Shaft Position Influence on Technical Characteristics of Universal Two-Stages Helical Speed Reducers

Directory of Open Access Journals (Sweden)

Мilan Rackov

2005-10-01

Full Text Available Purchasers of speed reducers decide on buying those reducers, that can the most approximately satisfy their demands with much smaller costs. Amount of used material, ie. mass and dimensions of gear unit influences on gear units price. Mass and dimensions of gear unit, besides output torque, gear unit ratio and efficiency, are the most important parameters of technical characteristics of gear units and their quality. Centre distance and position of shafts have significant influence on output torque, gear unit ratio and mass of gear unit through overall dimension of gear unit housing. Thus these characteristics are dependent on each other. This paper deals with analyzing of centre distance and shaft position influence on output torque and ratio of universal two stages gear units.

OPTIMIZATION OF PLY STACKING SEQUENCE OF COMPOSITE DRIVE SHAFT USING PARTICLE SWARM ALGORITHM

Directory of Open Access Journals (Sweden)

CHANNAKESHAVA K. R.

2011-06-01

Full Text Available In this paper an attempt has been made to optimize ply stacking sequence of single piece E-Glass/Epoxy and Boron /Epoxy composite drive shafts using Particle swarm algorithm (PSA. PSA is a population based evolutionary stochastic optimization technique which is a resent heuristic search method, where mechanics are inspired by swarming or collaborative behavior of biological population. PSA programme is developed to optimize the ply stacking sequence with an objective of weight minimization by considering design constraints as torque transmission capacity, fundamental natural frequency, lateral vibration and torsional buckling strength having number of laminates, ply thickness and stacking sequence as design variables. The weight savings of the E-Glass/epoxy and Boron /Epoxy shaft from PAS were 51% and 85 % of the steel shaft respectively. The optimum results of PSA obtained are compared with results of genetic algorithm (GA results and found that PSA yields better results than GA.

Coaxial twin-shaft magnetic fluid seals applied in vacuum wafer-handling robot

Science.gov (United States)

Cong, Ming; Wen, Haiying; Du, Yu; Dai, Penglei

2012-07-01

Compared with traditional mechanical seals, magnetic fluid seals have unique characters of high airtightness, minimal friction torque requirements, pollution-free and long life-span, widely used in vacuum robots. With the rapid development of Integrate Circuit (IC), there is a stringent requirement for sealing wafer-handling robots when working in a vacuum environment. The parameters of magnetic fluid seals structure is very important in the vacuum robot design. This paper gives a magnetic fluid seal device for the robot. Firstly, the seal differential pressure formulas of magnetic fluid seal are deduced according to the theory of ferrohydrodynamics, which indicate that the magnetic field gradient in the sealing gap determines the seal capacity of magnetic fluid seal. Secondly, the magnetic analysis model of twin-shaft magnetic fluid seals structure is established. By analyzing the magnetic field distribution of dual magnetic fluid seal, the optimal value ranges of important parameters, including parameters of the permanent magnetic ring, the magnetic pole tooth, the outer shaft, the outer shaft sleeve and the axial relative position of two permanent magnetic rings, which affect the seal differential pressure, are obtained. A wafer-handling robot equipped with coaxial twin-shaft magnetic fluid rotary seals and bellows seal is devised and an optimized twin-shaft magnetic fluid seals experimental platform is built. Test result shows that when the speed of the two rotational shafts ranges from 0-500 r/min, the maximum burst pressure is about 0.24 MPa. Magnetic fluid rotary seals can provide satisfactory performance in the application of wafer-handling robot. The proposed coaxial twin-shaft magnetic fluid rotary seal provides the instruction to design high-speed vacuum robot.

Calculation Of The Brushless DC Motor Shaft Speed With Allowances For Incorrect Alignment Of Sensors

Directory of Open Access Journals (Sweden)

Kolano Krzysztof

2015-09-01

Full Text Available The paper treats of correcting calculation errors of the BLDC motor speed, based on the time elapsed between successive changes in the shaft position sensor signal. The developed method enables correction of errors of the deployment of sensors as well as rotating elements of the observation system of the motor shaft position. The correction algorithm performance was analysed with the aid of a model implemented in Matlab-Simulink environment. After confirming usefulness of the developed method through simulation, its usefulness was verified in real closed-loop feedback systems with a BLDC motor. The results of measurements carried out at the developed laboratory station are presented.

Analysis of parameters effects on crack breathing and propagation in shaft of rotor dynamic systems

Directory of Open Access Journals (Sweden)

M. Serier

2013-01-01

Full Text Available In this paper the design of experiment method is used to investigate and explain the effects of the rotor parameters on crack breathing and propagation in the shaft. Three factors are considered which have an influence on the behavior and the propagation of the crack: the rotational speed, the length of the rotor and the diameter of the shaft. The elaborated mathematical model allows determining the effects and interaction of speed, diameter and length on crack breathing mechanism.The model also determines the optimal values of the parameters to achieve high performance.

Optimization Study of Shaft Tubular Turbine in a Bidirectional Tidal Power Station

Directory of Open Access Journals (Sweden)

Xinfeng Ge

2013-01-01

Full Text Available The shaft tubular turbine is a form of tidal power station which can provide bidirectional power. Efficiency is an important turbine performance indicator. To study the influence of runner design parameters on efficiency, a complete 3D flow-channel model of a shaft tubular turbine was developed, which contains the turbine runner, guide vanes, and flow passage and was integrated with hybrid grids calculated by steady-state calculation methods. Three aspects of the core component (turbine runner were optimized by numerical simulation. All the results were then verified by experiments. It was shown that curved-edge blades are much better than straight-edge blades; the optimal blade twist angle is 7°, and the optimal distance between the runner and the blades is 0.75–1.25 times the diameter of the runner. Moreover, the numerical simulation results matched the experimental data very well, which also verified the correctness of the optimal results.

Optimal energy control of a crushing process based on vertical shaft impactor

International Nuclear Information System (INIS)

Numbi, B.P.; Xia, X.

2016-01-01

Highlights: • Energy optimal control strategy of a VSI crushing process is modeled. • Potential of a daily energy cost saving of about 49.7% is shown. • Potential of a daily energy saving of about 15.3% is shown. • Most of energy cost saving is due to the optimal load shifting under time-of-use tariff. • Energy saving is due to the operation of the process at the boundary of the admissible region. - Abstract: This paper presents an optimal control model to improve the operation energy efficiency of a vertical shaft impact (VSI) crushing process. The optimal control model takes the energy cost as the performance index to be minimized by accounting for the time-of-use tariff and process constraints such as storage capacity of the VSI crusher hopper, capacity of the main storage system, flow rate limits, cascade ratio setting, production requirement and product quality requirement. The control variables in the developed model are the belt conveyor feed rate, the material feed rate into the VSI crusher rotor, the bi-flow or cascade feed rate and the rotor tip speed of the crusher. These four control variables are optimally coordinated in order to improve the operation energy efficiency of the VSI crushing process. Simulation results based on a crushing process in a coal-fired power plant demonstrate a potential of a daily energy cost saving of about 49.7% and energy saving of about 15.3% in a high-demand season weekday.

Shaft Position Influence on Technical Characteristics of Universal Two-Stages Helical Speed Reducers

OpenAIRE

Мilan Rackov; Zeljko Kanovic; Sinisa Kuzmanovic; Ruzica Trbojevic

2005-01-01

Purchasers of speed reducers decide on buying those reducers, that can the most approximately satisfy their demands with much smaller costs. Amount of used material, ie. mass and dimensions of gear unit influences on gear units price. Mass and dimensions of gear unit, besides output torque, gear unit ratio and efficiency, are the most important parameters of technical characteristics of gear units and their quality. Centre distance and position of shafts have significant influence on output t...

Rotary shaft seal

International Nuclear Information System (INIS)

Langebrake, C.O.

1984-01-01

The invention is a novel rotary shaft seal assembly which provides positive-contact sealing when the shaft is not rotated and which operates with its sealing surfaces separated by a film of compressed ambient gas whose width is independent of the speed of shaft rotation. In a preferred embodiment, the assembly includes a disc affixed to the shaft for rotation therewith. Axially movable, non-rotatable plates respectively supported by sealing bellows are positioned on either side of the disc to be in sealing engagement therewith. Each plate carries piezoelectric transducer elements which are electrically energized at startup to produce films of compressed ambient gas between the confronting surfaces of the plates and the disc. Following shutdown of the shaft, the transducer elements are de-energized. A control circuit responds to incipient rubbing between the plate and either disc by altering the electrical input to the transducer elements to eliminate rubbing

Influences of the guide bearing stiffness on the critical speed of rotation in the main shaft system

International Nuclear Information System (INIS)

Bai, B; Zhang, L X; Zhao, L

2012-01-01

An analysis is carried out on the natural vibration characteristics of the main shaft system of a hydro-turbine generating set. The critical speed of rotation in different orders are calculated based on simplified real parameters and the influences of different guide bearing stiffness on the critical speed are analyzed. The results show that the up guide bearing has little influence on the critical speed; however, the down and the water guide bearings strongly affect the critical speed and to a certain extent the 'saturation' phenomenon happens; as all of these three bearings stiffness become larger at the same time, the critical speed also increases significantly. So it is necessary to consider the effect of the bearing stiffness when doing an estimation of the critical speed.

Determination of the critical bending speeds of a multy-rotor shaft from the vibration signal analysis

Science.gov (United States)

Crâştiu, I.; Nyaguly, E.; Deac, S.; Gozman-Pop, C.; Bârgău, A.; Bereteu, L.

2018-01-01

The purpose of this paper is the development and validation of an impulse excitation technique to determine flexural critical speeds of a single rotor shaft and multy-rotor shaft. The experimental measurement of the vibroacoustic response is carried out by using a condenser microphone as a transducer. By the means of Modal Analysis using Finite Element Method (FEM), the natural frequencies and shape modes of one rotor and three rotor specimens are determined. The vibration responses of the specimens, in simple supported conditions, are carried out using algorithms based on Fast Fourier Transform (FFT). To validate the results of the modal parameters estimated using Finite Element Analysis (FEA) these are compared with experimental ones.

Ultrasonic test of highly stressed gear shafts

Energy Technology Data Exchange (ETDEWEB)

Schreiner, T [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H [Siemens Power Generation (Germany)

1999-12-31

In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

Ultrasonic test of highly stressed gear shafts

Energy Technology Data Exchange (ETDEWEB)

Schreiner, T. [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W. [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J. [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H. [Siemens Power Generation (Germany)

1998-12-31

In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

MPPT Algorithm for Small Wind Systems based on Speed Control Strategy

Directory of Open Access Journals (Sweden)

Ciprian VLAD

2008-07-01

Full Text Available This paper presents experimental results of an autonomous low-power wind energy conversion system (WECS, based on a permanent-magnet synchronous generator (PMSG connected directly to the wind turbine. The purpose of this paper is to present an improving method for MPPT (Maximum Power Point Tracking algorithm based shaft rotational speed optimal control. The proposed method concern the variable delay compensation between measured wind speed from anemometer and wind shaft rotational speed proportional signal. Experimental results aiming to prove the efficiency of the proposed method are presented.

High Specific Stiffness Shafts and Advanced Bearing Coatings for Gas Turbine Engines Final Report CRADA No. TC-1089-95

Energy Technology Data Exchange (ETDEWEB)

Barbee, Troy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chin, Herbert [United Technologies Corporation, East Hartford, CT (United States)

2017-11-09

At the time of the CRADA, the largest in-service gas-turbine aircraft engines strove for increased thrust and power density to meet the requirements for take-off thrust, given the increase in take-off gross weight (TOGW) associated with longer range transport requirements. The trend in modem turbo shaft engines was toward turbine shafts with higher and higher length-to-diameter ratios, which reduced the shaft critical speed. Using co nventional shaft materials, this lead to shafts that needed to operate near or above sensitive shaft bending critical speeds, therefore requiring multiple bearings and/ or multiple squeeze-film dampers to control the dynamic response. Using new materials and d esign concepts this project demonstrated the use of new shaft materials which could provide increased shaft speed range above existing maximum engine speeds without encountering a critic al speed event and high vector deflections. This increased main shaft speed also resulted in decreased bearing life associated with lower heat dissipation and higher centrifugal forces. Thus, a limited effort was devoted to feasibility of higher performance bearing coatings to mitigate the speed effects.

Vertically loaded pivot bearing for high-speed shafts

International Nuclear Information System (INIS)

Zippe, G.; Werner, D.; Keller, A.; Stephan, E.

1974-01-01

The pivot bearing subjected to vertical loads has a pivot with a rounded end and a diametral slot and a cup-shaped recess in the bearing box. The end of the pivot and the recess constitute a gap which widens towards the periphery of the bearing. The bearing box carries an attachment with a clearance, the shape of a hollow cylinder and accomodating the pivot and its shaft. To feed the lubricating oil surrounding and filling the bearing there is a groove either in the wall of the clearance or at the end of the pivot in the direction of rotation of the shaft or against it. The oil carried to the support point flows back into the oil bath surrounding the bearing through a slot in the bearing box. (DG) [de

Instant PageSpeed optimization

CERN Document Server

Jaiswal, Sanjeev

2013-01-01

Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. Instant PageSpeed Optimization is a hands-on guide that provides a number of clear, step-by-step exercises for optimizing your websites for better performance and improving their efficiency.Instant PageSpeed Optimization is aimed at website developers and administrators who wish to make their websites load faster without any errors and consume less bandwidth. It's assumed that you will have some experience in basic web technologies like HTML, CSS3, JavaScript, and the basics of netw

Ship speed optimization: Concepts, models and combined speed-routing scenarios

DEFF Research Database (Denmark)

Psaraftis, Harilaos N.; Kontovas, Christos A.

2014-01-01

The purpose of this paper is to clarify some important issues as regards ship speed optimization at the operational level and develop models that optimize ship speed for a spectrum of routing scenarios in a single ship setting. The paper's main contribution is the incorporation of those fundament...... parameters and other considerations that weigh heavily in a ship owner's or charterer's speed decision and in his routing decision, wherever relevant. Various examples are given so as to illustrate the properties of the optimal solution and the various trade-offs that are involved....

Shaft seal assembly for high speed and high pressure applications

Science.gov (United States)

Hadt, W. F.; Ludwig, L. P. (Inventor)

1979-01-01

A seal assembly is provided for reducing the escape of fluids from between a housing and a shaft rotably mounted in the housing. The seal assembly comprises a pair of seal rings resiliently connected to each other and disposed in side-by-side relationship. In each seal ring, both the internal bore surface and the radial face which faces away from the other seal ring are provided with a plurality of equi-spaced recesses. The seal faces referred to are located adjacent a seating surface of the housing. Under normal operating conditions, the seal assembly is stationary with respect to the housing, and the recesses generate life, keep the assembly spaced from the rotating shaft and allow slip therebetween. The seal assembly can seize on the shaft, and slip will then occur between the radial faces and the housing.

Computer-assisted three-dimensional correlation between the femoral neck-shaft angle and the optimal entry point for antegrade nailing.

Science.gov (United States)

Anastopoulos, George; Chissas, Dionisios; Dourountakis, Joseph; Ntagiopoulos, Panagiotis G; Magnisalis, Evaggelos; Asimakopoulos, Antonios; Xenakis, Theodore A

2010-03-01

Optimal entry point for antegrade femoral intramedullary nailing (IMN) remains controversial in the current medical literature. The definition of an ideal entry point for femoral IMN would implicate a tenseless introduction of the implant into the canal with anatomical alignment of the bone fragments. This study was undertaken in order to investigate possible existing relationships between the true 3D geometric parameters of the femur and the location of the optimum entry point. A sample population of 22 cadaveric femurs was used (mean age=51.09+/-14.82 years). Computed-tomography sections every 0.5mm for the entire length of femurs were produced. These sections were subsequently reconstructed to generate solid computer models of the external anatomy and medullary canal of each femur. Solid models of all femurs were subjected to a series of geometrical manipulations and computations using standard computer-aided-design tools. In the sagittal plane, the optimum entry point always lied a few millimeters behind the femoral neck axis (mean=3.5+/-1.5mm). In the coronal plane the optimum entry point lied at a location dependent on the femoral neck-shaft angle. Linear regression on the data showed that the optimal entry point is clearly correlated to the true 3D femoral neck-shaft angle (R(2)=0.7310) and the projected femoral neck-shaft angle (R(2)=0.6289). Anatomical parameters of the proximal femur, such as the varus-valgus angulation, are key factors in the determination of optimal entry point for nailing. The clinical relevance of the results is that in varus hips (neck-shaft angle shaft angle between 120 degrees and 130 degrees , the optimal entry point lies just medially to the trochanter tip (at the piriformis fossa) and the use of stiff implants is safe. In hips with neck-shaft angle over 130 degrees the anatomical axis of the canal is medially to the base of the neck, in a "restricted area". In these cases the entry point should be located at the insertion of the

Nonsynchronous vibrations observed in a supercritical power transmission shaft

Science.gov (United States)

Darlow, M. S.; Zorzi, E. S.

