Seidel (NBGS method. TAPINS is characterized by applicability to transients with non-equilibrium effects, better prediction of the transient behavior of a pressurizer containing non-condensable gas, and code assessment by using the experimental data from the autonomous integral effect tests in the RTF (REX-10 Test Facility. Details on the hydrodynamic models as well as a part of validation results that reveal the features of TAPINS are presented in this paper.

  4. Empirical analysis of the stress-strain relationship between hydraulic head and subsidence in the San Joaquin Valley Aquifer

    Science.gov (United States)

    Neff, K. L.; Farr, T.

    2016-12-01

    Aquifer subsidence due to groundwater abstraction poses a significant threat to aquifer sustainability and infrastructure. The need to prevent permanent compaction to preserve aquifer storage capacity and protect infrastructure begs a better understanding of how compaction is related to groundwater abstraction and aquifer hydrogeology. The stress-strain relationship between hydraulic head changes and aquifer compaction has previously been observed to be hysteretic in both empirical and modeling studies. Here, subsidence data for central California's San Joaquin Valley derived from interferometric synthetic aperture radar (InSAR) for the period 2007-2016 is examined relative to hydraulic head levels in monitoring and production wells collected by the California Department of Water Resources. Such a large and long-term data set is available for empirical analysis for the first time thanks to advances in InSAR data collection and geospatial data management. The California Department of Water Resources (DWR) funded this work to provide the background and an update on subsidence in the Central Valley to support future policy. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

  5. International benchmark study of advanced thermal hydraulic safety analysis codes against measurements on IEA-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hainoun, A., E-mail: pscientific2@aec.org.sy [Atomic Energy Commission of Syria (AECS), Nuclear Engineering Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Doval, A. [Nuclear Engineering Department, Av. Cmdt. Luis Piedrabuena 4950, C.P. 8400 S.C de Bariloche, Rio Negro (Argentina); Umbehaun, P. [Centro de Engenharia Nuclear – CEN, IPEN-CNEN/SP, Av. Lineu Prestes 2242-Cidade Universitaria, CEP-05508-000 São Paulo, SP (Brazil); Chatzidakis, S. [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States); Ghazi, N. [Atomic Energy Commission of Syria (AECS), Nuclear Engineering Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Park, S. [Research Reactor Design and Engineering Division, Basic Science Project Operation Dept., Korea Atomic Energy Research Institute (Korea, Republic of); Mladin, M. [Institute for Nuclear Research, Campului Street No. 1, P.O. Box 78, 115400 Mioveni, Arges (Romania); Shokr, A. [Division of Nuclear Installation Safety, Research Reactor Safety Section, International Atomic Energy Agency, A-1400 Vienna (Austria)

    2014-12-15

    Highlights: • A set of advanced system thermal hydraulic codes are benchmarked against IFA of IEA-R1. • Comparative safety analysis of IEA-R1 reactor during LOFA by 7 working teams. • This work covers both experimental and calculation effort and presents new out findings on TH of RR that have not been reported before. • LOFA results discrepancies from 7% to 20% for coolant and peak clad temperatures are predicted conservatively. - Abstract: In the framework of the IAEA Coordination Research Project on “Innovative methods in research reactor analysis: Benchmark against experimental data on neutronics and thermal hydraulic computational methods and tools for operation and safety analysis of research reactors” the Brazilian research reactor IEA-R1 has been selected as reference facility to perform benchmark calculations for a set of thermal hydraulic codes being widely used by international teams in the field of research reactor (RR) deterministic safety analysis. The goal of the conducted benchmark is to demonstrate the application of innovative reactor analysis tools in the research reactor community, validation of the applied codes and application of the validated codes to perform comprehensive safety analysis of RR. The IEA-R1 is equipped with an Instrumented Fuel Assembly (IFA) which provided measurements for normal operation and loss of flow transient. The measurements comprised coolant and cladding temperatures, reactor power and flow rate. Temperatures are measured at three different radial and axial positions of IFA summing up to 12 measuring points in addition to the coolant inlet and outlet temperatures. The considered benchmark deals with the loss of reactor flow and the subsequent flow reversal from downward forced to upward natural circulation and presents therefore relevant phenomena for the RR safety analysis. The benchmark calculations were performed independently by the participating teams using different thermal hydraulic and safety

  6. 快速锻造液压机动载因数分析%Dynamic load factor analysis for high-speed forging hydraulic press

    Institute of Scientific and Technical Information of China (English)

    高俊峰; 孙茂; 芦光荣; 刘崇民

    2012-01-01

    通过对20 MN下拉式快锻压机及对液压系统动载分析,介绍了快锻液压机组设计中动载因数的重要性;就如何降低液压冲击及振动提出了分析方法,尤其是分析了液压瞬变与流体在管道内的振动对机械系统振动的影响;提出了快锻液压机组设计中降低动载因数应遵守的准则.分析研究结果对液压系统设计中对泵、阀、管道等组件单元的选型与计算具有指导意义.%The importance of dynamic load factor in design of the high-speed hydraulic forging press was introduced through the dynamic load analysis for 20 MN pull-down type high-speed hydraulic forging press and its hydraulic system. The analytical method for how to reduce the hydraulic impact &- vibration was presented. The effect for the mechanical system vibration was especially analysed when the hydraulic transient and the fluid were vibrating in the piping. The criterion for the reducing dynamic load factor on the design of high-speed hydraulic forging press was provided. The analysis and research results have the guidance means for the model selection and calculation for pump, valve, piping and etc. in the hydraulic system designing.

  7. Analysis of Dither in PWM Control on Electro-hydraulic Proportional Valve

    Directory of Open Access Journals (Sweden)

    Guoping LIU

    2013-11-01

    Full Text Available Plus with modulation (PWM is widely used in proporational control systems for it is efficient, flexible and anti-interference. Due to the friction and hysteresis of electromagnet, hysteresis exists when hydraulic valve in steady-state, and hysteresis influences the dynamic characteristics of the valve seriously,the hysteresis can be improved by superimposing dithers with certain frequency and amplitude to the valve coil. Aiming at the character of anti-unloading power driver circuit ,this paper analyzed the parasitic dither which exists in ±24V PWM control,besides,the experiment shows that in a high frequency PWM, dither with independent frequency and amplitude can be generated by changing the frequency of the PWM, in this way, the dithers  and average current of coil  can be adjusted separately by changing PWM frequency and PWM duty cycle.  

  8. Development of a best estimate auditing code for CANDU thermal hydraulic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B.D.; Lee, W.J.; Lim, H.S. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-04-01

    The main purpose of this study is to develop a thermal hydraulic auditing code for the CANDU reactor, modifying the model of existing PWR auditing tool, i.e. RELAP5/MOD3. This scope of project is a second step of the whole project, and focus to the implementation of CANDU models based on the previous study. FORTRAN 90 language have been used for the development of RELAP5.MOD3/CANDU PC version. For the convenience of the previous Workstation users, the FOTRAN 77 version has been coded also and implanted into the original RELAP5 source file. The verification of model implementation has been performed through the simple verification calculations using the CANDU version. 6 refs., 15 figs., 7 tabs. (Author)

  9. Numerical analysis on thermal hydraulic performance of a flat plate heat pipe with wick column

    Science.gov (United States)

    Lu, Longsheng; Liao, Huosheng; Liu, Xiaokang; Tang, Yong

    2015-08-01

    A simplified thermal hydraulic model is developed to investigate the influence of wick column on the performance of a flat plate heat pipe (FPHP). The governing equations of the FPHP are solved by using the computational fluid dynamics package FLUENT. The temperature, velocity and pressure fields are obtained. The validity of the model is confirmed by comparing the present solutions with the open literature data. The numerical results show that with the increase of the wick column size, the maximum velocity of the liquid and vapor decreases while the total thermal resistance and capillary heat transfer limit of the FPHP increases gradually. The performance of the FPHP may degrade if the wick column is placed inside the vapor core asymmetrically.

  10. Characteristic analysis of a water hydraulic pilot-operated pressure-reducing valve

    Science.gov (United States)

    Mao, Xuyao; Hu, Junhua; Wu, Chao; Liu, Yiou; Liu, Yinshui

    2017-06-01

    Comprehensive characteristics of a seawater hydraulic pilot-operated pressure-reducing valve with constant pressure output were analyzed. A rated pressure of 15MPa and a rated flowrate of 40L/min were offered in the numerical work. Static and dynamic analyses show good behaviors: The settling time is less than 0.2s, the output pressure variation is about 0.3MPa at the maximum when input pressure or flowrate is flucturing, and the steady external leakage is below 0.025L/min. The pilot spring regulates the output pressure and the main spring has an ability to adjust the output pressure variation faintly. The narrow hole diameter of the adjustable damping plugs is negatively related to the respond time. And appropriately raising the spring chamber volume can evidently reduce outlet pressure impact of the valve when input mutations happen.

  11. Numerical discretization analysis of a HTR steam generator model for the thermal-hydraulics code trace

    Directory of Open Access Journals (Sweden)

    Esch Markus

    2014-01-01

    Full Text Available For future high temperature reactor projects, e. g., for electricity production or nuclear process heat applications, the steam generator is a crucial component. A typical design is a helical coil steam generator consisting of several tubes connected in parallel forming cylinders of different diameters. This type of steam generator was a significant component used at the thorium high temperature reactor. In the work presented the temperature profile is being analyzed by the nodal thermal hydraulics code TRACE for the thorium high temperature reactor steam generator. The influence of the nodalization is being investigated within the scope of this study and compared to experimental results from the past. The results of the standard TRACE code are compared to results using a modified Nusselt number for the primary side. The implemented heat transfer correlation was developed within the past German HTR program. This study shows that both TRACE versions are stable and provides a discussion of the nodalization requirements.

  12. Thermal hydraulic codes for LWR safety analysis - present status and future perspective

    Energy Technology Data Exchange (ETDEWEB)

    Staedtke, H. [Commission of the European Union, Ispra (Italy)

    1997-07-01

    The aim of the present paper is to give a review on the current status and future perspective of present best-estimate Thermal Hydraulic codes. Reference is made to internationally well-established codes which have reached a certain state of maturity. The first part of the paper deals with the common basic code features with respect to the physical modelling and their numerical methods used to describe complex two-phase flow and heat transfer processes. The general predictive capabilities are summarized identifying some remaining code deficiencies and their underlying limitations. The second part discusses various areas including physical modelling, numerical techniques and informatic structure where the codes could be substantially improved.

  13. NUMERICAL SIMULATION AND ANALYSIS OF PRESSURE PULSATION IN FRANCIS HYDRAULIC TURBINE WITH AIR ADMISSION

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this article, the three-dimensional unsteady multiphase flow is simulated in the whole passage of Francis hydraulic turbine. The pressure pulsation is predicted and compared with experimental data at positions in the draft tube, in front of runner, guide vanes and at the inlet of the spiral case. The relationship between pressure pulsation in the whole passage and air admission is analyzed. The computational results show: air admission from spindle hole decreases the pressure difference in the horizontal section of draft tube, which in turn decreases the amplitude of low-frequency pressure pulsation in the draft tube; the rotor-stator interaction between the air inlet and the runner increases the blade-frequency pressure pulsation in front of the runner.

  14. Thermal-hydraulic analysis techniques for axisymmetric pebble bed nuclear reactor cores. [PEBBLE code

    Energy Technology Data Exchange (ETDEWEB)

    Stroh, K.R.

    1979-03-01

    The pebble bed reactor's cylindrical core volume contains a random bed of small, spherical fuel-moderator elements. These graphite spheres, containing a central region of dispersed coated-particle fissile and fertile material, are cooled by high pressure helium flowing through the connected interstitial voids. A mathematical model and numerical solution technique have been developed which allow calculation of macroscopic values of thermal-hydraulic variables in an axisymmetric pebble bed nuclear reactor core. The computer program PEBBLE is based on a mathematical model which treats the bed macroscopically as a generating, conducting porous medium. The steady-state model uses a nonlinear Forchheimer-type relation between the coolant pressure gradient and mass flux, with newly derived coefficients for the linear and quadratic resistance terms. The remaining equations in the model make use of mass continuity, and thermal energy balances for the solid and fluid phases.

  15. Flower, a Model for the Analysis of Hydraulic Networks and Processes

    CERN Document Server

    Bottura, L

    2003-01-01

    We have developed in the past years a model that describes hydraulic networks that are typical of the cryogenic interconnection of superconducting magnets. The original model, called Flower, was used mostly to provide consistent boundary conditions for the operation of a magnet. The main limitations were associated with the number and nature of modelling elements available, and to the maximum size of the model that could be solved. Here we present an improvement of the model largely relaxing the above limitations by the addition of new modelling elements, such as parallel flow heat exchangers, and by a significant improvement in the numerics of the solver, using sparse matrix storage and solution techniques. We finally show a typical application to the case of a magnet quench in the LHC string.

  16. Dispersion and treatment performance analysis of an UASB reactor under different hydraulic loading rates.

    Science.gov (United States)

    Peña, M R; Mara, D D; Avella, G P

    2006-02-01

    Mixing and transport phenomena affect the efficiency of all bioreactor configurations. An even mixing pattern at the macro-level is desirable to provide good conditions for substrate transport to, and from, the microbial aggregates. The state of segregation of particulate material in the reactor is also important. The production of biogas in anaerobic reactors is another factor that affects mixing intensity and hence the interactions between the liquid, solid and gaseous phases. The CSTR model with some degree of short-circuiting, dead zones and bypassing flows seems to describe the overall hydrodynamics of UASBs. However, few data are available in the literature for full-scale reactors that relate process performance to mixing characteristics. Dispersion studies using LiCl were done for four hydraulic loading rates on a full-scale UASB treating domestic wastewater in Ginebra, Valle del Cauca, southwest Colombia. COD, TSS, and Settleable Solids were used to evaluate the performance of organic matter removal. The UASB showed a complete mixing pattern for hydraulic loading rates close to the design value (i.e. Q = 10-13l s(-1) and HRT=8-6 h). Gross mixing distortions and localised stagnant zones, short-circuiting and bypass flows were found in the sludge bed and blanket zones for both extreme conditions (underloading and overloading). The liquid volume contained below the gas-liquid-solid separator was found to contribute to the overall stagnant volume, particularly when the reactor was underloaded. The removal of organic matter showed a log-linear correlation with the dispersion number.

  17. A finite element analysis of a large thrust elastic metal-plastics bearing bush for a hydraulic turbine

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Presents the study on the pressure and friction fields of the lubricant film on the surface of a large thrust elastic metal-plastic bearing bush in a hydraulic turbine using the method of finite element analysis and the stress and displacement fields in the vertical direction of the bush surface obtained to provide a theoretical basis for the design of contour lines and investigation into the causes for destruction of bushes, and concludes with test results that 1 ) the stress on the surface of the bush is not uniform; 2) a tension stress tends to occur near the oil ingress and egress edges but it is minor; 3) the biggest displacement in the vertical direction appears where x = 84 and Y = 1 153 and has a value of 0.022 mm; 4) the deformation of the bearing bush is harmful to the maintenance of lubricant film.

  18. Detection of water contamination from hydraulic fracturing wastewater: a μPAD for bromide analysis in natural waters.

    Science.gov (United States)

    Loh, Leslie J; Bandara, Gayan C; Weber, Genevieve L; Remcho, Vincent T

    2015-08-21

    Due to the rapid expansion in hydraulic fracturing (fracking), there is a need for robust, portable and specific water analysis techniques. Early detection of contamination is crucial for the prevention of lasting environmental damage. Bromide can potentially function as an early indicator of water contamination by fracking waste, because there is a high concentration of bromide ions in fracking wastewaters. To facilitate this, a microfluidic paper-based analytical device (μPAD) has been developed and optimized for the quantitative colorimetric detection of bromide in water using a smartphone. A paper microfluidic platform offers the advantages of inexpensive fabrication, elimination of unstable wet reagents, portability and high adaptability for widespread distribution. These features make this assay an attractive option for a new field test for on-site determination of bromide.

  19. Hydrostratigraphic analysis of the MADE site with full-resolution GPR and direct-push hydraulic profiling

    Science.gov (United States)

    Dogan, M.; Van Dam, R. L.; Bohling, G.C.; Butler, J.J.; Hyndman, D.W.

    2011-01-01

    Full-resolution 3D Ground-Penetrating Radar (GPR) data were combined with high-resolution hydraulic conductivity (K) data from vertical Direct-Push (DP) profiles to characterize a portion of the highly heterogeneous MAcro Dispersion Experiment (MADE) site. This is an important first step to better understand the influence of aquifer heterogeneities on observed anomalous transport. Statistical evaluation of DP data indicates non-normal distributions that have much higher similarity within each GPR facies than between facies. The analysis of GPR and DP data provides high-resolution estimates of the 3D geometry of hydrostratigraphic zones, which can then be populated with stochastic K fields. The lack of such estimates has been a significant limitation for testing and parameterizing a range of novel transport theories at sites where the traditional advection-dispersion model has proven inadequate. ?? 2011 by the American Geophysical Union.

  20. Failure Analysis of T-38 Aircraft Burst Hydraulic Aileron Return Line

    Science.gov (United States)

    Martinez, J. E.; Figert, J. D.; Paton, R. M.; Nguyen, S. D.; Flint, A.

    2012-01-01

    During maintenance troubleshooting for fluctuating hydraulic pressures, a technician found that a right hand aileron return line, on the flight hydraulic side, was ruptured (Fig. 1, 2). This tubing is part of the Hydraulic Flight Control Aileron Return Reducer to Aileron Manifold and is suspected to be original to the T-38 Talon trainer aircraft. Ailerons are small hinged sections on the outboard portion of a wing used to generate rolling motion thereby banking the aircraft. The ailerons work by changing the effective shape of the airfoil of the outer portion of the wing [1]. The drawing, Northrop P/N 3-43033-55 (6/1960), specifies that the line is made from 0.375 inch OD, aluminum 5052-0 tubing with a 0.049 inch wall thickness. WW-T-787 requires the tube shall be seamless and uniform in quality and temper [2]. The test pressure for this line is 3000 psi, and the operational pressure for this line is estimated to be between 45 psi and 1500 psi based on dynamic loading during flight. Examination of the fracture surface found evidence of arrest bands originating on the inner diameter (Fig 3). Ductile dimples are observed on the tube fractures (Fig. 4). The etched cross-section revealed thinning and work-hardening in the burst region (Fig. 5). The wall thickness just outside the work-hardened fracture region measured 0.035". Barlow's Formula: P = 2St/D, where P is burst pressure, S is allowable stress, t is wall thickness and D is the outer diameter of tube. Using the ultimate tensile strength of 28 ksi and a measured wall thickness of 0.035 inches at burst, P = 5.2 ksi (burst pressure). Using the yield of 13 ksi (YS) for aluminum 5052-0, plastic deformation will happen at P = 2.4 ksi suggesting plastic deformation occurred at a proof pressure of 3.0 ksi. Conclusion: The burst resulted from high stress, low-cycle fatigue. Evidence of arrest bands originating on the inner diameter. Fracture is predominately shear dimples, characteristic of high load ductile fractures

  1. Computation and analysis of cavitating flow in Francis-class hydraulic turbines

    Science.gov (United States)

    Leonard, Daniel J.

    can occur more abruptly in the model than the prototype, due to lack of Froude similitude between the two. When severe cavitation occurs, clear differences are observed in vapor content between the scales. A stage-by-stage performance decomposition is conducted to analyze the losses within individual components of each scale of the machine. As cavitation becomes more severe, the losses in the draft tube account for an increasing amount of the total losses in the machine. More losses occur in the model draft tube as cavitation formation in the prototype draft tube is prevented by the larger hydrostatic pressure gradient across the machine. Additionally, unsteady Detached Eddy Simulations of the fully-coupled cavitating hydroturbine are performed for both scales. Both mesh and temporal convergence studies are provided. The temporal and spectral content of fluctuations in torque and pressure are monitored and compared between single-phase, cavitating, model, and prototype cases. A shallow draft tube induced runner imbalance results in an asymmetric vapor distribution about the runner, leading to more extensive growth and collapse of vapor on any individual blade as it undergoes a revolution. Unique frequency components manifest and persist through the entire machine only when cavitation is present in the hub vortex. Large maximum pressure spikes, which result from vapor collapse, are observed on the blade surfaces in the multiphase simulations, and these may be a potential source of cavitation damage and erosion. Multiphase CFD is shown to be an accurate and effective technique for simulating and analyzing cavitating flow in Francis-class hydraulic turbines. It is recommended that it be used as an industrial tool to supplement model cavitation experiments for all types of hydraulic turbines. Moreover, multiphase CFD can be equally effective as a research tool, to investigate mechanisms of cavitating hydraulic turbines that are not understood, and to uncover unique new

  2. Flow of variable-density formation water in deep sloping aquifers: minimizing the error in representation and analysis when using hydraulic-head distributions

    Science.gov (United States)

    Bachu, Stefan; Michael, Karsten

    2002-03-01

    Although not fully adequate, freshwater hydraulic heads have been used historically to represent and analyze variable-density flow in sloping aquifers in sedimentary basins. The use of environmental heads is valid only for strictly vertical flow in unconfined aquifers, while using variable-density hydraulic heads contravenes Darcy's law. Although the use of hydraulic-head surfaces is the simplest and quickest means of flow analysis and interpretation, preceding other methods such as numerical modeling, it introduces some errors that should be assessed and minimized in order to provide the most accurate flow representation. A first error is introduced when approximating the potential and buoyancy components along aquifer slope of the flow-driving force with their projections onto the horizontal plane. This error is most probably negligibly small for sloping aquifers in undisturbed sedimentary basins, but may be significant for aquifers dipping at a significant angle, such as in folded strata. A second error is introduced when using only hydraulic heads in the representation and analysis, and neglecting the buoyancy component of the flow-driving force. The significance of this error can be assessed by performing a Driving Force Ratio (DFR) analysis. There is no single or critical value of the DFR, below which the error in using hydraulic heads alone is negligible, and above which it is not acceptable anymore; rather, the decision regarding the error acceptability should and can be made on a case by case basis. The DFR, hence the errors in flow direction and magnitude, can be minimized for any given aquifer by using an optimum reference density in hydraulic-head calculations that is the areally-weighted average density of formation water in that aquifer. In flow analyses based on potentiometric surfaces, the use of freshwater as the reference density actually maximizes the errors introduced by the neglect of the buoyancy component of the flow-driving force because it

  3. Inconsistency in the average hydraulic models used in nuclear reactor design and safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jee Won; Roh, Gyu Hong; Choi, Hang Bok [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    One of important inconsistencies in the six-equation model predictions has been found to be the force experienced by a single bubble placed in a convergent stream of liquid. Various sets of governing equations yield different amount of forces to hold the bubble stationary in a convergent nozzle. By using the first order potential flow theory, it is found that the six-equation model can not be used to estimate the force experienced by a deformed bubble. The theoretical value of the particle stress of a bubble in a convergent nozzle flow has been found to be a function of the Weber number when bubble distortion is allowed. This force has been calculated by using different sets of governing equations and compared with the theoretical value. It is suggested in this study that the bubble size distribution function can be used to remove the presented inconsistency by relating the interfacial variables with different moments of the bubble size distribution function. This study also shows that the inconsistencies in the thermal-hydraulic governing equation can be removed by mechanistic modeling of the phasic interface. 11 refs., 3 figs. (Author)

  4. On the importance of geological data for hydraulic tomography analysis: Laboratory sandbox study

    Science.gov (United States)

    Zhao, Zhanfeng; Illman, Walter A.; Berg, Steven J.

    2016-11-01

    This paper investigates the importance of geological data in Hydraulic Tomography (HT) through sandbox experiments. In particular, four groundwater models with homogeneous geological units constructed with borehole data of varying accuracy are jointly calibrated with multiple pumping test data of two different pumping and observation densities. The results are compared to those from a geostatistical inverse model. Model calibration and validation performances are quantitatively assessed using drawdown scatterplots. We find that accurate and inaccurate geological models can be well calibrated, despite the estimated K values for the poor geological models being quite different from the actual values. Model validation results reveal that inaccurate geological models yield poor drawdown predictions, but using more calibration data improves its predictive capability. Moreover, model comparisons among a highly parameterized geostatistical and layer-based geological models show that, (1) as the number of pumping tests and monitoring locations are reduced, the performance gap between the approaches decreases, and (2) a simplified geological model with a fewer number of layers is more reliable than the one based on the wrong description of stratigraphy. Finally, using a geological model as prior information in geostatistical inverse models results in the preservation of geological features, especially in areas where drawdown data are not available. Overall, our sandbox results emphasize the importance of incorporating geological data in HT surveys when data from pumping tests is sparse. These findings have important implications for field applications of HT where well distances are large.

  5. Development of Effective Algorithm for Coupled Thermal-Hydraulics - Neutron-Kinetics Analysis of Reactivity Transient

    Energy Technology Data Exchange (ETDEWEB)

    Peltonen, Joanna

    2009-09-15

    Analyses of nuclear reactor safety have increasingly required coupling of full three dimensional neutron kinetics (NK) core models with system transient thermal-hydraulics (TH) codes. To produce results 'within a reasonable' computing time, the coupled codes use different spatial description of the reactor core. The TH code uses few, typically 5 to 20 TH channels, which represent the core. The NK code uses explicit node for each fuel assembly. Therefore, a spatial mapping of coarse grid TH and fine grid NK domain is necessary. However, improper mappings may result in loss of valuable information, thus causing inaccurate prediction of safety parameters. The purpose of this thesis is to study the sensitivity of spatial coupling (channel refinement and spatial mapping) and develop recommendations for NK-TH mapping in simulation of safety transients - Control Rod Drop, Turbine Trip, Feedwater Transient combined with stability performance (minimum pump speed of recirculation pumps). The research methodology consists of spatial coupling convergence study, as increasing number of TH channels and different mapping approach the reference case. The reference case consists of one TH channel per one fuel assembly. The comparison of results has been done under steady-state and transient conditions

  6. Thermal hydraulic analysis of reactivity accidents in MTR research reactors using RELAP5

    Energy Technology Data Exchange (ETDEWEB)

    El-Sahlamy, N.; Khedr, A. [Nuclear and Radiological Regulatory Authority (NRRA), Cairo (Egypt); D' Auria, F.D. [Pisa Univ. (Italy). Facolta di Ingegneria

    2015-12-15

    The present paper comes in the line with the international approach which use the best estimate codes, instead of conservative codes, to get more realistic prediction of system behavior under off-normal reactor conditions. The aim of the current work is to apply this approach using the thermal-hydraulic system code RELAP5/Mod3.3 in a reassessment of safety of the IAEA benchmark 10 MW Research Reactor. The assessment is performed for both slow and fast reactivity insertion transients at initial power of 1.0 W. The reactor power is calculated using the RELA5 point kinetic model. The reactivity feedback terms are considered in two steps. In the first step the feedback from changes in water density and fuel temperature (Doppler effects) are considered. In the second step the feedback from the water temperature changes is added. The results from the first step are compared with that published in IAEA-TECDOC-643 benchmarks. The comparison shows that RELAP5 over predicts the peak power and consequently the fuel, clad and coolant temperatures in case of fast reactivity insertion. The results from the second step show unjustified values for reactor power. Therefore, the model of reactivity feedback from water temperature changes in the RELAP5 code may have to be reviewed.

  7. Transient thermal hydraulic modeling and analysis of ITER divertor plate system

    Energy Technology Data Exchange (ETDEWEB)

    El-Morshedy, Salah El-Din [Argonne National Laboratory, Argonne, IL (United States); Atomic Energy Authority, Cairo (Egypt)], E-mail: selmorshedy@etrr2-aea.org.eg; Hassanein, Ahmed [Purdue University, West Lafayette, IN (United States)], E-mail: hassanein@purdue.edu

    2009-12-15

    A mathematical model has been developed/updated to simulate the steady state and transient thermal-hydraulics of the International Thermonuclear Experimental Reactor (ITER) divertor module. The model predicts the thermal response of the armour coating, divertor plate structural materials and coolant channels. The selected heat transfer correlations cover all operating conditions of ITER under both normal and off-normal situations. The model also accounts for the melting, vaporization, and solidification of the armour material. The developed model is to provide a quick benchmark of the HEIGHTS multidimensional comprehensive simulation package. The present model divides the coolant channels into a specified axial regions and the divertor plate into a specified radial zones, then a two-dimensional heat conduction calculation is created to predict the temperature distribution for both steady and transient states. The model is benchmarked against experimental data performed at Sandia National Laboratory for both bare and swirl tape coolant channel mockups. The results show very good agreements with the data for steady and transient states. The model is then used to predict the thermal behavior of the ITER plasma facing and structural materials due to plasma instability event where 60 MJ/m{sup 2} plasma energy is deposited over 500 ms. The results for ITER divertor response is analyzed and compared with HEIGHTS results.

  8. Numerical analysis of Coriolis effect on low-head hydraulic turbines

    Science.gov (United States)

    Ahn, S. H.; Xiao, Y. X.; Zhou, X. Z.; Zhang, J.; Zeng, C. J.; Luo, Y. Y.; Xu, W.; Wang, Z. W.

    2016-11-01

    For the low-head hydropower station, the operating head is low, and the turbine intake channel is relatively short. The turbine internal flow behaviour can be influenced by fluid flows in the upstream reservoir easily, then it would influence the turbine hydraulic performance. Water flows in the upstream reservoir can be influenced by the Coriolis force by the Earth rotation, and it differs at the different Rossby number. In this paper, the Coriolis effect on the approach flows and the turbine performances are investigated numerically for the low-head units. Firstly, the Coriolis effect (under the different latitudes and the same characteristic length scale) on reservoir flows was predicted. Secondly, the prototype performance of a bulb-type turbine was simulated including the reservoir flow with the Coriolis effect, and then the effect on the turbine performance is be discussed. Results show that the flow field in the upstream reservoir at the low Rossby number, the ratio of inertial force to Coriolis force, can sufficiently influence the turbine intake flows and the turbine performances. Adjusting the side-wall distance can reduce the Coriolis effects.

  9. Hydraulic characterization of volcanic rocks in Pahute Mesa using an integrated analysis of 16 multiple-well aquifer tests, Nevada National Security Site, 2009–14

    Science.gov (United States)

    Garcia, C. Amanda; Jackson, Tracie R.; Halford, Keith J.; Sweetkind, Donald S.; Damar, Nancy A.; Fenelon, Joseph M.; Reiner, Steven R.

    2017-01-20

    An improved understanding of groundwater flow and radionuclide migration downgradient from underground nuclear-testing areas at Pahute Mesa, Nevada National Security Site, requires accurate subsurface hydraulic characterization. To improve conceptual models of flow and transport in the complex hydrogeologic system beneath Pahute Mesa, the U.S. Geological Survey characterized bulk hydraulic properties of volcanic rocks using an integrated analysis of 16 multiple-well aquifer tests. Single-well aquifer-test analyses provided transmissivity estimates at pumped wells. Transmissivity estimates ranged from less than 1 to about 100,000 square feet per day in Pahute Mesa and the vicinity. Drawdown from multiple-well aquifer testing was estimated and distinguished from natural fluctuations in more than 200 pumping and observation wells using analytical water-level models. Drawdown was detected at distances greater than 3 miles from pumping wells and propagated across hydrostratigraphic units and major structures, indicating that neither faults nor structural blocks noticeably impede or divert groundwater flow in the study area.Consistent hydraulic properties were estimated by simultaneously interpreting drawdown from the 16 multiple-well aquifer tests with an integrated groundwater-flow model composed of 11 well-site models—1 for each aquifer test site. Hydraulic properties were distributed across volcanic rocks with the Phase II Pahute Mesa-Oasis Valley Hydrostratigraphic Framework Model. Estimated hydraulic-conductivity distributions spanned more than two orders of magnitude in hydrostratigraphic units. Overlapping hydraulic conductivity ranges among units indicated that most Phase II Hydrostratigraphic Framework Model units were not hydraulically distinct. Simulated total transmissivity ranged from 1,600 to 68,000 square feet per day for all pumping wells analyzed. High-transmissivity zones exceeding 10,000 square feet per day exist near caldera margins and extend

  10. Development of numerical modelling of analysis program for energy-dissipating behaviour of velocity dependent hydraulic damper

    Indian Academy of Sciences (India)

    M-H Shih; W-P Sung; M-J Wu

    2010-10-01

    A relief valve parallel to the throttle valve is added to a Velocity dependent hydraulic damper (VDHD) so that the orifice size that regulates the oil flow can be adjusted. This device adjustment will allow the damper to have an adaptive control of damping by changing its damping coefficient. A mathematical model including a serial friction model and a small damper that is parallel to the friction model added to the Maxwell model for simulating the actual energy-dissipating behaviour of the VDHD was proposed in this research. To extend the useful value of VDHD, a numerical analysis model based on the SAP2000 nonlinear analysis program was applied to simulate the energy-dissipating characteristics of VDHD in this study. The analysis results obtained by using the mathematical model and the proposed SAP2000 numerical model conform to the seismic resistant test results, and confirm that the SAP2000 nonlinear analysis program can accurately describe the actual energy-dissipating behaviour of the VDHD installed on structures under various energy-dissipating situations.

  11. Development of Thermal-hydraulic Analysis Methodology for Multi-module Breeding Blankets in K-DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geon-Woo; Lee, Jeong-Hun; Park, Goon-Cherl; Cho, Hyoung-Kyu [Seoul National University, Seoul (Korea, Republic of); Im, Kihak [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    In this paper, the purpose of the analyses is to extend the capability of MARS-KS to the entire blanket system which includes a few hundreds of single blanket modules. Afterwards, the plan for the whole blanket system analysis using MARS-KS is introduced and the result of the multiple blanket module analysis is summarized. A thermal-hydraulic analysis code for a nuclear reactor safety, MARS-KS, was applied for the conceptual design of the K-DEMO breeding blanket thermal analysis. Then, a methodology to simulate multiple blanket modules was proposed, which uses a supervisor program to handle each blanket module individually at first and then distribute the flow rate considering pressure drops arises in each module. For a feasibility test of the proposed methodology, 10 outboard blankets in a toroidal field sector were simulated, which are connected with each other through the inlet and outlet common headers. The calculation results of flow rates, pressure drops, and temperatures showed the validity of the calculation and thanks to the parallelization using MPI, almost linear speed-up could be obtained.

  12. Methods and Models for the Coupled Neutronics and Thermal-Hydraulics Analysis of the CROCUS Reactor at EFPL

    Directory of Open Access Journals (Sweden)

    A. Rais

    2015-01-01

    Full Text Available In order to analyze the steady state and transient behavior of the CROCUS reactor, several methods and models need to be developed in the areas of reactor physics, thermal-hydraulics, and multiphysics coupling. The long-term objectives of this project are to work towards the development of a modern method for the safety analysis of research reactors and to update the Final Safety Analysis Report of the CROCUS reactor. A first part of the paper deals with generation of a core simulator nuclear data library for the CROCUS reactor using the Serpent 2 Monte Carlo code and also with reactor core modeling using the PARCS code. PARCS eigenvalue, radial power distribution, and control rod reactivity worth results were benchmarked against Serpent 2 full-core model results. Using the Serpent 2 model as reference, PARCS eigenvalue predictions were within 240 pcm, radial power was within 3% in the central region of the core, and control rod reactivity worth was within 2%. A second part reviews the current methodology used for the safety analysis of the CROCUS reactor and presents the envisioned approach for the multiphysics modeling of the reactor.