1979-01-01

A flexible shaft is prone to a number of vibration phenomena which occur at frequencies other than synchronous with rotational speed. Nonsynchronous vibrations from several sources were observed while running a test rig designed to simulate the operation of a supercritical power transmission shaft. The test rig was run first with very light external damping and then with a higher level of external damping, for comparison. As a result, the effect of external damping on the nonsynchronous vibrations of the test rig was observed. All of these nonsynchronous vibrations were of significant amplitude. Their presence in the vibrations spectra for a supercritical power transmission shaft at various speeds in the operating range indicates that very careful attention to all of the vibration spectra should be made in any supercritical power transmission shafting. This paper presents a review of the analysis performed and a comparison with experimental data. A thorough discussion of the observed nonsynchronous whirl is also provided.

Generalized solution of design optimization and failure analysis of composite drive shaft

Energy Technology Data Exchange (ETDEWEB)

Kollipalli, K.; Shivaramakrishna, K.V.S.; Prabhakaran, R.T.D. [Birla Institute of Technology and Science, Goa (India)

2012-07-01

Composites have an edge over conventional metals like steel and aluminum due to higher stiffness-to-weight ratio and strength-to-weight ratio. Due to these advantages, composites can bring out a revolutionary change in materials used in automotive engineering, as weight savings has positive impacts on other attributes like fuel economy and possible noise, vibration and harshness (NVH). In this paper, the drive line system of an automotive system is targeted for use of composites by keeping constraints in view such as such as torque transmission, torsional buckling load and fundamental natural frequency. Composite drive shafts made of three different composites ('HM Carbon/HS Carbon/E-glass'-epoxy) was modeled using Catia V5R16 CPD workbench and a finite element analysis with boundary conditions, fiber orientation and stacking sequence was performed using ANSYS Composite module. Results obtained were compared to theoretical results and were found to be accurate and in the limits. This paper also speaks on drive shaft modeling and analysis generalization i.e., changes in stacking sequence in the future can be incorporated directly into ANSYS model without modeling it again in Catia. Hence the base model and analysis method made up in this analysis generalization facilitated by CAD/CAE can be used to carry out any composite shaft design optimization process. (Author)

High-Speed Shaft Bearing Loads Testing and Modeling in the NREL Gearbox Reliability Collaborative: Preprint

Energy Technology Data Exchange (ETDEWEB)

McNiff, B.; Guo, Y.; Keller, J.; Sethuraman, L.

2014-12-01

Bearing failures in the high speed output stage of the gearbox are plaguing the wind turbine industry. Accordingly, the National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC) has performed an experimental and theoretical investigation of loads within these bearings. The purpose of this paper is to describe the instrumentation, calibrations, data post-processing and initial results from this testing and modeling effort. Measured HSS torque, bending, and bearing loads are related to model predictions. Of additional interest is examining if the shaft measurements can be simply related to bearing load measurements, eliminating the need for invasive modifications of the bearing races for such instrumentation.

Green maritime transportation: Speed and route optimization

DEFF Research Database (Denmark)

Psaraftis, Harilaos N.; Kontovas, Christos A.

2015-01-01

Among the spectrum of logistics-based measures for green maritime transportation, this chapter focuses on speed optimization. This involves the selection of an appropriate speed by the vessel, so as to optimize a certain objective. As ship speed is not fixed, depressed shipping markets and/or high...

Mathematically modelling the power requirement for a vertical shaft mowing machine

Directory of Open Access Journals (Sweden)

Jorge Simón Pérez de Corcho Fuentes

2008-09-01

Full Text Available This work describes a mathematical model for determining the power demand for a vertical shaft mowing machine, particularly taking into account the influence of speed on cutting power, which is different from that of other models of mowers. The influence of the apparatus’ rotation and translation speeds was simulated in determining power demand. The results showed that no chan-ges in cutting power were produced by varying the knives’ angular speed (if translation speed was constant, while cutting power became increased if translation speed was increased. Variations in angular speed, however, influenced other parameters deter-mining total power demand. Determining this vertical shaft mower’s cutting pattern led to obtaining good crop stubble quality at the mower’s lower rotation speed, hence reducing total energy requirements.

Analysis and optimization of dynamic model of eccentric shaft grinder

Science.gov (United States)

Gao, Yangjie; Han, Qiushi; Li, Qiguang; Peng, Baoying

2018-04-01

Eccentric shaft servo grinder is the core equipment in the process chain of machining eccentric shaft. The establishment of the movement model and the determination of the kinematic relation of the-axis in the grinding process directly affect the quality of the grinding process, and there are many error factors in grinding, and it is very important to analyze the influence of these factors on the work piece quality. The three-dimensional model of eccentric shaft grinder is drawn by Pro/E three-dimensional drawing software, the model is imported into ANSYS Workbench Finite element analysis software, and the finite element analysis is carried out, and then the variation and parameters of each component of the bed are obtained by the modal analysis result. The natural frequencies and formations of the first six steps of the eccentric shaft grinder are obtained by modal analysis, and the weak links of the parts of the grinder are found out, and a reference improvement method is proposed for the design of the eccentric shaft grinder in the future.

Simulation Analysis of Spherical Mechanical Seal Property of Marine Stern Shaft

OpenAIRE

Zhou Xu Hui; Zou Li

2016-01-01

The finite element model of spherical mechanical seal wasestablished with ANSYS, and the influence of seawater pressure, shaft speed and other factors on the sealing performance was discussed. The study results show that local contact situation of the spherical mechanical seal is in the outside of the seal rings, and both maximum contact pressure and temperature appearat the same position. As sea water pressure and stern shaft rotary speed are increased, the contact pressure and temperature o...

A joint routing and speed optimization problem

OpenAIRE

Fukasawa, Ricardo; He, Qie; Santos, Fernando; Song, Yongjia

2016-01-01

Fuel cost contributes to a significant portion of operating cost in cargo transportation. Though classic routing models usually treat fuel cost as input data, fuel consumption heavily depends on the travel speed, which has led to the study of optimizing speeds over a given fixed route. In this paper, we propose a joint routing and speed optimization problem to minimize the total cost, which includes the fuel consumption cost. The only assumption made on the dependence between the fuel cost an...

Effect of centrifugal force on natural frequency of lateral vibration of rotating shafts

Science.gov (United States)

Behzad, M.; Bastami, A. R.

2004-07-01

This paper investigates the effect of shaft rotation on its natural frequency. Apart from gyroscopic effect, the axial force originated from centrifugal force and the Poisson effect results in change of shaft natural frequency. D'Alembert principle for shaft in cylindrical co-ordinate system, along with the stress-strain relation, gives the non-homogenous linear differential equation, which can be used to calculate axial stress in the shaft. Numerical results of this study show that axial stress produced by shaft rotation has a major effect on the natural frequency of long high-speed shafts, while shaft diameter has no influence on the results. In addition, change in lateral natural frequency due to gyroscopic effect is compared with the results of this study.

Study on vibration characteristics of the shaft system for a dredging pump based on FEM

International Nuclear Information System (INIS)

Zhai, L M; Liu, X; He, L Y; Wang, Z W; Qin, L; Liu, C Y; He, Y

2012-01-01

The dynamic characteristics of the shaft system for a dredging pump were studied with the Finite Element Method (FEM) by SAMCEF ROTOR. At first, the influence of the fluid-solid coupling interaction of mud water and impeller, water sealing and pump shaft on the lateral critical speeds were analyzed. The results indicated that the mud water must be taken into consideration, while the water sealing need not to. Then the effects of radial and thrust rolling bearings on the lateral critical speeds were discussed, which shows that the radial bearing close to the impeller has greatest impact on the 1st order critical speed. At last, the upper and lower limits of the critical speeds of lateral, axial and torsional vibration were calculated. The rated speed of the dredging pump was far less than the predicted critical speed, which can ensure the safe operation of the unit. Each vibration mode is also shown in this paper. This dynamic analysis method offers some reference value on the research of vibration and stability of the shaft system in dredging pump.

Shaf rotation speed measurement device, its checking and variations checking

International Nuclear Information System (INIS)

Gadrault, Robert.

1976-01-01

Appliance for measuring the rotational speed of a shaft and monitoring of this speed and its changes. The uses to be made specifically concern the nuclear field and in this field the drive shafts of water coolant feed pumps. Detecting te rotation of the shaft concerned may be resolved with electronic sensors or proximity detectors which, because they are not in mechanical connexion with the shaft the speed of which they are to help detect, do not bring any lack of precision. The accuracy of the determination them depends only on the downstream processing of the data supplied by the sensor [fr

Miniature high speed compressor having embedded permanent magnet motor

Science.gov (United States)

Zhou, Lei (Inventor); Zheng, Liping (Inventor); Chow, Louis (Inventor); Kapat, Jayanta S. (Inventor); Wu, Thomas X. (Inventor); Kota, Krishna M. (Inventor); Li, Xiaoyi (Inventor); Acharya, Dipjyoti (Inventor)

2011-01-01

A high speed centrifugal compressor for compressing fluids includes a permanent magnet synchronous motor (PMSM) having a hollow shaft, the being supported on its ends by ball bearing supports. A permanent magnet core is embedded inside the shaft. A stator with a winding is located radially outward of the shaft. The PMSM includes a rotor including at least one impeller secured to the shaft or integrated with the shaft as a single piece. The rotor is a high rigidity rotor providing a bending mode speed of at least 100,000 RPM which advantageously permits implementation of relatively low-cost ball bearing supports.

Time optimal paths for high speed maneuvering

Energy Technology Data Exchange (ETDEWEB)

Reister, D.B.; Lenhart, S.M.

1993-01-01

Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

Coupling with concentric contact around motor shaft for line start synchronous motor

Science.gov (United States)

Melfi, Michael J.; Burdeshaw, Galen E.

2017-10-03

A method comprises providing a line-start synchronous motor. The motor has a stator, a rotor core disposed within the stator, and a motor shaft. In accordance with a step of the method, a coupling for coupling a load to the motor is provided. The coupling has a motor shaft attachment portion configured to provide substantially concentric contact around the shaft at the end of the motor shaft. The coupling has a load attachment portion configured to operatively connect to a load. In accordance with a step of the method, a load is coupled to the motor with the coupling, and driven from start to at least near synchronous speed during steady state operation of the motor with a load coupled thereto. The motor shaft attachment portion may comprise a bushing assembly with matching and opposed tapered surfaces that cooperate to secure the motor shaft attachment portion around the motor shaft.

Design analysis of a self-acting spiral-groove ring seal for counter-rotating shafts. [o ring seals

Science.gov (United States)

Dirusso, E.

1983-01-01

A self-acting spiral groove inter-shaft ring seal of nominal 16.33 cm (6.43 in.) diameter for sealing fan bleed air between counter rotating shafts in advanced turbofan engines was analyzed. The analysis focused on the lift force characteristics of the spiral grooves. A NASA Lewis developed computer program for predicting the performance of gas lubricated face seals was used to optimize the spiral groove geometry to produce maximum lift force. Load capacity curves (lift force as function of film thickness) were generated for four advanced turbofan engine operating conditions at relative seal speeds ranging from 17,850 to 29,800 rpm, sealed air pressures from 6 to 42 N/sq cm (9 to 60 psi) absolute and temperatures from 95 to 327 C (203 to 620 F). The relative seal sliding speed range was 152 to 255 m/sec (500 to 836 ft/sec). The analysis showed that the spiral grooves are capable of producing sufficient lift force such that the ring seal will operate in a noncontacting mode over the operating range of typical advanced turbofan engines.

Optimal stride frequencies in running at different speeds.

Directory of Open Access Journals (Sweden)

Ben T van Oeveren

Full Text Available During running at a constant speed, the optimal stride frequency (SF can be derived from the u-shaped relationship between SF and heart rate (HR. Changing SF towards the optimum of this relationship is beneficial for energy expenditure and may positively change biomechanics of running. In the current study, the effects of speed on the optimal SF and the nature of the u-shaped relation were empirically tested using Generalized Estimating Equations. To this end, HR was recorded from twelve healthy (4 males, 8 females inexperienced runners, who completed runs at three speeds. The three speeds were 90%, 100% and 110% of self-selected speed. A self-selected SF (SFself was determined for each of the speeds prior to the speed series. The speed series started with a free-chosen SF condition, followed by five imposed SF conditions (SFself, 70, 80, 90, 100 strides·min-1 assigned in random order. The conditions lasted 3 minutes with 2.5 minutes of walking in between. SFself increased significantly (p<0.05 with speed with averages of 77, 79, 80 strides·min-1 at 2.4, 2.6, 2.9 m·s-1, respectively. As expected, the relation between SF and HR could be described by a parabolic curve for all speeds. Speed did not significantly affect the curvature, nor did it affect optimal SF. We conclude that over the speed range tested, inexperienced runners may not need to adapt their SF to running speed. However, since SFself were lower than the SFopt of 83 strides·min-1, the runners could reduce HR by increasing their SFself.

Hydromechanical transmission with three simple planetary assemblies, one sun gear being mounted on the output shaft and the other two on a common shaft connected to an input-driven hydraulic module

Science.gov (United States)

Orshansky, Jr., deceased, Elias; Weseloh, William E.

1978-01-01

A power transmission having three simple planetary assemblies, each having its own carrier and its own planet, sun, and ring gears. A speed-varying module is connected in driving relation to the input shaft and in driving relationship to the sun gears of the first two planetary assemblies, these two sun gears being connected together on a common shaft. The speed-varying means may comprise a pair of hydraulic units hydraulically interconnected so that one serves as a pump while the other serves as a motor and vice versa, one of the units having a variable stroke and being connected in driving relation to the input shaft, the other unit, which may have a fixed stroke, being connected in driving relation to the sun gears. The input shaft is also connected to drive the second ring gear and, furthermore is clutchable to the carrier of the third planetary assembly. A brake grounds the first carrier in the first range and in reverse and causes drive to be delivered to the output through the first ring gear in a hydrostatic mode. The carrier of the second planetary assembly drives the ring gear of the third planetary assembly, which is clutchable to the output shaft, and the sun gear of the third planetary assembly is mounted rigidly to the output shaft.

Influence of parameters detuning on induction motor NFO shaft-sensorless scheme

Directory of Open Access Journals (Sweden)

KULIC, F.

2010-11-01

Full Text Available In this paper, the parameter sensitivity analysis of shaft-sensorless induction motor drive with natural field orientation (NFO scheme is performed. NFO scheme calculates rotor flux position using the rotor flux vector reference only, does not require significant processor power and therefore it is suitable for low cost shaft sensorless drives. This concept also eliminates the need for sensitive stator voltage vector integration and it is usable in low rotor speed range. However, low speeds are coupled with low stator voltage amplitudes, which inflate the NFO scheme sensitivity to an error in stator resistance parameter. Similar problems can also take place if mutual inductance parameter is detuned, but this time in whole speed range. This paper investigates the influence of each parameter error on the NFO control steady state characteristics and dynamic performance.

Improved circumferential shaft seal for aircraft gear transmissions

Science.gov (United States)

Ludwig, L. P.; Strom, T. N.

1973-01-01

Operation under simulated aircraft transmission conditions of speeds to 2850 m/min (9350 ft/min), lubricant temperatures to 394 K (250 F), shaft radial runouts to 0.254 mm (0.010 in.) F.I.R. (full indicator reading), and pressure differentials to 1.03 N/cm2 (1.5 psi) revealed that conventional circumferential seals leaked excessively. Modifying the conventional seal by adding helical grooves to the seal bore reduced leakage rates to within the acceptable level of 10 cm3/hr. The leakage rate of this modified seal was not significantly affected by lubricant flooding or by shaft radial runout.

Balancing of a power-transmission shaft with the application of axial torque

Science.gov (United States)

Zorzi, E. S.; Flemming, D.

1980-01-01

Evaluation of power transmission shafting for high-speed balancing has shown that when axial torque is applied, the imbalance response is altered. An increase in synchronous excitation always occurs if the axial torque level is altered from the value used during balancing; this was the case even when the shaft was balanced with torque applied. The twisting of the long slender shaft produces a change in the imbalance distribution sufficient to disrupt the balanced state. This paper presents a review of the analytic development of a weighted least squares approach to influence coefficient balancing and a review of experimental results. The analytic approach takes advantage of the fact that the past testing has shown that the influence coefficients are not significantly affected by the application of axial torque. The 3.60-m (12-ft) long aluminum shaft, 7.62 cm (3 in.) in diameter was run through the first flexural critical speed at torque levels ranging from zero-torque to 903.8 N-M (8000 lb-in.) in 112.9 N-M (1000 lb-in.) increments. Good comparison was achieved between predicted and experimental results.