  13. Post-test thermal-hydraulic analysis of two intermediate LOCA tests at the ROSA facility including uncertainty evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Freixa, J., E-mail: jordi@freixa.net [Paul Scherrer Institut (PSI) 5232 Villigen PSI (Switzerland); Kim, T.-W. [Paul Scherrer Institut (PSI) 5232 Villigen PSI (Switzerland); Manera, A. [University of Michigan, Ann Arbor, MI 48109 (United States)

    2013-11-15

    The OECD/NEA ROSA-2 project aims at addressing thermal-hydraulic safety issues relevant for light water reactors by building up an experimental database at the ROSA Large Scale Test Facility (LSTF). The ROSA facility simulates a PWR Westinghouse design with a four-loop configuration and a nominal power of 3423 MWth. Two intermediate break loss-of-coolant-accident (LOCA) experiments (Tests 1 and 2) have been carried out during 2010. The two tests were analyzed by using the US-NRC TRACE best estimate code, employing the same nodalization previously used for the simulation of small-break LOCA experiments of the ROSA-1 programme. A post-test calculation was performed for each test along with uncertainty analysis providing uncertainty bands for each relevant time trend. Uncertainties in the code modelling capabilities as well as in the initial and boundary conditions were taken into account, following the guidelines and lessons learnt through participation in the OECD/NEA BEMUSE programme. Two different versions of the TRACE code were used in the analysis, providing a qualitatively good prediction of the tests. However, the uncertainty analysis revealed differences between the performances of some models in the two versions. The most relevant parameters of the two experimental tests were falling within the computed uncertainty bands.

  14. Theoretical Analysis and Bench Tests of a Control-Surface Booster Employing a Variable Displacement Hydraulic Pump

    Science.gov (United States)

    Mathews, Charles W.; Kleckner, Harold F.

    1947-01-01

    The NACA is conducting a general investigation of servo-mechanisms for use in powering aircraft control surfaces. This paper presents a theoretical analysis and the results of bench tests of a control-booster system which employs a variable displacement hydraulic pump. The booster is intended for use in a flight investigation to determine the effects of various booster parameters on the handling qualities of airplanes. Such a flight investigation would aid in formulating specific requirements concerning the design of control boosters in general. Results of the theoretical analysis and the bench tests indicate that the subject booster is representative of types which show promise of satisfactory performance. The bench tests showed that the following desirable features were inherent in this booster system: (1) No lost motion or play in any part of the system; (2) no detectable lag between motion of the contra1 stick and control surface; and (3) Good agreement between control displacements and stick-force variations with no hysteresis in the stick-force characteristics. The final design configuration of this booster system showed no tendency to oscillate, overshoot, or have other undesirable transient characteristics common to boosters.

  15. An analysis of the proposed MITR-III core to establish thermal-hydraulic limits at 10 MW. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Harling, O.K.; Lanning, D.D.; Bernard, J.A.; Meyer, J.E.; Henry, A.F.

    1997-06-01

    The 5 MW Massachusetts Institute of Technology Research Reactor (MITR-II) is expected to operate under a new license beginning in 1999. Among the options being considered is an upgrade in the heat removal system to allow operation at 10 MW. The purpose of this study is to predict the Limiting Safety System Settings and Safety Limits for the upgraded reactor (MITR-III). The MITR Multi-Channel Analysis Code was written to analyze the response of the MITR system to a series of anticipated transients in order to determine the Limiting Safety System Settings and Safety Limits under various operating conditions. The MIT Multi-Channel Analysis Code models the primary and secondary systems, with special emphasis placed on analyzing the thermal-hydraulic conditions in the core. The code models each MITR fuel element explicitly in order to predict the behavior of the system during flow instabilities. The results of the code are compared to experimental data from MITR-II and other sources. New definitions are suggested for the Limiting Safety System Settings and Safety Limits. MITR Limit Diagrams are included for three different heat removal system configurations. It is concluded that safe, year-round operating at 10 MW is possible, given that the primary and secondary flow rates are both increased by approximately 40%.

  16. Thermal hydraulic performance analysis of the printed circuit heat exchanger using a helium test facility and CFD simulations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Hun [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); No, Hee Cheon [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)], E-mail: hcno@kaist.ac.kr; Lee, Jeong Ik; Jeon, Byong Guk [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2009-11-15

    The thermal-hydraulic performance of the PCHE was investigated using the KAIST helium test loop. Experiments were performed in the helium laminar region with 350 < Re < 1200. The hot/cold side inlet conditions were 25-550 {sup o}C/25-100 {sup o}C over the operating pressure of 1.5-1.9 MPa, respectively. Mass flow rates were controlled in the range of 40-100 kg/h. Pressure drop and temperature difference were measured at the inlet and outlet of the hot and cold sides. A global Fanning factor correlation and a global Nusselt number correlation were proposed using information only at the inlet and outlet of the hot and cold sides. A three-dimensional (3-D) numerical simulation was performed using FLUENT, a commercial computational fluid dynamics (CFD) code, to compare simulation results to the KAIST helium test data and to obtain the local Nusselt number in the PCHE. CFD predictions showed good agreement with experimental data. A local pitch-averaged Nusselt number correlation was proposed using local temperature, pressure, surface heat fluxes, and properties provided by CFD simulations. The system analysis code, GAMMA, was also utilized to identify which correlation was more applicable for system analysis. It turns out that the proposed local pitch-averaged Nusselt number correlation from CFD simulations is more appropriate than the global Nusselt number correlation developed from experimental data.

  17. Post-test thermal-hydraulic analysis of two intermediate LOCA tests at the ROSA facility including uncertainty evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Freixa, J.; Kim, T-W.; Manera, A. [Paul Scherrer Inst., Villigen (Switzerland)

    2011-07-01

    The OECD/NEA ROSA-2 project aims at addressing thermal-hydraulic safety issues relevant for light water reactors by building up an experimental database at the ROSA Large Scale Test Facility (LSTF). The ROSA facility simulates a PWR Westinghouse design with a four-loop configuration and a nominal power of 3423 MWth. Two intermediate break loss-of-coolant-accident (LOCA) experiments (Test 1 and 2) have been carried out during 2010. The two tests were analyzed by using the US-NRC TRACE best estimate code, employing the same nodalization previously used for the simulation of small-break LOCA experiments of the ROSA-1 program. A post-test calculation was performed for each test along with uncertainty analysis providing uncertainty bands for each relevant time trend. Uncertainties in the code modeling capabilities as well as in the initial and boundary conditions were taken into account, following the guidelines and lessons learnt through participation in the OECD/NEA BEMUSE program. Two different versions of the TRACE code were used in the analysis, providing a qualitatively good prediction of the tests. However, both versions showed deficiencies that need to be addressed. The most relevant parameters of the two experimental tests were falling within the computed uncertainty bands. (author)

  18. Conceptual design and cost analysis of hydraulic output unit for 15 kW free-piston Stirling engine

    Science.gov (United States)

    White, M. A.

    1982-01-01

    A long-life hydraulic converter with unique features was conceptually designed to interface with a specified 15 kW(e) free-piston Stirling engine in a solar thermal dish application. Hydraulic fluid at 34.5 MPa (5000 psi) is produced to drive a conventional hydraulic motor and rotary alternator. Efficiency of the low-maintenance converter design was calculated at 93.5% for a counterbalanced version and 97.0% without the counterbalance feature. If the converter were coupled to a Stirling engine with design parameters more typcial of high-technology Stirling engines, counterbalanced converter efficiency could be increased to 99.6%. Dynamic computer simulation studies were conducted to evaluate performance and system sensitivities. Production costs of the complete Stirling hydraulic/electric power system were evaluated at $6506 which compared with $8746 for an alternative Stirling engine/linear alternator system.

  19. 液压爬行现象探析及对策%Analysis and tactic of hydraulic crawling phenomenon

    Institute of Scientific and Technical Information of China (English)

    郭攀成

    2001-01-01

    液压爬行是影响液压缸低速运动性能的主要因素。从相对移动的金属表面的摩擦力特征入手,通过对液压滑台的试验研究,提出减小液压缸动、静摩擦力的差别以及提高传动系统的刚性是消除液压爬行的主要途径。%Hydraulic crawling is the main factor effect low-speed movingperformance of hydraulic cylinder.Decreasing difference between moving friction and stationiary friction and improving rigidity of actuating system are presented to be the main method to eliminate hydraulic crawling from friction character of relatively moving metal interface,and by trial study of hydraulic slide-stand.

  20. 液压CAT系统测试误差分析%Error Analysis of the Hydraulic CAT System Test

    Institute of Scientific and Technical Information of China (English)

    胡森; 胡晓波

    2011-01-01

    本文对液压CAT技术的发展现状和趋势进行了探讨,并对液压元件CAT系统误差来源进行了分析,介绍一些液压CAT系统误差处理办法.%The development status and trends of hydraulic CAT technology are discussed, and the error sources of hydraulic component CAT system were analyzed, and some approaches are introduced in this paper.

  1. Genome-Centric Analysis of Microbial Populations Enriched by Hydraulic Fracture Fluid Additives in a Coal Bed Methane Production Well.

    Science.gov (United States)

    Robbins, Steven J; Evans, Paul N; Parks, Donovan H; Golding, Suzanne D; Tyson, Gene W

    2016-01-01

    Coal bed methane (CBM) is generated primarily through the microbial degradation of coal. Despite a limited understanding of the microorganisms responsible for this process, there is significant interest in developing methods to stimulate additional methane production from CBM wells. Physical techniques including hydraulic fracture stimulation are commonly applied to CBM wells, however the effects of specific additives contained in hydraulic fracture fluids on native CBM microbial communities are poorly understood. Here, metagenomic sequencing was applied to the formation waters of a hydraulically fractured and several non-fractured CBM production wells to determine the effect of this stimulation technique on the in-situ microbial community. The hydraulically fractured well was dominated by two microbial populations belonging to the class Phycisphaerae (within phylum Planctomycetes) and candidate phylum Aminicenantes. Populations from these phyla were absent or present at extremely low abundance in non-fractured CBM wells. Detailed metabolic reconstruction of near-complete genomes from these populations showed that their high relative abundance in the hydraulically fractured CBM well could be explained by the introduction of additional carbon sources, electron acceptors, and biocides contained in the hydraulic fracture fluid.

  2. Dynamic Analysis of Hydraulic Pumping Units%液压抽油机动态特性分析

    Institute of Scientific and Technical Information of China (English)

    李桂喜; 许建中

    2001-01-01

    应用机械振动理论,对液压抽油机的动态特性进行了分析。结果表明,液压抽油机在准匀速悬点运动条件下,抽油泵的运动由两部分组成:一是随悬点一起的刚体运动,二是由于悬点支撑位移激发的振动响应,其振动频率为系统的固有频率。适当调整系统参数,抽油泵将出现超冲程现象,这对于提高采油效率将是有益的。在准匀速悬点位移作用下,将引起抽油杆柱的振动,导致杆柱中的动应力。杆柱中的最大振动位移随深度增加量值逐渐增大,最大动应力随深度增加而逐渐减小。最大动应力随深度不是线性变化的,而是为二次函数关系。%The dynamic analysis of hydraulic pumping units was carried out in this paper by using the theory of mechanical vibrations. The house-head movement of the pumping unit is mainly uniform,except the alternation period of upper-and down-strokes.Under the action of the house-head movement,the vibration of the system,the sucker-rod and,furthermore,the dynamic stress will be induced.The results indicate that the movement of the downhole pump includes two parts. One is the movement following the horse-head.The other is the dynamic response excited by the support movement.When the parameters of the system are selected reasonably,over-stroke of the pump will appear.This is because the movement of the hydraulic piston obeys a particular law.The maximum displacement increases,and the maximum dynamic stress decreases with depth.The changing of maximum dynamic stress with depth obeys quadratic law.

  3. HydrogeoSieveXL: an Excel-based tool to estimate hydraulic conductivity from grain-size analysis

    Science.gov (United States)

    Devlin, J. F.

    2015-06-01

    For over a century, hydrogeologists have estimated hydraulic conductivity ( K) from grain-size distribution curves. The benefits of the practice are simplicity, cost, and a means of identifying spatial variations in K. Many techniques have been developed over the years, but all suffer from similar shortcomings: no accounting of heterogeneity within samples (i.e., aquifer structure is lost), loss of grain packing characteristics, and failure to account for the effects of overburden pressure on K. In addition, K estimates can vary by an order of magnitude between the various methods, and it is not generally possible to identify the best method for a given sample. The drawbacks are serious, but the advantages have seen the use of grain-size distribution curves for K estimation continue, often using a single selected method to estimate K in a given project. In most cases, this restriction results from convenience. It is proposed here that extending the analysis to include several methods would be beneficial since it would provide a better indication of the range of K that might apply. To overcome the convenience limitation, an Excel-based spreadsheet program, HydrogeoSieveXL, is introduced here. HydrogeoSieveXL is a freely available program that calculates K from grain-size distribution curves using 15 different methods. HydrogeoSieveXL was found to calculate K values essentially identical to those reported in the literature, using the published grain-size distribution curves.

  4. The preliminary thermal–hydraulic analysis of a water cooled blanket concept design based on RELAP5 code

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guanghuai; Peng, Changhong; Guo, Yun, E-mail: guoyun79@ustc.edu.cn

    2016-11-01

    Highlights: • The superheated steam and PWR schemes are analyzed by RELAP5 code. • The influence of non-uniform heating sources is include. • A supposed slow flow decrease case is discussed and the PWR scheme is better. - Abstract: Water cooled blanket (WCB) is very important in the conceptual design and energy transfer in future fusion power plant. One conceptual design of WCB is under computational testing. RELAP5 code, which is mature and often used in transient analysis in Pressurizer water reactor (PWR), is selected as the simulation tool. The complex inner flow channels and heat sources are simplified according to its thermal–hydraulic characteristics. Then the nodal model for REALP5 is built for approximating the conceptual design. Two typical operating plans, superheated steam scheme and PWR scheme, are analyzed. After some adjustments of the inlet flow resistance coefficients of some flow channels, the reasonable stable conditions of both operation plans can be obtained. The stable fluid and wall temperature distributions and pressure drops are studied. At last, a supposed slow flow decreasing is discussed under two operating conditions separately. According to present results, the superheated steam scheme still needs to be further optimized. The PWR scheme shows a very good safety feature.

  5. Thermal Hydraulics Design and Analysis Methodology for a Solid-Core Nuclear Thermal Rocket Engine Thrust Chamber

    Science.gov (United States)

    Wang, Ten-See; Canabal, Francisco; Chen, Yen-Sen; Cheng, Gary; Ito, Yasushi

    2013-01-01

    Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions. This chapter describes a thermal hydraulics design and analysis methodology developed at the NASA Marshall Space Flight Center, in support of the nuclear thermal propulsion development effort. The objective of this campaign is to bridge the design methods in the Rover/NERVA era, with a modern computational fluid dynamics and heat transfer methodology, to predict thermal, fluid, and hydrogen environments of a hypothetical solid-core, nuclear thermal engine the Small Engine, designed in the 1960s. The computational methodology is based on an unstructured-grid, pressure-based, all speeds, chemically reacting, computational fluid dynamics and heat transfer platform, while formulations of flow and heat transfer through porous and solid media were implemented to describe those of hydrogen flow channels inside the solid24 core. Design analyses of a single flow element and the entire solid-core thrust chamber of the Small Engine were performed and the results are presented herein

  6. COBRA-SFS (Spent Fuel Storage): A thermal-hydraulic analysis computer code: Volume 2, User's manual

    Energy Technology Data Exchange (ETDEWEB)

    Rector, D.R.; Cuta, J.M.; Lombardo, N.J.; Michener, T.E.; Wheeler, C.L.

    1986-11-01

    COBRA-SFS (Spent Fuel Storage) is a general thermal-hydraulic analysis computer code used to predict temperatures and velocities in a wide variety of systems. The code was refined and specialized for spent fuel storage system analyses for the US Department of Energy's Commercial Spent Fuel Management Program. The finite-volume equations governing mass, momentum, and energy conservation are written for an incompressible, single-phase fluid. The flow equations model a wide range of conditions including natural circulation. The energy equations include the effects of solid and fluid conduction, natural convection, and thermal radiation. The COBRA-SFS code is structured to perform both steady-state and transient calculations; however, the transient capability has not yet been validated. This volume contains the input instructions for COBRA-SFS and an auxiliary radiation exchange factor code, RADX-1. It is intended to aid the user in becoming familiar with the capabilities and modeling conventions of the code.

  7. RDS - A systematic approach towards system thermal hydraulics input code development for a comprehensive deterministic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Salim, Mohd Faiz, E-mail: mohdfaizs@tnb.com.my [Nuclear Energy Department, Tenaga Nasional Berhad, Level 32, Dua Sentral, 50470 Kuala Lumpur (Malaysia); Roslan, Ridha [Nuclear Installation Division, Atomic Energy Licensing Board, Batu 24, Jalan Dengkil, 43800 Dengkil, Selangor (Malaysia); Ibrahim, Mohd Rizal Mamat [Technical Support Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

    2014-02-12

    Deterministic Safety Analysis (DSA) is one of the mandatory requirements conducted for Nuclear Power Plant licensing process, with the aim of ensuring safety compliance with relevant regulatory acceptance criteria. DSA is a technique whereby a set of conservative deterministic rules and requirements are applied for the design and operation of facilities or activities. Computer codes are normally used to assist in performing all required analysis under DSA. To ensure a comprehensive analysis, the conduct of DSA should follow a systematic approach. One of the methodologies proposed is the Standardized and Consolidated Reference Experimental (and Calculated) Database (SCRED) developed by University of Pisa. Based on this methodology, the use of Reference Data Set (RDS) as a pre-requisite reference document for developing input nodalization was proposed. This paper shall describe the application of RDS with the purpose of assessing its effectiveness. Two RDS documents were developed for an Integral Test Facility of LOBI-MOD2 and associated Test A1-83. Data and information from various reports and drawings were referred in preparing the RDS. The results showed that by developing RDS, it has made possible to consolidate all relevant information in one single document. This is beneficial as it enables preservation of information, promotes quality assurance, allows traceability, facilitates continuous improvement, promotes solving of contradictions and finally assisting in developing thermal hydraulic input regardless of whichever code selected. However, some disadvantages were also recognized such as the need for experience in making engineering judgments, language barrier in accessing foreign information and limitation of resources. Some possible improvements are suggested to overcome these challenges.

  8. RDS - A systematic approach towards system thermal hydraulics input code development for a comprehensive deterministic safety analysis

    Science.gov (United States)

    Salim, Mohd Faiz; Roslan, Ridha; Ibrahim, Mohd Rizal Mamat @

    2014-02-01

    Deterministic Safety Analysis (DSA) is one of the mandatory requirements conducted for Nuclear Power Plant licensing process, with the aim of ensuring safety compliance with relevant regulatory acceptance criteria. DSA is a technique whereby a set of conservative deterministic rules and requirements are applied for the design and operation of facilities or activities. Computer codes are normally used to assist in performing all required analysis under DSA. To ensure a comprehensive analysis, the conduct of DSA should follow a systematic approach. One of the methodologies proposed is the Standardized and Consolidated Reference Experimental (and Calculated) Database (SCRED) developed by University of Pisa. Based on this methodology, the use of Reference Data Set (RDS) as a pre-requisite reference document for developing input nodalization was proposed. This paper shall describe the application of RDS with the purpose of assessing its effectiveness. Two RDS documents were developed for an Integral Test Facility of LOBI-MOD2 and associated Test A1-83. Data and information from various reports and drawings were referred in preparing the RDS. The results showed that by developing RDS, it has made possible to consolidate all relevant information in one single document. This is beneficial as it enables preservation of information, promotes quality assurance, allows traceability, facilitates continuous improvement, promotes solving of contradictions and finally assisting in developing thermal hydraulic input regardless of whichever code selected. However, some disadvantages were also recognized such as the need for experience in making engineering judgments, language barrier in accessing foreign information and limitation of resources. Some possible improvements are suggested to overcome these challenges.

  9. Hydraulic model analysis of water distribution system, Rockwell International, Rocky Flats, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Perstein, J.; Castellano, J.A. [Hughes Associates, Inc., Wheaton, MD (United States)

    1989-01-20

    Rockwell International requested an analysis of the existing plant site water supply distribution system at Rocky Flats, Colorado, to determine its adequacy. On September 26--29, 1988, Hughes Associates, Inc., Fire Protection Engineers, accompanied by Rocky Flats Fire Department engineers and suppression personnel, conducted water flow tests at the Rocky Flats plant site. Thirty-seven flows from various points throughout the plant site were taken on the existing domestic supply/fire main installation to assure comprehensive and thorough representation of the Rocky Flats water distribution system capability. The analysis was completed in four phases which are described, together with a summary of general conclusions and recommendations.

  10. Reliability analysis of a hydraulic fill with respect to liquefaction and breaching

    NARCIS (Netherlands)

    Schweckendiek, T.; Van den Ham, G.A.; De Groot, M.B.; De Gijt, J.G.; Hudig, P.; Brassinga, H.E.

    2009-01-01

    A recently reclaimed site in the Port of Rotterdam will serve as location and foundation of an LNG terminal. LNG (Liquefied Natural Gas) is recognized as hazardous material and underlies strict safety requirements. As part of the safety assessment of the entire installation, a specific analysis had

  11. Reliability analysis of a hydraulic fill with respect to liquefaction and breaching

    NARCIS (Netherlands)

    Schweckendiek, T.; Van den Ham, G.A.; De Groot, M.B.; De Gijt, J.G.; Hudig, P.; Brassinga, H.E.

    2009-01-01

    A recently reclaimed site in the Port of Rotterdam will serve as location and foundation of an LNG terminal. LNG (Liquefied Natural Gas) is recognized as hazardous material and underlies strict safety requirements. As part of the safety assessment of the entire installation, a specific analysis had

  12. Thermal-hydraulic analysis under partial loss of flow accident hypothesis of a plate-type fuel surrounded by two water channels using RELAP5 code

    Directory of Open Access Journals (Sweden)

    Itamar Iliuk

    2016-01-01

    Full Text Available Thermal-hydraulic analysis of plate-type fuel has great importance to the establishment of safety criteria, also to the licensing of the future nuclear reactor with the objective of propelling the Brazilian nuclear submarine. In this work, an analysis of a single plate-type fuel surrounding by two water channels was performed using the RELAP5 thermal-hydraulic code. To realize the simulations, a plate-type fuel with the meat of uranium dioxide sandwiched between two Zircaloy-4 plates was proposed. A partial loss of flow accident was simulated to show the behavior of the model under this type of accident. The results show that the critical heat flux was detected in the central region along the axial direction of the plate when the right water channel was blocked.

  13. Application of Multi-Valued Weighting Logical Functions in the Analysis of a Degree of Importance of Construction Parameters on the Example of Hydraulic Valves

    Directory of Open Access Journals (Sweden)

    Deptuła A.

    2014-08-01

    Full Text Available In the optimization process, changes in the construction parameters value influence the behaviour of functions depending on time. Weighting logical coefficients for the stabilisation time are taken into consideration here, i.e., a shorter (better stabilisation time has a more important (bigger value of the weighting coefficient. An example of applying weighting logical functions in the analysis of a degree of importance of construction parameters of a hydraulic valve is presented in the paper

  14. Methodology of a PWR containment analysis during a thermal-hydraulic accident

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dayane F.; Sabundjian, Gaiane; Lima, Ana Cecilia S., E-mail: dayane.silva@usp.br, E-mail: gdjian@ipen.br, E-mail: aclima@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The aim of this work is to present the methodology of calculation to Angra 2 reactor containment during accidents of the type Loss of Coolant Accident (LOCA). This study will be possible to ensure the safety of the population of the surroundings upon the occurrence of accidents. One of the programs used to analyze containment of a nuclear plant is the CONTAIN. This computer code is an analysis tool used for predicting the physical conditions and distributions of radionuclides inside a containment building following the release of material from the primary system in a light-water reactor during an accident. The containment of the type PWR plant is a concrete building covered internally by metallic material and has limits of design pressure. The methodology of containment analysis must estimate the limits of pressure during a LOCA. The boundary conditions for the simulation are obtained from RELAP5 code. (author)

  15. Thermal-hydraulic analysis of LBE spallation target for accelerator-driven systems

    Indian Academy of Sciences (India)

    Aniseh Ahmed Atef Abdalla; Jiyang Yu; Yongwel Yang

    2013-01-01

    In an accelerator-driven subcritical system (ADS), a high-performance spallation neutron source is used to feed the subcritical reactor. Neutron generation depends on the proton beam intensity. If the beam intensity is increased by a given factor, the number of generated neutrons will increase. The mechanism yielding a high rate of neutron production per energy is the spallation process, and this mechanism produces very high-energy deposition in the spallation target material. Producing a high rate of neutrons is accompanied by creation of problems of decay heat cooling and radiological protection. As a first step in designing a full-scale industrial ADS, a small-scale experimental ADS, which is similar to the European experimental ADS (XADS) is analysed. The analysis presented in this paper is based on lead–bismuth eutectic (LBE) cooled XADS-type experimental reactors, designed during the European experimental (PDS-XADS) project. Computational fluid dynamics analysis has been carried out for the spallation target. Steady-state behaviour and shear stress transport turbulence model with the automatic wall treatment were applied in the present analysis.

  16. Simulation of the Passive Condensation Cooling Tank of the PASCAL Test Facility using the Component Thermal-hydraulic Analysis Code CUPID

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hyoung Kyu; Lee, Seung Jun; Yoon, Han Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The need for a multi-dimensional analysis of transient thermal hydraulic phenomena in a component of a nuclear reactor is increasing with the advanced design features, such as a direct vessel injection system, a gravity-driven safety injection system, and a passive cooling system. Motivated by this, the development of a new thermal-hydraulic analysis code, named CUPID, is in progress at KAERI (Korea Atomic Energy Research Institute). Its numerical solver and two-phase flow models have been verified against standard conceptual problems of single and two-phase flows and validated for thermal-hydraulic experiments in our previous studies. The simulation of the passive secondary cooling system, PAFS (Passive Auxiliary Feedwater System) has been considered as one of the practical applications of CUPID. In the present study, the PCCT (Passive Condensation Cooling Tank) of the PASCAL test facility was analyzed with CUPID prior to simulating the prototype PAFS system. The objectives of the PASCAL simulation were to validate physical models of CUPID and its applicability to the PAFS analysis. This paper presents the two-dimensional transient calculation results and the comparisons with the experimental data

  17. Study of a particle method for thermal-hydraulic analysis. 2

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Yoshiaki; Koshizuka, Seiichi [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    1997-03-01

    In liquid metal fast breeder reactors (LMFBRs), liquid metal of sodium is used as the coolant under the atmospheric pressure. Thus, the coolant system has free surfaces in the components. In addition, the structures should be thin enough to reduce thermal stresses because the coolant is used in a wide range of temperature. Therefore, troubles may take place due to the sloshing, its interactions with structures and fluid-structure coupling vibration induced by flows. However, there have been no numerical methods to analyze large deformations of free surfaces and structures. Moving Particle Semi-implicit (MPS) method can be applied to topological change as well as large deformations of continuum since the calculation is based on macroscopic particles. We have developed an algorithm for incompressible flow analysis and flows with wave breaking on a free surface were successfully calculated. The objectives of the present study are development of the MPS method to analyze fluid-structure interactions and analysis of sloshing in a tank made of elastic walls. As a conclusion , a numerical method for fluid-structure interactions with large deformations of free surfaces and structures is developed based on the MPS method in the present study. (J.P.N.)

  18. Determining the hydraulic and fracture properties of the Coal Seam Gas well by numerical modelling and GLUE analysis

    Science.gov (United States)

    Askarimarnani, Sara; Willgoose, Garry; Fityus, Stephen

    2017-04-01

    Coal seam gas (CSG) is a form of natural gas that occurs in some coal seams. Coal seams have natural fractures with dual-porosity systems and low permeability. In the CSG industry, hydraulic fracturing is applied to increase the permeability and extract the gas more efficiently from the coal seam. The industry claims that it can design fracking patterns. Whether this is true or not, the public (and regulators) requires assurance that once a well has been fracked that the fracking has occurred according to plan and that the fracked well is safe. Thus defensible post-fracking testing methodologies for gas generating wells are required. In 2009 a fracked well HB02, owned by AGL, near Broke, NSW, Australia was subjected to "traditional" water pump-testing as part of this assurance process. Interpretation with well Type Curves and simple single phase (i.e. only water, no gas) highlighted deficiencies in traditional water well approaches with a systemic deviation from the qualitative characteristic of well drawdown curves (e.g. concavity versus convexity of drawdown with time). Accordingly a multiphase (i.e. water and methane) model of the well was developed and compared with the observed data. This paper will discuss the results of this multiphase testing using the TOUGH2 model and its EOS7C constitutive model. A key objective was to test a methodology, based on GLUE monte-carlo calibration technique, to calibrate the characteristics of the frack using the well test drawdown curve. GLUE involves a sensitivity analysis of how changes in the fracture properties change the well hydraulics through and analysis of the drawdown curve and changes in the cone of depression. This was undertaken by changing the native coal, fracture, and gas parameters to see how changing those parameters changed the match between simulations and the observed well drawdown. Results from the GLUE analysis show how much information is contained in the well drawdown curve for estimating field scale

  19. Frequency analysis for the thermal hydraulic characterization of a natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Walmir M.; Macedo, Luiz A.; Sabundjian, Gaiane; Andrade, Delvonei A.; Umbehaun, Pedro E.; Conti, Thadeu N.; Mesquita, Roberto N.; Masotti, Paulo H.; Angelo, Gabriel, E-mail: wmtorres@ipen.b, E-mail: lamacedo@ipen.b, E-mail: gdjian@ipen.b, E-mail: delvonei@ipen.b, E-mail: umbehaun@ipen.b, E-mail: tnconti@ipen.b, E-mail: , E-mail: rnavarro@ipen.b, E-mail: pmasotti@ipen.b, E-mail: gabriel.angelo@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    This paper presents the frequency analysis studies of the pressure signals from an experimental natural circulation circuit during a heating process. The main objective is to identify the characteristic frequencies of this process using fast Fourier transform. Video images are used to associate these frequencies to the observed phenomenology in the circuit during the process. Sub-cooled and saturated flow boiling, heaters vibrations, overall circuit vibrations, chugging and geysering were observed. Each phenomenon has its specific frequency associated. Some phenomena and their frequencies must be avoided or attenuated since they can cause damages to the natural circulation circuit and its components. Special operation procedures and devices can be developed to avoid these undesirable frequencies. (author)

  20. Integrated Analysis of Interferometric SAR, Satellite Altimetry and Hydraulic Modeling to Quantify Louisiana Wetland Dynamics

    Science.gov (United States)

    Lee, Hyongki; Kim, Jin-woo; Lu, Zhong; Jung, Hahn Chul; Shum, C. K.; Alsdorf, Doug

    2012-01-01

    Wetland loss in Louisiana has been accelerating due primarily to anthropogenic and nature processes, and is being advocated as a problem with national importance. Accurate measurement or modeling of wetland-wide water level changes, its varying extent, its storage and discharge changes resulting in part from sediment loads, erosion and subsidence are fundamental to assessment of hurricane-induced flood hazards and wetland ecology. Here, we use innovative method to integrate interferometric SAR (InSAR) and satellite radar altimetry for measuring absolute or geocentric water level changes and applied the methodology to remote areas of swamp forest in coastal Louisiana. Coherence analysis of InSAR pairs suggested that the HH polarization is preferred for this type of observation, and polarimetric analysis can help to identi:fy double-bonnce backscattering areas in the wetland. Envisat radar altimeter-measured 18- Hz (along-track sampling of 417 m) water level data processed with regional stackfile method have been used to provide vertical references for water bodies separated by levees. The high-resolution (approx.40 m) relative water changes measured from ALOS PALSAR L-band and Radarsat-l C-band InSAR are then integrated with Envisat radar altimetry to obtain absolute water level. The resulting water level time series were validated with in situ gauge observations within the swamp forest. Furthermore, we compare our water elevation changes with 2D flood modeling from LISFLOOD hydrodynamic model. Our study demonstrates that this new technique allows retrospective reconstruction and concurrent monitoring of water conditions and flow dynamics in wetlands, especially those lacking gauge networks.

  1. Dynamic characteristics analysis of hydraulic pipes in fully hydraulic steering system of engineering vehicles%工程车辆全液压转向系统管路特性分析

    Institute of Scientific and Technical Information of China (English)

    葛振亮; 侯友山; 姜勇

    2011-01-01

    基于功率键合图理论建立了工程车辆全液压转向系统的数学模型.运用20sim键图软件重点研究了全液压转向系统管路的动态特性以及液压管路参数对转向系统动态特性的影响.研究结果表明:对于小管径及长管路转向系统,管路内液阻、液感较大,有利于抑制系统的高频振荡和冲击以增强转向系统的稳定性,但延长了系统的动态响应时间;对于大管径及短管路转向系统,管路液阻、液感较小,系统动态响应较快,但转向系统振荡剧烈,振荡幅度增大,振荡次数增多,不利于车辆的操作稳定性.提高油液的体积弹性模量利于改善系统的动态响应速度和稳定性.研究结果为全液压转向系统的设计及管网动态特性分析提供理论依据.%Based on power bond graph diagram method, the general mathematical model of fully hydraulic steering system(FHSS) was established. The dynamic characteristics of hydraulic pipes of FHSS and the influences of pipeline parameters on the steering system were mainly analyzed by using 20sim bond graph software. The study results show that for the long and small diameter pipeline steering systems, the fluid resistance and fluid sense get larger, which are conducive to suppress high-frequency oscillation and shock to enhance the stability of steering system, but prolong the system's dynamic response time; for the short and large diameter pipeline, the fluid resistance and fluid sense get smaller,the system responses rapidly, but the steering system endures intensive high-frequency oscillation, with the increasing of both amplitude and frequency, which is uncondueive to the stability of steering system. Increasing the volume elastic modulus of oil in the system can improve the dynamic response speed and stability. The study results provide a theoretical support for the design of fully hydraulic steering system and for the analysis of pipeline nets' dynamic characteristics.

  2. Comparative Analysis of Soluble Phosphate Amendments for the Remediation of Heavy Metal Contaminants: Effect on Sediment Hydraulic Conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Dawn M.; Icenhower, Jonathan P.; Owen, Antionette T.

    2006-07-10

    A series of conventional, saturated column experiments were conducted to evaluate the effect of utilizing in situ phosphate amendments, for subsurface, metal remediation, on sediment hydraulic conductivity. Experiments were conducted under mildly alkaline/calcareous conditions representative of conditions commonly encountered at sites across the arid western United States, which have been used in weapons and fuel production and display significant subsurface contamination. Results indicate the displacement of a single pore volume of either sodium monophosphate or phytic acid amendments causes approximately a 30% decrease in the hydraulic conductivity of the sediment. Long-chain polyphosphate amendments afford no measurable reduction in hydraulic conductivity. These results demonstrate (1) the utility of long-chain polyphosphate amendments for subsurface metal sequestration and (2) the necessity of conducting column experiments to completely evaluate the effects of subsurface remediation.

  3. Hydrodynamic analysis of clastic injection and hydraulic fracturing structures in the Jinding Zn-Pb deposit, Yunnan, China

    Directory of Open Access Journals (Sweden)

    Guoxiang Chi

    2012-01-01

    Full Text Available The Jinding Zn-Pb deposit has been generally considered to have formed from circulating basinal fluids in a relatively passive way, with fluid flow being controlled by structures and sedimentary facies, similar to many other sediments-hosted base metal deposits. However, several recent studies have revealed the presence of sand injection structures, intrusive breccias, and hydraulic fractures in the open pit of the Jinding deposit and suggested that the deposit was formed from explosive release of overpressured fluids. This study reports new observations of fluid overpressure-related structures from underground workings (Paomaping and Fengzishan, which show clearer crosscutting relationships than in the open pit. The observed structures include: 1 sand (±rock fragment dikes injecting into fractures in solidified rocks; 2 sand (±rock fragment bodies intruding into unconsolidated or semi-consolidated sediments; 3 disintegrated semi-consolidated sand bodies; and 4 veins and breccias formed from hydraulic fracturing of solidified rocks followed by cementation of hydrothermal minerals. The development of ore minerals (sphalerite in the cement of the various clastic injection and hydraulic fractures indicate that these structures were formed at the same time as mineralization. The development of hydraulic fractures and breccias with random orientation indicates small differential stress during mineralization, which is different from the stress field with strong horizontal shortening prior to mineralization. Fluid flow velocity may have been up to more than 11 m/s based on calculations from the size of the fragments in the clastic dikes. The clastic injection and hydraulic fracturing structures are interpreted to have formed from explosive release of overpressured fluids, which may have been related to either magmatic intrusions at depth or seismic activities that episodically tapped an overpressured fluid reservoir. Because the clastic injection

  4. Improvement of auditing technology of safety analysis through thermal-hydraulic separate effect tests

    Energy Technology Data Exchange (ETDEWEB)

    No, Hee Cheon; Park, Hyun Sik; Kim, Hyougn Tae; Moon, Young Min; Choi, Sung Won; Heo, Sun [Korea Advanced Institute Science and Technology, Taejon (Korea, Republic of)

    1999-04-15

    The loss-of-RHR accident during midloop operation has been important as results of the probabilistic safety analysis. The condensation models In RELAP5/MOD3 are not proper to analyze the midloop operation. To audit and improve the model in RELAP5/MOD3.2, several items of separate effect tests have been performed. The 29 sets of reflux condensation data is obtained and the correlation is developed with these heat transfer coefficient's data. In the experiment of the direct contact condensation in hot leg, the apparatus setting is finished and a few experimental data is obtained. Non-iterative model is used to predict the model in RELAP5/MOD3.2 with the results of reflux condensation and evaluates better than the present model. The results of the direct contact condensation in a hot leg represent to be similar with the present model. The study of the CCF and liquid entrainment in a surge line and pressurizer is selected as the third separate experiment and is on performance.

  5. Validation and Application of the Thermal Hydraulic System Code TRACE for Analysis of BWR Transients

    Directory of Open Access Journals (Sweden)

    V. H. Sánchez

    2012-01-01

    Full Text Available The Karlsruhe Institute of Technology (KIT is participating on (Code Applications and Maintenance Program CAMP of the US Nuclear Regulatory Commission (NRC to validate TRACE code for LWR transient analysis. The application of TRACE for the safety assessment of BWR requires a throughout verification and validation using experimental data from separate effect and integral tests but also using plant data. The validation process is normally focused on safety-relevant phenomena for example, pressure drop, void fraction, heat transfer, and critical power models. The purpose of this paper is to validate selected BWR-relevant TRACE-models using both data of bundle tests such as the (Boiling Water Reactor Full-Size Fine-Mesh Bundle Test BFBT and plant data recorded during a turbine trip event (TUSA occurred in a Type-72 German BWR plant. For the validation, TRACE models of the BFBT bundle and of the BWR plant were developed. The performed investigations have shown that the TRACE code is appropriate to describe main BWR-safety-relevant phenomena (pressure drop, void fraction, and critical power with acceptable accuracy. The comparison of the predicted global BWR plant parameters for the TUSA event with the measured plant data indicates that the code predictions are following the main trends of the measured parameters such as dome pressure and reactor power.

  6. A paradigm shift in predicting stormflow responses in an active tectonic region through a similarity analysis of pressure propagation in a hydraulic continuum

    Directory of Open Access Journals (Sweden)

    Makoto Tani

    2013-06-01

    Full Text Available Soil layers on hillslopes acts as systems in quasi-steady states generating rainfall-stormflow responses that are controlled by pressure propagation in a hydraulic continuum established when the rainfall volume is sufficiently large. A similarity analysis for quantifying the sensitivity of the stormflow response and recession limb to topographic and soil properties in a sloping permeable domain showed that the deviation of stormflow responses in the hydraulic continuum decreases due to the macropore effect. The rapid responses seem to be naturally derived from the evolution of the soil layer with the assistance of the vegetation-root system and effective drainage systems in zero-order catchments in active tectonic regions with heavy storms. To predict stormflow responses using distributed runoff models, a paradigm shift to consider this evolution process is needed because the simple stormflow responses and complex and heterogeneous catchment properties are poorly related, but may be mainly determined by soil evolution processes.

  7. 液压冲击的分析计算及减小措施%Analysis and Calculation of Hydraulic Impact and its Reduction Measures

    Institute of Scientific and Technical Information of China (English)

    徐成东

    2016-01-01

    从液压冲击发生的机理出发,提出造成液压冲击的两大因素是管道阀门突然关闭和运动部件迅速制动或换向,并对其分别进行了详细的分析和计算,提出了具体的减小措施。%Based on the occurrence mechanism of hydraulic impact , it is put forward that two causes of hydraulic impact are sudden closing of the pipeline valve and quick braking or reversing of the moving part .Detailed analysis and calculation have been performed respectively and specific reduction measures have been proposed .

  8. Analysis of 6-year fluid electric conductivity logs to evaluate the hydraulic structure of the deep drill hole at Outokumpu, Finland

    Science.gov (United States)

    Sharma, Prabhakar; Tsang, Chin-Fu; Kukkonen, Ilmo T.; Niemi, Auli

    2016-07-01

    Over the last two decades, the flowing fluid electric conductivity (FFEC) logging method has been applied in boreholes in the well-testing mode to evaluate the transmissivity, hydraulic head, and formation water electrical conductivity as a function of depth with a resolution of about 10-20 cm. FFEC profiles along the borehole are obtained under both shut-in and pumping conditions in a logging procedure that lasts only 3 or 4 days. A method for analyzing these FFEC logs has been developed and successfully employed to obtain formation parameters in a number of field studies. The present paper concerns the analysis of a unique set of FFEC logs that were taken from a deep borehole reaching down to 2.5 km at Outokumpu, Finland, over a 6-year time period. The borehole intersects paleoproterozoic metasedimentary, granitoid, and ophiolite-derived rocks. After the well was drilled, completed, and cleaned up, FFEC logs were obtained after 7, 433, 597, 948, and 2036 days. In analyzing these five profiles, we discovered the need to account for salinity diffusion from water in the formation to the borehole. Analysis results include the identification of 15 hydraulically conducting zones along the borehole, the calculation of flow rates associated with these 15 zones, as well as the estimation of the variation of formation water electrical conductivity as a function of depth. The calculated flow rates were used to obtain the tentative hydraulic conductivity values at these 15 depth levels.

  9. ELM - A SIMPLE TOOL FOR THERMAL-HYDRAULIC ANALYSIS OF SOLID-CORE NUCLEAR ROCKET FUEL ELEMENTS

    Science.gov (United States)

    Walton, J. T.

    1994-01-01

    ELM is a simple computational tool for modeling the steady-state thermal-hydraulics of propellant flow through fuel element coolant channels in nuclear thermal rockets. Written for the nuclear propulsion project of the Space Exploration Initiative, ELM evaluates the various heat transfer coefficient and friction factor correlations available for turbulent pipe flow with heat addition. In the past, these correlations were found in different reactor analysis codes, but now comparisons are possible within one program. The logic of ELM is based on the one-dimensional conservation of energy in combination with Newton's Law of Cooling to determine the bulk flow temperature and the wall temperature across a control volume. Since the control volume is an incremental length of tube, the corresponding pressure drop is determined by application of the Law of Conservation of Momentum. The size, speed, and accuracy of ELM make it a simple tool for use in fuel element parametric studies. ELM is a machine independent program written in FORTRAN 77. It has been successfully compiled on an IBM PC compatible running MS-DOS using Lahey FORTRAN 77, a DEC VAX series computer running VMS, and a Sun4 series computer running SunOS UNIX. ELM requires 565K of RAM under SunOS 4.1, 360K of RAM under VMS 5.4, and 406K of RAM under MS-DOS. Because this program is machine independent, no executable is provided on the distribution media. The standard distribution medium for ELM is one 5.25 inch 360K MS-DOS format diskette. ELM was developed in 1991. DEC, VAX, and VMS are trademarks of Digital Equipment Corporation. Sun4 and SunOS are trademarks of Sun Microsystems, Inc. IBM PC is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation.

  10. Applied hydraulic transients

    CERN Document Server

    Chaudhry, M Hanif

    2014-01-01

    This book covers hydraulic transients in a comprehensive and systematic manner from introduction to advanced level and presents various methods of analysis for computer solution. The field of application of the book is very broad and diverse and covers areas such as hydroelectric projects, pumped storage schemes, water-supply systems, cooling-water systems, oil pipelines and industrial piping systems. Strong emphasis is given to practical applications, including several case studies, problems of applied nature, and design criteria. This will help design engineers and introduce students to real-life projects. This book also: ·         Presents modern methods of analysis suitable for computer analysis, such as the method of characteristics, explicit and implicit finite-difference methods and matrix methods ·         Includes case studies of actual projects ·         Provides extensive and complete treatment of governed hydraulic turbines ·         Presents design charts, desi...

  11. Hydraulic Hybrid Vehicles

    Science.gov (United States)

    EPA and the United Parcel Service (UPS) have developed a hydraulic hybrid delivery vehicle to explore and demonstrate the environmental benefits of the hydraulic hybrid for urban pick-up and delivery fleets.

  12. Uncertainty analysis for results of thermal hydraulic codes of best-estimate-type; Analisis de incertidumbre para resultados de codigos termohidraulicos de mejor estimacion

    Energy Technology Data Exchange (ETDEWEB)

    Alva N, J.

    2010-07-01

    In this thesis, some fundamental knowledge is presented about uncertainty analysis and about diverse methodologies applied in the study of nuclear power plant transient event analysis, particularly related to thermal hydraulics phenomena. These concepts and methodologies mentioned in this work come from a wide bibliographical research in the nuclear power subject. Methodologies for uncertainty analysis have been developed by quite diverse institutions, and they have been widely used worldwide for application to results from best-estimate-type computer codes in nuclear reactor thermal hydraulics and safety analysis. Also, the main uncertainty sources, types of uncertainties, and aspects related to best estimate modeling and methods are introduced. Once the main bases of uncertainty analysis have been set, and some of the known methodologies have been introduced, it is presented in detail the CSAU methodology, which will be applied in the analyses. The main objective of this thesis is to compare the results of an uncertainty and sensibility analysis by using the Response Surface Technique to the application of W ilks formula, apply through a loss coolant experiment and an event of rise in a BWR. Both techniques are options in the part of uncertainty and sensibility analysis of the CSAU methodology, which was developed for the analysis of transients and accidents at nuclear power plants, and it is the base of most of the methodologies used in licensing of nuclear power plants practically everywhere. Finally, the results of applying both techniques are compared and discussed. (Author)

  13. Analysis of the Oscillating Mechanism of an Aerial Work Platform Based on ADAMS Hydraulic-Mechanical Coupling Simulation

    Institute of Scientific and Technical Information of China (English)

    GU De-jun; TENG Ru-min; GAO Shun-de; BAI Ri; GAO Kai-qing

    2008-01-01

    Rigid model of the aerial work platform and hydraulic model of the oscillating mechanism were established with ADAMS. The simulation of two parameters, cy-linder force and oil chamber pressure, was carried out. The simulation result is useful to the design of the oscillating mechanism.

  14. Numerical Analysis on the Formation of Fracture Network during the Hydraulic Fracturing of Shale with Pre-Existing Fractures

    Directory of Open Access Journals (Sweden)

    Jianming He

    2017-05-01

    Full Text Available In this paper, configurations of pre-existing fractures in cubic rock blocks were investigated and reconstructed for the modeling of experimental hydraulic fracturing. The fluid-rock coupling process of hydraulic fracturing was simulated based on the displacement discontinuities method. The numerical model was validated against the related laboratory experiments. The stimulated fracture configurations under different conditions can be clearly shown using the validated numerical model. First, a dominated fracture along the maximum principle stress direction is always formed when the stress difference is large enough. Second, there are less reopened pre-existing fractures, more newly formed fractures and less shear fractures with the increase of the cohesion value of pre-existing fractures. Third, the length of the stimulated shear fracture decreases rapidly with the increase of the friction coefficient, while the length of the tensile fracture has no correlation to the fiction coefficient. Finally, the increase of the fluid injection rate is favorable to the formation of a fracture network. The unfavorable effects of the large stress difference and the large cohesion of pre-existing fractures can be partly suppressed by an increase of the injection rate in the hydraulic fracturing treatment. The results of this paper are useful for understanding fracture propagation behaviors during the hydraulic fracturing of shale reservoirs with pre-existing fractures.

  15. Modeling and analysis of hydraulic dashpot for impact free operation in a shut-off rod drive mechanism

    Directory of Open Access Journals (Sweden)

    Narendra K. Singh

    2016-09-01

    Full Text Available Rotary hydraulic dashpot used for shut-off rod drive mechanism application of a nuclear reactor has been studied in this paper for impact free operation. The rotary hydraulic dashpot has been modeled as a system with 1 degree of freedom (DOF and the simulation results are experimentally validated. The dashpot is modeled as a hinge joint with moving and fixed vanes as rigid bodies. Shut-off rods are used to shut-down a nuclear reactor and hydraulic dashpot absorbs the energy of freely falling shut-off rod at the end of rod travel. With the increase in the environmental temperature the dashpot becomes underdamped at a point because of reduction in the viscosity of oil and results into impact on mechanism components. Hydraulic dashpot designs are finalized with an optimum combination of dashpot clearances and oil viscosity to meet the drop time criterion and impact free operation at room temperature as well as at elevated temperature. Also with the change in mechanical loads the dashpot becomes underdamped. So the study is further extended to see the effects of various parameters such as moment of inertia, constraint angle and applied moment on the dashpot. Study is focused on obtaining dashpot responses in terms of relative rotation, relative angular velocity and relative angular acceleration at various environmental temperatures. Finite element commercial code COMSOL Multiphysics 5.1 has been used for numerical simulations. Equations for both rigid body dynamics and heat transfer in solids are solved simultaneously. Thus, energy absorbed and local temperature rise in the dashpot operation is also obtained. Both simulation and experimental results at wide range of environmental temperature are presented and compared in this paper. This study forms a good tool to design a hydraulic dashpot, which gives impact free operation in a shut-off rod free fall.

  16. Meta-analysis reveals that hydraulic traits explain cross-species patterns of drought-induced tree mortality across the globe.

    Science.gov (United States)

    Anderegg, William R L; Klein, Tamir; Bartlett, Megan; Sack, Lawren; Pellegrini, Adam F A; Choat, Brendan; Jansen, Steven

    2016-05-03

    Drought-induced tree mortality has been observed globally and is expected to increase under climate change scenarios, with large potential consequences for the terrestrial carbon sink. Predicting mortality across species is crucial for assessing the effects of climate extremes on forest community biodiversity, composition, and carbon sequestration. However, the physiological traits associated with elevated risk of mortality in diverse ecosystems remain unknown, although these traits could greatly improve understanding and prediction of tree mortality in forests. We performed a meta-analysis on species' mortality rates across 475 species from 33 studies around the globe to assess which traits determine a species' mortality risk. We found that species-specific mortality anomalies from community mortality rate in a given drought were associated with plant hydraulic traits. Across all species, mortality was best predicted by a low hydraulic safety margin-the difference between typical minimum xylem water potential and that causing xylem dysfunction-and xylem vulnerability to embolism. Angiosperms and gymnosperms experienced roughly equal mortality risks. Our results provide broad support for the hypothesis that hydraulic traits capture key mechanisms determining tree death and highlight that physiological traits can improve vegetation model prediction of tree mortality during climate extremes.

  17. Statistical Safety Evaluation of BWR Turbine Trip Scenario Using Coupled Neutron Kinetics and Thermal Hydraulics Analysis Code SKETCH-INS/TRACE5.0

    Science.gov (United States)

    Ichikawa, Ryoko; Masuhara, Yasuhiro; Kasahara, Fumio

    The Best Estimate Plus Uncertainty (BEPU) method has been prepared for the regulatory cross-check analysis at Japan Nuclear Energy Safety Organization (JNES) on base of the three-dimensional neutron-kinetics/thermal- hydraulics coupled code SKETCH-INS/TRACE5.0. In the preparation, TRACE5.0 is verified against the large-scale thermal-hydraulic tests carried out with NUPEC facility. These tests were focused on the pressure drop of steam-liquid two phase flow and void fraction distribution. From the comparison of the experimental data with other codes (RELAP5/MOD3.3 and TRAC-BF1), TRACE5.0 was judged better than other codes. It was confirmed that TRACE5.0 has high reliability for thermal hydraulics behavior and are used as a best-estimate code for the statistical safety evaluation. Next, the coupled code SKETCH-INS/TRACE5.0 was applied to turbine trip tests performed at the Peach Bottom-2 BWR4 Plant. The turbine trip event shows the rapid power peak due to the voids collapse with the pressure increase. The analyzed peak value of core power is better simulated than the previous version SKETCH-INS/TRAC-BF1. And the statistical safety evaluation using SKETCH-INS/TRACE5.0 was applied to the loss of load transient for examining the influence of the choice of sampling method.

  18. Meta-analysis Reveals that Hydraulic Traits Explain Cross-Species Patterns of Drought-Induced Tree Mortality across the Globe

    Science.gov (United States)

    Anderegg, W.

    2016-12-01

    Drought-induced tree mortality has been observed globally and is expected to increase under climate change scenarios, with large potential consequences for the terrestrial carbon sink. Predicting mortality across species is crucial for assessing the effects of climate extremes on forest community biodiversity, composition, and carbon sequestration. However, the physiological traits associated with elevated risk of mortality in diverse ecosystems remain unknown, though these could greatly improve understanding and prediction of tree mortality in forests. We performed a meta-analysis on species' mortality rates across 475 species from 33 studies around the globe to assess which traits determine a species' mortality risk. We found that species-specific mortality anomalies from community mortality rate in a given drought were associated with plant hydraulic traits. Across all species, mortality was best predicted by a low hydraulic safety margin - the difference between typical minimum xylem water potential and that causing xylem dysfunction - and xylem vulnerability to embolism. Angiosperms and gymnosperms experienced roughly equal mortality risk. Our results provide broad support that hydraulic traits capture key mechanisms determining tree death and highlight that physiological traits can improve vegetation models' prediction of tree mortality during climate extremes. We conclude with thoughts about a revised framework for future tree mortality research.

  19. Simulation of the passive condensation cooling tank of the PASCAL test facility using the component thermal-hydraulic analysis code CUPID

    Energy Technology Data Exchange (ETDEWEB)

    Cho, H. K.; Lee, S. J.; Kang, K. H.; Yoon, H. Y. [Korea Atomic Energy Research Inst., 1045 Daeduk-daero, Daejeon (Korea, Republic of)

    2012-07-01

    For the analysis of transient two-phase flows in nuclear reactor components, a three-dimensional thermal hydraulics code, named CUPID, has been being developed. In the present study, the CUPID code was applied for the simulation of the PASCAL (PAFS Condensing Heat Removal Assessment Loop) test facility constructed with an aim of validating the cooling and operational performance of the PAFS (Passive Auxiliary Feedwater System). The PAFS is one of the advanced safety features adopted in the APR+ (Advanced Power Reactor +), which is intended to completely replace the conventional active auxiliary feedwater system. This paper presents the preliminary simulation results of the PASCAL facility performed with the CUPID code in order to verify its applicability to the thermal-hydraulic phenomena inside the system. A standalone calculation for the passive condensation cooling tank was performed by imposing a heat source boundary condition and the transient thermal-hydraulic behaviors inside the system, such as the water level, temperature and velocity, were qualitatively investigated. The simulation results verified that the natural circulation and boiling phenomena in the water pool can be well reproduced by the CUPID code. (authors)

  20. Thermal hydraulic analysis of the IPR-R1 TRIGA reactor; Analise termo-hidraulica do reator TRIGA IPR-R1

    Energy Technology Data Exchange (ETDEWEB)

    Veloso, Marcelo Antonio [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Fortini, Maria Auxiliadora [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2002-07-01

    The subchannel approach, normally employed for the analysis of power reactor cores that work under forced convection, have been used for the thermal hydraulic evaluation of a TRIGA Mark I reactor, named IPR-R1, at 250 kW power level. This was accomplished by using the PANTERA-1P subchannel code, which has been conveniently adapted to the characteristics of natural convection of TRIGA reactors. The analysis of results indicates that the steady state operation of IPR-R1 at 250 kW do not imply risks to installations, workers and public. (author)

  1. Analysis of Clearance Sealing Performance of Hydraulic Cylinder for Wave Energy%波浪能间隙密封液压缸性能分析

    Institute of Scientific and Technical Information of China (English)

    李刚; 张亚群; 游亚戈

    2016-01-01

    The life of the sealing ring affects the whole life of the hydraulic cylinder, and then affects the development of wave energy power generation in the form of hydraulic pressure energy convert. In this paper, a new kind of end seal and piston seal method was put forwarded based on the mechanism of annular gap lubrication and sealing. Considering the effects of shear stress on the near wall of the narrow gap, annular gap flow field mathematical model was established with goals of solving the leakage, power, and friction of gap sealing hydraulic cylinder. Results of experimental analysis and numerical solution show thatthe method of clearance seal could improve the working life and the efficiency of the hydraulic cylinder which working in high frequency.%密封圈的寿命影响整个液压缸的工作寿命,从而影响以液压能为转换形式的波浪能发电的发展。本文根据环形间隙润滑与密封机理,提出一种新型端头密封和活塞密封的方法。考虑到狭小间隙内近壁面剪切应力的影响,建立了环形间隙流场数学模型,以求解间隙密封液压缸的泄漏量、功率损失、摩擦力为目标。数值模拟与实验分析的结果表明该间隙密封方法能够提高高频动作液压缸的工作寿命和效率。

  2. Controls of Hydraulic Wind Turbine

    Directory of Open Access Journals (Sweden)

    Zhang Yin

    2016-01-01

    Full Text Available In this paper a hydraulic wind turbine generator system was proposed based on analysis the current wind turbines technologies. The construction and principles were introduced. The mathematical model was verified using MATLAB and AMsim. A displacement closed loop of swash plate of motor and a speed closed loop of generator were setup, a PID control is introduced to maintain a constant speed and fixed frequency at wind turbine generator. Simulation and experiment demonstrated that the system can connect grid to generate electric and enhance reliability. The control system demonstrates a high performance speed regulation and effectiveness. The results are great significant to design a new type hydraulic wind turbine system.

  3. XJ250修井机液压盘式刹车液压控制系统仿真分析%Simulation Analysis of the Hydraulic Control System of the Hydraulic Disc Brake on the X J250 Workover Rig

    Institute of Scientific and Technical Information of China (English)

    张连业; 吴文秀; 刘威

    2012-01-01

    Taking as the object of study the hydraulic control system of the hydraulic disc brake on the XJ250 workover rig, the mathematical model on the basis of global flow and hydraulic cylinder piston motion equation was established by analyzing the structure of the control system. The AMESim simulation model for the hydraulic control system of the braking system was constructed and the model parameters and simulation parameters were set. The var- iation of the typical sine curve hydraulic source signal and excitation electromagnetic valve signal was used to carry out a simulation study of the response system of the operating brake hydraulic control system. The sudden opening of the step switch signal was used to conduct a simulation analysis of the urgency brake hydraulic system response. The hydraulic dynamic response curve of the main valve port of the hydraulic control system in the process of operating brake and urgency brake was derived. The simulation result is in agreement with the practical operation. The simulation analysis offers a reference for the improvement of the performance of the hydraulic control system of the workover rig disc brake.%以XJ250修井机液压盘式刹车的液压控制系统为研究对象,通过分析液压盘式刹车的液压控制系统结构,建立了基于全局流量与液压缸活塞运动方程的数学模型;构建了液压控制系统的AMESim仿真模型,设置了模型参数及仿真参数。以典型的正弦曲线液压源信号及激励电磁阀信号变化仿真研究工作制动液压控制系统响应性能,以阶跃开关信号突然开启模拟分析紧急制动液压系统响应。得到了工作制动及紧急制动过程中液压控制系统主要阀口处液压动态响应曲线,仿真结果与实际运行情况相符。该仿真分析为修井机液压盘式刹车液压控制系统性能的改进与完善提供了参考。

  4. 水下生产控制系统液压动力模拟分析%Hydraulic Power Simulation Analysis for Subsea Production Control System

    Institute of Scientific and Technical Information of China (English)

    周声结; 戚蒿

    2013-01-01

    对水下生产系统的液压系统、电力系统和通信系统进行不同工况下的性能分析是保障水下生产装置安全可靠工作的关键.以中海石油(中国)有限公司湛江分公司某气田开发工程项目水下生产系统的液压系统构架及参数分析为例,介绍了运用“The Control Simulator”软件进行液压动力分析的要点.分析在最小和最大井口关断压力下阀门的开关响应时间、阀门打开之后压力恢复时间、序列阀门开启时间、ESD指令下关阀响应时间等,并将分析结果和实际生产情况进行对比,可知该液压系统的各项性能指标均满足相应标准和规范的要求.%The performance analyses in various cases for hydraulic system,power system and communication system of subsea production system are the key to ensure the subsea production equipment working reliably.Based on the hydraulic system architecture and performance analysis of a gas field development project of CNOOC Ltd._ Zhanjiang,the key points of applying software "The Control Simulator" to make hydraulic system performance analysis were presented.By analyzing valve actuator operating time,hydraulic pressure recovering times,valve opening time in series,valve closing time in ESD command under maximum and minimum wellhead shut-in pressure and comparing the conclusions with actual operating case,it is shown that the hydraulic system meets the requirement of corresponding standard.

  5. Modeling and Analysis of Granite Matrix Pore Structure and Hydraulic Characteristics in 2D and 3D Networks

    Science.gov (United States)

    Gvozdik, L.; Polak, M.; Zaruba, J.; Vanecek, M.

    2010-12-01

    chamber at a constant hydraulic gradient were simulated. As an input data, the values of total porosity measured by several laboratory methods, the results of mercury porosimetry and the statistical evaluation of the size and shape of microfractures measured with electron and optical microscopy were used. For each model solution calibrated on laboratory-measured data the sensitivity analysis of the influence of dimension and character of the microfractures on permeability of rock matrix were carried out. Results will be used in the next phase of the project for model evaluation of transport (advection-dispersion and diffusion) properties of the rock matrix. The presented work is supported by the Ministry of Industry and Trade of Czech Republic under project No. FR-TI1/367.

  6. Design and optimization of the WEST ICRH antenna front face components based on thermal and hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhaoxi, E-mail: chenzx@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Vulliez, Karl [Laboratoire d’étanchéité, DEN/DTEC/SDTC, Commissariat à l’énergie atomique et aux énergies alternatives, 2 rue James Watt, 26700 Pierrelatte (France); Ferlay, Fabien; Martinez, André; Mollard, Patrick; Hillairet, Julien; Doceul, Louis; Bernard, Jean-Michel; Larroque, Sébastien; Helou, Walid [CEA, IRFM, F-13108, Saint-Paul-Lez-Durance (France); Song, Yuntao; Yang, Qingxi; Wang, Yongsheng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-05-15

    Highlights: • Three ICRH antennas are designed to realize continuous-wave operation. • Fully active cooling structure is designed which takes the balance of structure safety and cooling performance. • High cooling efficiency is achieved for the current cooling circuit design based on the thermal-hydraulic simulation. - Abstract: The WEST (Tungsten (W) Environment in Steady-state Tokamak) is an upgrade of Tore-Supra (TS) which aims it into an X-point magnetic configuration tokamak equipped with an actively cooled tungsten divertor. To be a platform of ITER technologies of high heat flux components testing, three sets of Ion Cyclotron Resonant Heating (ICRH) antennas have been designed to inject 9 MW during 30 s or 3 MW during 1000 s. The antenna design is based on a load resilient prototype successfully tested in Tore Supra in 2007. In order to allow continuous-wave (CW) operations, the mechanical design of the WEST ICRH antenna is emphasized on its cooling performances by designing fully active cooling structure. Two kinds of cooling water loops are used, with temperature and pressure of 70 °C/30 bar and 25 °C/5.2 bar, respectively. The hot water loop is used for the Faraday screen (FS) and the housing box (HB), while the cold water loop is used for the straps, the matching capacitors and the impedance transformer. To enhance the heat removal ability and control the pressure drop, the cooling channels in the FS and HB are drilled directly and parallel connected as much as possible. By performing the hydraulic–thermal analysis, the lack of cooling efficiency was found in the front face of lateral collector where 1 MW/m{sup 2} is imposed and fluid dead zones were found in some of the bars. After optimization, the cooling performance of the cooling circuit increased significantly. With a mass flow rate of 2.5 kg/s, the total pressure drop is 3.1 bar, and the peak temperatures on the FS and HB are 500 °C and 261 °C, respectively. Besides, no cavitation is

  7. YZC28-200液压机主液压缸泄漏故障分析及其改进%Analysis of the Main Hydraulic Cylinder Leakage Fault of YZC28-200 Hydraulic Press and Relevant Improvement

    Institute of Scientific and Technical Information of China (English)

    赵小飞; 周淑红

    2011-01-01

    The cause that over low compression rate of the O ring of the main hydraulic cylinder resulted in the main hydraulic cylinder leakage of YZC28-200 hydraulic press is analyzed. The addition of a trench to the plunger end has solved the leakage problem, which ensures the normal operation of the improved hydraulic press.%分析了YZC28—200液压机主液压缸发生泄漏的原因,其是由主液压缸O形密封圈压缩率过小所致。采用在柱塞端部新增沟槽的方法解决了这一泄漏问题,改进后液压机工作正常。

  8. A maximum likelihood estimator for bedrock fracture transmissivities and its application to the analysis and design of borehole hydraulic tests

    Science.gov (United States)

    West, Anthony C. F.; Novakowski, Kent S.; Gazor, Saeed

    2006-06-01

    We propose a new method to estimate the transmissivities of bedrock fractures from transmissivities measured in intervals of fixed length along a borehole. We define the scale of a fracture set by the inverse of the density of the Poisson point process assumed to represent their locations along the borehole wall, and we assume a lognormal distribution for their transmissivities. The parameters of the latter distribution are estimated by maximizing the likelihood of a left-censored subset of the data where the degree of censorship depends on the scale of the considered fracture set. We applied the method to sets of interval transmissivities simulated by summing random fracture transmissivities drawn from a specified population. We found the estimated distributions compared well to the transmissivity distributions of similarly scaled subsets of the most transmissive fractures from among the specified population. Estimation accuracy was most sensitive to the variance in the transmissivities of the fracture population. Using the proposed method, we estimated the transmissivities of fractures at increasing scale from hydraulic test data collected at a fixed scale in Smithville, Ontario, Canada. This is an important advancement since the resultant curves of transmissivity parameters versus fracture set scale would only previously have been obtainable from hydraulic tests conducted with increasing test interval length and with degrading equipment precision. Finally, on the basis of the properties of the proposed method, we propose guidelines for the design of fixed interval length hydraulic testing programs that require minimal prior knowledge of the rock.

  9. Thermal-hydraulic analysis of NSSS and containment response during extended station blackout for Maanshan PWR plant

    Energy Technology Data Exchange (ETDEWEB)

    Yuann, Yng-Ruey, E-mail: ryyuann@iner.gov.tw; Hsu, Keng-Hsien, E-mail: hardlycampus@iner.gov.tw; Lin, Chin-Tsu, E-mail: jtling@iner.gov.tw

    2015-07-15

    Highlights: • Calculate NSSS and containment transient response during extended SBO of 24 h. • RELAP5-3D and GOTHIC models are developed for Maanshan PWR plant. • Reactor coolant pump seal leakage is specifically modeled for each loop. • Analyses are performed with and without secondary-side depressurization, respectively. • Considering different total available time for turbine driven auxiliary feedwater system. - Abstract: A thermal-hydraulic analysis has been performed with respect to the response of the nuclear steam supply system (NSSS) and the containment during an extended station blackout (SBO) duration of 24 h in Maanshan PWR plant. Maanshan plant is a Westinghouse three-loop PWR design with rated core thermal power of 2822 MWt. The analyses in the NSSS and the containment are based on the RELAP5-3D and GOTHIC models, respectively. Important design features of the plant in response to SBO are considered in the respective models, e.g., the steam generator PORVs, turbine driven auxiliary feedwater system (TDAFWS), accumulators, reactor coolant pump (RCP) seal design, various heat structures in the containment, etc. In the analysis it is assumed that the shaft seal in each RCP failed due to loss of seal cooling and the RCS fluid flows to the containment directly. Some parameters calculated from the RELPA5-3D model are input to the containment GOTHIC model, including the RCS average temperature and the RCP seal leakage flow and enthalpy. The RCS average temperature is used to drive the sensible heat transfer to the containment. It is found that the severity of the event depends mainly on whether the secondary side is depressurized or not. If the secondary side is depressurized in time (within 1 h after SBO) and the TDAFWS is available greater than 19 h, then the reactor core will be covered with water throughout the SBO duration, which ensures the integrity of the reactor core. On the contrary, if the secondary side is not depressurized, then the RCS

  10. Electro Hydraulic Hitch Control

    DEFF Research Database (Denmark)

    Hansen, M. R.; Andersen, T. O.; Nielsen, B.

    2003-01-01

    system for agricultural applications and driving for transportation. During tranport phases, the lack of suspension causes the vehicle to bounce and pitch, and makes it difficalt to control. Many systems have been proposed to cope with the oscillatory behavior, and different solutions exist. Common......This paper present and discusses R&D results on electro hydraulic hitch control for off-road vehicle, in particular active damping of oscillation occuring on tractors. The research deals with analysis and control of the oscillations occuring on tractors which are design without any susspection...... for most of the systems are that they operate on the hydrailc actuators generally providing the motive forces for moving the implement and/or attachment, typically a plough. The basic idea and physical working principle are to use the implement, moveable relative to the vehicle, as a damper mass. The paper...

  11. Integrating hydraulic equivalent sections into a hydraulic geometry study

    Science.gov (United States)

    Jia, Yanhong; Yi, Yujun; Li, Zhiwei; Wang, Zhaoyin; Zheng, Xiangmin

    2017-09-01

    Hydraulic geometry (HG) is an important geomorphic concept that has played an indispensable role in hydrological analyses, physical studies of streams, ecosystem and aquatic habitat studies, and sedimentology research. More than 60 years after Leopold and Maddock (1953) first introduced the concept of HG, researchers have still not uncovered the physical principles underlying HG behavior. One impediment is the complexity of the natural river cross section. The current study presents a new way to simplify the cross section, namely, the hydraulic equivalent section, which is generalized from the cross section in the ;gradually varied flow of an alluvial river; (GVFAR) and features hydrodynamic properties and bed-building laws similar to those of the GVFAR. Energy balance was used to derive the stage Z-discharge Q relationship in the GVFAR. The GVFAR in the Songhua River and the Yangtze River were selected as examples. The data, including measured discharge, river width, water stage, water depth, wet area, and cross section, were collected from the hydrological yearbooks of typical hydrological stations on the Songhua River and the Yangtze River from 1955 to 1987. The relationships between stage Z-discharge Q and cross-sectional area A-stage Z at various stations were analyzed, and ;at-a-station hydraulic geometry; (AHG) relationships were obtained in power-law forms. Based on derived results and observational data analysis, the Z-Q and Z-A relationships of AHG were similar to rectangular weir flows, thus the cross section of the GVFAR was generalized as a compound rectangular, hydraulic equivalent cross section. As to bed-building characteristics, the bankfull discharge method and the stage-discharge-relation method were used to calculate the dominant variables of the alluvial river. This hydraulic equivalent section has the same Z-Q relation, Z-A relation, dominant discharge, dominant river width, and dominant water depth as the cross section in the GVFAR. With the

  12. VERTICAL VEGETATION STRUCTURE ANALYSIS AND HYDRAULIC ROUGHNESS DETERMINATION USING DENSE ALS POINT CLOUD DATA - A VOXEL BASED APPROACH

    Directory of Open Access Journals (Sweden)

    M. Vetter

    2012-09-01

    Full Text Available In this contribution the complexity of the vertical vegetation structure, based on dense airborne laser scanning (ALS point cloud data (25 echoes/m2 , is analyzed to calculate vegetation roughness for hydraulic applications. Using the original 3D ALS point cloud, three levels of abstractions are derived (cells, voxels and connections to analyze ALS data based on a 1×1 m2 raster over the whole data set. A voxel structure is used to count the echoes in predefined detrended height levels within each cell. In general, it is assumed that the number of voxels containing echoes is an indicator for elevated objects and consequently for increased roughness. Neighboring voxels containing at least one data point are merged together to connections. An additional height threshold is applied to connect vertical neighboring voxels with a certain distance in between. Thus, the connections indicate continuous vegetation structures. The height of the surface near or lowest connection is an indicator for hydrodynamic roughness coefficients. For cells, voxels and connections the laser echoes are counted within the structure and various statistical measures are calculated. Based on these derived statistical parameters a rule-based classification is developed by applying a decision tree to assess vegetation types. Roughness coefficient values such as Manning's n are estimated, which are used as input for 2D hydrodynamic-numerical modeling. The estimated Manning’s values from the ALS point cloud are compared with a traditional Manning's map. Finally, the effect of these two different Manning's n maps as input on the 2D hydraulics are quantified by calculating a height difference model of the inundated depth maps. The results show the large potential of using the entire vertical vegetation structure for hydraulic roughness estimation.