Short-Term Wind Speed Forecasting Using Support Vector Regression Optimized by Cuckoo Optimization Algorithm

Directory of Open Access Journals (Sweden)

Jianzhou Wang

2015-01-01

Full Text Available This paper develops an effectively intelligent model to forecast short-term wind speed series. A hybrid forecasting technique is proposed based on recurrence plot (RP and optimized support vector regression (SVR. Wind caused by the interaction of meteorological systems makes itself extremely unsteady and difficult to forecast. To understand the wind system, the wind speed series is analyzed using RP. Then, the SVR model is employed to forecast wind speed, in which the input variables are selected by RP, and two crucial parameters, including the penalties factor and gamma of the kernel function RBF, are optimized by various optimization algorithms. Those optimized algorithms are genetic algorithm (GA, particle swarm optimization algorithm (PSO, and cuckoo optimization algorithm (COA. Finally, the optimized SVR models, including COA-SVR, PSO-SVR, and GA-SVR, are evaluated based on some criteria and a hypothesis test. The experimental results show that (1 analysis of RP reveals that wind speed has short-term predictability on a short-term time scale, (2 the performance of the COA-SVR model is superior to that of the PSO-SVR and GA-SVR methods, especially for the jumping samplings, and (3 the COA-SVR method is statistically robust in multi-step-ahead prediction and can be applied to practical wind farm applications.

The effects of an annular fluid on the critical speed of a rotating shaft

International Nuclear Information System (INIS)

Guidez, J.; Axisa; Gibert; Girard; Fardeau.

1981-11-01

Prediction of vibrations of rotors when passing through the flexural critical velocities is important for industrial applications. Pumps of nuclear reactors are a typical example characterized by a rotor which rotates at relatively low speed in a dense fluid like water or sodium. In such configurations critical velocities and natural frequencies of the equivalent beam system may differ significantly, mainly because of fluids effects. A brief review of the physical mechanisms involved is presented and a numerical code: ROTOR, based on the finite element method, is described which allows for a linear analysis of rotors, taking into account also the non conservative forces associated with the gyroscopic and the fluid effects. Finally the practical importance of fluid is emphasized by some experimental results obtained on two pump-shaft models working in water. Results are discussed in relation with the code expectations. For completely immersed rotors the computed critical velocities are found to be in good agreement with the experimental values. However for partially immersed rotors further experimental and theoretical work is still needed

Algorithm for the calculation of vibration inherent frequencies bending from two-shafts transmission

Directory of Open Access Journals (Sweden)

Grigore Jan-Cristian

2017-01-01

Full Text Available The operation of the speed shaft transmissions at or near the natural frequency of the pulses at the resonance phenomenon leads to bending, when the amplitude of the oscillations increases sharply, causing deterioration or complete destruction thereof. To avoid system resonance operation is necessary to know the most accurate values its pulsations and taking appropriate constructive measures to avoid overlapping with disturbing frequency harmonics (operating speeds.This paper presents an algorithm for calculating the pulsation and vibration modes in bending, and based on numerical simulations performed on a real two-shafts transmission and will draw conclusions drawn diagrams.

Direct shaft torque measurements in a transient turbine facility

International Nuclear Information System (INIS)

Beard, Paul F; Povey, Thomas

2011-01-01

This paper describes the development and implementation of a shaft torque measurement system for the Oxford Turbine Research Facility (formerly the Turbine Test Facility (TTF) at QinetiQ, Farnborough), or OTRF. As part of the recent EU TATEF II programme, the facility was upgraded to allow turbine efficiency measurements to be performed. A shaft torque measurement system was developed as part of this upgrade. The system is unique in that, to the authors' knowledge, it provided the first direct measurement of shaft torque in a transient turbine facility although the system has wider applicability to rotating test facilities in which power measurement is a requirement. The adopted approach removes the requirement to quantify bearing friction, which can be difficult to accurately calibrate under representative operating conditions. The OTRF is a short duration (approximately 0.4 s run time) isentropic light-piston facility capable of matching all of the non-dimensional parameters important for aerodynamic and heat studies, namely Mach number, Reynolds number, non-dimensional speed, stage pressure ratio and gas-to-wall temperature ratio. The single-stage MT1 turbine used for this study is a highly loaded unshrouded design, and as such is relevant to modern military, or future civil aero-engine design. Shaft torque was measured directly using a custom-built strain gauge-based torque measurement system in the rotating frame of reference. This paper describes the development of this measurement system. The system was calibrated, including the effects of temperature, to a traceable primary standard using a purpose-built facility. The bias and precision uncertainties of the measured torque were ±0.117% and ±0.183%, respectively. To accurately determine the shaft torque developed by a turbine in the OTRF, small corrections due to inertial torque (associated with changes in the rotational speed) and aerodynamic drag (windage) are required. The methods for performing these

Shaft Boring Machine: A method of mechanized vertical shaft excavation

International Nuclear Information System (INIS)

Goodell, T.M.

1991-01-01

The Shaft Boring Machine (SBM) is a vertical application of proven rock boring technology. The machine applies a rotating cutter wheel with disk cutters for shaft excavation. The wheel is thrust against the rock by hydraulic cylinders and slews about the shaft bottom as it rotates. Cuttings are removed by a clam shell device similar to conventional shaft mucking and the muck is hoisted by buckets. The entire machine moves down (and up) the shaft through the use of a system of grippers thrust against the shaft wall. These grippers and their associated cylinders also provide the means to maintain verticality and stability of the machine. The machine applies the same principles as tunnel boring machines but in a vertical mode. Other shaft construction activities such as rock bolting, utility installation and shaft concrete lining can be accomplished concurrent with shaft boring. The method is comparable in cost to conventional sinking to a depth of about 460 meters (1500 feet) beyond which the SBM has a clear host advantage. The SBM has a greater advantage in productivity in that it can excavate significantly faster than drill and blast methods

Piezoceramics-based Devices for Active Balancing of Flexible Shafts

NARCIS (Netherlands)

Sloetjes, P.J.; de Boer, Andries; Sas, P.; De Munck, M.

2006-01-01

This paper focuses on vibration control of flexible shafts by means of rotorfixed piezoelectric materials. The target is to realize compact solutions for the suppression of problematic resonant vibration at so-called flexural critical speeds. For analysis, parametric finite element models of

A new hybrid model optimized by an intelligent optimization algorithm for wind speed forecasting

International Nuclear Information System (INIS)

Su, Zhongyue; Wang, Jianzhou; Lu, Haiyan; Zhao, Ge

2014-01-01

Highlights: • A new hybrid model is developed for wind speed forecasting. • The model is based on the Kalman filter and the ARIMA. • An intelligent optimization method is employed in the hybrid model. • The new hybrid model has good performance in western China. - Abstract: Forecasting the wind speed is indispensable in wind-related engineering studies and is important in the management of wind farms. As a technique essential for the future of clean energy systems, reducing the forecasting errors related to wind speed has always been an important research subject. In this paper, an optimized hybrid method based on the Autoregressive Integrated Moving Average (ARIMA) and Kalman filter is proposed to forecast the daily mean wind speed in western China. This approach employs Particle Swarm Optimization (PSO) as an intelligent optimization algorithm to optimize the parameters of the ARIMA model, which develops a hybrid model that is best adapted to the data set, increasing the fitting accuracy and avoiding over-fitting. The proposed method is subsequently examined on the wind farms of western China, where the proposed hybrid model is shown to perform effectively and steadily

Optimal speeds for walking and running, and walking on a moving walkway.

Science.gov (United States)

Srinivasan, Manoj

2009-06-01

Many aspects of steady human locomotion are thought to be constrained by a tendency to minimize the expenditure of metabolic cost. This paper has three parts related to the theme of energetic optimality: (1) a brief review of energetic optimality in legged locomotion, (2) an examination of the notion of optimal locomotion speed, and (3) an analysis of walking on moving walkways, such as those found in some airports. First, I describe two possible connotations of the term "optimal locomotion speed:" that which minimizes the total metabolic cost per unit distance and that which minimizes the net cost per unit distance (total minus resting cost). Minimizing the total cost per distance gives the maximum range speed and is a much better predictor of the speeds at which people and horses prefer to walk naturally. Minimizing the net cost per distance is equivalent to minimizing the total daily energy intake given an idealized modern lifestyle that requires one to walk a given distance every day--but it is not a good predictor of animals' walking speeds. Next, I critique the notion that there is no energy-optimal speed for running, making use of some recent experiments and a review of past literature. Finally, I consider the problem of predicting the speeds at which people walk on moving walkways--such as those found in some airports. I present two substantially different theories to make predictions. The first theory, minimizing total energy per distance, predicts that for a range of low walkway speeds, the optimal absolute speed of travel will be greater--but the speed relative to the walkway smaller--than the optimal walking speed on stationary ground. At higher walkway speeds, this theory predicts that the person will stand still. The second theory is based on the assumption that the human optimally reconciles the sensory conflict between the forward speed that the eye sees and the walking speed that the legs feel and tries to equate the best estimate of the forward

Using combined system of shaft guides for buckets during shaft deepening

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.; Ivenskii, N.S.; Alekhin, P.I.

1981-06-01

This paper discusses a system of shaft guides used in the Krasnopol'evsk underground coal mine. The existing skip shaft 514 m deep is deepened to a depth of 700 m. Shaft design is adapted to a system of two pairs of skips, however, only one pair of skips is in operation and the other has been removed. The free space can be used to remove rock material from shaft bottom. It is noted that a system of buckets moving along elastic shaft guides made of rope or along rigid shaft guides can be used. Both solutions have numerous advantages. If rope guides are used time consuming installation of shaft guides is unnecessary in the zone close to the bottom. If rigid guides are used capacity of the bucket can be significantly increased. A system which combines advantages of both solutions is used: in the lower part of the shaft being deepened, buckets are guided by rope, and in the upper zone in which rigid shaft guides have been installed the bucket moves along rigid guides and rope guides simultaneously. Design of the element guiding the bucket is shown in two diagrams. It is noted that using the combined system of shaft guides increases capacity of the hoisting system by 1.5 times.

Numerical analysis on the action of centrifuge force in magnetic fluid rotating shaft seals

Science.gov (United States)

Zou, Jibin; Li, Xuehui; Lu, Yongping; Hu, Jianhui

2002-11-01

The magnetic fluid seal is suitable for high-speed rotating shaft seal applications. Centrifuge force will have evident influence on magnetic fluid rotating shaft seals. The seal capacity of the rotating shaft seal can be improved or increased by some measures. Through hydrodynamic analysis the moving status of the magnetic fluid is worked out. By numerical method, the magnetic field and the isobars in the magnetic fluid of a seal device are computed. Then the influence of the centrifuge force on the magnetic fluid seal is calculated quantitatively.

Numerical analysis on the action of centrifuge force in magnetic fluid rotating shaft seals

International Nuclear Information System (INIS)

Zou Jibin; Li Xuehui; Lu Yongping; Hu Jianhui

2002-01-01

The magnetic fluid seal is suitable for high-speed rotating shaft seal applications. Centrifuge force will have evident influence on magnetic fluid rotating shaft seals. The seal capacity of the rotating shaft seal can be improved or increased by some measures. Through hydrodynamic analysis the moving status of the magnetic fluid is worked out. By numerical method, the magnetic field and the isobars in the magnetic fluid of a seal device are computed. Then the influence of the centrifuge force on the magnetic fluid seal is calculated quantitatively

Optimization of powered Stirling heat engine with finite speed thermodynamics

International Nuclear Information System (INIS)

Ahmadi, Mohammad H.; Ahmadi, Mohammad Ali; Pourfayaz, Fathollah; Bidi, Mokhtar; Hosseinzade, Hadi; Feidt, Michel

2016-01-01

Highlights: • Based on finite speed method and direct method, the optimal performance is investigated. • The effects of major parameters on the optimal performance are investigated. • The accuracy of the results was compared with previous works. - Abstract: Popular thermodynamic analyses including finite time thermodynamic analysis was lately developed based upon external irreversibilities while internal irreversibilities such as friction, pressure drop and entropy generation were not considered. The aforementioned disadvantage reduces the reliability of the finite time thermodynamic analysis in the design of an accurate Stirling engine model. Consequently, the finite time thermodynamic analysis could not sufficiently satisfy researchers for implementing in design and optimization issues. In this study, finite speed thermodynamic analysis was employed instead of finite time thermodynamic analysis for studying Stirling heat engine. The finite speed thermodynamic analysis approach is based on the first law of thermodynamics for a closed system with finite speed and the direct method. The effects of heat source temperature, regenerating effectiveness, volumetric ratio, piston stroke as well as rotational speed are included in the analysis. Moreover, maximum output power in optimal rotational speed was calculated while pressure losses in the Stirling engine were systematically considered. The result reveals the accuracy and the reliability of the finite speed thermodynamic method in thermodynamic analysis of Stirling heat engine. The outcomes can help researchers in the design of an appropriate and efficient Stirling engine.

Balancing Biomechanical Constraints: Optimal Escape Speeds When There Is a Trade-off between Speed and Maneuverability.

Science.gov (United States)

Clemente, C J; Wilson, R S

2015-12-01

The ability for prey to escape a pursuing predator is dependent both on the prey's speed away from the threat and on their ability to rapidly change directions, or maneuverability. Given that the biomechanical trade-off between speed and maneuverability limits the simultaneous maximization of both performance traits, animals should not select their fastest possible speeds when running away from a pursuing predator but rather a speed that maximizes the probability of successful escape. We explored how variation in the relationship between speed and maneuverability-or the shape of the trade-off-affects the optimal choice of speed for escaping predators. We used tablet-based games that simulated interactions between predators and prey (human subjects acting as predators attempting to capture "prey" moving across a screen). By defining a specific relationship between speed and maneuverability, we could test the survival of each of the possible behavioral choices available to this phenotype, i.e., the best combination of speed and maneuverability for prey fitness, based on their ability to escape. We found that the shape of the trade-off function affected the prey's optimal speed for success in escaping, the prey's maximum performance in escaping, and the breadth of speeds over which the prey's performance was high. The optimal speed for escape varied only when the trade-off between speed and maneuverability was non-linear. Phenotypes possessing trade-off functions for which maneuverability was only compromised at high speeds exhibited lower optimal speeds. Phenotypes that exhibited greater increases in maneuverability for any decrease in speed were more likely to have broader ranges of performance, meaning that individuals could attain their maximum performance across a broader range of speeds. We also found that there was a differential response of the subject's learning to these different components of locomotion. With increased experience through repeated trials

A novel vibration-based fault diagnostic algorithm for gearboxes under speed fluctuations without rotational speed measurement

Science.gov (United States)

Hong, Liu; Qu, Yongzhi; Dhupia, Jaspreet Singh; Sheng, Shuangwen; Tan, Yuegang; Zhou, Zude

2017-09-01

The localized failures of gears introduce cyclic-transient impulses in the measured gearbox vibration signals. These impulses are usually identified from the sidebands around gear-mesh harmonics through the spectral analysis of cyclo-stationary signals. However, in practice, several high-powered applications of gearboxes like wind turbines are intrinsically characterized by nonstationary processes that blur the measured vibration spectra of a gearbox and deteriorate the efficacy of spectral diagnostic methods. Although order-tracking techniques have been proposed to improve the performance of spectral diagnosis for nonstationary signals measured in such applications, the required hardware for the measurement of rotational speed of these machines is often unavailable in industrial settings. Moreover, existing tacho-less order-tracking approaches are usually limited by the high time-frequency resolution requirement, which is a prerequisite for the precise estimation of the instantaneous frequency. To address such issues, a novel fault-signature enhancement algorithm is proposed that can alleviate the spectral smearing without the need of rotational speed measurement. This proposed tacho-less diagnostic technique resamples the measured acceleration signal of the gearbox based on the optimal warping path evaluated from the fast dynamic time-warping algorithm, which aligns a filtered shaft rotational harmonic signal with respect to a reference signal assuming a constant shaft rotational speed estimated from the approximation of operational speed. The effectiveness of this method is validated using both simulated signals from a fixed-axis gear pair under nonstationary conditions and experimental measurements from a 750-kW planetary wind turbine gearbox on a dynamometer test rig. The results demonstrate that the proposed algorithm can identify fault information from typical gearbox vibration measurements carried out in a resource-constrained industrial environment.

Development of the laser alignment system with PSD used for shaft calibration

Science.gov (United States)

Jiao, Guohua; Li, Yulin; Hu, Baowen

2006-02-01

Shaft calibration is an important technique during installation and maintenance of a rotating machine. It requires unique and high-precision measurement instruments with calculation capability, and relies on experience on heavy, high-speed, or high-temperature machines. A high-precision laser alignment system has been designed using PSD (Position Sensing Detector) to change traditional manual way of shaft calibration and to make the measurement easier and more accurate. The system is comprised of two small measuring units (Laser transmitter and detector) and a hand operated control unit or a PC. Such a laser alignment system has been used in some actual shaft alignment with offset resolution 1.5μm and angular resolution 0.1°.

Using neural networks to speed up optimization algorithms

CERN Document Server

Bazan, M

2000-01-01

The paper presents the application of radial-basis-function (RBF) neural networks to speed up deterministic search algorithms used for the design and optimization of superconducting LHC magnets. The optimization of the iron yoke of the main dipoles requires a number of numerical field computations per trial solution as the field quality depends on the excitation of the magnets. This results in computation times of about 30 minutes for each objective function evaluation (on a DEC-Alpha 600/333) and only the most robust (deterministic) optimization algorithms can be applied. Using a RBF function approximator, the achieved speed-up of the search algorithm is in the order of 25% for problems with two parameters and about 18% for problems with three and five design variables. (13 refs).