  13. 心墙水力劈裂与孔压关系的探讨%The analysis of the relationship between hydraulic fracture and the pore pressure

    Institute of Scientific and Technical Information of China (English)

    张红日; 党发宁; 兰素恋; 魏见海

    2012-01-01

    基于Biot固结理论的有效应力二维数值模拟方法,研究了堆石坝的粘土心墙水力劈裂过程中孔隙水压力的变化.分析了坝体竣工期粘土心墙中的拱效应,探讨了从竣工固结到蓄水过程和稳定渗流期粘土心墙中孔隙水压力的变化分布特点,并对心墙发生水力劈裂的可能性进行判断.研究结果表明:堆石坝粘土心墙内部孔隙水压力梯度的模拟分析能更加合理地解释水力劈裂发生与蓄水速度和心墙低渗透性的关系,因此,分析考虑水位上升过程中粘土心墙内孔隙水压力分布情况是研究心墙水力劈裂发生机理的重点.%Based on the consolidation theory of Biot effective stress analysis method, two-dimensional numerical simulation is adopted to study the dam from the completion of the dam to the clay core run-time pore pressure changes in the process. Arching effect of the completion period and the changes with the completion of the process of consolidation on the stability of the water flow in the pore water pressure distribution are analyzed based on the analysis of clay core dams, the mechanism of hydraulic fracture on the basis of the core wall of the dam occurred in the hydraulic is determined with the possibility of splitting. The results show that the simulation of gradient internal pore water pressure for the clay core of rockfilled dam core can reasonably explain the occurrence of hydraulic fracturing with water speed, and the low permeability of the core wall has great effects. When hydraulic fracture occurred with the core wall mechanism of the core wall, the distribution of clay pore water pressure must be taken into account.

  14. Analysis and control of hydraulic support stability in fully-mechanized longwall face to the dip with great mining height

    Institute of Scientific and Technical Information of China (English)

    HUA Xin-zhu; WANG Jia-chen

    2008-01-01

    The working condition of the hydraulic support in working face can be dividedinto three kinds of situations in the following: roof fall and collapse with cavity, advancingsupport and supporting. Took single support with four-pole in Iongwall face to the dip asresearch object, control method was studied to avoid support instability in three situationsmentioned above. Based on these researches, the major factors of influencing on supportstability and its controlling measures were put forward. According to specific conditions ofworking face 1215(3), which is fully-mechanized and Iongwall face to the dip with greatmining height in Zhangji Coal Mine, Huainan Mining Group, the effective measures wastaken to control supports stability.

  15. Simulation Analysis of Working Device of Hydraulic Excavator%液压挖掘机工作装置的仿真分析

    Institute of Scientific and Technical Information of China (English)

    蔡琦; 杨建鸣

    2014-01-01

    为了实现液压挖掘机工作装置的优化,找出工作时的特殊尺寸,采用 Pro/E 建立三维模型并与ADAMS虚拟样机结合仿真分析。根据动臂、斗杆、铲斗三个液压缸的运动状态,得到铲斗齿尖X方向和 Y方向的位移曲线图。通过与原设计值的比较为进一步的分析提供设计的基础。%In order to optimize the implementation of the working device of hydraulic excavator, find the special size, through Pro/E, this paper built 3D model and made simulation analysis combined with the ADAMS virtual prototype . According to the motion state of boom , bucket rod , and three hydraulic cylinders , displacement curves is obtained bucket tip X direction and Y direction . Design basis for further analysis is provided by comparing with the original design value .

  16. Neutronic and Thermal-Hydraulic Safety Analysis for the Optimization of the Uranium Foil Target in the RSG-GAS Reactor

    Directory of Open Access Journals (Sweden)

    S. Pinem

    2016-12-01

    Full Text Available The G. A. Siwabessy Multipurpose Reactor (Reaktor Serba Guna G.A. Siwabessy, RSG-GAS has an average thermal neutron flux of 2×1014 neutron/(cm2 sec at the nominal power of 30 MW. With such a high thermal neutron flux, the reactor is suitable for the production of Mo-99 which is widely used as a medical diagnostic radioisotope. This paper describes a safety analysis to determine the optimum LEU foil target by using a coupled neutronic and thermal-hydraulic code, MTR-DYN. The code has been developed based on the three-dimensional multigroup neutron diffusion theory. The best estimated results can be achieved by using a coupled neutronic and thermal-hydraulic code. The calculation results show that the optimum LEU foil target is 54 g corresponding to the reactivity change of less than the limit value of 500 pcm. From the safety analysis for the case when the primary flow rate decreased by 15% from its nominal value, it was found that the peak temperatures of the coolant and cladding are 69.5°C and 127.9°C, respectively. It can be concluded that the optimum LEU foil target can be irradiated safely without exceeding the limit value.

  17. Thermally Actuated Hydraulic Pumps

    Science.gov (United States)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  18. 管端加厚液压机振动分析及消除措施%Vibration Analysis and Eliminating Measures of Pipe End Thickening Hydraulic Press

    Institute of Scientific and Technical Information of China (English)

    王秀鑫; 刘志奇; 张军丽; 丁浩伦

    2015-01-01

    This paper describes the oil drill pipe hydraulic which for the processing of oil drill pipe ends. For this hydraulic machine with the poor stable performance, commutation unloading big shock and vibration problems that caused by the large inertia movement, the high pres-sure and large flow. Through in-depth analysis of its system working principle and working vibration phenomena, found that the filling valve not fully discharge pressure and inadequate relief delay, causing the main reason for vibration impact and poor performance stability. Finally, a reasonable and effective technical solutions to address the impact of the hydraulic cylinder vibration generated when the relief return, im-prove performance and stability of its work.%该文介绍了用于石油钻杆加工的管端加厚液压机.针对该液压机流量大、压力高和运动惯量大所造成的稳定性能差、换向卸荷振动冲击大等问题,通过对其系统原理与工作振动现象进行深入的分析,发现充液阀无法充分卸压和卸压延时不足是其产生振动冲击、造成稳定性能差的主要原因;最后提出了合理有效的技术方案,解决了该液压机油缸卸压回程时产生的振动冲击,提高了其工作时稳定性能.

  19. Trends in hydraulic fracturing distributions and treatment fluids, additives, proppants, and water volumes applied to wells drilled in the United States from 1947 through 2010: data analysis and comparison to the literature

    Science.gov (United States)

    Gallegos, Tanya J.; Varela, Brian A.

    2015-01-01

    Hydraulic fracturing is presently the primary stimulation technique for oil and gas production in low-permeability, unconventional reservoirs. Comprehensive, published, and publicly available information regarding the extent, location, and character of hydraulic fracturing in the United States is scarce. This national spatial and temporal analysis of data on nearly 1 million hydraulically fractured wells and 1.8 million fracturing treatment records from 1947 through 2010 (aggregated in Data Series 868) is used to identify hydraulic fracturing trends in drilling methods and use of proppants, treatment fluids, additives, and water in the United States. These trends are compared to the literature in an effort to establish a common understanding of the differences in drilling methods, treatment fluids, and chemical additives and of how the newer technology has affected the water use volumes and areal distribution of hydraulic fracturing. Historically, Texas has had the highest number of records of hydraulic fracturing treatments and associated wells in the United States documented in the datasets described herein. Water-intensive horizontal/directional drilling has also increased from 6 percent of new hydraulically fractured wells drilled in the United States in 2000 to 42 percent of new wells drilled in 2010. Increases in horizontal drilling also coincided with the emergence of water-based “slick water” fracturing fluids. As such, the most current hydraulic fracturing materials and methods are notably different from those used in previous decades and have contributed to the development of previously inaccessible unconventional oil and gas production target areas, namely in shale and tight-sand reservoirs. Publicly available derivative datasets and locations developed from these analyses are described.

  20. 基于FluidSIM-Hydraulic的注塑机液压回路控制分析%Control Analysis for Hydraulic Loop of Plastic Injection Molding Machine Based on FluidSIM-Hydraulic

    Institute of Scientific and Technical Information of China (English)

    叶金玲; 周钦河; 黄诚

    2015-01-01

    Hydraulic control system of plastic injection molding machine was designed using FluidSIM⁃Hydraulic software. The structure and working principle of the plastic injection molding machine were introduced, its hydraulic loop and electric loop were de⁃signed and optimized. The plastic injection molding machine has gained good affection in actual production.%基于FluidSIM⁃Hydraulic软件对注塑机液压回路控制系统进行分析。介绍了注塑机的结构原理,并优化设计了液压回路及电气控制系统,通过二者有效的结合成功地将模拟仿真后的模型应用到了实际生产中,取得了良好的效果。

  1. Nonlinear dynamic analysis and robust controller design for Francis hydraulic turbine regulating system with a straight-tube surge tank

    Science.gov (United States)

    Liang, Ji; Yuan, Xiaohui; Yuan, Yanbin; Chen, Zhihuan; Li, Yuanzheng

    2017-02-01

    The safety and stability of hydraulic turbine regulating system (HTRS) in hydropower plants become increasingly important since the rapid development and the broad application of hydro energy technology. In this paper, a novel mathematical model of Francis hydraulic turbine regulating system with a straight-tube surge tank based on a few state-space equations is introduced to study the dynamic behaviors of the HTRS system, where the existence of possible unstable oscillations of this model is studied extensively and presented in the forms of the bifurcation diagram, time waveform plot, phase trajectories, and power spectrum. To eliminate these undesirable behaviors, a specified fuzzy sliding mode controller is designed. In this hybrid controller, the sliding mode control law makes full use of the proposed model to guarantee the robust control in the presence of system uncertainties, while the fuzzy system is applied to approximate the proper gains of the switching control in sliding mode technique to reduce the chattering effect, and particle swarm optimization is developed to search the optimal gains of the controller. Numerical simulations are presented to verify the effectiveness of the designed controller, and the results show that the performances of the nonlinear HTRS system assisted with the proposed controller is much better than that with the commonly used optimal PID controller.

  2. Analysis of Tidal DC Resistivity Time Series for Periodic Saltwater Mixing Patterns and Determination of Hydraulic Ground Properties

    Science.gov (United States)

    Sutter, E. M.; Ingham, M.

    2016-12-01

    Saline intrusion research using geoelectrical time-lapse monitoring, is often directed towards imaging the saltwater-freshwater boundary and the amount of seawater mixing within a coastal aquifer. However, these time series can contain additional information about subsurface hydrologic properties like hydraulic conductivity and permeability which are crucial elements in coastal groundwater management. In this study, DC resistivity time series from tidal time-lapse monitoring surveys of a shallow coastal sand and gravel aquifer in New Zealand have been analysed for recurring patterns of percentage seawater mixing in different portions of the aquifer. The results show a distinctly different behaviour of percentage seawater change with time for several horizontal locations along two profile lines with varying depth. In addition, the geoelectric time series have been cross-correlated with tidal stage data approximated near the survey location in order to find portions of the aquifer that exhibit different time lags with respect to a diurnal tidal cycle. First results yield a remarkably similar picture to resistivity ratios obtained between high and low tide inversion models of the DC resistivity time series both at different locations and for different seasons. The two methods indicate a correlation between rising and falling tides and the resistivity changes observed from geoelectrical monitoring studies .This may be used to distinguish between more or less hydraulically conductive portions of a coastal aquifer.

  3. Dynamic thermal-hydraulic modeling and stack flow pattern analysis for all-vanadium redox flow battery

    Science.gov (United States)

    Wei, Zhongbao; Zhao, Jiyun; Skyllas-Kazacos, Maria; Xiong, Binyu

    2014-08-01

    The present study focuses on dynamic thermal-hydraulic modeling for the all-vanadium flow battery and investigations on the impact of stack flow patterns on battery performance. The inhomogeneity of flow rate distribution and reversible entropic heat are included in the thermal-hydraulic model. The electrolyte temperature in tanks is modeled with the finite element modeling (FEM) technique considering the possible non-uniform distribution of electrolyte temperature. Results show that the established model predicts electrolyte temperature accurately under various ambient temperatures and current densities. Significant temperature gradients exist in the battery system at extremely low flow rates, while the electrolyte temperature tends to be the same in different components under relatively high flow rates. Three stack flow patterns including flow without distribution channels and two cases of flow with distribution channels are compared to investigate their effects on battery performance. It is found that the flow rates are not uniformly distributed in cells especially when the stack is not well designed, while adding distribution channels alleviates the inhomogeneous phenomenon. By comparing the three flow patterns, it is found that the serpentine-parallel pattern is preferable and effectively controls the uniformity of flow rates, pressure drop and electrolyte temperature all at expected levels.

  4. Comparison of four methods to assess hydraulic conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Benson, C.H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Civil and Environmental Engineering; Gunter, J.A. [Gunter (John A.), Round Rock, TX (United States); Boutwell, G.P. [STE, Inc., Baton Rouge, LA (United States); Trautwein, S.J. [Trautwein Soil Testing Equipment Co., Houston, TX (United States); Berzanskis, P.H. [Hoechst-Celanese, Inc., Pampa, TX (United States)

    1997-10-01

    A hydraulic conductivity assessment that was conducted on four test pads constructed to the same specifications with soil from the same source by four different contractors is described. The test pads had distinctly different field hydraulic conductivities, even though they were constructed with similar soil, to similar compaction conditions, and with similar machinery. Adequate hydration time was key in achieving low field hydraulic conductivity. More extensive processing was another factor responsible for low field hydraulic conductivity. Four different test methods were used to assess the hydraulic conductivity of each test pad: (1) sealed double-ring infiltrometers (SDRIs); (2) two-stage borehole permeameters; (3) laboratory hydraulic conductivity tests on large block specimens; and (4) laboratory hydraulic conductivity tests on small specimens collected in thin-wall sampling tubes. The tests were conducted independently by each of the writers. After the tests were completed, the results were submitted and compared. Analysis of the test results show that the three large-scale test methods generally yield similar hydraulic conductivities. For two of the test pads, however, the hydraulic conductivities of the specimens collected in sampling tubes were significantly lower than the field hydraulic conductivities. Both of these test pads had high field hydraulic conductivity. Thus, there is little value in using small specimens to assess field hydraulic conductivity.

  5. Handbook of hydraulic fluid technology

    CERN Document Server

    Totten, George E

    2011-01-01

    ""The Handbook of Hydraulic Fluid Technology"" serves as the foremost resource for designing hydraulic systems and for selecting hydraulic fluids used in engineering applications. Featuring new illustrations, data tables, as well as practical examples, this second edition is updated with essential information on the latest hydraulic fluids and testing methods. The detailed text facilitates unparalleled understanding of the total hydraulic system, including important hardware, fluid properties, and hydraulic lubricants. Written by worldwide experts, the book also offers a rigorous overview of h

  6. Morphostructural analysis applied for susceptibility assessment of environmental degradation by linear hydraulic erosions in the countryside of São Paulo State

    Directory of Open Access Journals (Sweden)

    Márcia Sayuri Morinaga

    2015-03-01

    Full Text Available The Westside of the State of São Paulo, in Brazil, is known by its strong agricultural vocation and erosion problems. The natural conditions and the occupation dynamic were propitious to the emergence of this kind of environmental degradation in the soil, resulting in loss of usable area, siltation of water bodies, and demands on infrastructure. Linear hydraulic erosions, such as gullies, have as forming factors the climate, soil, land slope, and usage. In order to enrich the knowledge on this subject, the present work aimed at an analysis of the ductile geologic deformations, and subordinate brittle, and its relations to the accelerated linear hydraulic erosions in the region of Marília, in the State of São Paulo, through the interpretation of the elements of drainage and remote sensing images. In general, there was correspondence between the areas potentially susceptible to erosion diagnosed by morphostructural mapping and topography, with the current state of degradation that is a result from a century of exploitation of the land. The morphostructural and topographic analyses bring the understanding of subsurface water dynamics, and can be applied to territorial planning.

  7. A coupled hydrological-hydraulic flood inundation model calibrated using post-event measurements and integrated uncertainty analysis in a poorly gauged Mediterranean basin

    Science.gov (United States)

    Hdeib, Rouya; Abdallah, Chadi; Moussa, Roger; Colin, Francois

    2017-04-01

    Developing flood inundation maps of defined exceedance probabilities is required to provide information on the flood hazard and the associated risk. A methodology has been developed to model flood inundation in poorly gauged basins, where reliable information on the hydrological characteristics of floods are uncertain and partially captured by the traditional rain-gauge networks. Flood inundation is performed through coupling a hydrological rainfall-runoff (RR) model (HEC-HMS) with a hydraulic model (HEC-RAS). The RR model is calibrated against the January 2013 flood event in the Awali River basin, Lebanon (300 km2), whose flood peak discharge was estimated by post-event measurements. The resulting flows of the RR model are defined as boundary conditions of the hydraulic model, which is run to generate the corresponding water surface profiles and calibrated against 20 post-event surveyed cross sections after the January-2013 flood event. An uncertainty analysis is performed to assess the results of the models. Consequently, the coupled flood inundation model is simulated with design storms and flood inundation maps are generated of defined exceedance probabilities. The peak discharges estimated by the simulated RR model were in close agreement with the results from different empirical and statistical methods. This methodology can be extended to other poorly gauged basins facing common stage-gauge failure or characterized by floods with a stage exceeding the gauge measurement level, or higher than that defined by the rating curve.

  8. Innovative and Advanced Coupled Neutron Transport and Thermal Hydraulic Method (Tool) for the Design, Analysis and Optimization of VHTR/NGNP Prismatic Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rahnema, Farzad; Garimeela, Srinivas; Ougouag, Abderrafi; Zhang, Dingkang

    2013-11-29

    This project will develop a 3D, advanced coarse mesh transport method (COMET-Hex) for steady- state and transient analyses in advanced very high-temperature reactors (VHTRs). The project will lead to a coupled neutronics and thermal hydraulic (T/H) core simulation tool with fuel depletion capability. The computational tool will be developed in hexagonal geometry, based solely on transport theory without (spatial) homogenization in complicated 3D geometries. In addition to the hexagonal geometry extension, collaborators will concurrently develop three additional capabilities to increase the code’s versatility as an advanced and robust core simulator for VHTRs. First, the project team will develop and implement a depletion method within the core simulator. Second, the team will develop an elementary (proof-of-concept) 1D time-dependent transport method for efficient transient analyses. The third capability will be a thermal hydraulic method coupled to the neutronics transport module for VHTRs. Current advancements in reactor core design are pushing VHTRs toward greater core and fuel heterogeneity to pursue higher burn-ups, efficiently transmute used fuel, maximize energy production, and improve plant economics and safety. As a result, an accurate and efficient neutron transport, with capabilities to treat heterogeneous burnable poison effects, is highly desirable for predicting VHTR neutronics performance. This research project’s primary objective is to advance the state of the art for reactor analysis.

  9. The Use of Hydraulic Head and Atmospheric Tritium to Identify Presence of Fractures in Clayey Aquitards: Numerical Analysis

    Science.gov (United States)

    Farah, E. A.; Parker, B. L.; Cherry, J. A.

    2003-12-01

    Surficial clayey aquitards can provide underlying aquifers with strong protection from contamination if vertically connected open fractures are absent. Hence, methods are needed to identify such contaminant pathways. An existing two-dimensional model for steady-state groundwater flow and solute transport (FRACTRAN) was used for cross-sectional simulations to assess the prospects for using field measurements of hydraulic head and atmospheric (i.e. bomb) tritium in surficial aquitards to determine presence and nature of hydraulically connected fractures. Simulations for a 15-m thick horizontal aquitard, with shallow water table and downward groundwater flow, show that field measurements of head and tritium at points appropriately spaced along a horizontal line at the lower part of the aquitard provide unique insight since they offer the highest chance for detecting vertical fractures. Simulations represented sets of predominant vertical and horizontal fractures of uniform aperture (25 æm) and variable length. The simulations focused on fracture-network features assigned based on the literature of field investigations. The horizontal profiles show peaks and troughs for head, and always peaks for tritium concentrations at fracture localities. Use of only head or tritium alone may locate fractures, but may not discover whether each fracture is connected to the ground surface or aquifer top, or both. On the other hand, the coupled patterns of head and tritium can be used to identify fractures more accurately. For example, a head trough and a tritium sharp peak represent a fully penetrating fracture, while a head peak and a rounded-tip tritium peak represent a partially penetrating fracture. Moreover, these two are easily differentiated from an embedded fracture that is represented by a relatively small head trough and a short sharp tritium peak. The method of monitoring along a horizontal line was applied to the conceptual 15-m thick aquitard imitating horizontal

  10. Stochastic analysis of the efficiency of coupled hydraulic-physical barriers to contain solute plumes in highly heterogeneous aquifers

    Science.gov (United States)

    Pedretti, Daniele; Masetti, Marco; Beretta, Giovanni Pietro

    2017-10-01

    The expected long-term efficiency of vertical cutoff walls coupled to pump-and-treat technologies to contain solute plumes in highly heterogeneous aquifers was analyzed. A well-characterized case study in Italy, with a hydrogeological database of 471 results from hydraulic tests performed on the aquifer and the surrounding 2-km-long cement-bentonite (CB) walls, was used to build a conceptual model and assess a representative remediation site adopting coupled technologies. In the studied area, the aquifer hydraulic conductivity Ka [m/d] is log-normally distributed with mean E (Ya) = 0.32 , variance σYa2 = 6.36 (Ya = lnKa) and spatial correlation well described by an exponential isotropic variogram with integral scale less than 1/12 the domain size. The hardened CB wall's hydraulic conductivity, Kw [m/d], displayed strong scaling effects and a lognormal distribution with mean E (Yw) = - 3.43 and σYw2 = 0.53 (Yw =log10Kw). No spatial correlation of Kw was detected. Using this information, conservative transport was simulated across a CB wall in spatially correlated 1-D random Ya fields within a numerical Monte Carlo framework. Multiple scenarios representing different Kw values were tested. A continuous solute source with known concentration and deterministic drains' discharge rates were assumed. The efficiency of the confining system was measured by the probability of exceedance of concentration over a threshold (C∗) at a control section 10 years after the initial solute release. It was found that the stronger the aquifer heterogeneity, the higher the expected efficiency of the confinement system and the lower the likelihood of aquifer pollution. This behavior can be explained because, for the analyzed aquifer conditions, a lower Ka generates more pronounced drawdown in the water table in the proximity of the drain and consequently a higher advective flux towards the confined area, which counteracts diffusive fluxes across the walls. Thus, a higher σYa2 results

  11. Evaluation of TASS/SMR with steady state analysis of high temperature/high pressure thermal-hydraulic test facility (VISTA)

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Dong Ju; Choi, Yong Won; Park, Chang Hwan; Lee, Un Chul [Seoul National University, Seoul (Korea, Republic of); Hwang, Young Dong; Lee, Kyu Hyung; Kim, Hee Chul [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2005-07-01

    The TASS/SMR code is the revised version of the TASS code, which is the result of code development effort of KAERI since 1997, for safety analysis of NPP coolant system. Lately, it is scheduled to evaluate thermal-hydraulic phenomena during several transient periods of SMART-P with TASS/SMR. To establish the pertinence of the calculative results of TASS/SMR, there should be a process of validation and verification of TASS/SMR. The objective of this study is validating the numerical capability and reliability of TASS/SMR with steady state analysis of VISTA (Experimental Verification by Integral Simulation of Transient and Accidents) that was designed to simulate SMART-P.

  12. Thermal-Hydraulic Analysis of PDS-XADS Spallation Target%PDS-XADS散裂靶热工水力分析

    Institute of Scientific and Technical Information of China (English)

    艾尼塞; 俞冀阳; 杨永伟

    2013-01-01

    本文对小型加速器驱动的次临界系统(ADS)-PDS-XADS散裂靶进行了热工水力分析.分析的XADS型实验堆基于欧洲PDS-XADS实验项目的设计,使用铅铋合金(LBE)作为冷却剂.散裂靶是ADS的核心部件之一,用以确保反应堆功率维持在指定水平.本文利用计算流体力学软件ANSYSCFX 11.0对散裂靶的下部区域进行热工水力分析.分析采用稳态计算、剪切应力输运(SST)湍流模型,在壁面边界条件处采用自动壁面函数法,针对不同的散裂靶设计进行计算流体力学(CFD)分析,最后根据散裂靶设计限值选择最优设计方案.%The thermal-hydraulic analysis of PDS-XADS spallation target for 80 MW reactor core power was studied. PDS-XADS is a small scale experimental accelerator driven sub-critical system (ADS). The analysis presented in this paper was based on lead bismuth eutectic (LBE) cooled XADS type experimental reactors, which are the designs of the European experimental PDS-XADS project. The spallation target is a very important component of ADS because it is responsible to keep the reactor power at the required level by spallation reactions. A high rate of neutron production by spallation reaction creates the problem of decay heat cooling. LBE flow is properly cooled, but the window is not properly cooled because of the stagnation point in the pole of the window. It would be very difficult to keep the window temperature below the design limit, which is an important design limit challenge. Thermal-hydraulic analysis of LBE spallation target was carried out by using ANSYS CFX 11.0. The detailed CFD analysis, which reveals thermal and hydraulic conditions in the window and spallation region, was carried out for different spallation target designs. Finally, the spallation target design limit was used to choose the best design.

  13. Importance of physical and hydraulic characteristics to unionid mussels: A retrospective analysis in a reach of large river

    Science.gov (United States)

    Zigler, S.J.; Newton, T.J.; Steuer, J.J.; Bartsch, M.R.; Sauer, J.S.

    2008-01-01

    Interest in understanding physical and hydraulic factors that might drive distribution and abundance of freshwater mussels has been increasing due to their decline throughout North America. We assessed whether the spatial distribution of unionid mussels could be predicted from physical and hydraulic variables in a reach of the Upper Mississippi River. Classification and regression tree (CART) models were constructed using mussel data compiled from various sources and explanatory variables derived from GIS coverages. Prediction success of CART models for presence-absence of mussels ranged from 71 to 76% across three gears (brail, sled-dredge, and dive-quadrat) and 51% of the deviance in abundance. Models were largely driven by shear stress and substrate stability variables, but interactions with simple physical variables, especially slope, were also important. Geospatial models, which were based on tree model results, predicted few mussels in poorly connected backwater areas (e.g., floodplain lakes) and the navigation channel, whereas main channel border areas with high geomorphic complexity (e.g., river bends, islands, side channel entrances) and small side channels were typically favorable to mussels. Moreover, bootstrap aggregation of discharge-specific regression tree models of dive-quadrat data indicated that variables measured at low discharge were about 25% more predictive (PMSE = 14.8) than variables measured at median discharge (PMSE = 20.4) with high discharge (PMSE = 17.1) variables intermediate. This result suggests that episodic events such as droughts and floods were important in structuring mussel distributions. Although the substantial mussel and ancillary data in our study reach is unusual, our approach to develop exploratory statistical and geospatial models should be useful even when data are more limited. ?? 2007 Springer Science+Business Media B.V.

  14. Simulation Analysis of ZY7200/18/40 Hydraulic Support Based on ANSYS%基于ANSYS的ZY7200/18/40液压支架仿真分析

    Institute of Scientific and Technical Information of China (English)

    商献伟

    2015-01-01

    With ZY72000/18/40 two column screen type hydraulic support as the object, using a combination of Pro/E and ANSYS, to simulate different conditions imposed by the combination of pad hydraulic support force as boundary conditions of processing, and the pipe as the external force imposed on the base of the top beam and forces applied to the bracket, the contact method of dealing with the structure of the hydraulic support contact problem, under the five conditions of hydraulic support in finite element strength analysis, draw the support in the law of stress and strain under different working conditions, find the location of the hydraulic support are prone to damage, provides a theoretical basis for the design of the hydraulic support, and this method can be applied to the hydraulic support design phase.%以ZY72000/18/40型两柱掩护式液压支架为对象,利用Pro/E与ANSYS相结合的方式,把模拟不同工况的组合垫块所施加给液压支架的力作为边界条件,并将立柱施加给顶梁和底座的作用力作为外力施加到支架上,采用接触法处理液压支架结构中存在的接触问题,在5种工况下对液压支架进行有限元强度分析,得出了支架在不同工况下的应力及应变规律,找到了液压支架容易产生损坏的位置,为液压支架的设计改进提供了理论依据。

  15. South Davis Sewer District Pump Station Hydraulic Capacity Evaluation

    OpenAIRE

    Dixon, James W

    2011-01-01

    In 2010, South Davis Sewer District (SDSD) determined that possible hydraulic problems existed in their various pump stations operating within their treatment plants. A hydraulic analysis was conducted for the pump stations to diagnose the problems and provide possible alternative solutions. This analysis was conducted by using hydraulic minor loss equations to determine the amount of flow that the pumps were capable of producing and then comparing those results to the required demands in the...

  16. Uncertainty analysis of a combined Artificial Neural Network - Fuzzy logic - Kriging system for spatial and temporal simulation of Hydraulic Head.

    Science.gov (United States)

    Tapoglou, Evdokia; Karatzas, George P.; Trichakis, Ioannis C.; Varouchakis, Emmanouil A.

    2015-04-01

    The purpose of this study is to evaluate the uncertainty, using various methodologies, in a combined Artificial Neural Network (ANN) - Fuzzy logic - Kriging system, which can simulate spatially and temporally the hydraulic head in an aquifer. This system uses ANNs for the temporal prediction of hydraulic head in various locations, one ANN for every location with available data, and Kriging for the spatial interpolation of ANN's results. A fuzzy logic is used for the interconnection of these two methodologies. The full description of the initial system and its functionality can be found in Tapoglou et al. (2014). Two methodologies were used for the calculation of uncertainty for the implementation of the algorithm in a study area. First, the uncertainty of Kriging parameters was examined using a Bayesian bootstrap methodology. In this case the variogram is calculated first using the traditional methodology of Ordinary Kriging. Using the parameters derived and the covariance function of the model, the covariance matrix is constructed. A common method for testing a statistical model is the use of artificial data. Normal random numbers generation is the first step in this procedure and by multiplying them by the decomposed covariance matrix, correlated random numbers (sample set) can be calculated. These random values are then fitted into a variogram and the value in an unknown location is estimated using Kriging. The distribution of the simulated values using the Kriging of different correlated random values can be used in order to derive the prediction intervals of the process. In this study 500 variograms were constructed for every time step and prediction point, using the method described above, and their results are presented as the 95th and 5th percentile of the predictions. The second methodology involved the uncertainty of ANNs training. In this case, for all the data points 300 different trainings were implemented having different training datasets each time

  17. FEMA DFIRM Hydraulic Structures

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer and accompanying attribute table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the...

  18. Constant-Pressure Hydraulic Pump

    Science.gov (United States)

    Galloway, C. W.

    1982-01-01

    Constant output pressure in gas-driven hydraulic pump would be assured in new design for gas-to-hydraulic power converter. With a force-multiplying ring attached to gas piston, expanding gas would apply constant force on hydraulic piston even though gas pressure drops. As a result, pressure of hydraulic fluid remains steady, and power output of the pump does not vary.

  19. 便携式液压打桩机现状分析%Status Analysis of Portable Hydraulic Hammers

    Institute of Scientific and Technical Information of China (English)

    张步恩; 余俊锋; 彭博

    2015-01-01

    In the flood rescue process,traditional bundle and throw wicker rock pillows, firewood pile revetment, rock?loft and other emergency technologies in emergency and rescue play significant roles. These methods require a lot of wood pipes to fasten the wicker pillows and willow branches;In highway construction project, the construction and maintenance of fences also need large amount of steel piles. So it can concluded that in a variety of rescue methods, piling is an in dispensable process.In the piling work of flood rescue,dike reinforcement before and after the flood sea?son, rivers, lakes, ponds and embankment maintenance and highway construction and maintenance, the machine in?stead of human piling operation is a technological revolution.Based on the status and principle research and review of domestic portable hammer,the technical level of domestic portable hydraulic hammers is clarified, for the view of the current shortcomings, it lies the theoretical basis for the design and development of new portable hydraulic hammers.%防洪抢险过程中,传统捆抛柳石枕、桩柴护岸、柳石楼厢等抢险技术发挥着巨大无比的作用,在这些应急抢险方法中,需要大量木桩以便固定柳枕和厢埽.在公路建设工程中,两边护栏的建设维护也需要大量钢管桩.由此可见,打桩是各种抢护方法中不可缺少的一道工序.而在抗洪抢险,汛期前后的堤防加固,维护江、湖、河、塘等堤岸以及公路建设维护的打桩作业中,由机械劳动代替人力打桩作业是一次技术性革命.本文通过对国内各类便携式打桩机现状、原理进行研究总结,明确国内便携式液压打桩机技术水平及存在的缺陷,为设计研发新型便携式液压打桩机奠定理论基础.

  20. On the hydraulic behaviour of ITER Shield Blocks #14 and #08. Computational analysis and comparison with experimental tests

    Energy Technology Data Exchange (ETDEWEB)

    Di Maio, P.A. [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo Viale delle Scienze, 90128, Palermo (Italy); Merola, M.; Mitteau, R.; Raffray, R. [ITER Organization, Route de Vinon sur Verdon, 13067 Saint Paul, Lez Durance (France); Vallone, E., E-mail: eug.vallone@gmail.com [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo Viale delle Scienze, 90128, Palermo (Italy)

    2016-11-01

    Highlights: • A benchmarking activity has been carried out focusing the attention on the cooling circuits of ITER Shield Blocks #08 and #14. • A theoretical-computational fluid-dynamic approach based on the Finite Volume Method has been followed, adopting a commercial code. • Hydraulic characteristic functions and spatial distributions of coolant mass flow rate, velocity and pressure drop have been assessed. • Results obtained have allowed code benchmarking for Blanket modules and the numerical predictions have been found to be generally lower than but quite close to the experimental results (lower than 10%). - Abstract: As a consequence of its position and functions, the ITER blanket system will be subjected to significant heat loads under nominal reference conditions. Therefore, the design of its cooling system is particularly demanding. Coolant water is distributed individually to the 440 blanket modules (BMs) through manifold piping, which makes it a highly parallelized system. The mass flow rate distribution is finely tuned to meet all operation constraints: adequate margin to burn out in the plasma facing components, even distribution of water flow among the so-called plasma-facing “fingers” of the Blanket First Wall panels, high enough water flow rate to avoid excessive water temperature in the outlet pipes, maximum allowable water velocity lower than 7 m/s in manifold pipes. Furthermore the overall pressure drop and flow rate in each BM shall be within the fixed specified design limit to avoid an unduly unbalance of cooling among the 440 modules. Analyses have to be carried out following a computational fluid-dynamic (CFD) approach based on the finite volume method and adopting a CFD commercial code to assess the thermal-hydraulic behaviour of each single circuit of the ITER blanket cooling system. This paper describes the code benchmarking needed to determine the best method to get reliable and timely results. Since experimental tests are

  1. On the importance of geological data for three-dimensional steady-state hydraulic tomography analysis at a highly heterogeneous aquifer-aquitard system

    Science.gov (United States)

    Zhao, Zhanfeng; Illman, Walter A.

    2017-01-01

    Hydraulic tomography (HT) has been shown to map subsurface heterogeneity accurately through the joint interpretation of multiple pumping tests. Previous research has shown that smooth hydraulic conductivity (K) estimates are obtained beyond where pumping/observation data are available using the geostatistical inversion approach, when the inversion begins with a homogeneous K and when data densities are not high. However, geological data are typically available through outcrops and borehole logs to provide geological variability. Therefore, we investigate the usefulness of geological data for HT analysis at a highly heterogeneous field site by: (1) comparing calibrated geological models of two different resolutions to two homogeneous and four highly parameterized geostatistical inverse models, in terms of both model calibration and validation performances as well as correspondence of estimated K values with permeameter-estimated K profiles along boreholes; and (2) using geological models as prior information for the geostatistical inversion approach. Results reveal that the simultaneous calibration of geological models to seven pumping test data yields K values that correctly reflect the general patterns of vertical distributions of permeameter-estimated K. We also find that the geostatistical inversion approach using a geological model as prior information performs better for both model calibration and validation than using a homogenous K as a prior, and more importantly, improves the correspondence of K estimates to permeameter test results along wells, as well as in preserving geological features where drawdown measurements are lacking. Overall, our results suggest the joint use of both geological and pumping test data for HT analysis when accurate geological data are available.

  2. Flow Curve Determination at Large Plastic Strain Levels: Limitations of the Membrane Theory in the Analysis of the Hydraulic Bulge Test

    Science.gov (United States)

    Lemoine, X.; Iancu, A.; Ferron, G.

    2011-05-01

    Nowadays, an accurate determination of the true stress-strain curve is a key-element for all finite element (FE) forming predictions. Since the introduction of Advanced High Strength Steels (AHSS) for the automotive market, the standard uniaxial tension test suffers the drawback of relatively low uniform elongations. The extrapolation of the uniaxial stress-strain curve up to large strains is not without consequence in forming predictions—especially formability and springback. One of the means to solve this problem is to use experimental tests where large plastic strain levels can be reached. The hydraulic bulge test is one of these tests. The effective plastic strain levels reached in the bulge test are of about 0.7. From an experimental standpoint, the biaxial flow stress is estimated using measurement of fluid pressure, and calculation of thickness and curvature at the pole, via appropriate measurements and assumptions. The biaxial stress at the pole is determined using the membrane equilibrium equation. The analysis proposed in this paper consists of performing "virtual experiments" where the results obtained by means of FE calculations are used as input data for determining the biaxial stress-strain law in agreement with the experimental procedure. In this way, a critical discussion of the experimental procedure can be made, by comparing the "experimental" stress-strain curve (Membrane theory curve) with the "reference" one introduced in the simulations. In particular, the influences of the "(die diameter)/thickness" ratio and of the plastic anisotropy are studied, and limitations of the hydraulic bulge test analysis are discussed.

  3. Analysis and Online Diagnosis on Plugging Fault of Servo Valve in Electro-hydraulic Regulating System of Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    WANG Xuanyin; LI Xiaoxiao; LI Fushang

    2009-01-01

    Through the study on the output signals of the electro-hydraulic regulating system in the thermal power plant, a novel method for online diagnosis of the plugging fault in the servo valve is presented. With the use of the AMESIM software, the changes of the piston displacement, the oil pressure, the magnitude attenuation and the phase lag of the system under different plugging states are studied after simulation. Besides, the influences of the symmetrical and unsymmetrical plugging on the system are also compared and the characteristic table is given. The duo-neural network is put forward to achieve an online diagnosis on the plugging fault of the servo valve. The first level of network helps to make the qualitative diagnosis of the plugging position while the second level is for the quantitative diagnosis of the degree of the plugged position. The research results show that plugging at different positions exerts different influences on the performance of the system. The unsymmetrical plugging mainly affects the regulation time while the symmetrical plugging leads to great changes in the magnitude attenuation and the phase lag.

  4. CFD Analysis on the Thermal Hydraulic Performance of an SAH Duct with Multi V-Shape Roughened Ribs

    Directory of Open Access Journals (Sweden)

    Anil Kumar

    2016-05-01

    Full Text Available This study presents the heat transfer and fluid flow characteristics in a rib-roughened SAH (solar air heater channel. The artificial roughness of the rectangular channel was in the form of a thin circular wire in discrete multi V-pattern rib geometries. The effect of this geometry on heat transfer, fluid flow, and performance augmentation was investigated using the CFD (computational fluid dynamics. The roughness parameters were a relative discrete distance of 0.69, a relative rib height of 0.043, a relative rib pitch of 10, a relative rib width of 6.0, and a flow-attack-angle of 60°. The discrete width ratios and Reynolds numbers ranged from 0.5 to 2.0 and from 2000 to 20,000, respectively. The CFD results using the renormalization k-epsilon model were in good agreement with the empirical relationship. This model was used to investigate the heat transfer and fluid flow characteristics in the multi V-pattern rib roughened SAH channel. The thermo-hydraulic performance was found to be the best for the discrete width ratio of 1.0. A discrete multi V-pattern rib combined with dimple staggered ribs also had better overall thermal performance compared to other rib shapes.

  5. 掩护式液压支架姿态分析%Analysis of postures of shield hydraulic support

    Institute of Scientific and Technical Information of China (English)

    朱殿瑞; 廉自生; 贺志凯

    2012-01-01

    以掩护式液压支架为研究对象,分析支架可能出现的各种姿态,建立支架某一姿态的运动学数学模型,计算出支架各部件关键点处的空间位置,结合三维建模软件UG建立几何模型,并对支架进行运动仿真。通过仿真可知,顶梁倾角的改变,对支架的梁端距变化量、平衡千斤顶连接耳座的中心距、立柱倾角均有一定的影响。%Taking a shield hydraulic support as the study object, the paper analyzed all possible postures of the support, and established a kinematic math model of one posture of the support. In addition, it calculated the space positions of key points of support components, and conducted the kinematic simulation of the support based on 3D modeling software UG. The simulation results showed that the variation of obliquity of the top girder had some influence on the distance between girder ends of the support, central distance between connecting lugs of the balancing jack as well as the column obliquity.

  6. Thermo-Hydraulic Analysis of Heat Storage Filled with the Ceramic Bricks Dedicated to the Solar Air Heating System.

    Science.gov (United States)

    Nemś, Magdalena; Nemś, Artur; Kasperski, Jacek; Pomorski, Michał

    2017-08-12

    This article presents the results of a study into a packed bed filled with ceramic bricks. The designed storage installation is supposed to become part of a heating system installed in a single-family house and eventually to be integrated with a concentrated solar collector adapted to climate conditions in Poland. The system's working medium is air. The investigated temperature ranges and air volume flow rates in the ceramic bed were dictated by the planned integration with a solar air heater. Designing a packed bed of sufficient parameters first required a mathematical model to be constructed and heat exchange to be analyzed, since heat accumulation is a complex process influenced by a number of material properties. The cases discussed in the literature are based on differing assumptions and different formulas are used in calculations. This article offers a comparison of various mathematical models and of system operating parameters obtained from these models. The primary focus is on the Nusselt number. Furthermore, in the article, the thermo-hydraulic efficiency of the investigated packed bed is presented. This part is based on a relationship used in solar air collectors with internal storage.

  7. Unsteady flow analysis of an axial flow hydraulic turbine with collection devices comprising a different number of blades

    Science.gov (United States)

    Nishi, Yasuyuki; Inagaki, Terumi; Li, Yanrong; Hirama, Sou; Kikuchi, Norio

    2015-06-01

    We previously devised a new type of portable hydraulic turbine that uses the kinetic energy of an open-channel flow to improve output power by catching and accelerating the flow. The turbine contains an axial flow runner with an appended collection device and a diffuser section that is not axisymmetric. The objective of this study is to determine how interference between the collection device and the runner influences performance characteristics of the turbine. We investigated the performance characteristics of the turbine and flow field for different numbers of blades during both unsteady and steady flow. During an unsteady flow, the maximum values of power coefficients for three and two blades increased by approximately 8.8% and 21.4%, respectively, compared to those during a steady flow. For the three-blade runner, the power coefficient showed small fluctuations, but for the two-blade runner, the power coefficient showed large fluctuations. These fluctuations in the power coefficient are attributed to fluctuations in the loading coefficient, which were generated by interference between the runner and the diffuser section of the collection device.

  8. Neutronic and thermal-hydraulic analysis of new irradiation channels inside the Moroccan TRIGA Mark II research reactor core.

    Science.gov (United States)

    Chham, E; El Bardouni, T; Benaalilou, K; Boukhal, H; El Bakkari, B; Boulaich, Y; El Younoussi, C; Nacir, B

    2016-10-01

    This study was conducted to improve the capacity of radioisotope production in the Moroccan TRIGA Mark II research reactor, which is considered as one of the most important applications of research reactors. The aim of this study is to enhance the utilization of TRIGA core in the field of neutron activation and ensure an economic use of the fuel. The main idea was to create an additional irradiation channel (IC) inside the core. For this purpose, three new core configurations are proposed, which differ according to the IC position in the core. Thermal neutron flux distribution and other neutronic safety parameters such as power peaking factors, excess reactivity, and control rods worth reactivity were calculated using the Monte Carlo N-Particle Transport (MCNP) code and neutron cross-section library based on ENDF/B-VII evaluation. The calculated thermal flux in the central thimble (CT) and in the added IC for the reconfigured core is compared with the thermal flux in the CT of the existing core, which is taken as a reference. The results show that all the obtained fluxes in CTs are very close to the reference value, while a remarkable difference is observed between the fluxes in the new ICs and reference. This difference depends on the position of IC in the reactor core. To demonstrate that the Moroccan TRIGA reactor could safely operate at 2MW, with new configurations based on new ICs, different safety-related thermal-hydraulic parameters were investigated. The PARET model was used in this study to verify whether the safety margins are met despite the new modifications of the core. The results show that it is possible to introduce new ICs safely in the reactor core, because the obtained values of the parameters are largely far from compromising the safety of the reactor.

  9. Assessing the impact of uncertainty on flood risk estimates with reliability analysis using 1-D and 2-D hydraulic models

    Directory of Open Access Journals (Sweden)

    L. Altarejos-García

    2012-07-01

    Full Text Available This paper addresses the use of reliability techniques such as Rosenblueth's Point-Estimate Method (PEM as a practical alternative to more precise Monte Carlo approaches to get estimates of the mean and variance of uncertain flood parameters water depth and velocity. These parameters define the flood severity, which is a concept used for decision-making in the context of flood risk assessment. The method proposed is particularly useful when the degree of complexity of the hydraulic models makes Monte Carlo inapplicable in terms of computing time, but when a measure of the variability of these parameters is still needed. The capacity of PEM, which is a special case of numerical quadrature based on orthogonal polynomials, to evaluate the first two moments of performance functions such as the water depth and velocity is demonstrated in the case of a single river reach using a 1-D HEC-RAS model. It is shown that in some cases, using a simple variable transformation, statistical distributions of both water depth and velocity approximate the lognormal. As this distribution is fully defined by its mean and variance, PEM can be used to define the full probability distribution function of these flood parameters and so allowing for probability estimations of flood severity. Then, an application of the method to the same river reach using a 2-D Shallow Water Equations (SWE model is performed. Flood maps of mean and standard deviation of water depth and velocity are obtained, and uncertainty in the extension of flooded areas with different severity levels is assessed. It is recognized, though, that whenever application of Monte Carlo method is practically feasible, it is a preferred approach.

  10. Hydraulic pump common fault analysis and elimination method%液压泵常见故障分析及排除方法

    Institute of Scientific and Technical Information of China (English)

    杨秀荣

    2013-01-01

      液压泵是液压系统中动力元件,相当于人的“心脏”,当液压泵出现故障后液压系统油液系统将无法正常工作。本文分别就三种液压泵对其常见的故障及排除方法进行了探讨。%The hydraulic pump is a hydraulic dynamic component in the system,the equivalent of a man’s\\“heart\\”,when the hydraulic system of hydraulic pump fault occurs after the oil system will not work properly.This paper has three kinds of hydraulic pump for the common failures and troubleshooting methods are discussed in this paper.

  11. The IAEA Coordinated Research Program on HTGR Reactor Physics, Thermal-hydraulics and Depletion Uncertainty Analysis: Description of the Benchmark Test Cases and Phases

    Energy Technology Data Exchange (ETDEWEB)

    Frederik Reitsma; Gerhard Strydom; Bismark Tyobeka; Kostadin Ivanov

    2012-10-01

    The continued development of High Temperature Gas Cooled Reactors (HTGRs) requires verification of design and safety features with reliable high fidelity physics models and robust, efficient, and accurate codes. The uncertainties in the HTR analysis tools are today typically assessed with sensitivity analysis and then a few important input uncertainties (typically based on a PIRT process) are varied in the analysis to find a spread in the parameter of importance. However, one wish to apply a more fundamental approach to determine the predictive capability and accuracies of coupled neutronics/thermal-hydraulics and depletion simulations used for reactor design and safety assessment. Today there is a broader acceptance of the use of uncertainty analysis even in safety studies and it has been accepted by regulators in some cases to replace the traditional conservative analysis. Finally, there is also a renewed focus in supplying reliable covariance data (nuclear data uncertainties) that can then be used in uncertainty methods. Uncertainty and sensitivity studies are therefore becoming an essential component of any significant effort in data and simulation improvement. In order to address uncertainty in analysis and methods in the HTGR community the IAEA launched a Coordinated Research Project (CRP) on the HTGR Uncertainty Analysis in Modelling early in 2012. The project is built on the experience of the OECD/NEA Light Water Reactor (LWR) Uncertainty Analysis in Best-Estimate Modelling (UAM) benchmark activity, but focuses specifically on the peculiarities of HTGR designs and its simulation requirements. Two benchmark problems were defined with the prismatic type design represented by the MHTGR-350 design from General Atomics (GA) while a 250 MW modular pebble bed design, similar to the INET (China) and indirect-cycle PBMR (South Africa) designs are also included. In the paper more detail on the benchmark cases, the different specific phases and tasks and the latest

  12. Characterization of hydraulic connections between mine shaft and caprock based on time series analysis of water level changes for the flooded Asse I salt mine in northern Germany

    Energy Technology Data Exchange (ETDEWEB)

    Brauchler, Ralf; Mettier, Ralph; Schulte, Peter [AF-Consult Switzerland AG, Baden (Switzerland); Fuehrboeter, Jens Fred [Bundesamt fuer Strahlenschutz, Salzgitter (Germany)

    2015-07-01

    In the context of safe enclosure of nuclear waste in salt formations, one of the main challenges is potential water inflow into the excavations. In this context, the hydraulic relationship between the abandoned Asse I salt mine and the salt dissolution network at the base of the caprock of the Asse salt structure in northern Germany is characterized by utilizing time series analysis of water level changes. The data base comprises a time series of water level measurements over eight years with a temporal resolution of 15 minutes (in general) and up to 2 minutes for specific intervals. The water level measurements were collected in the shaft of the flooded mine, which is filled with ground rock salt until a depth of 140 m, and a deep well, which is screened in 240 m depth at the salt dissolution zone at the base of the caprock. The distance between the well and the shaft is several hundred meters. Since the beginning of the continuous observations in the 1970s, the shaft has shown periodically abrupt declines of the water level of several meters occurring in intervals of approx. 8 to 10 years. The time series analysis consists of trend, Fourier-, autocorrelation and cross-correlation analysis. The analysis showed that during times with small water level changes the measured water level in the well and the shaft are positively correlated whereas during the abrupt water level drops in the shaft, the measured water levels between the shaft and the well are negatively correlated. A potential explanation for this behavior is that during times with small changes, the measured water levels in the well and in the shaft are influenced by the same external events with similar response times. In contrast, during the abrupt water level decline events in the shaft, a negatively correlated pressure signal is induced in the well, which supports the assumption of a direct hydraulic connection between the shaft and the well via flooded excavations and the salt dissolution network

  13. Trend of hydraulic units

    Energy Technology Data Exchange (ETDEWEB)

    Deshimaru, Jun' ichi

    1988-11-01

    The gear, vane and piston pumps occupy a more then 90% share in the hydraulic pumps. Comparatively large pumps are mainly variable delivery piston pumps. The piston pumps are comparatively high in output density (output per unit weight), indicating the hydraulic pump in performance, and tend to become higher and higher in it. Though they are mainly 210 to 350kgf/cm/sup 2/ in rated pressure, some of them come to surpass 400kgf/cm/sup 3/ in it. While the progress in computation also requires the high speed operation, high accuracy and other severe conditions for the hydraulic units, which accordingly and increasingly intensify the requirement for hydraulic oil in abrasion resistibility, oxidation stability and response characteristics. While cavitation comes to easily occur, which considerably and disadvantageously influences hydraulic oil in life through degradation, noise level and respondingness. From now on, the development of high performance oil and study of mechanical structure are important. 19 references, 9 figures, 2 tables.

  14. Hydraulic characterization of hydrothermally altered Nopal tuff

    Energy Technology Data Exchange (ETDEWEB)

    Green, R.T.; Meyer-James, K.A. [Southwest Research Institute, San Antonio, TX (United States); Rice, G. [George Rice and Associates, San Antonio, TX (United States)

    1995-07-01

    Understanding the mechanics of variably saturated flow in fractured-porous media is of fundamental importance to evaluating the isolation performance of the proposed high-level radioactive waste repository for the Yucca Mountain site. Developing that understanding must be founded on the analysis and interpretation of laboratory and field data. This report presents an analysis of the unsaturated hydraulic properties of tuff cores from the Pena Blanca natural analog site in Mexico. The basic intent of the analysis was to examine possible trends and relationships between the hydraulic properties and the degree of hydrothermal alteration exhibited by the tuff samples. These data were used in flow simulations to evaluate the significance of a particular conceptual (composite) model and of distinct hydraulic properties on the rate and nature of water flow.

  15. The analysis of antireflection range in coal seam hydraulic fracturing%本煤层水压致裂增透范围分析

    Institute of Scientific and Technical Information of China (English)

    赵源; 曹树刚; 李勇; 覃乐

    2015-01-01

    在理论分析水压致裂起裂机理和起裂方向的基础上,应用煤岩损伤破裂过程渗流-应力耦合分析系统,对5种不同地应力条件下的本煤层水压致裂过程进行模拟,得到了煤体的起裂方向、起裂压力和扩展压力.研究发现:侧压系数λ<1时,煤体基本沿垂直方向起裂,起裂压力和扩展压力呈逐步增长的趋势;λ>1 时,煤体的起裂方向为水平,起裂压力和扩展压力表现出平缓降低的趋势;在λ=1时,运用3种屈服准则进行了对比分析,得到了不同判别准则下的最小起裂水压.通过对λ=1.2时的受力状态进行深入分析,提出了压裂增透范围为宏观裂隙区、微裂隙贯通区、微裂隙产生区(受拉区)和原生裂隙扰动区(压应力恢复区)之和;利用数值图像处理得到的增透面积增长趋势符合二次函数的关系.%Based on the theoretical analysis of crack initiation mechanism and crack direction of hy-draulic fracturing, the hydraulic fracturing process of coal seam under five different in-situ stress situa-tions has been simulated by using the seepage-stress coupling analysis system of coal and/or rock dam-age & fracture process, and hence, the crack initiation direction, initial pressure and expansion pressure have been obtained. Studies have found that, the crack direction is vertical, with the initial pressure as well as the expansion pressure presenting as gradual increasing trend when the lateral pressure coeffi-cientλ<1. When the lateral pressure coefficientλ>1, the crack direction is horizontal, with the initial pressure and the expansion pressure presenting as gradually decreasing trend. When the lateral pressure coefficientλ=1, by carrying out three different kinds of yield criterion contrastive analysis, the minimum initial pressure are respectively obtained under the different kinds of yield criterion. Through the further stress analysis, i.e., when coefficientλ=1.2, studies have proposed

  16. Cavitation in Hydraulic Machinery

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, M.

    1996-11-01

    The main purpose of this doctoral thesis on cavitation in hydraulic machinery is to change focus towards the coupling of non-stationary flow phenomena and cavitation. It is argued that, in addition to turbulence, superimposed sound pressure fluctuations can have a major impact on cavitation and lead to particularly severe erosion. For the design of hydraulic devices this finding may indicate how to further limit the cavitation problems. Chapter 1 reviews cavitation in general in the context of hydraulic machinery, emphasizing the initial cavitation event and the role of the water quality. Chapter 2 discusses the existence of pressure fluctuations for situations common in such machinery. Chapter 3 on cavitation dynamics presents an algorithm for calculating the nucleation of a cavity cluster. Chapter 4 describes the equipment used in this work. 53 refs., 55 figs.,10 tabs.

  17. Collaborative Design and Analysis of Hydraulic Valve Block Based on UG/ANSYS Workbench%基于UG/ANSYS Workbench的液压阀块协同设计与分析

    Institute of Scientific and Technical Information of China (English)

    胡峰; 蒋廉华; 曾春军

    2016-01-01

    针对液压阀块集成度高、结构紧凑、空间结构复杂的问题,阐述了液压阀块的设计原则。以液压制动系统的液压阀块为例,为了高效快捷完成其设计工作,采用UG三维软件对其进行建模设计。同时,结合ANSYS Workbench分析软件,对其进行强度有限元分析,保证了结构强度的可靠性。%Aiming at the problem of high integration degree,compact structure and complicated spatial structure of hydraulic valve,the design principle of hydraulic valve block is expounded.Taking the hydraulic valve block of hydraulic braking system for example,in order to conveniently and rapidly design,the 3D software of UG is used for designing.At the same time,com-bined with Workbench ANSYS analysis software,the strength finite element analysis was carried out,to ensure the reliability of structural strength.

  18. Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography

    Energy Technology Data Exchange (ETDEWEB)

    Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.

    2012-01-10

    In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

  19. Hydraulics and pneumatics

    CERN Document Server

    Parr, Andrew

    2006-01-01

    Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. This is frequently accomplished by means of electrical equipment (such as motors or solenoids), or via devices driven by air (pneumatics) or liquids (hydraulics).This book has been written by a process control engineer as a guide to the operation of hydraulic and pneumatic systems for all engineers and technicians who wish to have an insight into the components and operation of such a system.This second edition has been fully updated to include all recent developments su

  20. Popeye Project: Hydraulic umbilical

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, K.G.; Williams, V.T.

    1996-12-31

    For the Popeye Project, the longest super-duplex hydraulic umbilical in the world was installed in the Gulf of Mexico. This paper reports on its selection and project implementation. Material selection addresses corrosion in seawater, water-based hydraulic fluid, and methanol. Five alternatives were considered: (1) carbon-steel with traditional coating and anodes, (2) carbon-steel coated with thermally sprayed aluminum, (3) carbon-steel sheathed in aluminum, (4) super-duplex, and (5) titanium. The merits and risks associated with each alternative are discussed. The manufacture and installation of the selected umbilical are also reported.

  1. Statistical analysis of determining the filtration heterogeneity of foundation rock mass of hydraulic structures on the example of the boguchanskaya hpp

    Directory of Open Access Journals (Sweden)

    Chernyshev Sergey Nikolaevich

    2016-01-01

    Full Text Available In the article the authors carried out a statistical analysis of mass determination of the filtration coefficient, which allows us to construct the most accurate calculation model of seepage field of inhomogeneous bedrock foundation of the dam needed for seepage calculations and to predict seepage regime of hydraulic structures and their grounds. The algorithm can be applied to analyze heterogeneity based on the large set of definitions of the properties of soil, subject to the condition that within the engineering geological element of random fluctuations of the index properties or some of its functions, e.g., logarithm of index properties, obey normal distribution law. In the latter case, all digital values of the index should be recalculated and presented in the form, in which they submit to the law of normal distribution. The authors received effective evaluation of the filtration coefficient on the basis of the law of statistical distribution. Correspondence of each component to a particular genetic element of the array is derived from the premise, adopted prior to the mathematical analysis: we divided the total distribution into separate normal distributions, and normal distribution is only true for a genetically separate engineering-geological element. After finding boundary values of the distributions it is required to determine the cut regions, in which relevant engineering-geological elements are localized, with the help of specially designed algorithm. In order to clarify geological distinction between the various lithological zones, zones of weathered and fractured zones, we use numerical data of filtration sampling. Then we put the numerical values of the index properties of lgq on which segmentation of the array occurs, on a geological cross section, respectively, for each well. After assigning numerical codes to the individual values of the indicator properties you can begin to image the geological section, where we combine the

  2. 自由锻造液压机的技术现状及设计分析%Technique status and design analysis of free forging hydraulic press

    Institute of Scientific and Technical Information of China (English)

    谢广玉; 李秀珠; 胡海燕

    2013-01-01

    阐述了自由锻造液压机的发展过程和我国锻造压机的技术现状,对自由锻造液压机的几种结构型式和传动方式进行了比较,说明了锻造油压机的技术特点.%The developing process of free forging hydraulic press and technique status in China has been described in the text. Several structural modes and transmission modes of free forging hydraulic press have been compared, and the technical characteristics of forging hydraulic press have been introduced.

  3. Hydraulic Arm Modeling via Matlab SimHydraulics

    OpenAIRE

    Věchet, Stanislav; Krejsa, Jiří

    2009-01-01

    System modeling is a vital tool for cost reduction and design process speed up in most engineering fields. The paper is focused on modeling of hydraulic arm as a part of intelligent prosthesis project, in the form of 2DOF open kinematic chain. The arm model combines mechanical, hydraulic and electric subsystems and uses Matlab as modeling tool. SimMechanics Matlab extension is used for mechanical part modeling, SimHydraulics toolbox is used for modeling of hydraulic circuit used for actuating...

  4. The STAT7 Code for Statistical Propagation of Uncertainties In Steady-State Thermal Hydraulics Analysis of Plate-Fueled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Floyd E. [Argonne National Lab. (ANL), Argonne, IL (United States); Hu, Lin-wen [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Nuclear Reactor Lab.; Wilson, Erik [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-12-01

    The STAT code was written to automate many of the steady-state thermal hydraulic safety calculations for the MIT research reactor, both for conversion of the reactor from high enrichment uranium fuel to low enrichment uranium fuel and for future fuel re-loads after the conversion. A Monte-Carlo statistical propagation approach is used to treat uncertainties in important parameters in the analysis. These safety calculations are ultimately intended to protect against high fuel plate temperatures due to critical heat flux or departure from nucleate boiling or onset of flow instability; but additional margin is obtained by basing the limiting safety settings on avoiding onset of nucleate boiling. STAT7 can simultaneously analyze all of the axial nodes of all of the fuel plates and all of the coolant channels for one stripe of a fuel element. The stripes run the length of the fuel, from the bottom to the top. Power splits are calculated for each axial node of each plate to determine how much of the power goes out each face of the plate. By running STAT7 multiple times, full core analysis has been performed by analyzing the margin to ONB for each axial node of each stripe of each plate of each element in the core.

  5. Multiple Module Simulation of Water Cooled Breeding Blankets in K-DEMO Using Thermal-Hydraulic Analysis Code MARS-KS

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geon-Woo; Lee, Jeong-Hun; Park, Goon-Cherl; Cho, Hyoung-Kyu [Seoul National University, Seoul (Korea, Republic of); Im, Kihak [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    A preliminary concept for the Korean fusion demonstration reactor (K-DEMO) has been studied by the National Fusion Research Institute (NFRI) based on the National Fusion Roadmap of Korea. The feasibility studies have been performed in order to establish the conceptual design guidelines of the breeding blanket. As a part of the NFRI research, Seoul National University (SNU) is conducting thermal design, evaluation and validation of the water-cooled breeding blanket for the K-DEMO reactor. The purpose of this study is to extend the capability of MARS-KS to the overall blanket system analysis which includes 736 blanket modules in total. The strategy for the multi-module blanket system analysis using MARS-KS is introduced and the analysis result of the 46 blanket modules of single sector was summarized. A thermal-hydraulic analysis code for a nuclear reactor safety, MARS-KS, was applied for thermal analysis of the conceptual design of the K-DEMO breeding blanket. Then, a methodology to simulate multiple blanket modules was proposed, which uses a supervisor program to handle each blanket module individually at first and then distribute the flow rate considering the pressure drop that occurs in each module. For a feasibility test of the proposed methodology, 46 blankets in a sector, which are connected with each other through the common headers for the sector inlet and outlet, were simulated. The calculation results of flow rates, pressure drops, and temperatures showed the validity of the calculation. Because of parallelization using the MPI system, the computational time could be reduced significantly. In future, this methodology will be extended to an efficient simulation of multiple sectors, and further validation for transient simulation will be carried out for more practical applications.

  6. HYDRAULICS, TUSCARAWAS COUNTY, OHIO, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydraulic procedures for estimating flood discharges for a flood insurance...

  7. Fault Analysis and Processing of INBA Closed Loop Hydraulic System%INBA闭环液压系统故障分析与处理

    Institute of Scientific and Technical Information of China (English)

    沈文卫; 黄敬; 李丹; 余其军

    2013-01-01

    INBA法是一种新型高炉炉渣处理技术.INBA的驱动方式为闭式液压系统驱动低速大扭矩液压马达,并经过链条来带动转鼓旋转.该文对闭式液压系统进行了说明.同时对INBA液压系统的常见故障进行了分析,并给了处理方法.%INBA method is a new type of blast furnace slag processing technology.INBA's driving way is closed hydraulic system which drives hydraulic motor which have low-speed big torque.Motor through the chain to drive the drum rotating.This article mainly introduces the closed hydraulic system.At the same time,The INBA's common failures of hydraulic system is analysed and the processing method is given.

  8. Hydraulic hoist-press

    Energy Technology Data Exchange (ETDEWEB)

    Babayev, Z.B.; Abashev, Z.V.

    1982-01-01

    The efficiency expert of the Angrenskiy production-technological administration of the production association Sredazugol A. V. Bubnov has suggested a hydraulic hoist-press for repairing road equipment which is a device consisting of lifting mechanism, press and test stand for verifying the high pressure hoses and pumps.

  9. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...

  10. Water Treatment Technology - Hydraulics.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on hydraulics provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: head loss in pipes in series, function loss in…

  11. Simulation Analysis of Slewing System for Hybrid Hydraulic Excavator%油液混合动力挖掘机回转系统仿真分析

    Institute of Scientific and Technical Information of China (English)

    郑辉; 吴文海; 邓斌; 刘桓龙; 柯坚

    2012-01-01

    In order to recover the braking energy from braking process of slewing platform of hydraulic excavator, a hybrid hydraulic excavator energy recovery system was proposed in which accumulator was used to recover the braking energy. The differences of the principle of the slewing hydraulic system between the hybrid hydraulic excavator and the ordinary excavator were elaborated. The simulation model was built based on AMESim. Simulation results show that using the hybrid hydraulic excavator, the power loss of the hydraulic pumps and the pressure fluctuations of the hydraulic motors are reduced. In the energy saving aspect, the energy recovery efficiency of the accumulator can reach 70% , and the reuse efficiency of the hydraulic energy can reach 72. 8%. So the system has high recovery efficiency and the energy saving purpose is achieved.%为了回收挖掘机回转平台制动过程中的制动能量,设计了油液混合动力挖掘机回转系统,利用蓄能器回收回转平台的制动能量.阐述油液混合动力回转系统和普通回转系统液压原理的不同,建立AMESim模型并进行仿真分析.仿真结果表明:油液混合动力挖掘机回转系统在一定程度上降低了液压泵的功率损耗和液压马达的压力波动;在节能方面,蓄能器的能量回收效率达到70.0%,再利用效率达到72.8%,利用率较高,达到节能的目的.

  12. Application of Ferrography to Fault Diagnosis of Hydraulic Systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper deals with research on the successful use of ferrography as a wear measurement method for condition monitoring and fault diagnosis of hydraulic systems.The analysis program and progression is discussed, and a case study for condition monitoring and fault diagnosis of hydraulic systems by means of ferrography is also reviewed.

  13. Analysis of clinically important factors on the performance of advanced hydraulic, microprocessor-controlled exo-prosthetic knee joints based on 899 trial fittings

    Science.gov (United States)

    Hahn, Andreas; Lang, Michael; Stuckart, Claudia

    2016-01-01

    Abstract The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable. PMID:27828871

  14. Analysis of clinically important factors on the performance of advanced hydraulic, microprocessor-controlled exo-prosthetic knee joints based on 899 trial fittings.

    Science.gov (United States)

    Hahn, Andreas; Lang, Michael; Stuckart, Claudia

    2016-11-01

    The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component.This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied.Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive.Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.

  15. Thermal-Hydraulic Analysis of an Experimental Reactor Cavity Cooling System with Air. Part I: Experiments; Part II: Separate Effects Tests and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Corradin, Michael [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Anderson, M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Muci, M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Hassan, Yassin [Texas A & M Univ., College Station, TX (United States); Dominguez, A. [Texas A & M Univ., College Station, TX (United States); Tokuhiro, Akira [Univ. of Idaho, Moscow, ID (United States); Hamman, K. [Univ. of Idaho, Moscow, ID (United States)

    2014-10-15

    This experimental study investigates the thermal hydraulic behavior and the heat removal performance for a scaled Reactor Cavity Cooling System (RCCS) with air. A quarter-scale RCCS facility was designed and built based on a full-scale General Atomics (GA) RCCS design concept for the Modular High Temperature Gas Reactor (MHTGR). The GA RCCS is a passive cooling system that draws in air to use as the cooling fluid to remove heat radiated from the reactor pressure vessel to the air-cooled riser tubes and discharged the heated air into the atmosphere. Scaling laws were used to preserve key aspects and to maintain similarity. The scaled air RCCS facility at UW-Madison is a quarter-scale reduced length experiment housing six riser ducts that represent a 9.5° sector slice of the full-scale GA air RCCS concept. Radiant heaters were used to simulate the heat radiation from the reactor pressure vessel. The maximum power that can be achieved with the radiant heaters is 40 kW with a peak heat flux of 25 kW per meter squared. The quarter-scale RCCS was run under different heat loading cases and operated successfully. Instabilities were observed in some experiments in which one of the two exhaust ducts experienced a flow reversal for a period of time. The data and analysis presented show that the RCCS has promising potential to be a decay heat removal system during an accident scenario.

  16. TRAC-PF1/MOD1: an advanced best-estimate computer program for pressurized water reactor thermal-hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Liles, D.R.; Mahaffy, J.H.

    1986-07-01

    The Los Alamos National Laboratory is developing the Transient Reactor Analysis Code (TRAC) to provide advanced best-estimate predictions of postulated accidents in light-water reactors. The TRAC-PF1/MOD1 program provides this capability for pressurized water reactors and for many thermal-hydraulic test facilities. The code features either a one- or a three-dimensional treatment of the pressure vessel and its associated internals, a two-fluid nonequilibrium hydrodynamics model with a noncondensable gas field and solute tracking, flow-regime-dependent constitutive equation treatment, optional reflood tracking capability for bottom-flood and falling-film quench fronts, and consistent treatment of entire accident sequences including the generation of consistent initial conditions. The stability-enhancing two-step (SETS) numerical algorithm is used in the one-dimensional hydrodynamics and permits this portion of the fluid dynamics to violate the material Courant condition. This technique permits large time steps and, hence, reduced running time for slow transients.