Correlation of operating parameters on turbine shaft vibrations

Science.gov (United States)

Dixit, Harsh Kumar; Rajora, Rajeev

2016-05-01

The new generation of condition monitoring and diagnostics system plays an important role in efficient functioning of power plants. In most of the rotating machine, defects can be detected by such a system much before dangerous situation occurs. It allows the efficient use of stationary on-line continuous monitoring system for condition monitoring and diagnostics as well. Condition monitoring of turbine shaft can not only reduce expenses of maintenance of turbo generator of power plants but also prevents likely shutdown of plant, thereby increases plant load factor. Turbo visionary parameters are essential part of health diagnosis system of turbo generator. Particularly steam pressure, steam temperature and lube oil temperature are important parameters to monitor because they are having much influence on turbine shaft vibration and also governing systems are available for change values of those parameters. This paper includes influence of turbo visionary parameters i.e., steam temperature, steam pressure, lube oil temperature, turbine speed and load on turbine shaft vibration at turbo generator at 195 MW unit-6,Kota Super Thermal Power Station by measuring vibration amplitude and analyze them in MATLAB.

Transient Torsional Analysis of a Belt Conveyor Drive with Pneumatic Flexible Shaft Coupling

Directory of Open Access Journals (Sweden)

Kaššay Peter

2017-03-01

Full Text Available Development and application of pneumatic flexible shaft couplings have been in the center of our department research activities for a long time. These couplings are able to change torsional stiffness by changing pressure in their flexible elements – air bellows. Until now we have dealt with the use of pneumatic flexible shaft couplings for tuning mechanical systems working with periodically alternating load torque at steady state. Some mechanical systems, however, operate with a static load torque at constant speed (e.g. hoists, elevators, etc., where it is necessary to consider the suitability of shaft coupling in terms of load torque at transient conditions (run-up and braking. Therefore we decided to analyze the use of pneumatic flexible shaft couplings also in this type of mechanical systems on an example of conveyor belt drive.

Shaft adjuster

Science.gov (United States)

Harry, Herbert H.

1989-01-01

Apparatus and method for the adjustment and alignment of shafts in high power devices. A plurality of adjacent rotatable angled cylinders are positioned between a base and the shaft to be aligned which when rotated introduce an axial offset. The apparatus is electrically conductive and constructed of a structurally rigid material. The angled cylinders allow the shaft such as the center conductor in a pulse line machine to be offset in any desired alignment position within the range of the apparatus.

Impact of Optimization and Parallelism on Factorization Speed of SIQS

Directory of Open Access Journals (Sweden)

Dominik Breitenbacher

2016-06-01

Full Text Available This paper examines optimization possibilities of Self-Initialization Quadratic Sieve (SIQS, which is enhanced version of Quadratic Sieve factorization method. SIQS is considered the second fastest factorization method at all and the fastest one for numbers shorter than 100 decimal digits, respectively. Although, SIQS is the fastest method up to 100 decimal digits, it cannot be effectively utilized to work in polynomial time. Therefore, it is desirable to look for options how to speed up the method as much as possible. Two feasible ways of achieving it are code optimization and parallelism. Both of them are utilized in this paper. The goal of this paper is to show how it is possible to take advantage of parallelism in SIQS as well as reach a large speed-up thanks to detailed source code analysis with optimization. Our implementation process consists of two phases. In the first phase, the complete serial algorithm is implemented in the simplest way which does not consider any requirements for execution speed. The solution from the first phase serves as the reference implementation for further experiments. An improvement of factorization speed is performed in the second phase of the SIQS implementation, where we use the method of iterative modifications in order to examine contribution of each proposed step. The final optimized version of the SIQS implementation has achieved over 200x speed-up.

Control design for axial flux permanent magnet synchronous motor which operates above the nominal speed

Directory of Open Access Journals (Sweden)

Xuan Minh Tran

2017-04-01

Full Text Available The axial flux permanent magnet synchronous motor (AFPM motor using magnet bearings instead of ball-bearings at both two shaft ends could allow rotational speed of shaft much greater than nominal speed. One of the solutions to increase motor speed higher than its nameplate speed is reducing rotor’s pole magnetic flux of rotor (Yp. This paper proposes a method to boost the speed of AFPM motor above nominal speed by adding a reversed current isd of (Yp.

Monitoring for shaft cracks on reactor recirculation pumps

International Nuclear Information System (INIS)

Kowal, M.G.; O'Brien, J.T. Jr.

1989-01-01

The article discusses the vibration characteristics associated with a boiling water reactor (BWR) recirculation pump. It also describes the application of diagnostic techniques and shaft crack theory to an on-line diagnostic monitoring system for reactor recirculation pumps employed at Philadelphia Electric Company's Peach Bottom Atomic Power Station. Specific emphasis is placed on the unique monitoring techniques associated with these variable speed vertical pumps

Neuro-Fuzzy DC Motor Speed Control Using Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

Boumediene ALLAOUA

2009-12-01

Full Text Available This paper presents an application of Adaptive Neuro-Fuzzy Inference System (ANFIS control for DC motor speed optimized with swarm collective intelligence. First, the controller is designed according to Fuzzy rules such that the systems are fundamentally robust. Secondly, an adaptive Neuro-Fuzzy controller of the DC motor speed is then designed and simulated; the ANFIS has the advantage of expert knowledge of the Fuzzy inference system and the learning capability of neural networks. Finally, the ANFIS is optimized by Swarm Intelligence. Digital simulation results demonstrate that the deigned ANFIS-Swarm speed controller realize a good dynamic behavior of the DC motor, a perfect speed tracking with no overshoot, give better performance and high robustness than those obtained by the ANFIS alone.

Offset Compound Gear Inline Two-Speed Drive

Science.gov (United States)

Stevens, Mark A. (Inventor); Handschuh, Robert F. (Inventor); Lewicki, David G. (Inventor)

2014-01-01

A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction.

Influence of the shaft rotation on the stability of magnetic fluid shaft seal characteristics

Science.gov (United States)

Krakov, M. S.; Nikiforov, I. V.

2008-12-01

Distribution of the magnetic particles concentration in a magnetic fluid shaft seal is studied numerically for a rotating shaft. It is revealed that the shaft rotation causes not only an azimuthal flow of the magnetic fluid, but a meridional flow as well. This meridional flow prevents the growth of magnetic particle concentration in the gap of the magnetic fluid shaft seal. As a result, the burst pressure of the magnetic fluid shaft seal for the rotating shaft is stable and does not change with time. Figs 6, Refs 7.

Pre-cementation of deep shaft

Science.gov (United States)

Heinz, W. F.

1988-12-01

Pre-cementation or pre-grouting of deep shafts in South Africa is an established technique to improve safety and reduce water ingress during shaft sinking. The recent completion of several pre-cementation projects for shafts deeper than 1000m has once again highlighted the effectiveness of pre-grouting of shafts utilizing deep slimline boreholes and incorporating wireline technique for drilling and conventional deep borehole grouting techniques for pre-cementation. Pre-cementation of deep shaft will: (i) Increase the safety of shaft sinking operation (ii) Minimize water and gas inflow during shaft sinking (iii) Minimize the time lost due to additional grouting operations during sinking of the shaft and hence minimize costly delays and standing time of shaft sinking crews and equipment. (iv) Provide detailed information of the geology of the proposed shaft site. Informations on anomalies, dykes, faults as well as reef (gold bearing conglomerates) intersections can be obtained from the evaluation of cores of the pre-cementation boreholes. (v) Provide improved rock strength for excavations in the immediate vicinity of the shaft area. The paper describes pre-cementation techniques recently applied successfully from surface and some conclusions drawn for further considerations.

Simulation Analysis of Spherical Mechanical Seal Property of Marine Stern Shaft

Directory of Open Access Journals (Sweden)

Zhou Xu Hui

2016-01-01

Full Text Available The finite element model of spherical mechanical seal wasestablished with ANSYS, and the influence of seawater pressure, shaft speed and other factors on the sealing performance was discussed. The study results show that local contact situation of the spherical mechanical seal is in the outside of the seal rings, and both maximum contact pressure and temperature appearat the same position. As sea water pressure and stern shaft rotary speed are increased, the contact pressure and temperature of the spherical seal surface are raised, and when the contact pressure of seal surface is 0, the spherical seal surface forms two zones including contact one and clearance zone. The former is near the outside of the seal ring, the lateris close to the inside of one. These research results are of important theoretical significance and engineering application value for the development of new kinds of mechanical seals, and improvement of both safety and survivability of underwater vehicles.

Proposal of a high rigidity and high speed rotating mechanism using a new concept hydrodynamic bearing in X-ray tube for high speed computed tomography

International Nuclear Information System (INIS)

Hattori, Hitoshi; Fukushima, Harunobu; Yoshii, Yasuo; Nakamuta, Hironori; Iwase, Mitsuo; Kitade, Koichi

2009-01-01

In this paper, a high rigidity and high speed rotating mechanism using a new concept hydrodynamic bearing in X-ray tube for high speed computed tomography is proposed. In order to obtain both the stability and the high load carrying capacity, the hydrodynamic bearing lubricated by liquid metal (Gallium alloy), named as the hybrid hydrodynamic bearing generates the lubricating film by wedge effect on the plane region between the spiral grooves under high loading condition. The parallelism between the bearing and the rotating body can be secured by optimizing the rigidity distribution of stationary shaft in the proposed rotating mechanism. By carrying out the fundamental design by numerical analyses, it has been made clear that the hybrid hydrodynamic bearing and the rotating mechanism are suitable for the X-ray tube used in the CT with ever-increasingly scanning speed. (author)

Asymmetry in gait pattern following tibial shaft fractures

DEFF Research Database (Denmark)

Larsen, Peter; Læssøe, Uffe; Rasmussen, Sten

2017-01-01

INTRODUCTION: Despite the high number of studies evaluating the outcomes following tibial shaft fractures, the literature lacks studies including objective assessment of patients' recovery regarding gait pattern. The purpose of the present study was to evaluate whether gait patterns at 6 and 12...... months post-operatively following intramedullary nailing of a tibial shaft fracture are different compared with a healthy reference population. PATIENTS AND METHODS: The study design was a prospective cohort study. The primary outcome measurement was the gait patterns at 6 and 12 months post......-operatively measured with a 6-metre-long pressure-sensitive mat. The mat registers footprints and present gait speed, cadence as well as temporal and spatial parameters of the gait cycle. Gait patterns were compared to a healthy reference population. RESULTS: 49 patients were included with a mean age of 43.1 years (18...

HOC Based Blind Identification of Hydroturbine Shaft Volterra System

Directory of Open Access Journals (Sweden)

Bing Bai

2017-01-01

Full Text Available In order to identify the quadratic Volterra system simplified from the hydroturbine shaft system, a blind identification method based on the third-order cumulants and a reversely recursive method are proposed. The input sequence of the system under consideration is an unobservable independent identically distributed (i.i.d., zero-mean and non-Gaussian stationary signal, and the observed signals are the superposition of the system output signal and Gaussian noise. To calculate the third-order moment of the output signal, a computer loop judgment method is put forward to determine the coefficient. When using optimization method to identify the time domain kernels, we combined the traditional optimization algorithm (direct search method with genetic algorithm (GA and constituted the hybrid genetic algorithm (HGA. Finally, according to the prototype observation signal and the time domain kernel parameters obtained from identification, the input signal of the system can be gained recursively. To test the proposed method, three numerical experiments and engineering application have been carried out. The results show that the method is applicable to the blind identification of the hydroturbine shaft system and has strong universality; the input signal obtained by the reversely recursive method can be approximately taken as the random excitation acted on the runner of the hydroturbine shaft system.

Cloud-based shaft torque estimation for electric vehicle equipped with integrated motor-transmission system

Science.gov (United States)

Zhu, Xiaoyuan; Zhang, Hui; Yang, Bo; Zhang, Guichen

2018-01-01

In order to improve oscillation damping control performance as well as gear shift quality of electric vehicle equipped with integrated motor-transmission system, a cloud-based shaft torque estimation scheme is proposed in this paper by using measurable motor and wheel speed signals transmitted by wireless network. It can help reduce computational burden of onboard controllers and also relief network bandwidth requirement of individual vehicle. Considering possible delays during signal wireless transmission, delay-dependent full-order observer design is proposed to estimate the shaft torque in cloud server. With these random delays modeled by using homogenous Markov chain, robust H∞ performance is adopted to minimize the effect of wireless network-induced delays, signal measurement noise as well as system modeling uncertainties on shaft torque estimation error. Observer parameters are derived by solving linear matrix inequalities, and simulation results using acceleration test and tip-in, tip-out test demonstrate the effectiveness of proposed shaft torque observer design.

Efficiency of particle swarm optimization applied on fuzzy logic DC motor speed control

Directory of Open Access Journals (Sweden)

Allaoua Boumediene

2008-01-01

Full Text Available This paper presents the application of Fuzzy Logic for DC motor speed control using Particle Swarm Optimization (PSO. Firstly, the controller designed according to Fuzzy Logic rules is such that the systems are fundamentally robust. Secondly, the Fuzzy Logic controller (FLC used earlier was optimized with PSO so as to obtain optimal adjustment of the membership functions only. Finally, the FLC is completely optimized by Swarm Intelligence Algorithms. Digital simulation results demonstrate that in comparison with the FLC the designed FLC-PSO speed controller obtains better dynamic behavior and superior performance of the DC motor, as well as perfect speed tracking with no overshoot.

Adaptive neuro-fuzzy inference system to improve the power quality of a split shaft microturbine power generation system

Science.gov (United States)

Oğuz, Yüksel; Üstün, Seydi Vakkas; Yabanova, İsmail; Yumurtaci, Mehmet; Güney, İrfan

2012-01-01

This article presents design of adaptive neuro-fuzzy inference system (ANFIS) for the turbine speed control for purpose of improving the power quality of the power production system of a split shaft microturbine. To improve the operation performance of the microturbine power generation system (MTPGS) and to obtain the electrical output magnitudes in desired quality and value (terminal voltage, operation frequency, power drawn by consumer and production power), a controller depended on adaptive neuro-fuzzy inference system was designed. The MTPGS consists of the microturbine speed controller, a split shaft microturbine, cylindrical pole synchronous generator, excitation circuit and voltage regulator. Modeling of dynamic behavior of synchronous generator driver with a turbine and split shaft turbine was realized by using the Matlab/Simulink and SimPowerSystems in it. It is observed from the simulation results that with the microturbine speed control made with ANFIS, when the MTPGS is operated under various loading situations, the terminal voltage and frequency values of the system can be settled in desired operation values in a very short time without significant oscillation and electrical production power in desired quality can be obtained.

FINITE ELEMENT ANALYSIS OF CENTRELESS-LUNETTE TURNING OF HEAVY SHAFT

Directory of Open Access Journals (Sweden)

Yu. V. Vasilevich

2017-01-01

Full Text Available Dynamics of huge renovated lathe is simulated. Turning scheme concerns to heavy rotor shaft finishing. Lofty parts and milling head may create dynamic problems. Static, modal and harmonic frequency response function simulations were provided. Bearing system consists of bed, support, tool, lunettes, tailstock. Headstock didn’t take part in shaft holding. Static and dynamic rigidities founded 3–4 times less for support than for shaft. Tool rigidity lessens from 186.5 to 11.9 N/µm for speeding from slow to near resonance turning. Twelve lathe eigenmodes were evaluated. Two eigenmodes are most dangerous. It is “shaft swinging on lunettes” (M1, 26.7 Hz and “support pecking” (M3, 54.4 Hz. Bed has excessive flexibility due to through holes and lack of inner ribbing. Polymer concrete filling is moderately effective. Changing two-lunette (2L scheme to three-lunette (3L increases rigidity of shaft at 2.09 times at statics but gives limited action in dynamics. Resonant peaks on frequency response function are lowered only at 1.32 times for M1, M3. Effect of dynamic damping is revealed under condition of proximity middle lunette to lofty support. Support serves as tuned mass damper. Measures of machine tool reinforcement are simulated. Shaft swinging according to M1 may hardly be blocked by passive means. It would be better to bypass it. “Support pecking” resonance (M3 succumbs to only full set of measures. Small effect of partial reinforcement is predicted. Three frequency intervals are recommended for turn-milling at huge lathe: pre-resonant (<20 Hz, inter-resonant (35–45 Hz and post-resonant (>65 Hz. The last one is more suited. Next design step is to create triangle inner ribbing system or caissons inside of bed.

Design analysis of a self-acting spiral-groove ring seal for counter-rotating shafts

Science.gov (United States)

Dirusso, E.

1983-01-01

A self-acting spiral groove inter-shaft ring seal of nominal 16.33 cm (6.43 in.) diameter for sealing fan bleed air between counter-rotating hafts in advanced turbofan engines was analyzed. The analysis focused on the lift force characteristics of the spiral grooves. A NASA Lewis developed computer program for predicting the performance of gas lubricated face seals was used to optimize the spiral groove geometry to produce maximum lift force. Load capacity curves (lift force as function of film thickness) were generated for four advanced turbofan engine operating conditions at relative seal speeds ranging from 17,850 to 29,800 rpm, sealed air pressures from 6 to 42 N/sq cm (9 to 60 psi) absolute and temperatures from 95 deg to 327 C (203 deg to 620 F). The relative seal sliding speed range was 152 to 255 m/sec (500 to 836 ft/sec). The analysis showed that the spiral grooves are capable of producing sufficient lift force such that the ring seal will operate in a noncontacting mode over the operating range of typical advanced turbofan engines.

A Fuzzy Optimization Model for High-Speed Railway Timetable Rescheduling

Directory of Open Access Journals (Sweden)

Li Wang

2012-01-01

Full Text Available A fuzzy optimization model based on improved symmetric tolerance approach is introduced, which allows for rescheduling high-speed railway timetable under unexpected interferences. The model nests different parameters of the soft constraints with uncertainty margin to describe their importance to the optimization purpose and treats the objective in the same manner. Thus a new optimal instrument is expected to achieve a new timetable subject to little slack of constraints. The section between Nanjing and Shanghai, which is the busiest, of Beijing-Shanghai high-speed rail line in China is used as the simulated measurement. The fuzzy optimization model provides an accurate approximation on train running time and headway time, and hence the results suggest that the number of seriously impacted trains and total delay time can be reduced significantly subject to little cost and risk.

Stability analysis of internally damped rotating composite shafts using a finite element formulation

Science.gov (United States)

Ben Arab, Safa; Rodrigues, José Dias; Bouaziz, Slim; Haddar, Mohamed

2018-04-01

This paper deals with the stability analysis of internally damped rotating composite shafts. An Euler-Bernoulli shaft finite element formulation based on Equivalent Single Layer Theory (ESLT), including the hysteretic internal damping of composite material and transverse shear effects, is introduced and then used to evaluate the influence of various parameters: stacking sequences, fiber orientations and bearing properties on natural frequencies, critical speeds, and instability thresholds. The obtained results are compared with those available in the literature using different theories. The agreement in the obtained results show that the developed Euler-Bernoulli finite element based on ESLT including hysteretic internal damping and shear transverse effects can be effectively used for the stability analysis of internally damped rotating composite shafts. Furthermore, the results revealed that rotor stability is sensitive to the laminate parameters and to the properties of the bearings.

Nonlinear Output Feedback Control of Underwater Vehicle Propellers using Advance Speed Feedback

DEFF Research Database (Denmark)

Fossen, T.I.; Blanke, M.

1999-01-01

More accurate propeller shaft speed controllers can be designed by using nonlinear control theory. In this paper, an output feedback controller reconstructing the advance speed (speed of water going into the propeller) from vehicle speed measurements is derived. For this purpose a three-state model...... minimizes thruster losses due to variations in propeller axial inlet flow which is a major problem when applying conventional vehicle-propeller control systems. The proposed controller is simulated for an underwater vehicle equipped with a single propeller. From the simulations it can be concluded...... of propeller shaft speed, forward (surge) speed of the vehicle and axial inlet flow of the propeller is applied. A nonlinear observer in combination with an output feedback integral controller are derived by applying Lyapunov stability theory and exponential stability is proven. The output feedback controller...

Modeling and Design Optimization of Variable-Speed Wind Turbine Systems

Directory of Open Access Journals (Sweden)

Ulas Eminoglu

2014-01-01

Full Text Available As a result of the increase in energy demand and government subsidies, the usage of wind turbine system (WTS has increased dramatically. Due to the higher energy production of a variable-speed WTS as compared to a fixed-speed WTS, the demand for this type of WTS has increased. In this study, a new method for the calculation of the power output of variable-speed WTSs is proposed. The proposed model is developed from the S-type curve used for population growth, and is only a function of the rated power and rated (nominal wind speed. It has the advantage of enabling the user to calculate power output without using the rotor power coefficient. Additionally, by using the developed model, a mathematical method to calculate the value of rated wind speed in terms of turbine capacity factor and the scale parameter of the Weibull distribution for a given wind site is also proposed. Design optimization studies are performed by using the particle swarm optimization (PSO and artificial bee colony (ABC algorithms, which are applied into this type of problem for the first time. Different sites such as Northern and Mediterranean sites of Europe have been studied. Analyses for various parameters are also presented in order to evaluate the effect of rated wind speed on the design parameters and produced energy cost. Results show that proposed models are reliable and very useful for modeling and optimization of WTSs design by taking into account the wind potential of the region. Results also show that the PSO algorithm has better performance than the ABC algorithm for this type of problem.

Extension of the Consolidation 3 shaft

Energy Technology Data Exchange (ETDEWEB)

Bohnenkamp, G [Gesteins- und Tiefbau G.m.b.H., Recklinghausen (Germany, F.R.)

1978-02-01

The conversion of a mine shaft into a central winning shaft is described, in particular planning principles, problems to be solved, preliminary work, timber drawing, extension work, shaft deepening, and the installation of shaft internals.

Designing vertical mine shafts under conditions of increasing shaft depth with rock hoisting to the operating mining level

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.

1983-05-01

A system for shaft excavation in deep coal mines with mining depth exceeding 1,000 m is discussed. During mine sinking rocks are removed to the ground surface. When depth of a deep mine shaft is increased rocks are removed to the operating mining level, causing lower investment costs than the system with rock hoisting to the ground surface. The Yuzhgiproshakht design firm carries out investigations on the optimum methods for increasing shaft depth in coal mines. Coal mines with the following coal output are included in evaluations: 0.9, 1.2, 1.5, and 1.8 Mt/year. Mine shaft depth of 600, 800, 1000, 1200, 1400 and 1600 m is analyzed. Shaft depth is increased by 100, 200, 300 or 400 m. Shaft sinking rate ranges from 10 to 70 m/month. Effects of rock hoisting from the shaft bottom on the hoisting scheme in a mine shaft are analyzed. Position of hoisting bucket in relation to cages or skips moving in a shaft is investigated. Investigation results are given in 5 schemes. Analyses show that use of a shaft sinking system with rock hoisting to the ground surface during shaft excavation and with rock hoisting to the operating mining level during shaft depth increasing is economical when a shaft with skips is from 7 to 8 m in diameter or when a cage shaft is 6 m, 7 m or 8 m in diameter. Use of standardized shaft excavation systems is recommended. (In Russian)

Circumferential shaft seal

Science.gov (United States)

Ludwig, L. P. (Inventor)

1981-01-01

A circumferential shaft seal comprising two sealing rings held to a rotating shaft by means of a surrounding elastomeric band is disclosed. The rings are segmented and are of a rigid sealing material such as carbon or a polyimide and graphite fiber composite.

Determining basic parameters of shafts with cage hoisting systems in mines with steep seams

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.

1982-05-01

This paper analyzes problems associated with increasing depth of mine shafts in operating coal mines. Schemes of shaft excavation in mines with steep coal seams are analyzed. Removal of mine rock and the ground surface by existing mine shafts is most economical in most cases. Yuzhgiproshakht has investigated a number of hoisting schemes during mine shaft excavation in order to select the optimum shaft diameter which permits shaft reconstruction and deepening to be optimized. The following conditions are analyzed: coal output of a coal mine ranges from 0.9 megatons (Mt) to 1.8 Mt/year, mining depth ranges from 600 m to 1600 m (with intermediary depth of 800, 1000, 1200 and 1400 m also considered). Separate hoisting of coal and rock waste is used. Shaft sinking rate ranges from 10 to 50 m/month. The following hoisting schemes are analyzed: two independent systems which consist of a cage with counterweight, three systems of a cage with counterweight, double cage system and a cage with counterweight. Hoisting schemes are shown in 9 diagrams. Investigations show that a 7 to 8 m diameter of mine shafts is most economic. In mine shafts 7 m in diameter equipped with two cages with counterweights one of the cages is removed to form a free space for the hoisting bucket. In the 8 m shaft equipped with a double cage system and a cage with counterweight the cage with counterweight is removed to form a free place for the hoisting bucket used during shaft excavation.

Time-limited optimal dynamics beyond the Quantum Speed Limit

DEFF Research Database (Denmark)

Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan

2015-01-01

The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off between the fidelity and the duration in a system driven......-off expressed in terms of the direct Hilbert velocity provides a robust prediction of the quantum speed limit and allows to adapt the control optimization such that it yields a predefined fidelity. The results are verified numerically in a multilevel system with a constrained Hamiltonian, and a classification...

Analysis and topology optimization design of high-speed driving spindle

Science.gov (United States)

Wang, Zhilin; Yang, Hai

2018-04-01

The three-dimensional model of high-speed driving spindle is established by using SOLIDWORKS. The model is imported through the interface of ABAQUS, A finite element analysis model of high-speed driving spindle was established by using spring element to simulate bearing boundary condition. High-speed driving spindle for the static analysis, the spindle of the stress, strain and displacement nephogram, and on the basis of the results of the analysis on spindle for topology optimization, completed the lightweight design of high-speed driving spindle. The design scheme provides guidance for the design of axial parts of similar structures.

Reconsidering the effects of respiratory constraints on the optimal running speed.

Science.gov (United States)

Willcockson, Michael A; Wall-Scheffler, Cara M

2012-07-01

Although both humans and quadrupeds frequently coordinate breathing and limb movement during running, early studies in humans focused on how increased breathing flexibility in humans allowed for relaxed or even transient coordination during locomotion. This difference was used to explain why quadrupeds had an optimal running speed whereas humans did not. Recent research, however, has clearly demonstrated that humans, like quadrupeds, have an optimal running speed. Because these findings are new, it remains unclear why this is true: whether because entrainment in humans was more important than initially predicted or because another restraint is acting. Here, we try to explain the observed minimum cost of transport (CoT) by analyzing metabolic cost with respect to entrainment and a standard set of anthropometrics. We measured the energetic cost of human running at five different speeds and calculated individual CoT curves for each participant (N = 9). Simultaneously, entrainment was determined by the degree to which a poststimulus histogram (breaths per 0.05-s bin after a footfall) differed from a uniform plot. We compared the degree of entrainment to each participant's optimal running speed and found that although all of our subjects clearly entrained at some speeds, entrainment was not a function of CoT (P = 0.897). Because entrainment was also not correlated with speed (P = 0.304), it seems that bipedalism removed the respiratory constraints associated with quadrupedalism as originally suggested. Unlike quadrupeds, for whom respiratory constraints remain implicated in the speed dependence of CoT, constraints that lead to a minimum CoT for people must involve other mechanisms of efficiency such as the storage and release of energy in the lower limbs.

Improving the Response of a Wheel Speed Sensor by Using a RLS Lattice Algorithm

Science.gov (United States)

Hernandez, Wilmar

2006-01-01

Among the complete family of sensors for automotive safety, consumer and industrial application, speed sensors stand out as one of the most important. Actually, speed sensors have the diversity to be used in a broad range of applications. In today's automotive industry, such sensors are used in the antilock braking system, the traction control system and the electronic stability program. Also, typical applications are cam and crank shaft position/speed and wheel and turbo shaft speed measurement. In addition, they are used to control a variety of functions, including fuel injection, ignition timing in engines, and so on. However, some types of speed sensors cannot respond to very low speeds for different reasons. What is more, the main reason why such sensors are not good at detecting very low speeds is that they are more susceptible to noise when the speed of the target is low. In short, they suffer from noise and generally only work at medium to high speeds. This is one of the drawbacks of the inductive (magnetic reluctance) speed sensors and is the case under study. Furthermore, there are other speed sensors like the differential Hall Effect sensors that are relatively immune to interference and noise, but they cannot detect static fields. This limits their operations to speeds which give a switching frequency greater than a minimum operating frequency. In short, this research is focused on improving the performance of a variable reluctance speed sensor placed in a car under performance tests by using a recursive least-squares (RLS) lattice algorithm. Such an algorithm is situated in an adaptive noise canceller and carries out an optimal estimation of the relevant signal coming from the sensor, which is buried in a broad-band noise background where we have little knowledge of the noise characteristics. The experimental results are satisfactory and show a significant improvement in the signal-to-noise ratio at the system output.

Natural Frequncies of Coupled Blade-Bending and Shaft-Torsional Vibrations

Directory of Open Access Journals (Sweden)

B.O. Al-Bedoor

2007-01-01

Full Text Available In this study, the coupled shaft-torsional and blade-bending natural frequencies are investigated using a reduced order mathematical model. The system-coupled model is developed using the Lagrangian approach in conjunction with the assumed modes method to discretize the blade bending deflection. The model accounts for the blade stagger (setting angle, the system rotating speed and its induced stiffening effect. The coupled equations of motion are linearized based on the small deformation theory for the blade bending and shaft torsional deformation to enable calculation of the system natural frequencies for various combinations of system parameters. The obtained coupled eignvalue system is ready for use as a reference for comparison for larger size finite element simulations and for the use as a fast check on natural frequencies for the coupled blade bending and shaft torsional vibrations in the design and diagnostics processes. Some results on the predicted natural frequencies are graphically presented and discussed pertinent to the coupling controlling factors and their effects. In addition, the predicted coupled natural frequencies are validated using the Finite Element Commercial Package (Pro-Mechanica where good agreements are found.

风机转动速度调节的PID优化算法研究%Research on PID Optimization Algorithm for Rotating Speed Regulation of Wind Turbine

Institute of Scientific and Technical Information of China (English)

李家伟

2015-01-01

With control optimizing of the rotational speed of the wind turbine, improve the output power and the power trans-mission efficiency of the wind turbine, the interference of magnetic loss coupling by the wind turbine rotor blade in the con-trol, it is difficult to achieve effective speed regulation, The algorithm has the defects of nonlinear distortion. A wind turbine of PID based on optimal control of rotating speed adjustment optimization, analysis of rotating speed adjusting parameter model of wind turbine, the wind turbine rotor blade speed adjustment control optimization objective function, the design of three layers PID neural network, the PID variable structure control, wind turbine speed shaft connected with the rotor axis the gear box, the aerodynamic excitation brake operation, speed regulation, effectively restrain the interference of wind tur-bine rotor blade control strong coupling magnetic loss, improve the speed of rotation to adjust the output control perfor-mance of wind turbine. The simulation results show that, the method can effectively realize the wind turbine speed control, it can improve the wind turbine efficiency and output gain.%通过对风机转动速度的优化控制调节,提高风机的输出功率和电能传输效率,风机转子叶片控制中受到强耦合的磁损耗的干扰,难以实现有效的转速调节,提出一种基于PID优化控制的风机转动速度调节优化算法,分析风机转动速度调节控制参数模型,构建风机转子叶片速度调节的优化控制目标函数,设计三层前向PID神经网络,通过PID变结构控制,风机的低速轴将转子轴心与齿轮箱连接,激发空气动力闸的运行,进行转速调节,有效地抑制了风机转子叶片控制中强耦合磁损耗的干扰,提高了风机转动速度调节输出控制性能.仿真结果表明,采用该方法能有效实现风机转速调节控制,提高风机运行效率和输出增益.

Optimal stride frequencies in running at different speeds

NARCIS (Netherlands)

Van Oeveren, Ben T.; De Ruiter, Cornelis J.; Beek, Peter J.; Van Dieën, Jaap H.

2017-01-01

During running at a constant speed, the optimal stride frequency (SF) can be derived from the u-shaped relationship between SF and heart rate (HR). Changing SF towards the optimum of this relationship is beneficial for energy expenditure and may positively change biomechanics of running. In the

Chaos optimization algorithms based on chaotic maps with different probability distribution and search speed for global optimization

Science.gov (United States)

Yang, Dixiong; Liu, Zhenjun; Zhou, Jilei

2014-04-01

Chaos optimization algorithms (COAs) usually utilize the chaotic map like Logistic map to generate the pseudo-random numbers mapped as the design variables for global optimization. Many existing researches indicated that COA can more easily escape from the local minima than classical stochastic optimization algorithms. This paper reveals the inherent mechanism of high efficiency and superior performance of COA, from a new perspective of both the probability distribution property and search speed of chaotic sequences generated by different chaotic maps. The statistical property and search speed of chaotic sequences are represented by the probability density function (PDF) and the Lyapunov exponent, respectively. Meanwhile, the computational performances of hybrid chaos-BFGS algorithms based on eight one-dimensional chaotic maps with different PDF and Lyapunov exponents are compared, in which BFGS is a quasi-Newton method for local optimization. Moreover, several multimodal benchmark examples illustrate that, the probability distribution property and search speed of chaotic sequences from different chaotic maps significantly affect the global searching capability and optimization efficiency of COA. To achieve the high efficiency of COA, it is recommended to adopt the appropriate chaotic map generating the desired chaotic sequences with uniform or nearly uniform probability distribution and large Lyapunov exponent.

Theoretical and experimental study on the magnetic fluid seal of reciprocating shaft

Science.gov (United States)

Li, Decai; Xu, Haiping; He, Xinzhi; Lan, Huiqing

2005-03-01

The authors obtain anti-pressure formula of reciprocating shaft magnetic fluid seal from general Navier-Stokes equation. In order to verify the correctness of the anti-pressure formula, the authors set up a magnetic fluid anti-pressure experiment rig for a reciprocating seal. Finally, the authors have verified influence of speed and stroke on the seal anti-pressure.