  17. Analysis for Clamping Force of Hydraulic Slide-valve Spool Based on Fluent%基于Fluent的液压滑阀阀芯卡紧力研究

    Institute of Scientific and Technical Information of China (English)

    陈奎生; 周雯娟; 郭媛; 付曙光; 张宏伟; 蒋俊

    2011-01-01

    Through simulation and analysis, the changes in clamping force of the hydraulic slide-valve spool when the spool skewed were studied, with no pressure-equalizing grooves, three rectangular grooves, five rectangular grooves and five triangular grooves. The simulation results show; opening pressure-equalizing grooves in the valve can reduce clamping force; the more pressure equalizing grooves open, the smaller the clamping force becomes. With the same amount, clamping force of spool with rectangular grooves is larger than that with triangle grooves, but the spool with rectangular grooves is more conducive to become concentric.%通过仿真分析,研究液压滑阀阀芯在不开均压槽、开3条矩形槽、开5条矩形槽、开5条三角形槽4种情况下,阀芯歪斜时阀芯卡紧力的变化.由仿真结果可知:阀芯歪斜时,在阀芯上开均压槽可以有效减小卡紧力,开的均压槽越多,卡紧力越小;开相同数量的矩形槽比三角槽的卡紧力大,但是更利于使阀芯趋于同心.

  18. Thermal-hydraulic analysis of heat transfer in subchannels of the European high performance supercritical Water-Cooled Reactor for different CFD turbulence models

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Landy Y.; Rojas, Leorlen Y.; Gamez, Abel; Rosales, Jesus; Gonzalez, Daniel; Garcia, Carlos, E-mail: lcastro@instec.cu, E-mail: leored1984@gmail.com, E-mail: agamezgmf@gmail.com, E-mail: jrosales@instec.cu, E-mail: danielgonro@gmail.com, E-mail: cgh@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Oliveira, Carlos Brayner de, E-mail: cabol@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Dominguez, Dany S., E-mail: dsdominguez@gmail.com [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil). Pos-Graduacao em Modelagem Computacional

    2015-07-01

    Chosen as one of six Generation‒IV nuclear-reactor concepts, Supercritical Water-cooled Reactors (SCWRs) are expected to have high thermal efficiencies within the range of 45 - 50% owing to the reactor's high pressures and outlet temperatures. In this reactor, the primary water enters the core under supercritical-pressure condition (25 MPa) at a temperature of 280 deg C and leaves it at a temperature of up to 510 deg C. Due to the significant changes in the physical properties of water at supercritical-pressure, the system is susceptible to local temperature, density and power oscillations. The behavior of supercritical water into the core of the SCWR, need to be sufficiently studied. Most of the methods available to predict the effects of the heat transfer phenomena within the pseudocritical region are based on empirical one-directional correlations, which do not capture the multidimensional effects and do not provide accurate results in regions such as the deteriorated heat transfer regime. In this paper, computational fluid dynamics (CFD) analysis was carried out to study the thermal-hydraulic behavior of supercritical water flows in sub-channels of a typical European High Performance Light Water Reactor (HPLWR) fuel assembly using commercial CFD code CFX-14. It was determined the steady-state equilibrium parameters and calculated the temperature and density distributions. A comparative study for different turbulence models were carried out and the obtained results are discussed. (author)

  19. Effect of Natural Fractures on Hydraulic Fracturing

    Science.gov (United States)

    Ben, Y.; Wang, Y.; Shi, G.

    2012-12-01

    Hydraulic Fracturing has been used successfully in the oil and gas industry to enhance oil and gas production in the past few decades. Recent years have seen the great development of tight gas, coal bed methane and shale gas. Natural fractures are believed to play an important role in the hydraulic fracturing of such formations. Whether natural fractures can benefit the fracture propagation and enhance final production needs to be studied. Various methods have been used to study the effect of natural fractures on hydraulic fracturing. Discontinuous Deformation Analysis (DDA) is a numerical method which belongs to the family of discrete element methods. In this paper, DDA is coupled with a fluid pipe network model to simulate the pressure response in the formation during hydraulic fracturing. The focus is to study the effect of natural fractures on hydraulic fracturing. In particular, the effect of rock joint properties, joint orientations and rock properties on fracture initiation and propagation will be analyzed. The result shows that DDA is a promising tool to study such complex behavior of rocks. Finally, the advantages of disadvantages of our current model and future research directions will be discussed.

  20. Analysis on electrohydraulic speed servo control schemes for anti-explosion hydraulic hoisters%防爆液压提升机电液伺服调速控制方案分析

    Institute of Scientific and Technical Information of China (English)

    丁海港; 赵继云; 赵亮

    2011-01-01

    Based on the analysis of construction and disadvantages of hydraulic control system existing in hydraulic hoisters,a pump controlled motor speed servo system was set up to simulate the close loop control and process of hydraulic hoisters,and then dynamic performances of the system with/without position loop were analyzed,and a conclusion was gained:the electrohydraulic servo control for hydraulic hoisters should ensure the displacement of a variable displacement pump to be regulated independently while motor's rotary speed are fed back and to be controlled in closed loop.Based on this theory,in terms of automatic transformation for traditional anti-explosion hydraulic hoisters,those electrohydraulic speed servo control systems with /without a position loop were designed.%在分析现有液压提升机的液压控制系统的结构与特点的基础上,建立泵控马达电液伺服调速系统,以模拟液压提升机的闭环控制与运行工况,通过对带/不带位置环泵控马达伺服系统的调速特性的分析,指出液压提升机的电液伺服控制应在引入马达转速反馈形成转速闭环的同时,保证变量泵的排量是独立可控的,并以此为据,针对传统液压提升机进行自动化改造,设计了带/不带位置环的防爆液压提升机电液伺服调速系统。

  1. Thermal Hydraulic Stability in a Coaxial Thermosyphon

    Institute of Scientific and Technical Information of China (English)

    YANG Jianhui; LU Wenqiang; LI Qing; LI Qiang; ZHOU Yuan

    2005-01-01

    The heat transfer and thermal hydraulic stability in a two-phase thermosyphon with coaxial riser and down-comer has been experimentally investigated and theoretically analyzed to facilitate its application in cold neutron source. The flow in a coaxial thermosyphon was studied experimentally for a variety of heating rates, transfer tube lengths, charge capacities, and area ratios. A numerical analysis of the hydraulic balance between the driving pressure head and the resistance loss has also been performed. The results show that the presented coaxial thermosyphon has dynamic performance advantages relative to natural circulation in a boiling water reactor.

  2. Mathematical and geological approaches to minimizing the data requirements for statistical analysis of hydraulic conductivity. Technical completion report

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, F.M.; Wilson, J.L.; Gutjahr, A.L.; Love, D.W.; Davis, J.M.; Lohmann, R.C.; Colarullo, S.J.; Gotkowitz, M.B.

    1992-12-01

    Field scale heterogeneity has been recognized as a dominant control on solute dispersion in groundwater. Numerous random field models exist for quantifying heterogeneity and its influence on solute transport. Minimizing data requirements in model selection and subsequent parameterization will be necessary for efficient application of quantitative models in contaminated subsurface environments. In this study, a detailed quantitative sedimentological study is performed to address the issue of incorporating geologic information into the geostatistical characterization process. A field air-minipermeameter is developed for rapid in-situ measurements. The field study conducted on an outcrop of fluvial/interfluvial deposits of the Pliocene- Pleistocene Sierra Ladrones Formation in the Albuquerque Basin of central New Mexico. Architectural element analysis is adopted for mapping and analysis of depositional environment. Geostatistical analysis is performed at two scales. At the architectural element scale, geostatistical analysis of assigned mean log-permeabilities of a 0.16 km{sup 2} peninsular region indicates that the directions of maximum and minimum correlation correspond to the directions of the large-scale depositional processes. At the facies scale, permeability is found to be adequately represented as a log-normal process. Log-permeability within individual lithofacies appears uncorrelated. The overall correlation structure at the facies scale is found to be a function of the mean log-permeability and spatial distribution of the individual lithofacies. Based on field observations of abrupt spatial changes in lithology and hydrologic properties, an algorithm for simulating multi-dimensional discrete Markov random fields. Finally, a conceptual model is constructed relating the information inferred from dimensional environment analysis to the various random fields of heterogeneity.

  3. In-situ falling-head test for hydraulic conductivity: Evaluation in layered sediments of an analysis derived for homogenous sediments

    Science.gov (United States)

    Burnette, Matthew C.; Genereux, David P.; Birgand, François

    2016-08-01

    The hydraulic conductivity (K) of streambeds is a critical variable controlling interaction of groundwater and surface water. The Hvorslev analysis for estimating K from falling-head test data has been widely used since the 1950s, but its performance in layered sandy sediments common in streams and lakes has not previously been examined. Our numerical simulations and laboratory experiments show that the Hvorslev analysis yields accurate K values in both homogenous sediment (for which the analysis was originally derived) and layered deposits with low-K sand over high-K sand. K from the Hvorslev analysis deviated significantly from true K only when two conditions were present together: (1) high-K sand was present over low-K sand, and (2) the bottom of the permeameter in which K was measured was at or very near the interface between high-K and low-K. When this combination of conditions exists, simulation and laboratory sand tank results show that in-situ Hvorslev K underestimates the true K of the sediment within a permeameter, because the falling-head test is affected by low-K sediment outside of (below the bottom of) the permeameter. In simulation results, the maximum underestimation (occurring when the bottom of the permeameter was at the interface of high K over low K) was by a factor of 0.91, 0.59, and 0.12 when the high-K to low-K ratio was 2, 10, and 100, respectively. In laboratory sand tank experiments, the underestimation was by a factor of about 0.83 when the high-K to low-K ratio was 2.3. Also, this underestimation of K by the Hvorslev analysis was about the same whether the underlying low-K layer was 2 cm or 174 cm thick (1% or 87% of the domain thickness). Numerical model simulations were useful in the interpretation of in-situ field K profiles at streambed sites with layering; specifically, scaling the model results to the maximum measured K at the top of the field K profiles helped constrain the likely ratio of high K to low K at field locations with

  4. Remotely Adjustable Hydraulic Pump

    Science.gov (United States)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  5. Undular Hydraulic Jump

    Directory of Open Access Journals (Sweden)

    Oscar Castro-Orgaz

    2015-04-01

    Full Text Available The transition from subcritical to supercritical flow when the inflow Froude number Fo is close to unity appears in the form of steady state waves called undular hydraulic jump. The characterization of the undular hydraulic jump is complex due to the existence of a non-hydrostatic pressure distribution that invalidates the gradually-varied flow theory, and supercritical shock waves. The objective of this work is to present a mathematical model for the undular hydraulic jump obtained from an approximate integration of the Reynolds equations for turbulent flow assuming that the Reynolds number R is high. Simple analytical solutions are presented to reveal the physics of the theory, and a numerical model is used to integrate the complete equations. The limit of application of the theory is discussed using a wave breaking condition for the inception of a surface roller. The validity of the mathematical predictions is critically assessed using physical data, thereby revealing aspects on which more research is needed

  6. Helical coil thermal hydraulic model

    Science.gov (United States)

    Caramello, M.; Bertani, C.; De Salve, M.; Panella, B.

    2014-11-01

    A model has been developed in Matlab environment for the thermal hydraulic analysis of helical coil and shell steam generators. The model considers the internal flow inside one helix and its associated control volume of water on the external side, both characterized by their inlet thermodynamic conditions and the characteristic geometry data. The model evaluates the behaviour of the thermal-hydraulic parameters of the two fluids, such as temperature, pressure, heat transfer coefficients, flow quality, void fraction and heat flux. The evaluation of the heat transfer coefficients as well as the pressure drops has been performed by means of the most validated literature correlations. The model has been applied to one of the steam generators of the IRIS modular reactor and a comparison has been performed with the RELAP5/Mod.3.3 code applied to an inclined straight pipe that has the same length and the same elevation change between inlet and outlet of the real helix. The predictions of the developed model and RELAP5/Mod.3.3 code are in fairly good agreement before the dryout region, while the dryout front inside the helical pipes is predicted at a lower distance from inlet by the model.

  7. Coupled analysis of core thermal hydraulics and fuel performance to evaluate a thermally induced fuel failure in an SFR subassembly

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sun Rock; Chang, Doo Soo; Kim, Sang Ji [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    A limiting factor analysis in a core thermal design is highly important to assure the safe and reliable operation of a reactor system. In a sodium cooled fast reactor (SFR), the coolant thermal conductivity is about hundreds of times larger than the thermal conductivity of water. Moreover, the coolant boiling temperature in an SFR is around 900 .deg. C, which is much higher than that of the water coolant in a PWR. Considering typical operating temperatures, an SFR has about a 300 .deg. C thermal margin to its boiling point. Therefore, instead of DNBR (Departure from Nucleate Boiling Ratio) in a PWR, the core thermal design of SFRs requires assuring proper fuel performance and safety, where the design limits are highly related to the temperature distribution and material behavior under various operating conditions. Typical limiting factors in SFRs are the thermal component of the plastic hoop strain, radial primary hoop stress, and cumulative damage factor during normal operation. However, the previous fuel performance codes only evaluate a single fuel pin performance, which neglects the radial peaking factors and reveals too conservative results. In this work, the multi physics analysis is performed using both thermalhydraulic and fuel performance codes.

  8. Flood analysis in mixed-urban areas reflecting interactions with the complete water cycle through coupled hydrologic-hydraulic modelling.

    Science.gov (United States)

    Sto Domingo, N D; Refsgaard, A; Mark, O; Paludan, B

    2010-01-01

    The potential devastating effects of urban flooding have given high importance to thorough understanding and management of water movement within catchments, and computer modelling tools have found widespread use for this purpose. The state-of-the-art in urban flood modelling is the use of a coupled 1D pipe and 2D overland flow model to simultaneously represent pipe and surface flows. This method has been found to be accurate for highly paved areas, but inappropriate when land hydrology is important. The objectives of this study are to introduce a new urban flood modelling procedure that is able to reflect system interactions with hydrology, verify that the new procedure operates well, and underline the importance of considering the complete water cycle in urban flood analysis. A physically-based and distributed hydrological model was linked to a drainage network model for urban flood analysis, and the essential components and concepts used were described in this study. The procedure was then applied to a catchment previously modelled with the traditional 1D-2D procedure to determine if the new method performs similarly well. Then, results from applying the new method in a mixed-urban area were analyzed to determine how important hydrologic contributions are to flooding in the area.

  9. Predictive 1-D thermal-hydraulic analysis of the prototype HTS current leads for the ITER correction coils

    Science.gov (United States)

    Heller, R.; Bauer, P.; Savoldi, L.; Zanino, R.; Zappatore, A.

    2016-12-01

    We present an analysis of the prototype high-temperature superconducting (HTS) current leads (CLs) for the ITER correction coils, which will operate at 10 kA. A copper heat exchanger (HX) of the meander-flow type is included in the CL design and covers the temperature range between room temperature and 65 K, whereas the HTS module, where Bi-2223 stacked tapes are positioned on the outer surface of a stainless steel hollow cylindrical support, covers the temperature range between 65 K and 4.5 K. The HX is cooled by gaseous helium entering at 50 K, whereas the HTS module is cooled by conduction from the cold end of the CL. We use the CURLEAD code, developed some years ago and now supplemented by a new set of correlations for the helium friction factor and heat transfer coefficient in the HX, recently derived using Computational Fluid Dynamics. Our analysis is aimed first of all at a "blind" design-like prediction of the CL performance, for both steady state and pulsed operation. In particular, the helium mass flow rate needed to guarantee the target temperature at the HX-HTS interface, the temperature profile, and the pressure drop across the HX will be computed. The predictive capabilities of the CURLEAD model are then assessed by comparison of the simulation results with experimental data obtained in the test of the prototype correction coil CLs at ASIPP, whose results were considered only after the simulations were performed.

  10. Hydraulic Analysis of the Contribution of Emergency Water to C. N. Almaraz Systems Affected as a Result of the Complementary Technical Instructions issued by the CSN after Fukushima; Analisis Hidraulico del aporte de agua de emergencia a los sistemas de C. N. Almaraz afectados como consecuencia de las instrucciones tecnicas complementarias emitidas por el CSN tras Fukusima

    Energy Technology Data Exchange (ETDEWEB)

    Vilar Carmona, G.; Puertas Munoz, S.; Arguello Tara, A.; Sanz Roman, F. J.

    2013-07-01

    This paper presents the study and hydraulic analysis of the capacity required contribution of emergency water to the Almaraz NPP to power systems deal with the accidental events outside the bases of design defined in the Complementary technical instructions generated by the CSN after Fukushima. Through the program of balanced hydraulic SBAL, developed by entrepreneurs Grouped (EE.AA) and used in multiple security systems analysis, and based on designs and requirements to be fulfilled by the Almaraz NPP of the different strategies are set, have developed a series of hydraulic models that they have allowed the definition and dimensioning of the portable media and the new connections required in the central systems.

  11. 航空液压油箱密封结构的改进及可靠性建模分析%Improvement and Reliability Modeling Analysis of Aviation Hydraulic Oil Tank Sealing Structure

    Institute of Scientific and Technical Information of China (English)

    焦留芳; 鲁兴红

    2015-01-01

    为提高航空液压油箱使用寿命,通过分析某液压油箱的密封结构,指出液压油箱中比较关键或容易出现问题的密封结构,并进行一系列改进。根据密封件的失效机制及失效原因,通过对失效条件进行组合、简化,建立密封结构可靠性分析模型,评估密封改进方案的可行性。航空液压油箱寿命试验和实际应用均验证了可靠性模型的正确性。密封件的可靠性建模分析方法,可用于液压油箱密封方案设计、设计方案评估、故障分析等。%In order to improve the service life of a aviation hydraulic oil tank,its sealing structure was analyzed. The sealing structures of the hydraulic tank which are key or prone to problems were pointed out,and a series of improvements were performed.According to the failure mechanism and the failure reason of the seal,the reliability analysis model of the sealing structure was established through combining and simplifying the failure conditions,and the feasibility of the seal improvement scheme was evaluated.The correctness of the reliability model was verified by the life tests and the practical application of aviation hydraulic tank. The reliability analysis method of the seal parts can be used for the design of the sealing scheme,the design scheme and the fault analysis of the hydraulic oil tank.

  12. Verification and Validation of the PLTEMP/ANL Code for Thermal-Hydraulic Analysis of Experimental and Test Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kalimullah, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Olson, Arne P. [Argonne National Lab. (ANL), Argonne, IL (United States); Feldman, E. E. [Argonne National Lab. (ANL), Argonne, IL (United States); Hanan, N. [Argonne National Lab. (ANL), Argonne, IL (United States); Dionne, B. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-04-07

    The document compiles in a single volume several verification and validation works done for the PLTEMP/ANL code during the years of its development and improvement. Some works that are available in the open literature are simply referenced at the outset, and are not included in the document. PLTEMP has been used in conversion safety analysis reports of several US and foreign research reactors that have been licensed and converted. A list of such reactors is given. Each chapter of the document deals with the verification or validation of a specific model. The model verification is usually done by comparing the code with hand calculation, Microsoft spreadsheet calculation, or Mathematica calculation. The model validation is done by comparing the code with experimental data or a more validated code like the RELAP5 code.

  13. Hydraulic System Design of Hydraulic Actuators for Large Butterfly Valves

    OpenAIRE

    HUANG, Ye; Liu, Changsheng; Shiongur Bamed

    2014-01-01

    Hydraulic control systems of butterfly valves are presently valve-controlled and pump-controlled. Valve-controlled hydraulic systems have serious power loss and generate much heat during throttling. Pump-controlled hydraulic systems have no overflow or throttling losses but are limited in the speed adjustment of the variable-displacement pump, generate much noise, pollute the environment, and have motor power that does not match load requirements, resulting in low efficiency under...

  14. The Analysis of Bailing Hydraulic Control System for a Large Extinguishing Aircraft%某灭火型飞机汲水液压控制系统分析

    Institute of Scientific and Technical Information of China (English)

    胡刚; 裴沛

    2015-01-01

    该文是对某大型灭火飞机汲水液压控制系统的设计进行分析,通过对汲水斗收放时间、收放同步性及外载荷等的计算分析,验证了汲水液压控制系统设计的可行性。%This article is designed to analyze bailing hydraulic control system for a large fire-fighting aircraft, by the time of the bailing buck-et retractable, retractable synchronization and external load calculation and analysis to verify bailing hydraulic control system Feasibility of design.

  15. The Design of Double-acting Hollow Hydraulic Cylinder and Its Finite Element Analysis%双作用空心液压缸的设计及有限元分析

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      设计了一种双作用空心液压缸,利用Solid Works软件对其进行三维特征建模,并以Simulation对该空心液压缸进行有限元网格划分、载荷分析、应力、应变分析及安全分析。验证了设计的合理性和空心液压缸在承受载荷时的安全性,并证明产品的设计周期被减短了。%A double-acting hollow hydraulic cylinder is designed by using the Solid Works software for 3 d feature modeling. And then the finite element mesh, load, stress and strain analysis and security analysis of the hollow hy-draulic cylinder are carried out by using the Simulation. The rationality of the design and the security of the hollow hydraulic cylinder when under load are proved, and product design cycle is shortened.

  16. Thermal-hydraulic analysis of the CFETR blanket first wall%CFTER包层第一壁热工水力分析

    Institute of Scientific and Technical Information of China (English)

    魏川子; 宋云涛; 雷明准

    2016-01-01

    简要描述了CFETR氦冷固态增殖包层的结构设计,介绍了包层第一壁的冷却结构。用ANSYS CFX程序对 CFETR 包层第一壁进行了热工水力分析。研究了如何获得第一壁的最佳出口温度,并保证第一壁结构材料的热负荷承受能力。讨论了通过改变冷却管道粗糙度和优化冷却管道布置两种方法对第一壁结构进行优化。结果表明,优化的冷却回路既满足了材料的许用温度要求,又满足了氦气的出口温度要求。%This article describes the overall design of CFETR helium cooling solid breeding blanket and the cooling structure of the blanket first wall. Thermal-hydraulic analysis of the CFETR blanket first wall was carried out using ANSYS CFX code. Research on how to get the best outlet temperature and satisfy the limit of the first wall material allowable temperature was done. One way is to promote the tube roughness and another way is to optimize the cooling circulation. The results show that the optimization of the cooling loops can satisfy the requirements of the material allowable temperature and the outlet temperature.

  17. 挖掘机正流量泵控液压系统的特性分析%Analysis on positive flow pump control system of hydraulic excavator

    Institute of Scientific and Technical Information of China (English)

    贾文华; 殷晨波; 曹东辉; 陈克雷

    2011-01-01

    采用泵控挖掘机液压系统特性分析方法,在分析泵的输出特性的基础上,给出确定先导压力信号和控制泵排量的方法,并对泵的输出特性进行了仿真和实验研究.结果表明:正流量控制下,泵的排量由执行器流量需求和油泵的p-Q曲线动态实时调节,系统具有良好的负载流量适应性和负载敏感性,其液压系统中不存在负压,只有约0.5 MPa的背压,回油功率损失几乎为0.%Some problems were studied for the positive flow control of pump system of hydraulic excavator. Based on the analysis of pump output characteristics, the control method for pilot pressure and the pump displacement was given. The pump output characteristics were investigated by simulation and experiment. Results showed that flow was adjusted by flow required by actuator and the p - Q curve of main pump. For the positive system, the excavator had good load flow adaptability and load sensitivity. The power loss of returning oil path was almost zero. In the returning path, the negative pressure was only 0.5 Mpa for the positive system.

  18. Hydraulic System Design of Hydraulic Actuators for Large Butterfly Valves

    Directory of Open Access Journals (Sweden)

    Ye HUANG

    2014-09-01

    Full Text Available Hydraulic control systems of butterfly valves are presently valve-controlled and pump-controlled. Valve-controlled hydraulic systems have serious power loss and generate much heat during throttling. Pump-controlled hydraulic systems have no overflow or throttling losses but are limited in the speed adjustment of the variable-displacement pump, generate much noise, pollute the environment, and have motor power that does not match load requirements, resulting in low efficiency under light loads and wearing of the variable-displacement pump. To overcome these shortcomings, this article designs a closed hydraulic control system in which an AC servo motor drives a quantitative pump that controls a spiral swinging hydraulic cylinder, and analyzes and calculates the structure and parameters of a spiral swinging hydraulic cylinder. The hydraulic system adjusts the servo motor’s speed according to the requirements of the control system, and the motor power matches the power provided to components, thus eliminating the throttling loss of hydraulic circuits. The system is compact, produces a large output force, provides stable transmission, has a quick response, and is suitable as a hydraulic control system of a large butterfly valve.

  19. Experimental and Analysis for Self-excited Pressure Oscillations and Noise of Hydraulic Jet Pipe Servo-valve%液压射流管伺服阀自激振荡和噪声实验与分析

    Institute of Scientific and Technical Information of China (English)

    邹贤珍

    2016-01-01

    在液压流场中,液压伺服阀的高频噪声主要来自于自身的震荡。采用压电式动态压力传感器和扩音器对液压射流管伺服阀的自激振荡和噪声进行检测。试验中,将伺服阀的进口压力控制在11~21 MPa。为了将实验数据精准化,利用FFT和小波分析法对压力震荡信号和噪声信号进行处理。根据分析结果找出自激振荡和噪声产生的原因,并为降低液压伺服阀的自激振荡和噪声提供了方法。%In the hydraulic flow field, the high frequency noise of the hydraulic servo-valve is mainly derived from its own shock. Using the piezoelectric dynamic pressure sensor and amplifier, hydraulic jet pipe servo-valve self-excited vibration and noise were de-tected.In the test, the inlet pressure of the servo-valve was controlled in 11~21 MPa.In order to make the experimental data accurate, FFT and wavelet analysis method were used to deal with the pressure oscillation signal and noise signal.According to the analysis re-sults, the causes of the self-excited oscillation and noise were found out.It provides method for reducing vibration and noise of hydrau-lic servo-valve.

  20. Finite element analysis of 80 MN inclined double-column rapid forging hydraulic press%80MN双柱斜置式快速锻造液压机有限元分析

    Institute of Scientific and Technical Information of China (English)

    闫红红; 李永堂; 刘兴; 张亦工

    2013-01-01

    以我国第1台最大吨位80 MN双柱式快速锻造液压机为研究对象,应用Pro/E三维建模软件和ANSYS有限元分析软件相结合的方式建立有限元模型,采用接触法处理液压机各部分连接关系,分析了双柱斜置式多拉杆全预紧结构;对偏载镦粗工况下的受力状态进行了整机数值模拟,通过对计算结果分析,得到液压机的受力特点和变形规律,为液压机结构设计和优化提供依据.%The first largest tonnage 80 MN double-column rapid forging hydraulic press in China was studied. The finite element model was established with the combination of Pro/E 3D modeling software and the ANSYS finite element analysis software. The connection relationship of each part of the hydraulic press was handled through the contact method. The multi-rod whole pretension structure of inclined double-column was analyzed. The stress state of eccentric load upsetting condition was numerical simulated. Through the analysis of calculation results, the stress state and deformation law of hydraulic press is received. It provides a basis for the structural design and optimization of hydraulic press.

  1. Issues Related To Troubleshooting Of Avionic Hydraulic Units

    Directory of Open Access Journals (Sweden)

    Jastrzębski Grzegorz

    2014-12-01

    Full Text Available The paper outlines workflows associated with troubleshooting of avionic hydraulic systems with detailed description of the troubleshooting algorithm and classification of diagnostic signals provided by avionic hydraulic systems and their subassemblies. Attention is paid to measurement sequences for diagnostic signals from hydraulic systems, circuits and units. Detailed description is dedicated to an innovative design of a troubleshooting device intended for direct measurements of internal leaks from avionic hydraulic units. Advantages of the proposed measurement method are summarized with benefits from use of the presented device and compared against the methods that are currently in use. Subsequent phases of the troubleshooting process are described with examples of measurement results that have been acquired from subassemblies of hydraulic systems of SU-22 aircrafts currently in service at Polish Air Forces with consideration given to cases when the permissible threshold of diagnostic signals were exceeded. Finally, all results from investigations are subjected to thorough analysis.

  2. Reactive barriers: hydraulic performance and design enhancements.

    Science.gov (United States)

    Painter, B D M

    2004-01-01

    The remediation of contaminated ground water is a multibillion-dollar global industry. Permeable reactive barriers (PRBs) are one of the leading technologies being developed in the search for alternatives to the pump-and-treat method. Improving the hydraulic performance of these PRBs is an important part of maximizing their potential to the industry. Optimization of the hydraulic performance of a PRB can be defined in terms of finding the balance between capture, residence time, and PRB longevity that produces a minimum-cost acceptable design. Three-dimensional particle tracking was used to estimate capture zone and residence time distributions. Volumetric flow analysis was used for estimation of flow distribution across a PRB and in the identification of flow regimes that may affect the permeability or reactivity of portions of the PRB over time. Capture zone measurements extended below the base of partially penetrating PRBs and were measured upgradient from the portion of aquifer influenced by PRB emplacement. Hydraulic performance analysis of standard PRB designs confirmed previously presented research that identified the potential for significant variation in residence time and capture zone. These variations can result in the need to oversize the PRB to ensure that downgradient contaminant concentrations do not exceed imposed standards. The most useful PRB design enhancements for controlling residence time and capture variation were found to be customized downgradient gate faces, velocity equalization walls, deeper emplacement of the funnel than the gate, and careful manipulation of the hydraulic conductivity ratio between the gate and the aquifer.

  3. Performances of a balanced hydraulic motor with planetary gear train

    Science.gov (United States)

    Yu, Hongying; Luo, Changjie; Wang, Huimin

    2012-07-01

    The current research of a balanced hydraulic motor focuses on the characteristics of the motor with three planet gears. References of a balanced hydraulic motor with more than three planet gears are hardly found. In order to study the characteristics of a balanced hydraulic motor with planetary gear train that includes more than three planet gears, on the basis of analysis of the structure and working principle of a balanced hydraulic motor with planetary gear train, formulas are deduced for calculating the hydraulic motor's primary performance indexes such as displacement, unit volume displacement, flowrate fluctuation ratio, etc. Influences of the gears' tooth number on displacement and flowrate characteristics are analyzed. In order to guarantee the reliability of sealing capability, the necessary conditions that tooth number of the sun gear and the planet gears should satisfy are discussed. Selecting large unit volume displacement and small displacement fluctuation ratio as designing objectives, a balanced hydraulic motor with three planet gears and a common gear motor are designed under the conditions of same displacement, tooth addendum coefficien and clearance coefficient. By comparing the unit volume displacement and fluctuation ratio of the two motors, it can be seen that the balanced hydraulic motor with planetary gear train has the advantages of smaller fluctuation ratio and larger unit volume displacement. The results provide theoretical basis for choosing gear tooth-number of this kind of hydraulic motor.

  4. 水力振荡器降低摩擦阻力影响的分析%Analysis on the Influence of Frictional Resistance Reduction by Hydraulic Oscillator

    Institute of Scientific and Technical Information of China (English)

    孙庆春; 郭宝林; 赵利锋

    2015-01-01

    In deviated well drilling, drill stems will naturally be pressed close to the borehole wall on the bottom side owing to the gravity with static frictional resistance produced, which will further evolve into backing pressure and lead to toolface, lower ROP and reduced drilling footage in a single trip;if not timely moving about the pipe, sticking accident is likely oc-cur and even more with well abandoned.Therefore, friction reduction and backing pressure relieving become important parts of safe drilling.The magnitude of friction is decided by the component force and static friction coefficient of drill strings weight in borehole trajectory normal direction.In sliding drilling, some ways such as adding lubricant into the mud or making a short tirp ( for borehole dressing) were adopted to reduce the static friction coefficient for the purpose of reduc-ing friction and relieving backing pressure.In term of the classical physics, the static friction is greater than sliding fric-tion;therefore, backing pressure relieving can be achieved by transforming the static friction into slide friction.In this pa-per, the application effects are evaluated based on the cause analysis on the friction, the mechanism of hydraulic oscillator and its application in Sulige gasfiled and Yumen, Daqing as well as some other oilfields.And the matters of attention in the use of hydraulic oscillator are discussed through the field test in Ya K1-7 well of Yumen oilfield.%在斜井钻进中,钻具基于重力影响会自然贴合下井壁,并与井壁产生静摩阻,滑动钻进中则进一步演变为托压现象,常导致工具面摆置困难、机械钻速降低、单趟钻进尺减少等问题;若活动钻具不及时,则有可能引发钻具粘卡事故,严重时可致单井报废. 因此,降低摩阻、减缓托压已然成为安全钻井的重要环节. 摩阻大小由钻柱自重在井眼轨迹法线方向上的分力和静摩擦系数来决定. 在滑动钻进中,技术人员往往通

  5. DLC coatings for hydraulic applications

    Institute of Scientific and Technical Information of China (English)

    Luca NOBILI; Luca MAGAGNIN

    2009-01-01

    Replacement of lubricating oils with water or low-viscosity fluids is highly desirable in many industrial fields, on account of the environmental and economical advantages. Low lubricity of water might be insufficient for proper operation of hydraulic components, and diamond-like carbon(DLC) coatings are very attractive as solid lubricant films. A remote-plasma PACVD process was utilized to deposit hydrogenated DLC coatings (a-C:H) on different substrates. Microindentation measurements show that the coating hardness is around 35 GPa. Tribological behavior was evaluated by block-on-ring tests performed in water and water with alumina. The wear rate was calculated after measuring the wear volume by a laser profilemeter. Morphological and compositional analysis of the wear tracks reveal that coating failure may occur by abrasive wear or delamination, depending on the substrate properties. Hard and smooth substrates give the best results and dispersed alumina particles increase the wear rate.

  6. Analysis of load reduction possibilities using a hydraulic soft yaw system for a 5-MW turbine and its sensitivity to yaw-bearing friction

    DEFF Research Database (Denmark)

    Stubkier, S.; Pedersen, H. C.; Jonkman, J. M.

    2014-01-01

    With the increasing size of wind turbines and with increasing lifetime demands, new methods for load reduction in the turbines need to be examined. One method is to make the yaw system of the turbine flexible, thereby dampening the loads to the system. This paper presents a hydraulic soft yaw...

  7. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...... of the laws of physics on the system. The unknown (or uncertain) parameters are estimated with Maximum Likelihood (ML) parameter estimation. The identified model has been evaluated by comparing the measurements with simulation of the model. The identified model was much more capable of describing the dynamics...... of the system than the deterministic model....

  8. Hydraulic mining method

    Science.gov (United States)

    Huffman, Lester H.; Knoke, Gerald S.

    1985-08-20

    A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

  9. Spinning hydraulic jump

    Science.gov (United States)

    Abderrahmane, Hamid; Kasimov, Aslan

    2013-11-01

    We report an experimental observation of a new symmetry breaking of circular hydraulic jump into a self-organized structure that consists of a spinning polygonal jump and logarithmic-spiral waves of fluid elevation downstream. The waves are strikingly similar to spiral density waves in galaxies. The fluid flow exhibits counterparts of salient morphological features of galactic flows, in particular the outflow from the center, jets, circum-nuclear rings, gas inflows toward the galactic center, and vortices. The hydrodynamic instability revealed here may have a counterpart that plays a role in the formation and sustainability of spiral arms in galaxies.

  10. 46 CFR 28.880 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... hydraulic equipment and the adjacent work area. Protection shall be afforded to the operator of hydraulic... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.880 Section 28.880 Shipping... INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.880 Hydraulic equipment. (a) Each hydraulic system must...

  11. Development and Verification of Thermal-hydraulic Analysis Code for Annular Fuel%环形燃料热工水力性能分析程序开发及验证

    Institute of Scientific and Technical Information of China (English)

    刁均辉; 季松涛; 张应超

    2015-01-01

    本工作开发了环形燃料子通道分析程序SAAF。采用SAAF计算了西屋公司四环路压水堆所用环形燃料组件的热工水力性能,并与VIPRE‐01的计算结果进行比较。结果表明,SAAF与VIPRE‐01的计算结果符合较好,SAAF可用于环形燃料热工水力设计分析。%A sub‐channel thermal‐hydraulic analysis code named SAAF (sub‐channel analyzer for annular fuel) for annular fuel was developed .The thermal‐hydraulic prop‐erties of annular fuel pins for Westinghouse 4‐loop PWR were calculated by SAAF code , and the calculating results of SAAF and VIPRE‐01 codes were compared .The results show that the SAAF code can be used to determine the thermal‐hydraulic properties of the annular fuel .