Experimental Investigation of A Twin Shaft Micro Gas-Turbine System

International Nuclear Information System (INIS)

Sadig, Hussain; Sulaiman, Shaharin Anwar; Ibrahim, Idris

2013-01-01

Due to the fast depletion of fossil fuels and its negative impact on the environment, more attention has been concentrated to find new resources, policies and technologies, which meet the global needs with regard to fuel sustainability and emissions. In this paper, as a step to study the effect of burning low calorific value fuels on gas-turbine performance; a 50 kW slightly pressurized non-premixed tubular combustor along with turbocharger based twin shaft micro gas-turbine was designed and fabricated. A series of tests were conducted to characterize the system using LPG fuel. The tests include the analysis of the temperature profile, pressure and combustor efficiency as well as air fuel ratio and speed of the second turbine. The tests showed a stable operation with acceptable efficiency, air fuel ratio, and temperature gradient for the single and twin shaft turbines.

An exploratory shaft facility in SALT: Draft shaft study plan

International Nuclear Information System (INIS)

1987-03-01

This draft Shaft Study Plan describes a program of testing and monitoring in the Exploratory Shafts of a candidate high-level nuclear waste repository site in Deaf Smith County, Texas. The purpose of the programs to assist with site characterization in support of a determination of site suitability for development as a repository design and performance assessment evaluations. The program includes a variety of geological, geophysical, geomechanical, thermomechanical, and geohydrological testing and monitoring. The program is presented as a series of separate studies concerned with geological, geomechanical, and geohydrological site characterization, and with evaluating the mechanical and hydrological response of the site to construction of the shafts. The various studies, and associated test or monitoring methods are shown. The procedure used in developing the test program has been to initially identify the information necessary to satisfy (1) federal, state, and local requirements, and (2) repository program requirements. These information requirements have then been assessed to determine which requirements can be addressed wholly or in significant part by monitoring and testing from within the shafts. Test methods have been identified to address specific information requirements. 67 refs., 39 figs., 31 tabs

Forced sustained swimming exercise at optimal speed enhances growth of juvenile yellowtail kingfish (Seriola lalandi)

NARCIS (Netherlands)

Palstra, A.P.; Mes, D.; Kusters, K.; Roques, J.A.C.; Flik, G.; Kloet, K.; Blonk, R.J.W.

2015-01-01

Swimming exercise at optimal speed may optimize growth performance of yellowtail kingfish in a recirculating aquaculture system. Therefore, optimal swimming speeds (U-opt in m s(-1) or body lengths s(-1), BL s(-1)) were assessed and then applied to determine the effects of long-term forced and

Surrogate Based Optimization of Aerodynamic Noise for Streamlined Shape of High Speed Trains

Directory of Open Access Journals (Sweden)

Zhenxu Sun

2017-02-01

Full Text Available Aerodynamic noise increases with the sixth power of the running speed. As the speed increases, aerodynamic noise becomes predominant and begins to be the main noise source at a certain high speed. As a result, aerodynamic noise has to be focused on when designing new high-speed trains. In order to perform the aerodynamic noise optimization, the equivalent continuous sound pressure level (SPL has been used in the present paper, which could take all of the far field observation probes into consideration. The Non-Linear Acoustics Solver (NLAS approach has been utilized for acoustic calculation. With the use of Kriging surrogate model, a multi-objective optimization of the streamlined shape of high-speed trains has been performed, which takes the noise level in the far field and the drag of the whole train as the objectives. To efficiently construct the Kriging model, the cross validation approach has been adopted. Optimization results reveal that both the equivalent continuous sound pressure level and the drag of the whole train are reduced in a certain extent.

The effect of induction motor shaft diameter on motor performance

Directory of Open Access Journals (Sweden)

Asım Gökhan Yetgin

2017-10-01

Full Text Available Induction motors are used in many areas from the past to the present and in different fields with the development of technology has continued to be used. It is obvious that induction motors as an improvement to the efficiency in terms of energy saving would cause great benefit. In that context, induction motor manufacturers and designers are constantly trying out new methods to improve motor performance and efficiency. In this study, what would be the optimum diameter of the shaft in order to increase the efficiency of the induction motor were investigated. In the study, 5.5 kW, 7.5 kW and 11 kW motors analyzes were also performed. Obtained shaft diameter values were compared with the manufacturer values. In addition, critical points such as the magnetic flux values, weight values and performances of the motors were examined and optimal shaft diameter values for each motor have been determined.

Shaft siting decision

International Nuclear Information System (INIS)

1987-08-01

This study identifies and establishes relative guidelines to be used for siting of repository shafts. Weights were determined for the significant factors that impact the selection of shaft locations for a nuclear waste repository in salt. The study identified a total of 45 factors. A panel of experienced mining people utilized the Kepner-Tregoe (K-T) Decision Analysis Process to perform a structured evaluation of each significant shaft siting factor. The evaluation determined that 22 of the factors were absolute constraints and that the other 23 factors were desirable characteristics. The group established the relative weights for each of the 23 desirable characteristics by using a paired comparison method. 8 refs., 2 figs., 5 tabs

Analysis of nonlinear vibrations and stability of rotating asymmetrical nano-shafts incorporating surface energy effects

Science.gov (United States)

Ghodousi, Maryam; Shahgholi, Majid; Payganeh, Gholamhassan

2018-03-01

The objective of the present work is to investigate the nonlinear vibrations of the rotating asymmetrical nano-shafts by considering surface effect. In order to compute the surface stress tensor, the surface elasticity theory is used. The governing nonlinear equations of motion are obtained with the aid of variational approach. Bubnov-Galerkin is a very effective method for exploiting the reduced-order model of the equations of motion. The averaging method is employed to analyze the reduced-order model of the system. For this purpose, the well-known Van der Pol transformation in the complex form and angle-action transformation are utilized. The effect of surface stress on the forward and backward speeds, steady state responses of the system, fixed points, close orbits and stability of the solutions is examined. The preliminary results of the research show that the absolute values of forward and backward whirling speeds in the presence of surface effect with positive residual surface stress are higher than those of regarding the system without surface effect and in the presence of surface effect with negative residual surface stress. In addition, it is seen that the undamped rotating asymmetrical nano-shaft, for specified value of detuning parameter, in the absence or presence of surface effect has various number of stable and unstable periodic solutions. Besides, there is different number of separatrix (homoclinic orbit type). Furthermore, bifurcations, number of solutions and their stability for damped rotating asymmetrical nano-shaft are investigated. Also, the above results have been obtained for rotating symmetrical nano-shaft.

Representative assessment of long bone shaft biomechanical properties: an optimized testing method

NARCIS (Netherlands)

Bramer, J. A.; Barentsen, R. H.; vd Elst, M.; de Lange, E. S.; Patka, P.; Haarman, H. J.

1998-01-01

Whole bone bending tests are commonly used in mechanical evaluation of long bones. Reliable information about the midshaft can only be obtained if the bending moment is uniformly distributed along the shaft, and if the distribution of the bending stress is not adversely influenced by rigid clamping

Forging Long Shafts On Disks

Science.gov (United States)

Tilghman, Chris; Askey, William; Hopkins, Steven

1989-01-01

Isothermal-forging apparatus produces long shafts integral with disks. Equipment based on modification of conventional isothermal-forging equipment, required stroke cut by more than half. Enables forging of shafts as long as 48 in. (122 cm) on typical modified conventional forging press, otherwise limited to making shafts no longer than 18 in. (46cm). Removable punch, in which forged material cools after plastic deformation, essential novel feature of forging apparatus. Technology used to improve such products as components of gas turbines and turbopumps and of other shaft/disk parts for powerplants, drive trains, or static structures.

Optimal design of high-speed loading spindle based on ABAQUS

Science.gov (United States)

Yang, Xudong; Dong, Yu; Ge, Qingkuan; Yang, Hai

2017-12-01

The three-dimensional model of high-speed loading spindle is established by using ABAQUS’s modeling module. A finite element analysis model of high-speed loading spindle was established by using spring element to simulate bearing boundary condition. The static and dynamic performance of the spindle structure with different specifications of the rectangular spline and the different diameter neck of axle are studied in depth, and the influence of different spindle span on the static and dynamic performance of the high-speed loading spindle is studied. Finally, the optimal structure of the high-speed loading spindle is obtained. The results provide a theoretical basis for improving the overall performance of the test-bed

Laser shaft alignment measurement model

Science.gov (United States)

Mo, Chang-tao; Chen, Changzheng; Hou, Xiang-lin; Zhang, Guoyu

2007-12-01

Laser beam's track which is on photosensitive surface of the a receiver will be closed curve, when driving shaft and the driven shaft rotate with same angular velocity and rotation direction. The coordinate of arbitrary point which is on the curve is decided by the relative position of two shafts. Basing on the viewpoint, a mathematic model of laser alignment is set up. By using a data acquisition system and a data processing model of laser alignment meter with single laser beam and a detector, and basing on the installation parameter of computer, the state parameter between two shafts can be obtained by more complicated calculation and correction. The correcting data of the four under chassis of the adjusted apparatus moving on the level and the vertical plane can be calculated. This will instruct us to move the apparatus to align the shafts.

Fast visual prediction and slow optimization of preferred walking speed.

Science.gov (United States)

O'Connor, Shawn M; Donelan, J Maxwell

2012-05-01

People prefer walking speeds that minimize energetic cost. This may be accomplished by directly sensing metabolic rate and adapting gait to minimize it, but only slowly due to the compounded effects of sensing delays and iterative convergence. Visual and other sensory information is available more rapidly and could help predict which gait changes reduce energetic cost, but only approximately because it relies on prior experience and an indirect means to achieve economy. We used virtual reality to manipulate visually presented speed while 10 healthy subjects freely walked on a self-paced treadmill to test whether the nervous system beneficially combines these two mechanisms. Rather than manipulating the speed of visual flow directly, we coupled it to the walking speed selected by the subject and then manipulated the ratio between these two speeds. We then quantified the dynamics of walking speed adjustments in response to perturbations of the visual speed. For step changes in visual speed, subjects responded with rapid speed adjustments (lasting 300 s). The timing and direction of these responses strongly indicate that a rapid predictive process informed by visual feedback helps select preferred speed, perhaps to complement a slower optimization process that seeks to minimize energetic cost.

Synchronous motor with soft start element formed between the motor rotor and motor output shaft to successfully synchronize loads that have high inertia and/or high torque

Science.gov (United States)

Umans, Stephen D; Nisley, Donald L; Melfi, Michael J

2014-10-28

A line-start synchronous motor has a housing, a rotor shaft, and an output shaft. A soft-start coupling portion is operatively coupled to the output shaft and the rotor shaft. The soft-start coupling portion is configurable to enable the synchronous motor to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling. The synchronous motor is sufficiently rated to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling.

Construction of blind shafts with the PVS 3500 planetary full shaft drilling machine

International Nuclear Information System (INIS)

Glogowski, P.; Kolditz, H.

1992-01-01

The PVS 3500 planetary full shaft drilling machine has proved as a prototype in the construction of two blind shafts. The drilling rate of 8 m/shift or 25.6 m 3 /MS is outstanding for the initial use of this drilling machine. Blind shafts were cut from the solid by a dry drilling method for the first time. It opens up the possibility of making available storage boreholes for larger quantities of radioactive waste with low activity and for toxic waste materials. (orig.)

Fuzzy Constrained Predictive Optimal Control of High Speed Train with Actuator Dynamics

Directory of Open Access Journals (Sweden)

Xi Wang

2016-01-01

Full Text Available We investigate the problem of fuzzy constrained predictive optimal control of high speed train considering the effect of actuator dynamics. The dynamics feature of the high speed train is modeled as a cascade of cars connected by flexible couplers, and the formulation is mathematically transformed into a Takagi-Sugeno (T-S fuzzy model. The goal of this study is to design a state feedback control law at each decision step to enhance safety, comfort, and energy efficiency of high speed train subject to safety constraints on the control input. Based on Lyapunov stability theory, the problem of optimizing an upper bound on the cruise control cost function subject to input constraints is reduced to a convex optimization problem involving linear matrix inequalities (LMIs. Furthermore, we analyze the influences of second-order actuator dynamics on the fuzzy constrained predictive controller, which shows risk of potentially deteriorating the overall system. Employing backstepping method, an actuator compensator is proposed to accommodate for the influence of the actuator dynamics. The experimental results show that with the proposed approach high speed train can track the desired speed, the relative coupler displacement between the neighbouring cars is stable at the equilibrium state, and the influence of actuator dynamics is reduced, which demonstrate the validity and effectiveness of the proposed approaches.

Integrated analysis of rock mass deformation within shaft protective pillar

Directory of Open Access Journals (Sweden)

Ewa Warchala

2016-01-01

Full Text Available The paper presents an analysis of the rock mass deformation resulting from mining in the vicinity of the shaft protection pillar. A methodology of deformation prediction is based on a deterministic method using Finite Element Method (FEM. The FEM solution is based on the knowledge of the geomechanical properties of the various geological formations, tectonic faults, types of mining systems, and the complexity of the behaviour of the rock mass. The analysis gave the stress and displacement fields in the rock mass. Results of the analysis will allow for design of an optimal mining system. The analysis is illustrated by an example of the shaft R-VIII Rudna Mine KGHM Polish Copper SA.

The SSC access shafts calculational study

International Nuclear Information System (INIS)

Baishev, I.S.; Mokhov, N.V.; Toohig, T.E.

1991-06-01

The SSC generic shaft requirements and access spacing are considered elsewhere. The shafts connecting the ground surface with the underground accelerator tunnel deliver to the surface some portion of the radiation created in the tunnel. The radiation safety problem of access shafts consists of two major questions: Does the dose equivalent at the ground surface exceed permissible limits? If it exceeds those limits, what additional shielding measures are required? A few works deal with this problem for high energy machines. This work is an attempt to answer these questions for the basic types of shafts specific to the SSC magnet delivery, utility and personnel shafts using full-scale Monte-Carlo calculations of the entire process from hadronic cascades in the lattice elements to particles scattered in the tunnel, niches, alcoves, shafts and surface bunkers and buildings. 9 refs., 16 figs., 1 tab

Multi-objective PID Optimization for Speed Control of an Isolated Steam Turbine using Gentic Algorithm

OpenAIRE

Sanjay Kr. Singh; D. Boolchandani; S.G. Modani; Nitish Katal

2014-01-01

This study focuses on multi-objective optimization of the PID controllers for optimal speed control for an isolated steam turbine. In complex operations, optimal tuning plays an imperative role in maintaining the product quality and process safety. This study focuses on the comparison of the optimal PID tuning using Multi-objective Genetic Algorithm (NSGA-II) against normal genetic algorithm and Ziegler Nichols methods for the speed control of an isolated steam turbine. Isolated steam turbine...

Thermoconvective flow velocity in a high-speed magnetofluid seal after it has stopped

OpenAIRE

Krakov, M. S.; Nikiforov, I. V.

2012-01-01

Convective flow is investigated in the high-speed (linear velocity of the shaft seal is more than 1 m/s) magnetofluid shaft seal after it has been stopped. Magnetic fluid is preliminarily heated due to viscous friction in the moving seal. After the shaft has been stopped, nonuniform heated fluid remains under the action of a high-gradient magnetic field. Numerical analysis has revealed that in this situation, intense thermomagnetic convection is initiated. The velocity of magnetic fluid depen...

Optimising a shaft's geometry by applying genetic algorithms

Directory of Open Access Journals (Sweden)

María Alejandra Guzmán

2005-05-01

Full Text Available Many engnieering design tasks involve optimising several conflicting goals; these types of problem are known as Multiobjective Optimisation Problems (MOPs. Evolutionary techniques have proved to be an effective tool for finding solutions to these MOPs during the last decade, Variations on the basic generic algorithm have been particulary proposed by different researchers for finding rapid optimal solutions to MOPs. The NSGA (Non-dominated Sorting Generic Algorithm has been implemented in this paper for finding an optimal design for a shaft subjected to cyclic loads, the conflycting goals being minimum weight and minimum lateral deflection.

Energetic optimization of regenerative braking for high speed railway systems

International Nuclear Information System (INIS)

Frilli, Amedeo; Meli, Enrico; Nocciolini, Daniele; Pugi, Luca; Rindi, Andrea

2016-01-01

Highlights: • A model of longitudinal dynamics of the High-speed train ETR1000 is presented. • The model includes on board traction and braking subsystems. • Interactions between overhead line and power line are modelled. • The model is validated on real experimental data. • An energy storage strategy for a high-speed line is proposed. - Abstract: The current development trend in the railway field has led to an ever increasing interest for the energetic optimization of railway systems (especially considering the braking phases), with a strong attention to the mutual interactions between the loads represented by railway vehicles and the electrical infrastructure, including all the sub-systems related to distribution and smart energy management such as energy storage systems. In this research work, the authors developed an innovative coupled modelling approach suitable for the analysis of the energetic optimization of railway systems and based on the use of the new object oriented language Matlab-Simscape™, which presents several advantages with respect to conventional modelling tools. The proposed model has been validated considering an Italian Direct Current High-speed line and the High-speed train ETR 1000. Furthermore, the model has been used to perform an efficiency analysis, considering the use of energy storage devices. The results obtained with the developed model show that the use of energy recovery systems in high-speed railway can provide great opportunities of energy savings.