  12. Thermal Balance Analysis of Hydraulic System of Single Drum Vibratory Rollers%单钢轮振动压路机液压系统的热平衡分析

    Institute of Scientific and Technical Information of China (English)

    刘治文; 宋年波; 孟凡皓

    2014-01-01

    对单钢轮振动压路机液压系统的热源和散热进行分析。以某单钢轮振动压路机为研究对象进行热平衡试验,利用试验中测得的泵和马达的压力、温度等参数对液压系统的产热和散热功率进行计算,并通过试验验证液压系统热平衡理论分析计算方法的正确性,为单钢轮振动压路机液压系统的热平衡分析提供可靠的理论依据。%The heat source and heat-dissipating of the hydraulic system of a certain single drum vibratory roller are analyzed in this paper.The thermal balance experiment is conducted with a single drum vibratory roller and the heat-generating power and heat-dissipating power of the hydraulic system is calculated with such data as the pressure of pumps and motors as well as the temperature which are tested from the experiment.The theoretical analyzing and calculating method is finally verified to be right by the experiment,which can provide the reliable analyzing basis for the thermal balance analysis of hydraulic system of single drum vibratory rollers.

  13. 多孔管子管板液压胀接性能影响的分析%Hydraulic Expansion Infection Analysis of Multi-hole Tube to Tubesheet Joint

    Institute of Scientific and Technical Information of China (English)

    和广庆; 杨圆明; 李翠翠

    2015-01-01

    对单孔和多孔的管子管板的液压胀接进行理论计算和有限元分析,计算结果表明,在相同和不同胀接参数下,多孔胀接后和单孔胀接的残余接触压力有明显差异;选取不同布孔的管进行拉脱力试验,试验结果表明,多孔胀接后,管子拉脱力数值与孔区布置具有相关性。模拟分析和试验结果对胀接评定试样的制作、多孔胀接性能的评价提供了参考。%The residual contact pressure of single hole and multi-hole are different for tube to tubesheet hydraulic expansion by calculation and element analysis.The result shown that tube pull out force value have relationship with tube position in multi-hole tubesheet by hydraulic expansion test.It provide a refer-ence for hydraulic expansion qualification mockup manufacture and expansion evaluation of multi-hole tubesheet joint.

  14. Hydraulic Analysis, Washita County, Oklahoma

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Recent developments in digital terrain and geospatial database management technology make it possible to protect this investment for existing and future projects to...

  15. Hydraulic System Wear Debris Analysis.

    Science.gov (United States)

    1982-08-03

    drawn. Each one-=L sample was drawn with a clean plastic pipette of one-mL capacity. The samples were placed in clean Ferrogram preparation bottles ...and from cavities in a block which held linear seals into sampling bottles . Several photographs of this debris , which was deposited on Ferro- grams...silicon in the glass overshadowed the elements of the wear debris . To overcome this difficulty, the Ferrogram should be pre- pared on a carbon-filled

  16. Finite element modal analysis of 80 MN high speed forging hydraulic press%80MN快速锻造液压机的有限元模态分析

    Institute of Scientific and Technical Information of China (English)

    佘海斌; 张学良; 温淑花; 连晋华; 陈永会; 兰国生

    2013-01-01

    针对快速锻造液压机的有限元建模,本文将以往研究中的活动横梁与机架整体建模,改进为活动横梁与机架采用节点耦合和弹簧连接的方式建模,较好地模拟了液压机的工作连接情况.通过对80 MN快速锻造液压机进行有限元模态分析计算,获得了有限元模态频率和模态振型,模态频率分析表明本液压机的最小固有频率为3.8486 Hz,大于其工作频率1.25 Hz,液压机不会发生共振.模态振型分析表明第三阶振型的振幅相对其它阶大出21.9%以上,下横梁振动对液压机工作精度的影响较大.%In view of the finite element modeling for high speed forging hydraulic press, the method of node coupling and spring connection was used to model the move-beam and frame instead of the overal modeling used in the past research , which imitated the working connection conditions of hydraulic press well. Through analyzing and calculating finite element modes of vibration for 80 MN high speed forging hydraulic press, finite element model frequency and mode shape were got. The analysis of model frequency shows that minimum natural frequency of 3. 8486 Hz is greater than the operating frequency of 1. 25 Hz, so this hydraulic press will not happened to resonate. The analysis of mode shape shows that the amplitude of the third is 21. 9% larger than that of others, so the vibration of down-beam has a great impact on the work accuracy of hydraulic press.

  17. Finite element analysis for the arm of hydraulic excavators based on ABAQUS%应用 ABAQUS 的液压挖掘机动臂有限元分析

    Institute of Scientific and Technical Information of China (English)

    蒋小利; 江志刚; 张华; 胡晓莉

    2014-01-01

    The arm is a main component of a hydraulic excavator for completing the function ,the reasonability of the structure will directly affect the working performance and reliability of the hydraulic excavator .However,using the finite element method for structural analysis of excavator arm is the premise for ensuring the rationality for the structural design of the arm .Taking a certain type of hydraulic excavator(20t)as the research object,using finite element analysis software ABAQUS to carry out finite element analysis on its arm ,from which the cloud atlas of stress and deform was obtained .The analysis results show that the strength and stiffness for the arm was sufficient and theoretical guidance for the design and test of the arm was provided .%液压挖掘机动臂是完成液压挖掘机各项功能的主要构件,其结构设计的合理性直接关系到液压挖掘机的工作性能和可靠性。基于有限元分析方法的液压挖掘机动臂结构分析是保证液压挖掘机动臂结构设计合理性的前提,以某型液压挖掘机(20 t级)为研究对象,应用有限元分析软件ABAQUS对其动臂进行有限元分析,求得危险工况下该动臂的应力云图与位移云图,通过云图分析动臂的强度和刚度,为动臂的设计和试验提供参考。

  18. Hydraulic rams; a comparative investigation

    NARCIS (Netherlands)

    Tacke, J.H.P.M.

    1988-01-01

    A mathematical model describing the essential features of hydraulic ram operation is developed in order to clarify the possibilities and limitations of the ram relative to its site and its adjustments. The model distinguishes three different periods in the pumping cycle of the hydraulic ram: acceler

  19. Hydraulics. FOS: Fundamentals of Service.

    Science.gov (United States)

    John Deere Co., Moline, IL.

    This manual on hydraulics is one of a series of power mechanics texts and visual aids for training in the servicing of agricultural and industrial machinery. Focus is on oil hydraulics. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and laymen. The twelve chapters focus…

  20. Effect of hydraulic hysteresis on the stability of infinite slopes under steady infiltration

    Science.gov (United States)

    Chen, Pan; Mirus, Benjamin B.; Lu, Ning; Godt, Jonathan W.

    2017-01-01

    Hydraulic hysteresis, including capillary soil water retention (SWR), air entrapment SWR, and hydraulic conductivity, is a common phenomenon in unsaturated soils. However, the influence of hydraulic hysteresis on suction stress, and subsequently slope stability, is generally ignored. This paper examines the influence of each of these three types of hysteresis on slope stability using an infinite slope stability analysis under steady infiltration conditions. First, hypothetical slopes for representative silty and sandy soils are examined. Then a monitored hillslope in the San Francisco Bay Area, California is assessed, using observed rainfall conditions and measured hydraulic and geotechnical properties of the colluvial soil. Results show that profiles of suction stress and the corresponding factor of safety are generally strongly affected by hydraulic hysteresis. Results suggest that each of the three types of hydraulic hysteresis may play a major role in the occurrence of slope failure, indicating that ignoring hydraulic hysteresis will likely lead to underestimates of failure potential and hence to inaccurate slope stability analysis.

  1. Estimating Hydraulic Properties of the Floridan Aquifer System by Analysis of Earth-Tide, Ocean-Tide, and Barometric Effects, Collier and Hendry Counties, Florida

    Science.gov (United States)

    Merritt, Michael L.

    2004-01-01

    Aquifers are subjected to mechanical stresses from natural, non-anthropogenic, processes such as pressure loading or mechanical forcing of the aquifer by ocean tides, earth tides, and pressure fluctuations in the atmosphere. The resulting head fluctuations are evident even in deep confined aquifers. The present study was conducted for the purpose of reviewing the research that has been done on the use of these phenomena for estimating the values of aquifer properties, and determining which of the analytical techniques might be useful for estimating hydraulic properties in the dissolved-carbonate hydrologic environment of southern Florida. Fifteen techniques are discussed in this report, of which four were applied. An analytical solution for head oscillations in a well near enough to the ocean to be influenced by ocean tides was applied to data from monitor zones in a well near Naples, Florida. The solution assumes a completely non-leaky confining unit of infinite extent. Resulting values of transmissivity are in general agreement with the results of aquifer performance tests performed by the South Florida Water Management District. There seems to be an inconsistency between results of the amplitude ratio analysis and independent estimates of loading efficiency. A more general analytical solution that takes leakage through the confining layer into account yielded estimates that were lower than those obtained using the non-leaky method, and closer to the South Florida Water Management District estimates. A numerical model with a cross-sectional grid design was applied to explore additional aspects of the problem. A relation between specific storage and the head oscillation observed in a well provided estimates of specific storage that were considered reasonable. Porosity estimates based on the specific storage estimates were consistent with values obtained from measurements on core samples. Methods are described for determining aquifer diffusivity by comparing the

  2. Hydraulic Stability of Accropode Armour

    DEFF Research Database (Denmark)

    Jensen, T.; Burcharth, H. F.; Frigaard, Peter

    , and to assess the influence of core permeability on the hydraulic stability of Accropodes. Two structures were examined, one with a relatively permeable core and one with a relatively impermeable core. In November/December 1995, Ph.D.-student Marten Christensen carried out the model tests on the structure...... with permeable core (crushed granite with a gradation of 5-8 mm). The outcome of this study is described in "Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers" by Christensen & Burcharth (1995). In January/February 1996, Research Assistant Thomas Jensen carried out a similar study......The present report describes the hydraulic model tests of Accropode armour layers carried out at the Hydraulics Laboratory at Aalborg University from November 1995 through March 1996. The objective of the model tests was to investigate the hydraulic stability of Accropode armour layers...

  3. Hydraulic Stability of Accropode Armour

    DEFF Research Database (Denmark)

    Jensen, T.; Burcharth, H. F.; Frigaard, Peter

    , and to assess the influence of core permeability on the hydraulic stability of Accropodes. Two structures were examined, one with a relatively permeable core and one with a relatively impermeable core. In November/December 1995, Ph.D.-student Marten Christensen carried out the model tests on the structure...... with permeable core (crushed granite with a gradation of 5-8 mm). The outcome of this study is described in "Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers" by Christensen & Burcharth (1995). In January/February 1996, Research Assistant Thomas Jensen carried out a similar study......The present report describes the hydraulic model tests of Accropode armour layers carried out at the Hydraulics Laboratory at Aalborg University from November 1995 through March 1996. The objective of the model tests was to investigate the hydraulic stability of Accropode armour layers...

  4. Analysis of hydraulic tests of the Culebra and Magenta Dolomites and Dewey Lake Redbeds conducted at the Waste Isolation Pilot Plant Site

    Energy Technology Data Exchange (ETDEWEB)

    Beauheim, R.L. [Sandia National Labs., Albuquerque, NM (United States). Geohydrology Dept.; Ruskauff, G.J. [Duke Engineering and Services, Inc., Albuquerque, NM (United States)

    1998-09-01

    This report presents interpretations of hydraulic tests conducted at 15 well locations in the vicinity of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico between 1980 and 1996. The WIPP is a US Department of Energy (DOE) facility to demonstrate safe disposal of transuranic wastes arising form the nation`s defense programs. The WIPP repository lies within bedded halite of the Salado Formation, 2,155 ft below ground surface. The tests reported herein were, with two exceptions, conducted in the Culebra Dolomite member of the Rustler Formation, which overlies the Salado Formation. The remaining tests were conducted in the Magenta Member of the Rustler and in the overlying formation, the Dewey Lake Redbeds. This report completes the documentation of hydraulic-test interpretations used as input to the WIPP Compliance Certification Application (US DOE, 1996).

  5. Development and application of the coupled thermal-hydraulics and neutron-kinetics code ATHLET/BIPR-VVER for safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lizorkin, M.; Nikonov, S. [Kurchatov Institute for Atomic Energy, Moscow (Russian Federation); Langenbuch, S.; Velkov, K. [Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) mbH, Garching (Germany)

    2006-07-01

    The coupled thermal-hydraulics and neutron-kinetics code ATHLET/BIPR-VVER was developed within a co-operation between the RRC Kurchatov Institute (KI) and GRS. The modeling capability of this coupled code as well as the status of validation by benchmark activities and comparison with plant measurements are described. The paper is focused on the modeling of flow mixing in the reactor pressure vessel including its validation and the application for the safety justification of VVER plants. (authors)

  6. Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Mørkholt, M.

    As wind turbines increase in size, combined with increased lifetime demands, new methods for load reduction needs to be examined. One method is to make the yaw system of the turbine soft/flexible and hereby dampen the loads to the system, which is the focus of the current paper. By utilizing...... the HAWC2 aeroelastic code and an extended model of the NREL 5MW turbine combined with a simplified linear model of the turbine, the parameters of the soft yaw system are optimized to reduce loading in critical components. Results shows that a significant reduction in fatigue and extreme loads to the yaw...... system and rotor shaft when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. Based on the extrapolated loads, the duty cycles show that it is possible to construct...

  7. 沥青混凝土心墙坝水力劈裂发生机理及分析%Mechanism and analysis of occurrence of hydraulic fracturing for asphalt concrete core dam

    Institute of Scientific and Technical Information of China (English)

    邓建伟; 凤炜; 何建新

    2014-01-01

    The influence of hydraulic fracturing problem of soil core wall dam on the safety of embank-ment dam has been paid great attention in engineering field.This paper analyzed the mechanism that hy-draulic fracturing occurs in asphalt concrete core wall, and proposed that the horizontal seam produced in construction of compacted core wall's caused by “pine cone effect” and the low permeability of asphalt concrete are the important material conditions of hydraulic fracturing, while the“arch effect” and power-ful “water wedge effect” produced by transition material and core wall interactions are the hydraulic frac-ture mechanics conditions.The analysis of examples proved that the soil core wall and the asphalt con-crete core wall all exist the risk of hydraulic fracturing,which need to pay close attention in the field of water conservancy sector.It noted that high asphalt concrete core wall dam should be carefully studied and the core wall's impervious safety and reliability be evaluated.The result has a certain reference value for the design and construction of asphalt concrete core wall dam.%土质心墙坝的水力劈裂问题对土石坝安全的影响已引起工程界的高度重视。本文分析了沥青混凝土心墙发生水力劈裂的机理,提出心墙碾压施工“松塔效应”产生的水平缝和沥青混凝土的低透水性是发生水力劈裂的重要物质条件,而过渡料与心墙相互作用产生的“拱效应”及强大的“水楔”作用是发生水力劈裂的力学条件。通过实例分析证明沥青混凝土防渗心墙与土质心墙一样也存在水力劈裂的风险,需引起水利界的高度重视,对于高沥青混凝土心墙坝应审慎研究并评价心墙的防渗安全可靠性。分析结果对沥青混凝土心墙坝的设计与施工有一定参考意义。

  8. Comparative Analysis of Hydraulic Fracturing Wastewater Practices in Unconventional Shale Development: Newspaper Coverage of Stakeholder Concerns and Social License to Operate

    Directory of Open Access Journals (Sweden)

    Joel Gehman

    2016-09-01

    Full Text Available In this article we review prior literature regarding the concept of social license to operate, and related concepts, including corporate social responsibility, sustainable development, stakeholder management and cumulative effects. Informed by these concepts, we search for newspaper articles published in North American provinces and states where the Barnett, Duvernay, Marcellus and Montney shale plays are located. Using these data, we tabulate coverage of stakeholder concerns related to hydraulic fracturing and wastewater practices, and compare the extent to which these concerns vary over place and time. Our vocabulary analyses identify differences in the types and quantities of newspaper coverage devoted to concerns regarding hydraulic fracturing activities in general and wastewater practices in particular. We interpret these differences as suggesting that obtaining a social license to operate is likely not a one size fits all proposition. By understanding which stakeholder concerns are most salient in particular places and times, oil and gas operators and regulators can better tailor their strategies and policies to address local concerns. In other words, the findings from this study indicate that conventional understandings of risk as a technical or economic problem may not be adequate for dealing with unconventional resource challenges such as hydraulic fracturing. Operators and regulators may also need to manage social and cultural risks.

  9. 竖井贯流泵装置流道水力性能分析%Hydraulic Performance Analysis on the Flow Passage of Shaft Tubular Pump System

    Institute of Scientific and Technical Information of China (English)

    杨雪林; 黄毅; 陈国标

    2012-01-01

    针对竖井贯流泵装置中,进、出水流道水力损失所占比重较大的问题,通过分析泵装置流道的三维数值模拟结果,对流道型线进行了优化设计,获得了水力性能较好的型线方案。结合模型试验结果,表明流道型线优化后的水泵装置效率较高,具有较好的水力性能。%According to the facts that the hydraulic losses of inlet and outlet passage takes a large proportion in shaft tubular pump sets, 3D numerical simulation of pump sets'passage is analyzed, the passage shape is optimally designed and the passage shape with better hydraulic performance is obtained. Comparing with pump model device experiment, the pump sets with optimal passage shape is of high efficiency and good hydraulic performance.

  10. Hydraulic Turbine Cavitation Analysis Based on the Cordon Method%基于Cordon法的水轮机抗空蚀研究

    Institute of Scientific and Technical Information of China (English)

    桂家章; 梁兴

    2013-01-01

    水轮机空蚀与运行工况密切联系,其影响因素较多。为此针对国内某电站,采用cordon法预估电站空蚀破坏,并与电站实际空蚀破坏比较,进而分解cordon法,从水轮机转轮材料、吸出高度以及负荷利用系数等三方面,分析诱发水轮机空蚀的关键因素,提出相应抗空蚀措施,总结水轮机空蚀研究思路,为水电站设计、安全经济运行及技术改造提供具有实用价值的借鉴意见。%The hydraulic turbine cavitation is related with power station operation, and it is influenced by much reasons. Therefore, by comparison with actual cavitation damage, the estimate value which calculated by the cordon method is precise. Based on the cordon method, the cause of hydraulic turbine cavitation are analyzed from the aspects of runner material, suction height and load utilization coefficient, and the anti-measures of hydraulic turbine cavitation is researched. It is valuable for the safe and economic operation, and also useful for technical reformation in hydroelectric power station.

  11. Virtual Prototype Modeling and Simulation Analysis of Hydraulic Shaking Table%液压振动台虚拟样机建模及仿真分析

    Institute of Scientific and Technical Information of China (English)

    崔伟清; 范顺成; 李艳艳; 王胜凯

    2012-01-01

    The three-dimensional solid model of hydraulic shaking table was built by using UG software. The solid model built was imported into ADAMS software via the data interface to build virtual prototype of the hydraulic shaking table. Then Matlab was chosen for establishing control system. The control system and virtual prototype perform co-simulation was realized through data interchange technology. The frequency response characteristics of the hydraulic shaking table were analyzed through simulation.%利用UG软件建立液压振动台三维实体模型,将建立的实体模型通过数据接口导入ADAMS软件,建立起液压振动台虚拟样机.利用Matlab软件建立控制系统,与ADAMS建立的虚拟样机通过数据交换技术进行联合仿真,对振动台系统的频响特性进行分析.

  12. INFORMATION-MEASURING TEST SYSTEM OF DIESEL LOCOMOTIVE HYDRAULIC TRANSMISSIONS

    Directory of Open Access Journals (Sweden)

    I. V. Zhukovytskyy

    2015-08-01

    Full Text Available Purpose. The article describes the process of developing the information-measuring test system of diesel locomotives hydraulic transmission, which gives the possibility to obtain baseline data to conduct further studies for the determination of the technical condition of diesel locomotives hydraulic transmission. The improvement of factory technology of post-repair tests of hydraulic transmissions by automating the existing hydraulic transmission test stands according to the specifications of the diesel locomotive repair enterprises was analyzed. It is achieved based on a detailed review of existing foreign information-measuring test systems for hydraulic transmission of diesel locomotives, BelAZ earthmover, aircraft tug, slag car, truck, BelAZ wheel dozer, some brands of tractors, etc. The problem for creation the information-measuring test systems for diesel locomotive hydraulic transmission is being solved, starting in the first place from the possibility of automation of the existing test stand of diesel locomotives hydraulic transmission at Dnipropetrovsk Diesel Locomotive Repair Plant "Promteplovoz". Methodology. In the work the researchers proposed the method to create a microprocessor automated system of diesel locomotives hydraulic transmission stand testing in the locomotive plant conditions. It acts by justifying the selection of the necessary sensors, as well as the application of the necessary hardware and software for information-measuring systems. Findings. Based on the conducted analysis there was grounded the necessity of improvement the plant hydraulic transmission stand testing by creating a microprocessor testing system, supported by the experience of developing such systems abroad. Further research should be aimed to improve the accuracy and frequency of data collection by adopting the more modern and reliable sensors in tandem with the use of filtering software for electromagnetic and other interference. Originality. The

  13. Experimental hydraulic analysis in conduction tunnels at the trunk section working as a channel considering compound roughness; Analisis hidraulico experimental en tuneles de conduccion en seccion baul trabajando como canal, considerando rugosidades compuestas

    Energy Technology Data Exchange (ETDEWEB)

    Marengo-Mogollon, Humberto; Cortes-Cortes, Carlos [Comision Federal de Electricidad (Mexico); Arreguin-Cortes, Felipe I [Comision Nacional del Agua (Mexico)

    2008-01-15

    This paper presents the roughness coefficients of a conduction tunnel at the trunk section working as a channel obtained experimentally using a hydraulic model of the diversion tunnel of the Hydroelectric Project called El Cajon (Mexico). A comparative analysis between experimental and theoretical coefficients obtained in the literature is shown. [Spanish] Se presentan los coeficientes de rugosidad compuesta de un tunel de conduccion en seccion baul trabajando como canal obtenidos en forma experimental en un modelo hidraulico del tunel de desvio del Proyecto Hidroelectrico El Cajon (Mexico). Se muestra un analisis comparativo entre los coeficientes experimentales y los teoricos obtenidos en la literatura.

  14. Motion Planning Based Coordinated Control for Hydraulic Excavators

    Institute of Scientific and Technical Information of China (English)

    GAO Yingjie; JIN Yanchao; ZHANG Qin

    2009-01-01

    Hydraulic excavator is one type of the most widely applied construction equipment for various applications mainly because of its versatility and mobility. Among the tasks performed by a hydraulic excavator, repeatable level digging or flat surface finishing may take a large percentage. Using automated functions to perform such repeatable and tedious jobs will not only greatly increase the overall productivity but more importantly also improve the operation safety. For the purpose of investigating the technology without loss of generality, this research is conducted to create a coordinate control method for the boom, arm and bucket cylinders on a hydraulic excavator to perform accurate and effective works. On the basis of the kinematic analysis of the excavator linkage system, the tip trajectory of the end-effector can be determined in terms of three hydraulic cylinders coordinated motion with a visualized method. The coordination of those hydraulic cylinders is realized by controlling three electro-hydranlic proportional valves coordinately. Therefore,the complex control algorithm of a hydraulic excavator can be simplified into coordinated motion control of three individual systems.This coordinate control algorithm was validated on a wheeled hydraulic excavator, and the validation results indicated that this developed control method could satisfaetorily accomplish the auto-digging function for level digging or flat surface finishing.

  15. Physico-empirical approach for mapping soil hydraulic behaviour

    Directory of Open Access Journals (Sweden)

    G. D'Urso

    1997-01-01

    Full Text Available Abstract: Pedo-transfer functions are largely used in soil hydraulic characterisation of large areas. The use of physico-empirical approaches for the derivation of soil hydraulic parameters from disturbed samples data can be greatly enhanced if a characterisation performed on undisturbed cores of the same type of soil is available. In this study, an experimental procedure for deriving maps of soil hydraulic behaviour is discussed with reference to its application in an irrigation district (30 km2 in southern Italy. The main steps of the proposed procedure are: i the precise identification of soil hydraulic functions from undisturbed sampling of main horizons in representative profiles for each soil map unit; ii the determination of pore-size distribution curves from larger disturbed sampling data sets within the same soil map unit. iii the calibration of physical-empirical methods for retrieving soil hydraulic parameters from particle-size data and undisturbed soil sample analysis; iv the definition of functional hydraulic properties from water balance output; and v the delimitation of soil hydraulic map units based on functional properties.

  16. Stability of Hydraulic Systems with Focus on Cavitating Pumps

    OpenAIRE

    Brennen, C. E.; Braisted, D. M.

    1980-01-01

    Increasing use is being made of transmission matrices to characterize unsteady flows in hydraulic system components and to analyze the stability of such systems. This paper presents some general characteristics which should be examined in any experimentally measured transmission matrices and a methodology for the analysis of the stability of transmission matrices in hydraulic systems of order 2. These characteristics are then examined for cavitating pumps and the predicted instabilities (kn...

  17. Hydraulic conductivity of compacted zeolites.

    Science.gov (United States)

    Oren, A Hakan; Ozdamar, Tuğçe

    2013-06-01

    Hydraulic conductivities of compacted zeolites were investigated as a function of compaction water content and zeolite particle size. Initially, the compaction characteristics of zeolites were determined. The compaction test results showed that maximum dry unit weight (γ(dmax)) of fine zeolite was greater than that of granular zeolites. The γ(dmax) of compacted zeolites was between 1.01 and 1.17 Mg m(-3) and optimum water content (w(opt)) was between 38% and 53%. Regardless of zeolite particle size, compacted zeolites had low γ(dmax) and high w(opt) when compared with compacted natural soils. Then, hydraulic conductivity tests were run on compacted zeolites. The hydraulic conductivity values were within the range of 2.0 × 10(-3) cm s(-1) to 1.1 × 10(-7) cm s(-1). Hydraulic conductivity of all compacted zeolites decreased almost 50 times as the water content increased. It is noteworthy that hydraulic conductivity of compacted zeolite was strongly dependent on the zeolite particle size. The hydraulic conductivity decreased almost three orders of magnitude up to 39% fine content; then, it remained almost unchanged beyond 39%. Only one report was found in the literature on the hydraulic conductivity of compacted zeolite, which is in agreement with the findings of this study.

  18. 超临界水实验回路热工水力分析%Thermal-hydraulic Analysis of SWAMUP Test Facility

    Institute of Scientific and Technical Information of China (English)

    汪子迪; 曹臻; 刘晓晶; 程旭

    2015-01-01

    作为超临界水堆失水事故分析的关键现象,跨临界过程(即超临界水堆的压力从超临界状态降到次临界状态22.1 M Pa以下)受到国内外的关注。上海交通大学的超临界流体多功能实验回路(SWAMUP)计划对这一泄压过程进行实验研究。为确保该实验装置在实验过程中的安全性能,采用系统程序AT HLET‐SC对该实验回路进行预计算分析,主要针对该系统在泄压跨临界过程中的热工水力参数,包括系统压力、冷却剂流量、加热棒壁面温度等展开计算,并讨论一些重要参数如泄压速度、加热棒加热功率等对计算结果的影响。计算结果表明,修改后的 ATHLET‐SC程序可模拟跨临界瞬态过程,在实验过程中,加热棒壁面温度不会超过设计上限温度,然而,回路中换热器的内外最高压差将会达6 M Pa ,这一点需在实验中特别考虑。%T rans‐critical transients ,i .e .the pressure in the reactor system undergoing a rapid decrease from the supercritical pressure to the subcritical condition ,are of crucial importance for the LOCA analysis of supercritical water cooled reactor (SCWR) .To obtain more knowledge about this process ,the supercritical water multipurpose loop (SWAMUP) test facility in Shanghai Jiao Tong University (SJTU) will be applied to provide test data for the process .Some pre‐test calculations are necessary to show the feasibility of the experiment .In this study ,the trans‐critical transient analysis was per‐formed for the SWAMUP test facility with the system code ATHLET‐SC which was modified in SJTU .The system behaviors including system pressure ,coolant mass flow , and wall temperature of heating rod during the depressurization were presented .The effects of some important parameters such as depressurization rate ,heating power of heating rod on the system characteristics were also investigated .The results indicate that the revised

  19. Analysis of Hydraulic Responses from the ER-6-1 Multiple-Well Aquifer Test, Yucca Flat FY 2004 Testing Program, Nevada Test Site, Nye County, Nevada, Rev. No.: 0

    Energy Technology Data Exchange (ETDEWEB)

    Greg Ruskauff

    2005-06-01

    This report documents the interpretation and analysis of the hydraulic data collected for the Fiscal Year (FY) 2004 Multiple-Well Aquifer Test-Tracer Test (MWAT-TT) conducted at the ER-6-1 Well Cluster in Yucca Flat Corrective Action Unit (CAU) 97, on the Nevada Test Site (NTS). The MWAT-TT was performed to investigate CAU-scale groundwater flow and transport processes related to the transport of radionuclides from sources on the NTS through the Lower Carbonate Aquifer (LCA) Hydrostratigraphic Unit (HSU). The ER-6-1 MWAT-TT was planned and executed by contractor participants for the Underground Test Area (UGTA) Project of the Environmental Restoration (ER) program of the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO). Participants included Stoller-Navarro Joint Venture (SNJV), the Environmental Engineering Services Contractor; Bechtel Nevada (BN); the Desert Research Institute (DRI); Los Alamos National Laboratory; and the University of Nevada, Las Vegas-Harry Reid Center. The SNJV team consists of the S.M. Stoller Corporation, Navarro Research and Engineering, Battelle Memorial Institute, INTERA Inc., and Weston Solutions, Inc. The MWAT-TT was implemented according to the ''Underground Test Area Project, ER-6-1 Multi-Well Aquifer Test - Tracer Test Plan'' (SNJV, 2004a) issued in April 2004. The objective of the aquifer test was to determine flow processes and local hydraulic properties for the LCA through long-term constant-rate pumping at the well cluster. This objective was to be achieved in conjunction with detailed sampling of the composite tracer breakthrough at the pumping well, as well as with depth-specific sampling and logging at multiple wells, to provide information for the depth-discrete analysis of formation hydraulic properties, particularly with regard to fracture properties.

  20. Hydraulic Actuators with Autonomous Hydraulic Supply for the Mainline Aircrafts

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2014-01-01

    Full Text Available Applied in the aircraft control systems, hydraulic servo actuators with autonomous hydraulic supply, so-called, hydraulic actuators of integrated configuration, i.e. combination of a source of hydraulic power and its load in the single unit, are aimed at increasing control system reliability both owing to elimination of the pipelines connecting the actuator to the hydraulic supply source, and owing to avoidance of influence of other loads failure on the actuator operability. Their purpose is also to raise control system survivability by eliminating the long pipeline communications and their replacing for the electro-conductive power supply system, thus reducing the vulnerability of systems. The main reason for a delayed application of the hydraulic actuators in the cutting-edge aircrafts was that such aircrafts require hydraulic actuators of considerably higher power with considerable heat releases, which caused an unacceptable overheat of the hydraulic actuators. Positive and negative sides of the hydraulic actuators, their alternative options of increased reliability and survivability, local hydraulic systems as an advanced alternative to independent hydraulic actuators are considered.Now to use hydraulic actuators in mainline aircrafts is inexpedient since there are the unfairly large number of the problems reducing, first and last, safety of flights, with no essential weight and operational advantages. Still works to create competitive hydraulic actuators ought to be continued.Application of local hydraulic systems (LHS will allow us to reduce length of pressure head and drain pipelines and mass of pipelines, as well as to raise their general fail-safety and survivability. Application of the LHS principle will allow us to use a majority of steering drive advantages. It is necessary to allocate especially the following:- ease of meeting requirements for the non-local spread of the engine weight;- essentially reducing length and weight of

  1. Study of Dynamic Characteristics for Hydraulic System on 300MN Die-forging Press

    Science.gov (United States)

    Chen, Guoqiang; Tan, Jianping

    2017-06-01

    The faults such as seal breakdown and pressure sensor damage occur in 300MN Die-forging press frequently. First, the fault phenomenon and harm of the hydraulic system was compiled statistics, the theoretical analysis of the hydraulic impact of hydraulic system are carried out based on the momentum theorem; Then, the co-simulation model of hydraulic system was established by AMESim and Simulink software and the correctness was verified. Finally, the dynamic characteristics of hydraulic system for the key working condition “forging stroke changing to mold collision” was analyzed, the influences rules of system parameters such as the leak gap of valve, diameter of water way pipeline, emulsion temperature and air contain act on hydraulic system are obtained. This conclusions have a theoretical guiding significance to the improvement and maintains of high pressure and large flow hydraulic system.

  2. Vibration Modes and the Dynamic Behaviour of a Hydraulic Plunger Pump

    Directory of Open Access Journals (Sweden)

    Tianxiao Zhang

    2016-01-01

    Full Text Available Mechanical vibrations and flow fluctuation give rise to complex interactive vibration mechanisms in hydraulic pumps. The working conditions for a hydraulic pump are therefore required to be improved in the design stage or as early as possible. Considering the structural features, parameters, and operating environment of a hydraulic plunger pump, the vibration modes for two-degree-of-freedom system were established by using vibration theory and hydraulic technology. Afterwards, the analytical form of the natural frequency and the numerical solution of the steady-state response were deduced for a hydraulic plunger pump. Then, a method for the vibration analysis of a hydraulic pump was proposed. Finally, the dynamic responses of a hydraulic plunger pump are obtained through numerical simulation.

  3. Effect of thermokarst lake on soil saturated hydraulic conductivity and analysis of its influenced factors%热融湖塘对青藏高原土壤饱和导水率的影响及因素分析

    Institute of Scientific and Technical Information of China (English)

    高泽永; 王一博; 刘国华

    2014-01-01

    Thermkarst lakes as a typical landform unit are widely distributed in permafrost areas of the source region of the Yangtze River. The thermokarst lakes can have huge impact on soil properties, permafrost distribution, eco-hydrological processes, etc. on the lakeshore area with its development process. In this study, we analyzed the influence factors on physical and chemical properties of soil and made comparative analysis of the spatial difference of soil saturated hydraulic conductivity in the undisturbed lakeshore area, the dead root area of lakeshore, saline soil area of lakeshore and different slope areas around a typical thermokarst lake in permafrost areas of the source region of Yangtze River. Our results showed that soil saturated hydraulic conductivity differed among soils from different areas. The soil saturated hydraulic conductivity was in an order of dead root area of lakeshore > undisturbed lakeshore area > saline soil area of lakeshore. Compared with the soil of undisturbed lakeshore area, the soil saturated hydraulic conductivity of the dead root area of lakeshore increased by 70.1%, while the saline soil area decreased by 33.8%. The results showed soil environment had a great change with the formation of thermkarst lakes. The results suggested that the formation of the dead root area of lakeshore led to an increase in soil saturated hydraulic conductivity and a decrease of runoff capacity. Opposite results were found with the saline soil. At different slope areas of lakeshore, the greater the slope was, the greater the soil saturated hydraulic conductivity. Furthermore the maximum difference appeared at the middle position of the slope while soil saturated hydraulic conductivity of slope bottom did not obviously changed. The results also showed that with the different effects of thermkarst lakes, the cause of the variation of soil saturated hydraulic conductivity at the different areas was coupled with the influences of vegetation coverage, soil

  4. Hydraulic conductivity of organomodified soil

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, R.B.; Grant, J.M.; Voice, T.C.; Rakhshandehroo, G.; Xu, S.; Boyd, S.A. [Michigan State Univ., East Lansing, MI (United States)

    1995-11-01

    The effects of organomodification on soil hydraulic conductivity were investigated. Hydraulic conductivity and porosity of treated and untreated samples of a sandy loam were measured as a function of effective stress. Batch treatment with hexadecyltrimethyl ammonium (HDTMA) and dry packing produced organomodified samples that were 79% less conducive than untreated samples prior to loading. Treated samples lost less hydraulic conductivity as a result of loading than untreated samples so that treated samples had higher conductivity at high loads. Observed differences in conductivity are explained in terms of the role of the treated and untreated clay in controlling initial effective pore size and its change during consolidation.