New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

Directory of Open Access Journals (Sweden)

Nazim Mir-Nasiri

2008-11-01

Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion..

New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

Directory of Open Access Journals (Sweden)

Nazim Mir-Nasiri

2005-09-01

Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion.

30 CFR 56.19106 - Shaft sets.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shaft sets. 56.19106 Section 56.19106 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Shaft sets. Shaft sets shall be kept in good repair and clean of hazardous material. ...

Shaft and tunnel sealing considerations

International Nuclear Information System (INIS)

Kelsall, P.C.; Shukla, D.K.

1980-01-01

Much of the emphasis of previous repository sealing research has been placed on plugging small diameter boreholes. It is increasingly evident that equal emphasis should now be given to shafts and tunnels which constitute more significant pathways between a repository and the biosphere. The paper discusses differences in requirements for sealing shafts and tunnels as compared with boreholes and the implications for seal design. Consideration is given to a design approach for shaft and tunnel seals based on a multiple component design concept, taking into account the requirements for retrievability of the waste. A work plan is developed for the future studies required to advance shaft and tunnel sealing technology to a level comparable with the existing technology for borehole sealing

30 CFR 57.19106 - Shaft sets.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shaft sets. 57.19106 Section 57.19106 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND....19106 Shaft sets. Shaft sets shall be kept in good repair and clean of hazardous material. ...

Variable-Speed Power-Turbine Research at Glenn Research Center

Science.gov (United States)

Welch, Gerard E.; McVetta, Ashlie B.; Stevens, Mark A.; Howard, Samuel A.; Giel, Paul W.; Ameri, Ali, A.; To, Waiming; Skoch, Gary J.; Thurman, Douglas R.

2012-01-01

The main rotors of the NASA Large Civil Tilt-Rotor (LCTR) notional vehicle operate over a wide speed-range, from 100 percent at takeoff to 54 percent at cruise. The variable-speed power turbine (VSPT) offers one approach by which to effect this speed variation. VSPT aerodynamics challenges include high work factors at cruise, wide (40 to 60 ) incidence-angle variations in blade and vane rows over the speed range, and operation at low Reynolds numbers. Rotordynamics challenges include potential responsiveness to shaft modes within the 50 percent VSPT speed-range. A research effort underway at NASA Glenn Research Center, intended to address these key aerodynamic and rotordynamic challenges, is described. Conceptual design and 3-D multistage RANS and URANS analyses, conducted internally and under contract, provide expected VSPT sizing, stage-count, performance and operability information, and maps for system studies. Initial steps toward experimental testing of incidence-tolerant blading in a transonic linear cascade are described, and progress toward development/improvement of a simulation capability for multistage turbines with low Reynolds number transitional flow is summarized. Preliminary rotordynamics analyses indicate that viable concept engines with 50 percent VSPT shaft-speed range. Assessments of potential paths toward VSPT component-level testing are summarized.

Design of very high speed electric generators

International Nuclear Information System (INIS)

Labollita, Santiago

2008-01-01

This work approaches the design process of an electric generator suitable for running efficiently at high speed, driven by a turbo shaft.The axial flux concept was used.For the mechanical design of the prototype, cooling capacity and mounting method were considered, looking for simplicity of the parts evolved. Neodymium-iron-boron permanent magnets were used as magnetic source.For the electrical design, a calculation tool was developed in order to predict the prototype electrical parameters and optimize its geometry.The goal was to obtain 1 kW of electric power at a speed of 100,000 rpm.The efficiency and electrical behaviour of the prototype were characterized at speeds between 2,000 rpm and 30,000 rpm and then the behaviour at the design condition was predicted by obtaining an equivalent electric circuit.The estimated load voltage was 237 V as well as an electrical efficiency of 95%.Eddy current effects were not recognized. Increase of the internal resistance and decree of inductance were observed while raising the electric frequency.Finally, an electronic system was developed in order to use the prototype as a c.c. motor. Global performance was measured according to different supply characteristic. An optimum supply voltage was found.A maximum efficiency of 63% was reached. [es

Rotor-dynamic design aspects for a variable frequency drive based high speed cryogenic centrifugal pump in fusion devices

International Nuclear Information System (INIS)

Das, Jotirmoy; Vaghela, Hitensinh; Bhattacharya, Ritendra; Patel, Pratik; Shukla, Vinit; Shah, Nitin; Sarkar, Biswanath

2015-01-01

Superconducting magnets of large size are inevitable for fusion devices due to high magnetic field requirements. Forced flow cooling of the superconducting magnets with high mass flowrate of the order ∼3 kg/s is required to keep superconducting magnets within its safe operational boundaries during various plasma scenarios. This important requirement can be efficiently fulfilled by employing high capacity and high efficiency cryogenic centrifugal pumps. The efficiency > 70% will ensure overall lower heat load to the cryoplant. Thermo-hydraulic design of cryogenic centrifugal pump revealed that to achieve the operational regime with high efficiency, the speed should be ∼ 10,000 revolutions per minute. In this regard, the rotor-dynamic design aspect is quite critical from the operational stability point of view. The rotor shaft design of the cryogenic pump is primarily an outcome of optimization between thermal heat-in leak at cryogenic temperature level from ambient, cryogenic fluid impedance and designed rotation speed of the impeller wheel. The paper describes the basic design related to critical speed of the rotor shaft, rotor whirl and system instability prediction to explore the ideal operational range of the pump from the system stability point of view. In the rotor-dynamic analysis, the paper also describes the Campbell plots to ensure that the pump is not disturbed by any of the critical speeds, especially while operating near the nominal and enhanced operating modes. (author)

Designing optimum diameter of skip shafts in mines with inclined or steep coal seams

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.

1981-07-01

This paper discusses methods of increasing depth of operating shaft mines considering optimization of hoisting systems. The following solutions are analyzed: removing mined rock material to the surface, to operating horizon, to the deepest horizon, removing rock to the deepest horizon by enlarging a large diameter borehole. It is suggested that removing rock material to the surface is most economical. This solution is sometimes difficult to implement due to design of mine shafts. If a shaft is equipped with two pairs of skips, or with a pair of skips and two independent skips, one skip or a pair of skips can be removed to form free space for buckets used to hoist mined rock and coal. The bucket moves along rope shaft guides. Analysis of the optimum hoisting systems in shaft mines for coal mines with the following design capacity is carried out: 0.9, 1.2, 1.5 and 1.8 Mmt a year. The following depth of working horizons is evaluated: 600, 800, 1000, 1200, 1400 and 1600 m. It is assumed that coal and rock are hoisted separately. Advance rate ranges from 10 to 50 m/month. The results of analysis are shown in two tables. It is suggested that from the point of view of increasing depth of active mine shafts the following solutions are optimum: 7 m shaft with a system of three independently moving skips (two for coal, one for rock material), and 8 m shaft equipped with a pair of skips and two independent skips (one of the independently moving skips is used for rock hoisting). 4 refs.

High pressure shaft seal

International Nuclear Information System (INIS)

Martinson, A.R.; Rogers, V.D.

1980-01-01

In relation to reactor primary coolant pumps, mechanical seal assembly for a pump shaft is disclosed which features a rotating seal ring mounting system which utilizes a rigid support ring loaded through narrow annular projections in combination with centering non-sealing O-rings which effectively isolate the rotating seal ring from temperature and pressure transients while securely positioning the ring to adjacent parts. A stationary seal ring mounting configuration allows the stationary seal ring freedom of motion to follow shaft axial movement up to 3/4 of an inch and shaft tilt about the pump axis without any change in the hydraulic or pressure loading on the stationary seal ring or its carrier. (author)

Numerical optimization of circulation control airfoil at high subsonic speed

Science.gov (United States)

Tai, T. C.; Kidwell, G. H., Jr.

1984-01-01

A numerical procedure for optimizing the design of the circulation control airfoil for use at high subsonic speeds is presented. The procedure consists of an optimization scheme coupled with a viscous potential flow analysis for the blowing jet. The desired airfoil is defined by a combination of three baseline shapes (cambered ellipse and cambered ellipse with drooped and spiraled trailing edges). The coefficients of these shapes are used as design variables in the optimization process. Under the constraints of lift augmentation and lift-to-drag ratios, the airfoil, optimized at free-stream Mach 0.54 and alpha = -2 degrees can be characterized as a cambered ellipse with a drooped trailing edge. Experimental tests support the performance improvement predicted by numerical optimization.

Large shaft development test plan

International Nuclear Information System (INIS)

Krug, A.D.

1984-03-01

This test plan proposes the conduct of shaft liner tests as part of the large shaft development test proposed for the Hanford Site in support of the repository development program. The objectives of these tests are to develop techniques for measuring liner alignment (straightness), both construction assembly alignment and downhole cumulative alignment, and to assess the alignment information as a real time feedback to aid the installation procedure. The test plan is based upon installing a 16 foot ID shaft liner into a 20 foot diameter shaft to a depth of 1000 feet. This test plan is considered to be preliminary in that it was prepared as input for the decision to determine if development testing is required in this area. Should the decision be made to proceed with development testing, this test plan shall be updated and revised. 6 refs., 2 figs

Optimal swimming speed in head currents and effects on distance movement of winter-migrating fish

DEFF Research Database (Denmark)

Brodersen, J.; Nilsson, P.A.; Ammitzbøl, J.

2008-01-01

ecologically and economically important. We here use passive and active telemetry to study how winter migrating roach regulate swimming speed and distance travelled per day in response to variations in head current velocity. Furthermore, we provide theoretical predictions on optimal swimming speeds in head...... currents and relate these to our empirical results. We show that fish migrate farther on days with low current velocity, but travel at a greater ground speed on days with high current velocity. The latter result agrees with our predictions on optimal swimming speed in head currents, but disagrees...... with previously reported predictions suggesting that fish ground speed should not change with head current velocity. We suggest that this difference is due to different assumptions on fish swimming energetics. We conclude that fish are able to adjust both swimming speed and timing of swimming activity during...

Torsion of a growing shaft

Directory of Open Access Journals (Sweden)

Alexander V. Manzhirov

2017-12-01

Full Text Available The torsion of a shaft by rigid disks is considered. The shaft has the form of circular cylinder. Two rigid disks are attached to its end faces. The process of continuous growth of such shaft under the influence of twisting torques applied to the disks is studied. Dual series equations which reflect the mathematical content of the problem at the different stages of the growing process are derived and solved. Results of the numerical analysis and singularities of the qualitative mechanical behaviour of the fundamental characteristics are discussed.

Accuracy optimization of high-speed AFM measurements using Design of Experiments

DEFF Research Database (Denmark)

Tosello, Guido; Marinello, F.; Hansen, Hans Nørgaard

2010-01-01

Atomic Force Microscopy (AFM) is being increasingly employed in industrial micro/nano manufacturing applications and integrated into production lines. In order to achieve reliable process and product control at high measuring speed, instrument optimization is needed. Quantitative AFM measurement...... results are influenced by a number of scan settings parameters, defining topography sampling and measurement time: resolution (number of profiles and points per profile), scan range and direction, scanning force and speed. Such parameters are influencing lateral and vertical accuracy and, eventually......, the estimated dimensions of measured features. The definition of scan settings is based on a comprehensive optimization that targets maximization of information from collected data and minimization of measurement uncertainty and scan time. The Design of Experiments (DOE) technique is proposed and applied...

Boundary integral method for torsion of composite shafts

International Nuclear Information System (INIS)

Chou, S.I.; Mohr, J.A.

1987-01-01

The Saint-Venant torsion problem for homogeneous shafts with simply or multiply-connected regions has received a great deal of attention in the past. However, because of the mathematical difficulties inherent in the problem, very few problems of torsion of shafts with composite cross sections have been solved analytically. Muskhelishvili (1963) studied the torsion problem for shafts with cross sections having several solid inclusions surrounded by an elastic material. The problem of a circular shaft reinforced by a non-concentric round inclusion, a rectangular shaft composed of two rectangular parts made of different materials were solved. In this paper, a boundary integral equation method, which can be used to solve problems more complex than those considered by Katsikadelis et. al., is developed. Square shaft with two dissimilar rectangular parts, square shaft with a square inclusion are solved and the results compared with those given in the reference cited above. Finally, a square shaft composed of two rectangular parts with circular inclusion is solved. (orig./GL)

Results from Investigations of Torsional Vibration in Turbine Set Shaft Systems

Science.gov (United States)

Taradai, D. V.; Deomidova, Yu. A.; Zile, A. Z.; Tomashevskii, S. B.

2018-01-01

The article generalizes the results obtained from investigations of torsional vibration in the shaft system of the T-175/210-12.8 turbine set installed at the Omsk CHPP-5 combined heat and power plant. Three different experimental methods were used to determine the lowest natural frequencies of torsional vibration excited in the shaft system when the barring gear is switched into operation, when the generator is synchronized with the grid, and in response to unsteady disturbances caused by the grid and by the turbine control and steam admission system. It is pointed out that the experimental values of the lowest natural frequencies (to the fourth one inclusively) determined using three different methods were found to be almost completely identical with one another, even though the shaft system was stopped in the experiments carried out according to one method and the shaft system rotated at the nominal speed in those carried out according to two other methods. The need to further develop the experimental methods for determining the highest natural frequencies is substantiated. The values of decrements for the first, third, and fourth natural torsional vibration modes are obtained. A conclusion is drawn from a comparison between the calculated and experimental data on the shaft system's static twisting about the need to improve the mathematical models for calculating torsional vibration. The measurement procedure is described, and the specific features pertinent to the way in which torsional vibration manifests itself as a function of time and turbine set operating mode under the conditions of its long-term operation are considered. The fundamental measurement errors are analyzed, and their influence on the validity of measured parameters is evaluated. With an insignificant level of free and forced torsional vibrations set up under the normal conditions of turbine set and grid operation, it becomes possible to exclude this phenomenon from the list of main factors

Femoral shaft fractures

International Nuclear Information System (INIS)

Bender, C.E.; Campbell, D.C. II

1985-01-01

The femur is the longest, largest, and strongest bone in the body. Because of its length, width, and role as primary weight-bearing bone, it must tolerate the extremes of axial loading and angulatory stresses. Massive musculature envelopes the femur. This masculature provides abundant blood supply to the bone, which also allows great potential for healing. Thus, the most significant problem relating to femoral shaft fractures is not healing, but restoration of bone length and alignment so that the femoral shaft will tolerate the functional stresses demanded of it

High speed cryogenic self-acting, shaft seals for liquid rocket turbopumps

Science.gov (United States)

Burcham, R. E.

1983-01-01

Three self acting lift pad liquid oxygen face seals and two self acting gaseous helium circumferential seals for high speed liquid oxygen turbopump were evaluated. The development of a technology for reliable, 10 hour life, multiple start seals for use in high speed liquid oxygen turbopumps is discussed.

Shaft placement in a bedded salt repository

International Nuclear Information System (INIS)

Klasi, M.L.

1982-10-01

Preferred shaft pillar sizes and shaft locations were determined with respect to the induced thermal stresses in a generic bedded salt repository at a depth of 610 m with a gross thermal loading of 14.8 W/m 2 . The model assumes isotropic material properties, plane strain and linear elastic behavior. Various shaft locations were analyzed over a 25 year period. The thermal results show that for this time span, the stratigraphy is unimportant except for the region immediately adjacent to the repository. The thermomechanical results show that for the given repository depth of 610 m, a minimum central shaft pillar radius of 244 m is required to equal the material strength in the barrier pillar. An assumed constant stress and constant temperature distribution creep model of the central shaft region adjacent to the repository conservatively overestimates a creep closure of 310 mm in a 6.1 m diameter centrally-located shaft

Buoyancy and Pressure Driven Flow of Hot Gases in Vertical Shafts with Natural and Forced Ventilation

Science.gov (United States)

Tamm, Gunnar; Jaluria, Yogesh

2003-11-01

An experimental investigation has been carried out on the buoyancy and pressure induced flow of hot gases in vertical shafts, in order to simulate the propagation of combustion products in elevator shafts due to fire in multilevel buildings. Various geometrical configurations are studied, with regard to natural and forced ventilation imposed at the top or bottom of the vertical shaft. The aspect ratio is taken at a fixed value of 6 and the inflow conditions for the hot gases, at a vent near the bottom, are varied in terms of the Reynolds and Grashof numbers. Temperature measurements within the shaft allow a detailed study of the steady state thermal fields, from which optimal means for smoke alleviation in high-rise building fires may be developed. Flow visualization is also used to study the flow characteristics. The results obtained indicate a wall plume as the primary transport mechanism. Flow recirculation dominates at high Grashof number flows, while increased Reynolds numbers gives rise to greater mixing in the shaft. The development and stability of the flow and its effect on the spread of smoke and hot gases are assessed for the different shaft configurations and inlet conditions. It is found that the fastest smoke removal and lowest shaft temperatures occur for a configuration with natural ventilation at the top and forced ventilation up from the shaft bottom. It is also shown that forced ventilation can be used to arrest smoke spread, as well as to dilute the effects of the fire.