  5. Investigation and Development of the Thermal Preparation System of the Trailbuilder Machinery Hydraulic Actuator

    Science.gov (United States)

    Konev, V.; Polovnikov, E.; Krut, O.; Merdanov, Sh; Zakirzakov, G.

    2017-07-01

    It’s determined that the main part of trailbuilders operated in the North is the technology equipped by the hydraulic actuator. Further development of the northern territories will demand using of various means and ways machinery thermal preparation, and also the machinery of the northern fulfillment. On this basis problems in equipment operation are defined. One of the main is efficiency supplying of a hydraulic actuator. On the basis of the operating conditions’ analysis of trailbuilder hydraulic actuator operation it is determined, that under low negative temperatures the means of thermal preparation are necessary. The existing systems warm up only a hydraulic tank or warming up of the hydro equipment before the machinery operation is carried out under loading with intensive wears. Thus, with the purpose to raise the efficiency of thermal hydraulic actuator, operated far from stationary bases autonomous, energy saving, not expensive in creation and operation systems are necessary. In accordance with the analysis of means and ways of the thermal preparation of the hydraulic actuator and the thermal balance calculations of the (internal) combustion engine the system of the hydraulic actuator heating is offered and is being investigated. It contains a local hydraulic actuator warming up and the system of internal combustion engine heat utilization. Within research operation conditions of the local hydraulic actuator heating are viewed and determined, taking into account constructive changes to the local hydraulic actuator heating. Mathematical modelling of the heat technical process in the modernized hydraulic actuator is considered. As a result temperature changes of the heat-transfer and the hydraulic cylinder in time are determined. To check the theoretical researches and to define dependences on hydraulic actuator warming up, the experimental installation is made. It contains the measuring equipment, a small tank with the heat exchanger of the burnt gases

  6. Stem and leaf hydraulic properties are finely coordinated in three tropical rain forest tree species.

    Science.gov (United States)

    Nolf, Markus; Creek, Danielle; Duursma, Remko; Holtum, Joseph; Mayr, Stefan; Choat, Brendan

    2015-12-01

    Coordination of stem and leaf hydraulic traits allows terrestrial plants to maintain safe water status under limited water supply. Tropical rain forests, one of the world's most productive biomes, are vulnerable to drought and potentially threatened by increased aridity due to global climate change. However, the relationship of stem and leaf traits within the plant hydraulic continuum remains understudied, particularly in tropical species. We studied within-plant hydraulic coordination between stems and leaves in three tropical lowland rain forest tree species by analyses of hydraulic vulnerability [hydraulic methods and ultrasonic emission (UE) analysis], pressure-volume relations and in situ pre-dawn and midday water potentials (Ψ). We found finely coordinated stem and leaf hydraulic features, with a strategy of sacrificing leaves in favour of stems. Fifty percent of hydraulic conductivity (P50 ) was lost at -2.1 to -3.1 MPa in stems and at -1.7 to -2.2 MPa in leaves. UE analysis corresponded to hydraulic measurements. Safety margins (leaf P50 - stem P50 ) were very narrow at -0.4 to -1.4 MPa. Pressure-volume analysis and in situ Ψ indicated safe water status in stems but risk of hydraulic failure in leaves. Our study shows that stem and leaf hydraulics were finely tuned to avoid embolism formation in the xylem.

  7. The effect of measured and estimated soil hydraulic properties on simulated water regime in the analysis of grapevine adaptability to future climate

    Science.gov (United States)

    Bonfante, Antonello; Alfieri, Silvia Maria; Agrillo, Antonietta; Dragonetti, Giovanna; Mileti, Antonio; Monaco, Eugenia; De Lorenzi, Francesca

    2013-04-01

    In the last years many research works have been addressed to evaluate the impact of future climate on crop productivity and plant water use at different spatial scales (global, regional, field) by means of simulation models of agricultural crop systems. Most of these approaches use estimated soil hydraulic properties, through pedotransfer functions (PTF). This choice is related to soil data availability: soil data bases lack measured soil hydraulic properties, but generally they contain information that allow the application of PTF . Although the reliability of the predicted future climate scenarios cannot be immediately validated, we address to evaluate the effects of a simplification of the soil system by using PTF. Thus we compare simulations performed with measured soil hydraulic properties versus simulations carried out with estimated properties. The water regimes resulting from the two procedures are evaluated with respect to crop adaptability to future climate. In particular we will examine if the two procedures bring about different seasonal and spatial variations in the soil water regime patterns, and if these patterns influence adaptation options. The present case study uses the agro-hydrological model SWAP (soil-water-atmosphere and plant) and studies future adaptability of grapevine. The study area is a viticultural area of Southern Italy (Valle Telesina, BN) devoted to the production of high quality wines (DOC and DOCG), and characterized by a complex geomorphology and pedology. The future climate scenario (2021-2050) was constructed applying statistical downscaling techniques to GCMs scenarios. The moisture regime for 25 soils of the selected study area was calculated by means of SWAP model, using both measured and estimated soil hydraulic properties. In the simulation, the upper boundary conditions were derived from the regional climate scenarios. Unit gradient in soil water potential was set as lower boundary condition. Crop-specific input data and

  8. HYDRAULICS, ATHENS COUNTY, OHIO, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  9. HYDRAULICS, JACKSON COUNTY, KENTUCKY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  10. HYDRAULICS, MADISON COUNTY, ALABAMA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Hydraulic data was reviewed and approved by FEMA during the initial MT-2 processing. Recent developments in digital terrain and geospatial database management...

  11. HYDRAULICS, HAMPDEN COUNTY, MA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data in this submittal include spatial datasets and model outputs necessary for computation of the 1-percent flooding extent. The minimum requirement for...

  12. Hydraulic wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    1981-07-01

    The purpose of this research was to design, build and test a hydraulic wind energy system. This design used a three bladed turbine, which drove a hydraulic pump. The energy is transmitted from the pump through a long hose and into a hydraulic motor, where the energy is used. This wind system was built and tested during the winter of 1980-1981. The power train included a five meter, three bladed wind turbine, a 9.8:1 ratio gearbox, a 1.44 cubic inch displacement pump with a small supercharge gear pump attached. The hydraulic fluid was pumped through a 70', 3/4'' I-D-high pressure flexhose, then through a volume control valve and into a 1.44 cubic inch displacement motor. The fluid was returned through a 70', 1'' I-D-flexhose.

  13. Reliability modeling of hydraulic system of drum shearer machine

    Institute of Scientific and Technical Information of China (English)

    SEYED HADI Hoseinie; MOHAMMAD Ataie; REZA Khalookakaei; UDAY Kumar

    2011-01-01

    The hydraulic system plays an important role in supplying power and its transition to other working parts of a coal shearer machine.In this paper,the reliability of the hydraulic system of a drum shearer was analyzed.A case study was done in the Tabas Coal Mine in Iran for failure data collection.The results of the statistical analysis show that the time between failures (TBF)data of this system followed the 3-parameters Weibull distribution.There is about a 54% chance that the hydraulic system of the drum shearer will not fail for the first 50 h of operation.The developed model shows that the reliability of the hydraulic system reduces to a zero value after approximately 1 650 hours of operation.The failure rate of this system decreases when time increases.Therefore,corrective maintenance(run-to-failure)was selected as the best maintenance strategy for it.

  14. 14 CFR 29.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 29.1435 Section 29.1435... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each element of the hydraulic system...

  15. 14 CFR 23.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 23.1435 Section 23.1435... § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each hydraulic system and its elements must withstand, without yielding, the structural loads expected...

  16. 46 CFR 28.405 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.405 Section 28.405 Shipping... Operate With More Than 16 Individuals on Board § 28.405 Hydraulic equipment. (a) Each hydraulic system... than four times the system maximum operating pressure. (c) Each hydraulic system must be equipped...

  17. The Thermal Simulation Analysis of the Hydraulic Torque Converter based on the MTALAB%基于MATlAB的液力变矩器的热仿真分析

    Institute of Scientific and Technical Information of China (English)

    吴新; 连晋毅

    2013-01-01

    针对液力机械传动中液力变矩器发热量过大的问题,简述了液力变矩器的发热机理.在所构建的热计算模型的基础上,以某型推土机的液力变矩器为实例,运用MATLAB编程并得出了发动机与液力变矩器共同工作时发热量与传动比的关系曲线,并应用Simulink软件对不同传动比下的油温进行了仿真,仿真结果反映了油温的动态变化趋势.可为底盘油冷系统的分析和优化提供一定的技术参考.%According to the excessive heat of hydraulic mechanical transmission, heating mechanism on torque converter is explained. With a certain type of torque converter in bulldozers, the relationship between heat production and transmission ratio is described by Matlab programing, which on the basis of thermal analysis model. Meanwhile, the oil temperature on different ratio can be simulated by simulink, the result reflects the dynamic changing trend of hydraulic oil temperature. It will provide some technical reference for the analysis of chassis oil cooling system.

  18. Pre-test analysis of an integral effect test facility for thermal-hydraulic similarities of 6 inches coldleg break and DVI injection line break using MARS-1D

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Tae Soon; Choi, Ki Yong; Park, Hyun Sik; Euh, Dong Jin; Baek, Won Pil [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-03-01

    A pre-test analysis of a small-break loss-of-coolant accident (SBLOCA, DVI Line break) has been performed for the integral effect test loop of Korea Atomic Energy Research Institute (Korea Atomic Energy Research Institute-ITL), the construction of which will be started soon. The Korea Atomic Energy Research Institute-ITL is a full-height and 1/310 volume-scaled test facility based on the design features of the APR1400 (Korean Next Generation Reactor). This paper briefly introduces the basic design features of the Korea Atomic Energy Research Institute-ITL and presents the results of pre-test analysis for a postulated cold leg SBLOCA and DVI line break. Based on the same control logics and accident scenarios, the similarity between the Korea Atomic Energy Research Institute-ITL and the prototype plant, APR1400, is evaluated by using the MARS code, which is a multi-dimensional best-estimate thermal hydraulic code being developed by Korea Atomic Energy Research Institute. It is found that the Korea Atomic Energy Research Institute-ITL and APR 1400 have similar thermal hydraulic responses against the analyzed SBLOCA and DVI Line break scenario. It is also verified that the volume scaling law, applied to the design of the Korea Atomic Energy Research Institute-ITL, gives a reasonable results to keep a similarity with APR1400. 11 refs., 19 figs., 3 tabs. (Author)

  19. Safety estimation of high-pressure hydraulic cylinder using FSI method

    Institute of Scientific and Technical Information of China (English)

    KIM J.H.; HAN S.M.; KIM Y.J.

    2016-01-01

    Hydraulic cylinder is a primary component of the hydraulic valve systems.The numerical study of hydraulic cylinder to evaluate the stress analysis,the life assessment and the performance of operation characteristics in hydraulic cylinder were described.The calculation of safety factor,fatigue life,piston chamber pressure,rod chamber pressure and the change of velocity of piston with flow time after the beginning of hydraulic cylinder were incorporated.Numerical analysis was performed using the commercial CFD code,ANSYS with unsteady,dynamic mesh model,two-way FSI (fluid-struc-ture interaction)method and k-εturbulent model.The internal pressure in hydraulic cylinder through stress analysis show higher than those of the yield strength.

  20. Advanced Performance Hydraulic Wind Energy

    Science.gov (United States)

    Jones, Jack A.; Bruce, Allan; Lam, Adrienne S.

    2013-01-01

    The Jet Propulsion Laboratory, California Institute of Technology, has developed a novel advanced hydraulic wind energy design, which has up to 23% performance improvement over conventional wind turbine and conventional hydraulic wind energy systems with 5 m/sec winds. It also has significant cost advantages with levelized costs equal to coal (after carbon tax rebate). The design is equally applicable to tidal energy systems and has passed preliminary laboratory proof-of-performance tests, as funded by the Department of Energy.

  1. 液压四足机器人新型腿结构设计与性能分析%New Leg Module of Hydraulic Quadruped Robot Structure Design and Performance Analysis

    Institute of Scientific and Technical Information of China (English)

    俞志伟; 于浩; 许明理; 戴振东

    2011-01-01

    To achieve the robot of high load and uneven ground high adaptability motion demand, design a new leg structure of hydraulic driving quadruped robot. It puts forward the leg module mechanism, which is the four connecting rod leg module mechanism with a parallelogram structure, and compare the traditional slider-crank four bar linkage in motion performance. Based on the MATLAB software of SimMechanics module, a simulation analysis is carried out. The results show that the four connecting rod leg module mechanism that with a parallelogram structure have good transmission performance, and the legs structure of hydraulic cylinder movement more smoothly, and ensure the overall performance of the robot. It provides a new way for hydraulic driving quadruped robot of leg structure design.%为实现机器人的高负载、不平地面的高适应性运动要求,设计了一种新型的液压四足机器人腿结构.提出了腿模块机构,是带有平行四边形结构的四连杆腿模块机构,与传统的曲柄滑块四连杆机构进行了运动分析比较.基于MATLAB的SimMechanics软件模块,进行了仿真分析.结果表明带有平行四边形结构的四连杆腿模块机构具有较好的传动性能,该种腿结构的液压缸运动更为平稳,可确保机器人整体性能的优越性,为液压驱动的足式机器人腿结构设计提供新的设计途径.

  2. Hydraulic Fracturing and the Environment

    Science.gov (United States)

    Ayatollahy Tafti, T.; Aminzadeh, F.; Jafarpour, B.; de Barros, F.

    2013-12-01

    In this presentation, we highlight two key environmental concerns of hydraulic fracturing (HF), namely induced seismicity and groundwater contamination (GC). We examine the induced seismicity (IS) associated with different subsurface fluid injection and production (SFIP) operations and the key operational parameters of SFIP impacting it. In addition we review the key potential sources for possible water contamination. Both in the case of IS and GC we propose modeling and data analysis methods to quantify the risk factors to be used for monitoring and risk reduction. SFIP include presents a risk in hydraulic fracturing, waste water injection, enhanced oil recovery as well as geothermal energy operations. Although a recent report (NRC 2012) documents that HF is not responsible for most of the induced seismicities, we primarily focus on HF here. We look into vaious operational parameters such as volume and rate of water injection, the direction of the well versus the natural fracture network, the depth of the target and the local stress field and fault system, as well as other geological features. The latter would determine the potential for triggering tectonic related events by small induced seismicity events. We provide the building blocks for IS risk assessment and monitoring. The system we propose will involve adequate layers of complexity based on mapped seismic attributes as well as results from ANN and probabilistic predictive modeling workflows. This leads to a set of guidelines which further defines 'safe operating conditions' and 'safe operating zones' which will be a valuable reference for future SFIP operations. We also illustrate how HF can lead to groundwater aquifer contamination. The source of aquifer contamination can be the hydrocarbon gas or the chemicals used in the injected liquid in the formation. We explore possible pathways of contamination within and discuss the likelihood of contamination from each source. Many of the chemical compounds used

  3. Analysis of Thermal-Hydraulic Gravity/ Buoyancy Effects in the Testing of the ITER Poloidal Field Full Size Joint Sample (PF-FSJS)

    Science.gov (United States)

    Zanino, R.; Bruzzone, P.; Ciazynski, D.; Ciotti, M.; Gislon, P.; Nicollet, S.; Savoldi Richard, L.

    2004-06-01

    The PF-FSJS is a full-size joint sample, based on the NbTi dual-channel cable-in-conduit conductor (CICC) design currently foreseen for the International Thermonuclear Experimental Reactor (ITER) Poloidal Field coil system. It was tested during the summer of 2002 in the Sultan facility of CRPP at a background peak magnetic field of typically 6 T. It includes about 3 m of two jointed conductor sections, using different strands but with identical layout. The sample was cooled by supercritical helium at nominal 4.5-5.0 K and 0.9-1.0 MPa, in forced convection from the top to the bottom of the vertical configuration. A pulsed coil was used to test AC losses in the two legs resulting, above a certain input power threshold, in bundle helium backflow from the heated region. Here we study the thermal-hydraulics of the phenomenon with the M&M code, with particular emphasis on the effects of buoyancy on the helium dynamics, as well as on the thermal-hydraulic coupling between the wrapped bundles of strands in the annular cable region and the central cooling channel. Both issues are ITER relevant, as they affect the more general question of the heat removal capability of the helium in this type of conductors.

  4. CFD Analysis on the Air-Side Thermal-Hydraulic Performance of Multi-Louvered Fin Heat Exchangers at Low Reynolds Numbers

    Directory of Open Access Journals (Sweden)

    Arslan Saleem

    2017-06-01

    Full Text Available The air-side thermal-hydraulic performance of multi-louvered aluminium fin heat exchangers is investigated. A systematic numerical study has been performed to analyze the air-sde thermal hydraulic characteristics over a wide range of Reynolds number i.e., from 30 to 500. Air-side heat transfer coefficient and pressure drop were calculated and validated over the mentioned band of Reynolds numbers. The critical Reynolds number was determined numerically; and also the variation of flow pattern along with the air-side heat transfer coefficient and pressure drop in a multi-louvered heat exchanger associated with R e c r i has been reported. Moreover, a parametric study of the multi-louvered aluminium fin heat exchangers was also performed for 36 heat exchanger configurations with the louver angles (19–31°; fin pitches (1.0, 1.2, 1.4 mm and flow depths (16, 20, 24 mm; and the geometric configuration exhibiting the highest air-side heat transfer coefficient was reported. The air-side heat transfer coefficient and pressure drop results for different geometrical configurations were presented in terms of Colburn j factor and Fanning friction factor f; as a function of Reynolds number based on louver pitch.

  5. Replacement of pneumatic and hydraulic drives with electrical drives - Analysis of potential; Ersatz von pneumatischen und hydraulischen Antrieben durch Elektroantriebe. Potentialanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Berchten, S. [BEngineering, Bassersdorf (Switzerland); Ritz, Ch. [Schnyder Ingenieure AG, Steg (Switzerland)

    2006-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) discusses the potential offered by modern technologies to save energy. The replacement of energy-intensive methods of providing physical movement - such as with pneumatic and hydraulic drives - with electrical drives is discussed. Based on existing installations in industry, an estimate of the potential for making savings is presented. This shows that large energy savings can be made by directly converting electrical into mechanical energy. Using real world examples, end-users and decision-makers are shown two profit-scenarios involving the purchase of a new system or retrofitting an existing system. The scenarios take investments, operating costs and system life-cycle into account. Extrapolations provide estimates of savings-potentials for the Swiss electricity market. Various market sectors are looked at, including the metal-working, chemical, foodstuffs and packaging sectors. Examples of installations actually implemented, where electro-mechanical systems have replaced pneumatic and hydraulic drives, are given.

  6. 新型石油钻杆液压矫直机结构分析%Analysis and Design of Oil Drill Pipe Hydraulic Straightening Machine

    Institute of Scientific and Technical Information of China (English)

    石永军; 白立剑; 王维旭

    2013-01-01

    Considering the disadvantages of the existing drill pipe hydraulic straightening machines which have low straightening accuracy and low efficiency,a new kind of drill pipe hydraulic straightening machine was designed,adopting three-point straightening principle to straighten curving drill pipe.Its rotating mechanism first rotates the curving drill pipe and detects the curving position,and then the movable machine moves the drill pipe to make the curving position aligned to the pressure head.The finite element method is used to check the key parts of strength,which satisfied the operating requirement.%目前的钻杆矫直装置存在矫直精度低和工作效率低的问题.设计了一种新型的石油钻杆液压矫直机.采用三点矫直原理对弯曲钻杆进行矫直,通过旋转机构旋转钻杆,并检测出弯曲位置.由移动式主机移动钻杆,使弯曲位置对准压头,提高了工作效率和矫直精度.应用有限元方法分析了关键部件的强度,满足使用要求.

  7. Technologies and Innovations for Hydraulic Pumps

    OpenAIRE

    Ivantysynova, Monika

    2016-01-01

    Positive displacement machines working as hydraulic pumps or hydraulic motors have always been, are and will be an essential part of any hydraulic system. Current trends and future demands on energy efficient systems will not only drastically increase the number of positive displacement machines needed for modern efficient hydraulic circuits but will significantly change the performance requirements of pumps and motors. Throttleless system configurations will change the landscape of hydraulic...

  8. Motion Analysis and Control of a Single Leg of Hydraulically Actuated Quadruped Robots during Vertical Hopping%液压驱动四足机器人单腿竖直跳跃运动分析与控制

    Institute of Scientific and Technical Information of China (English)

    张雪峰; 秦现生; 冯华山; 谭小群; 李军; 杨雪宝

    2013-01-01

    针对非结构化环境下四足机器人高速高机动性要求,提出一种液压驱动单腿结构模式.面向竖直跳跃运动,建立液压驱动结构模式下单腿二阶段运动学模型和三阶段动力学模型;进行竖直跳跃运动状态分析、单腿整机质心以1.5 m/s速度瞬时起跳的竖直跳跃运动逆解和仿真;并对竖直跳跃运动过程中地面冲击对机体结构的影响、髋关节和膝关节液压缸动作特性和输出力特性及液压设计等进行讨论.同时,考虑单腿竖直跳跃的周期性,应用液压偏置单腿动力学模型,采用PD迭代学习控制算法进行关节轨迹跟踪控制.仿真结果表明轨迹跟踪迅速收敛且鲁棒性好,为后续样机研究提供设计和控制依据.%To address the requirements of high speed and mobility for quadruped robots under unstructured environments, a structure model of hydraulically actuated single leg is proposed. For vertical hopping, a two-phase kinematic model and a three-phase dynamic model of a single leg are established under the structure model. After that, the state analysis on the vertical hopping is conducted, and the inverse kinematics solution and the simulation of the hopping are also implemented for a single leg mass-center's instant vertical hopping with 1.5 m/s. Then, the ground impact on the body structure, the operation characteristics and the output force of the hip joint and knee joint's hydraulic cylinder, as well as the hydraulic system design during vertical hopping are discussed. Meanwhile, taking the periodicity of vertical hopping of a single leg into consideration, a PD (proportional-derivative) iterative learning control algorithm is applied to joint trajectory tracking, based on single leg's dynamic model with hydraulic offset. The simulation results indicate that rapid and robust convergence is achieved in trajectory tracking using the presented model, which offers the design and control references for the succeeding

  9. Estimation of ground water hydraulic parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hvilshoej, Soeren

    1998-11-01

    The main objective was to assess field methods to determine ground water hydraulic parameters and to develop and apply new analysis methods to selected field techniques. A field site in Vejen, Denmark, which previously has been intensively investigated on the basis of a large amount of mini slug tests and tracer tests, was chosen for experimental application and evaluation. Particular interest was in analysing partially penetrating pumping tests and a recently proposed single-well dipole test. Three wells were constructed in which partially penetrating pumping tests and multi-level single-well dipole tests were performed. In addition, multi-level slug tests, flow meter tests, gamma-logs, and geologic characterisation of soil samples were carried out. In addition to the three Vejen analyses, data from previously published partially penetrating pumping tests were analysed assuming homogeneous anisotropic aquifer conditions. In the present study methods were developed to analyse partially penetrating pumping tests and multi-level single-well dipole tests based on an inverse numerical model. The obtained horizontal hydraulic conductivities from the partially penetrating pumping tests were in accordance with measurements obtained from multi-level slug tests and mini slug tests. Accordance was also achieved between the anisotropy ratios determined from partially penetrating pumping tests and multi-level single-well dipole tests. It was demonstrated that the partially penetrating pumping test analysed by and inverse numerical model is a very valuable technique that may provide hydraulic information on the storage terms and the vertical distribution of the horizontal and vertical hydraulic conductivity under both confined and unconfined aquifer conditions. (EG) 138 refs.

  10. Monitoring hydraulic fracturing with seismic emission volume

    Science.gov (United States)

    Niu, F.; Tang, Y.; Chen, H.; TAO, K.; Levander, A.

    2014-12-01

    Recent developments in horizontal drilling and hydraulic fracturing have made it possible to access the reservoirs that are not available for massive production in the past. Hydraulic fracturing is designed to enhance rock permeability and reservoir drainage through the creation of fracture networks. Microseismic monitoring has been proven to be an effective and valuable technology to image hydraulic fracture geometry. Based on data acquisition, seismic monitoring techniques have been divided into two categories: downhole and surface monitoring. Surface monitoring is challenging because of the extremely low signal-to-noise ratio of the raw data. We applied the techniques used in earthquake seismology and developed an integrated monitoring system for mapping hydraulic fractures. The system consists of 20 to 30 state-of-the-art broadband seismographs, which are generally about hundreds times more sensible than regular geophones. We have conducted two experiments in two basins with very different geology and formation mechanism in China. In each case, we observed clear microseismic events, which may correspond to the induced seismicity directly associated with fracturing and the triggered ones at pre-existing faults. However, the magnitude of these events is generally larger than magnitude -1, approximately one to two magnitudes larger than those detected by downhole instruments. Spectrum-frequency analysis of the continuous surface recordings indicated high seismic energy associated with injection stages. The seismic energy can be back-projected to a volume that surrounds each injection stage. Imaging seismic emission volume (SEV) appears to be an effective way to map the stimulated reservior volume, as well as natural fractures.

  11. Application of optical fiber sensing technology in the hydraulic decoking monitoring system

    Science.gov (United States)

    Fan, Yun-feng; Tong, Xing-lin; Ji, Tao; Gao, Xue-qing; Zhong, Dong

    2013-09-01

    On the basis of the analysis of the current hydraulic decoking monitoring system, it is proposed that use optical fiber Bragg grating (FBG) vibration sensor and fiber Fabry-Perot (FP) acoustic sensors to online monitor vibration signal and audio signal hydraulic of the coke drum in the running state progress, analysis the vibration sensor and acoustic sensor used in the system. Based on the actual monitoring results in Sinopec Wuhan Branch , the fiber optic acoustic emission sensors is more suitable for the hydraulic decoking online monitoring system than the FBG vibration sensor ,which can more accurate monitor of hydraulic decoking.

  12. 热工水力子通道分析程序ATHAS的稳态验证%Steady-state Verification of Thermal-hydraulics Sub-channel Analysis Code ATHAS

    Institute of Scientific and Technical Information of China (English)

    刘伟; 朱元兵; 白宁; 单建强; 张博; 苟军利; 厉井钢

    2014-01-01

    GE3×3 test bundle experiments were simulated with sub-channel analysis code ATHAS.Comparisons of the obtained results by ATHAS code with the experimental measurements and other sub-channel codes show that ATHAS is capable to predict thermal-hydraulic parameters distribution in GE3 ×3 components accurately.All of this demonstrates the reasonable physical models and powerful application functions of ATHAS.The work of this thesis can be taken example by the design and development of thermal-hydraulic program of nuclear power plant in China.%利用具有自主知识产权的子通道程序 ATHAS对 GE3×3组件进行稳态计算,并将 ATHAS的预测值与实验测量值及其他子通道程序的预测值进行了对比分析,结果表明:ATHAS 能够准确预测GE3×3组件内的热工水力参数分布,展示了 ATHAS可靠的物理模型。本文对 ATHAS 进行稳态验证的思路和方法,对我国核电站热工水力软件自主化的设计开发具有借鉴意义。

  13. 一种单作用连续自动油压增压器运动特性分析%Movement Characteristics Analysis for Single-acting Continuous Automatic Hydraulic Turbocharger

    Institute of Scientific and Technical Information of China (English)

    王鹏; 黄伟; 宋维新

    2013-01-01

    Hydraulic turbocharger is widely used in pump stations,machine tools,clamping machinery and other equipments. Its operating parameters directly affect the performance of the whole device. Based on the compression of the liquid and Newton’s second law,the motion differential equations for continuous automatic hydraulic turbocharger in different sessions were established,laying foundation for further study to the dynamic characteristics. By analysis of pressurized cylinder leakage characteristics,the influence factors to the volumetric efficiency of the turbocharger were found.%油压增压器在液压泵站、机床、装夹机械等设备上广泛应用,其运行参数直接影响整机性能。在液体的压缩性和牛顿第二定律的基础上,建立一种单作用连续自动油压增压器不同工作阶段内部的运动微分方程,为进一步研究其动态特性打下基础;通过分析增压缸的泄漏特性,找到了影响增压器容积效率的因素。

  14. Analysis of The Clamping Force for 2D Electro-hydraulic Rotary Valve%2D电液转阀式换向阀阀芯卡紧力分析

    Institute of Scientific and Technical Information of China (English)

    童成伟; 阮健; 孔晨菁; 刘奎

    2016-01-01

    Introduces the working principle of 2D electro-hydraulic rotary valve, and puts forward a design scheme of 2D electro-ydraulic rotary valve.Based on the principle of gap flow and analysis of the radial clamping force of the spool of 2D electro-hydraulic rotary valve un-der eccentric conditions,the theoretical calculation formula of the clamping force of the spool is obtained.Using MATLAB software to draw the relationship of spool radial clamping force with eccentric angle and the angle of high and low pressure groove.%介绍了2D电液转阀式换向阀的工作原理,提出了一种2D电液转阀式换向阀的设计方案;应用缝隙流动原理,对2D电液转阀式换向阀阀芯在偏心情况下的径向卡紧力进行系统理论分析,得到阀芯液压卡紧力的理论计算公式;运用MATLAB软件进行数值计算,得出阀芯径向卡紧力与偏心角位置和高低压槽口夹角的关系。

  15. 液压挖掘机动臂节能系统分析%Analysis about Boom Energy Saving System of Hydraulic Excavator

    Institute of Scientific and Technical Information of China (English)

    吴文海; 柯坚; 李培; 刘桓龙; 于兰英

    2013-01-01

    针对液压挖掘机动臂下降过程中大量势能转化为热能的工况,对普通的动臂液压回路、动臂流量再生回路和动臂势能回收系统进行了分析和比较,根据动臂下降过程中能量的变化,改进设计了带势能回收的流量再生回路系统.以23t液压挖掘机为研究对象,分析并计算了4种回路的功率分配和能量损耗.采用仿真软件AMEsim建立仿真模型,对4种回路的运行参数和能量损耗进行对比,并对带势能回收的流量再生回路的关键参数进行分析.仿真结果表明:选择合适参数的带势能回收的流量再生回路大大降低了节流阀上能耗,具有较高的能量利用率.%Aiming at the situation of a lot of potential energy changing into heat during the hydraulic excavator's boom going down, the common boom hydraulic loop, boom flow-regeneration loop and boom potential energy recovery system were compared and analyzed. According to the energy changing in the process of boom going down, the flow-regeneration loop with energy recovery system was designed with improvement. By the study object of 23 ton hydraulic excavator, the power distribution and energy loss of the four loops were calculated analytically. The simulation model by AMEsim software was established, the running parameters and energy loss of the four loops were compared, and key parameters about the flow-regeneration loop with energy recovery device were analyzed. Simulation results show that the flow-regeneration loop with energy recovery device can greatly reduce the energy loss on the throttle valve by choosing suitable parameters, and has high energy using efficiency.

  16. CARR辐照压水堆小组件热工水力分析%Thermal-hydraulic Analysis of PWR Small Assembly for Irradiation Test of CARR

    Institute of Scientific and Technical Information of China (English)

    尹皓; 邹耀; 刘兴民

    2015-01-01

    T he thermal‐hydraulic behaviors of the PWR 4 × 4 small assembly tested in the high temperature and high pressure loop of China Advanced Research Reactor were analyzed .The CFD method was used to carry out 3D simulation of the model ,thus detailed thermal‐hydraulic parameters were obtained .Firstly ,the simplified model was simulated to give the 3D temperature and velocity distributions and analyze the heat transfer process .Then the whole scale small assembly model was simulated and the simulation results were compared with those of simplified rod bundle model .Its flow behavior was studied and flow mixing characteristics of the grids were analyzed ,and the mixing factor of the grid was calculated and can be used for further thermal‐hydraulic study .It is show n that the highest temperature of the fuel rod meets the design limit and the mixing effect of the grid is obvious .%分析压水堆4×4小组件在CARR高温高压回路中进行辐照考验时的热工水力问题。利用计算流体动力学(C FD )软件对其进行三维数值模拟,以获得详细的热工水力参数。首先,模拟简化的燃料棒束模型,得出三维温度与速度分布,并分析了传热过程。然后,模拟全尺寸小组件,与棒束模型所得的结果进行对比分析,着重研究其流动,并分析了格架的搅混特性,得出可应用于一维热工水力程序的搅混因子。结果表明,燃料棒最高温度可满足安全性要求,且格架的搅混作用明显。

  17. Variation of hydraulic gradient in nonlinear finite strain consolidation

    Institute of Scientific and Technical Information of China (English)

    谢新宇; 黄杰卿; 王文军; 李金柱

    2014-01-01

    In the research field of ground water, hydraulic gradient is studied for decades. In the consolidation field, hydraulic gradient is yet to be investigated as an important hydraulic variable. So, the variation of hydraulic gradient in nonlinear finite strain consolidation was focused on in this work. Based on lab tests, the nonlinear compressibility and nonlinear permeability of Ningbo soft clay were obtained. Then, a strongly nonlinear governing equation was derived and it was solved with the finite element method. Afterwards, the numerical analysis was performed and it was verified with the existing experiment for Hong Kong marine clay. It can be found that the variation of hydraulic gradient is closely related to the magnitude of external load and the depth in soils. It is interesting that the absolute value of hydraulic gradient (AVHG) increases rapidly first and then decreases gradually after reaching the maximum at different depths of soils. Furthermore, the changing curves of AVHG can be roughly divided into five phases. This five-phase model can be employed to study the migration of pore water during consolidation.

  18. Oscillatory Flow Testing in a Sandbox - Towards Oscillatory Hydraulic Tomography

    Science.gov (United States)

    Zhou, Y.; Lim, D.; Cupola, F.; Cardiff, M. A.

    2014-12-01

    Detailed knowledge of subsurface hydraulic properties is important for predicting groundwater flow and contaminant transport. The spatial variation of hydraulic properties in the shallow subsurface has been extensively studied in the past two decades. A recent approach to characterize subsurface properties is hydraulic tomography, in which pressure data from multiple constant-rate pumping tests is inverted using a numerical model. Many laboratory sandbox studies have explored the performance of hydraulic tomography under different controlled conditions and shown that detailed heterogeneity information can be extracted (Liu et al., 2002, Illman et al., 2007, 2008, 2010a, 2010b, Liu et al., 2007, 2008, Xiang et al., 2009, Yin and Illman, 2009, Liu and Kitanidis, 2011, Berg and Illman, 2011a). Recently, Cardiff et al. (2013) proposed a modified approach of Oscillatory Hydraulic Tomography (OHT) - in which periodic pumping signals of different frequencies are used for aquifer stimulation - to characterize aquifer properties. The potential advantages of OHT over traditional hydraulic tomography include: 1) no net injection or extraction of water; 2) little movement of existing contamination; 3) minimal impact of model boundary conditions; and 4) robust extraction of oscillatory signals from noisy data. To evaluate the premise of OHT, we built a highly-instrumented 2-D laboratory sandbox and record pressure responses to periodic pumping tests. In our setup, the laboratory sandbox is filled with sand of known hydraulic properties, and we measure aquifer responses at a variety of testing frequencies. The signals recorded are processed using Fourier-domain analysis, and compared against expected results under linear (Darcian) theory. The responses are analyzed using analytical and numerical models, which provide key insights as to: 1) how "effective" hydraulic properties estimated using homogeneous models are associated with aquifer heterogeneity; and 2) how OHT is able to

  19. A 6-DOF vibration isolation system for hydraulic hybrid vehicles

    Science.gov (United States)

    Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

    2006-03-01

    This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of