Connect-disconnect coupling for preadjusted rigid shafts

Science.gov (United States)

Bajkowski, F. W.; Holmberg, A.

1969-01-01

Coupling device enables a rigid shaft to be connected to or disconnected from a fixed base without disturbing the point of adjustment of the shaft in a socket or causing the shaft to rotate. The coupling consists of an externally threaded, internally slotted boss extending from the fixed base.

Shaft MisalignmentDetectionusing Stator Current Monitoring

OpenAIRE

Alok Kumar Verma, Somnath Sarangi and M.H. Kolekar

2013-01-01

This paper inspects the misaligned of shaft by usingdiagnostic medium such as current and vibration.Misalignments in machines can cause decrease inefficiency and in the long-run it may cause failurebecause of unnecessary vibration, stress on motor,bearings and short-circuiting in stator and rotorwindings.In this study, authors investigate the onsetof instability on a shaft mounted on journal bearings.Shaft displacement and stator current samples duringmachine run up under misaligned condition...

On the experimental prediction of the stability threshold speed caused by rotating damping

Science.gov (United States)

Vervisch, B.; Derammelaere, S.; Stockman, K.; De Baets, P.; Loccufier, M.

2016-08-01

An ever increasing demand for lighter rotating machinery and higher operating speeds results in a raised probability of instabilities. Rotating damping is one of the reasons, instability occurs. Rotating damping, or rotor internal damping, is the damping related to all rotating parts while non-rotating damping appearing in the non-rotating parts. The present study describes a rotating setup, designed to investigate rotating damping experimentally. An efficient experimental procedure is presented to predict the stability threshold of a rotating machine. The setup consists of a long thin shaft with a disk in the middle and clamped boundary conditions. The goal is to extract the system poles as a function of the rotating speed. The real parts of these poles are used to construct the decay rate plot, which is an indication for the stability. The efficiency of the experimental procedure relies on the model chosen for the rotating shaft. It is shown that the shaft behavior can be approximated by a single degree of freedom model that incorporates a speed dependent damping. As such low measurement effort and only one randomly chosen measurement location are needed to construct the decay rate plot. As an excitation, an automated impact hammer is used and the response is measured by eddy current probes. The proposed method yields a reliable prediction of the stability threshold speed which is validated through measurements.

Very-low speed control of PMSM based on EKF estimation with closed loop optimized parameters.

Science.gov (United States)

Xu, Dong; Zhang, Shaoguang; Liu, Jingmeng

2013-11-01

When calculating the speed from the position of permanent magnet synchronous motor (PMSM), the accuracy and real-time are limited by the precision of the sensor. This problem causes crawling and jitter at very-low speed. Using the angle from the position sensor, an extended Kalman filter (EKF) designed in dq-coordinate is presented to solve this problem. The usage of position sensor simplifies the model and improves the accuracy of speed estimation. Specially, a closed loop optimal (CLO) method is devised to overcome the difficulty to adjust the parameters of the EKF. The EKF is the feedback link of speed control, CLO method is derived from the perspective of the speed step response to optimize the measurement covariance matrix and the system covariance matrix of EKF. Simulation and experimental results, comparing the low-speed performance of the EKF and sensor feedback methods, prove the effectiveness of the method to adjust the parameters of EKF and the advantages in eliminating the low speed jitter. © 2013 ISA. Published by ISA. All rights reserved.

Update of 1972 status report on deep shaft studies

International Nuclear Information System (INIS)

1976-09-01

The following aspects of shaft sinking are considered: the effects of geology, factors affecting shaft size, the conventional shaft sinking techniques and the newer mechanized methods, several representative or difficult shafts, and certain long-term problems and solutions

Optimal design of a magneto-rheological brake absorber for torsional vibration control

International Nuclear Information System (INIS)

Nguyen, Q H; Choi, S B

2012-01-01

This research presents an optimal design of a magneto-rheological (MR) brake absorber for torsional vibration control of a rotating shaft. Firstly, the configuration of an MR brake absorber for torsional vibration control of a rotating shaft system is proposed. Then, the braking torque of the MR brake is derived based on the Bingham plastic model of the MR fluid. By assuming that the behaviour of the MR brake absorber is similar to that of a dry friction torsional damper, the optimal braking torque to control the torsional vibration is determined and validated by simulation. The optimal design problem of the MR brake absorber is then developed and a procedure to solve the optimal problem is proposed. Based on the proposed optimal design procedure, the optimal design of a specific rotating shaft system is performed. Vibration control performance of the shaft system employing the optimized MR brake absorber is then investigated through simulation and discussion on the results is given. (paper)

Optimal design of a magneto-rheological brake absorber for torsional vibration control

Science.gov (United States)

Nguyen, Q. H.; Choi, S. B.

2012-02-01

This research presents an optimal design of a magneto-rheological (MR) brake absorber for torsional vibration control of a rotating shaft. Firstly, the configuration of an MR brake absorber for torsional vibration control of a rotating shaft system is proposed. Then, the braking torque of the MR brake is derived based on the Bingham plastic model of the MR fluid. By assuming that the behaviour of the MR brake absorber is similar to that of a dry friction torsional damper, the optimal braking torque to control the torsional vibration is determined and validated by simulation. The optimal design problem of the MR brake absorber is then developed and a procedure to solve the optimal problem is proposed. Based on the proposed optimal design procedure, the optimal design of a specific rotating shaft system is performed. Vibration control performance of the shaft system employing the optimized MR brake absorber is then investigated through simulation and discussion on the results is given.

Incidence and epidemiology of tibial shaft fractures.

Science.gov (United States)

Larsen, Peter; Elsoe, Rasmus; Hansen, Sandra Hope; Graven-Nielsen, Thomas; Laessoe, Uffe; Rasmussen, Sten

2015-04-01

The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large and complete population and report the distribution of fracture classification, trauma mechanism and patient baseline demographics. Retrospective reviews of clinical and radiological records. A total of 196 patients were treated for 198 tibial shaft fractures in the years 2009 and 2010. The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have the highest frequency between the age of 30 and 40. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. The majority of tibial shaft fractures occur during walking, indoor activity and sports. The distribution among genders shows that males present a higher frequency of fractures while participating in sports activities and walking. Women present the highest frequency of fractures while walking and during indoor activities. This study shows an incidence of 16.9/100,000/year for tibial shaft fractures. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of a hydrophilic Fe-Co magnetic fluid to the oil seal of a rotary shaft

International Nuclear Information System (INIS)

Lee, J. H.; Ryu, B. O.; Song, W. S.; Hong, G. P.; Zoo, Y. S.

2003-01-01

Existing oil seals of rotary shafts are made of rubber or ceramic goods (rubber retainer or mechanical seal). Thus if they are used for a long time, lubricant's leakage is induced from the gap between the shaft and bearings because of stiffening and abrading on the quality of seals due to the friction between rotating shaft and oil seal. Therefore the oil seals is restricted to durability limits and caused to require a quick change of the seal parts and to require significant man - powers for the complicated fabrication of seals. This study is established from the idea for working out these problems. This seal is composed of magnetic fluid to stop up oil in seals. As magnetic fluid between shaft and oil seal stops up oil in seals during rotating shaft, there is a friction but isn't an abrasion between shaft and oil seal so that there is no problem of the durability limits. In this study, with Fe- Co magnetic fluid is produced by hydrophilic ethylene glycol medium, Fe- Co(30 % : Co) powder, ring structure's Nd- permanent magnet of magnetic field strength 3300 Gauss and pole-piece(thickness : 1 mm, mild steel plate). With this arrangement the performance is such that the maximum resisting pressure of the oil seal apparatus was measured to be 25 kg/ cm 2 at the shaft speed 1800 rpm. It is believed that this magnetic fluid of Fe-Co powder used at the oil seal apparatus is the highest value among magnetic fluids in use until now. In an innovation this can give the advantages of lower noise, longer durability, and airtight of sealing as the contact of shaft (solid) to be friction and magnetic fluid(liquid) to seal. For that reason, this magnetic fluid of Fe-Co powder not only has enough specificity about the oil seal of rotary shaft but also shows enough quality as resisting pressure seal apparatus. Applications of this seal include all kinds of pump like high damping seal. This seal apparatus is economical and has an excellent sealing efficiency which can not be

Geotechnical instrumentation for repository shafts

International Nuclear Information System (INIS)

Lentell, R.L.; Byrne, J.

1993-01-01

The US Congress passed the Nuclear Waste Policy Act in 1980, which required that three distinctly different geologic media be investigated as potential candidate sites for the permanent disposal of high-level nuclear waste. The three media that were selected for study were basalt (WA), salt (TX, LA, MS, UT), and tuff (NV). Preliminary Exploratory Shaft Facilities (ESF) designs were prepared for seven candidate salt sites, including bedded and domal salt environments. A bedded-salt site was selected in Deaf Smith County, TX for detailed site characterization studies and ESF Final Design. Although Congress terminated the Salt Repository Program in 1988, Final Design for the Deaf Smith ESF was completed, and much of the design rationale can be applied to subsequent deep repository shafts. This paper presents the rationale for the geotechnical instrumentation that was designed for construction and operational performance monitoring of the deep shafts of the in-situ test facility. The instrumentation design described herein can be used as a general framework in designing subsequent instrumentation programs for future high-level nuclear waste repository shafts

Hair Shaft Abnormality in Children: a Narrative Review

Directory of Open Access Journals (Sweden)

Ghasem Rahmatpour Rokni

2017-08-01

Full Text Available Background Hair is an ectodermal structure, and its formation is regulated by master genes important in embryology. Hair shaft consists of three major regions: the medulla, cortex and cuticle. Hair shaft abnormality will divide structural hair abnormalities into two broad categories - those associated with increased hair fragility and those not associated with increased hair fragility. We conducted a review study to assess hair shaft abnormality in children. Materials and Methods We conducted a review of all papers published on hair shaft abnormalities. A literature search was performed using PubMed, Scopus and Google Scholar on papers publish from 1990 to 2016. The search terms were: hair shaft abnormality, Hair loss, Hair fragility. All abstracts and full text English-language articles were studied. Results While common developmental and structural features are shared in hair follicles and hair shafts. Anomalies of the hair shaft are separated into those with and those without increased hair fragility. Conclusion Although hair has no vital function, it may serve as an indicator for human health. Clinical and morphological hair abnormalities can be clues to specific complex disorders. Hair shaft abnormalities can be inherited or acquired, can reflect a local problem or a systemic disease.

Joint optimization of green vehicle scheduling and routing problem with time-varying speeds

Science.gov (United States)

Zhang, Dezhi; Wang, Xin; Ni, Nan; Zhang, Zhuo

2018-01-01

Based on an analysis of the congestion effect and changes in the speed of vehicle flow during morning and evening peaks in a large- or medium-sized city, the piecewise function is used to capture the rules of the time-varying speed of vehicles, which are very important in modelling their fuel consumption and CO2 emission. A joint optimization model of the green vehicle scheduling and routing problem with time-varying speeds is presented in this study. Extra wages during nonworking periods and soft time-window constraints are considered. A heuristic algorithm based on the adaptive large neighborhood search algorithm is also presented. Finally, a numerical simulation example is provided to illustrate the optimization model and its algorithm. Results show that, (1) the shortest route is not necessarily the route that consumes the least energy, (2) the departure time influences the vehicle fuel consumption and CO2 emissions and the optimal departure time saves on fuel consumption and reduces CO2 emissions by up to 5.4%, and (3) extra driver wages have significant effects on routing and departure time slot decisions. PMID:29466370

Rotation speed measurement for turbine governor: torsion filtering by using Kalman filter

International Nuclear Information System (INIS)

Houry, M.P.; Bourles, H.

1996-01-01

The rotation speed of a turbogenerator is disturbed by its shaft torsion. Obtaining a filtered measure of this speed is a problem of a great practical importance for turbine governor. A good filtering of this speed must meet two requirements: it must cut frequencies of the shaft torsion oscillation and it must not reduce or delay the signal in the pass-band, i.e. at lower frequencies. At Electricite de France, the speed measure is used to set in motion the fast valving system as quickly as possible, after a short circuit close to the unit or rather an islanding. It is difficult to satisfy these two requirements by using conventional filtering methods. The standard solution consists in a first order filter: at Electricite de France, its time constant is equal to 80 ms. We have decided to improve this filtering by designing a new filter which cuts the frequencies of the shaft torsion oscillation without reducing the bandwidth to the speed measure. If one uses conventional methods to obtain a band stop filter, it is easy to obtain the desired magnitude but not a phase near zero in the whole pass-band. Therefore, we have chosen to design the filter by using Kalman'a theory. The measurement noise is modeled as a colored one, generated by a very lightly damped system driven by a while noise. The resulting Kalman filter is an effective band stop filter, whose phase nicely remains near zero in the whole pass-band. The digital simulations we made and the tests we carried out with the Electricite de France Micro Network laboratory show the advantages of the rotation speed filter we designed using Kalman's theory. With the proposed filter, the speed measure filtering is better in terms of reduction and phase shift. the result is that there are less untimely solicitations of the fast valving system. Consequently, this device improves the power systems stability by minimizing the risks of deep perturbations due to a temporary lack of generation and the risks of under-speed loss

Reliability assessment of underground shaft closure

International Nuclear Information System (INIS)

Fossum, A.F.; Munson, D.E.

1994-01-01

The intent of the WIPP, being constructed in the bedded geologic salt deposits of Southeastern New Mexico, is to provide the technological basis for the safe disposal of radioactive Transuranic (TRU) wastes generated by the defense programs of the United States. In determining this technological basis, advanced reliability and structural analysis techniques are used to determine the probability of time-to-closure of a hypothetical underground shaft located in an argillaceous salt formation and filled with compacted crushed salt. Before being filled with crushed salt for sealing, the shaft provides access to an underground facility. Reliable closure of the shaft depends upon the sealing of the shaft through creep closure and recompaction of crushed backfill. Appropriate methods are demonstrated to calculate cumulative distribution functions of the closure based on laboratory determined random variable uncertainty in salt creep properties

Electrostatic and tribological phenomena and their effect on the braking torque in the shaft-oil-lip seal system

Science.gov (United States)

Gajewski, Juliusz B.; Glogowski, Marek J.

2008-12-01

The former research [1] was carried out on the influence of tribocharging in a system: metal rotating shaft-oil-lip seal on its work, especially on changes in the shaft braking torque with the increasing angular shaft velocity and oil temperature. The results obtained suggested that there be a possibility of reducing the braking torque by an external electric field. The compensation for the electric field generated in the system by natural tribocharging was proposed. The reduction in the braking torque seemed possible while applying an external DC electric field to the system. In general, the torque tended to increase with the increasing DC electric field for a variety of the oils and lip seals used and for different shaft angular velocities (rotational speeds) and oil temperatures. The braking torque reduction was achieved only for one lip seal and some different oils, which was and is a promising, expected result. The research results were yet presented elsewhere [1-3] and here some novel attempt has been made to interpret the results obtained in their physical—tribological and especially electrostatic—aspects since there has been a lack of such an interpretation in the literature of the subject.

Electrostatic and tribological phenomena and their effect on the braking torque in the shaft-oil-lip seal system

International Nuclear Information System (INIS)

Gajewski, Juliusz B; Glogowski, Marek J

2008-01-01

The former research was carried out on the influence of tribocharging in a system: metal rotating shaft-oil-lip seal on its work, especially on changes in the shaft braking torque with the increasing angular shaft velocity and oil temperature. The results obtained suggested that there be a possibility of reducing the braking torque by an external electric field. The compensation for the electric field generated in the system by natural tribocharging was proposed. The reduction in the braking torque seemed possible while applying an external DC electric field to the system. In general, the torque tended to increase with the increasing DC electric field for a variety of the oils and lip seals used and for different shaft angular velocities (rotational speeds) and oil temperatures. The braking torque reduction was achieved only for one lip seal and some different oils, which was and is a promising, expected result. The research results were yet presented elsewhere [1-3] and here some novel attempt has been made to interpret the results obtained in their physical-tribological and especially electrostatic-aspects since there has been a lack of such an interpretation in the literature of the subject.

Control of internal packing seal clearances considering for shaft behavior during steam turbine operation

Energy Technology Data Exchange (ETDEWEB)

Pack, Min Sik; Lee, Si Yeon; Choi, Sung Choul; Lee, Jae Geun [Korea Plant Service and Engineering Co., Ltd., Seongnam (Korea, Republic of); Yang, Bo Suk [Pukyong National Univ., Busan (Korea, Republic of)

2004-07-01

This paper presents the characteristics of internal clearances for the interstage of blades and shaft gland seals on the steam turbine which are installed in tandem compound. Internal clearances was changed when the rotor turned in the cylindrical sleeve bearing due to the generation of oil film wedge. This presented concern is very useful to prevent the rubbing damage of seal edge between the fixed and moving parts in steam turbine due to the misalignment at the rotating and stationary parts. This method is applied for the unbalanced clearances distribution to the left and right sides in the turbine casing. A considerable amount of unbalanced clearances distribution trend is determined according to the rotating speed of rotor, size and type of journal bearing, oil viscosity, surface roughness of bearing and shaft, oil temperature, oil pressure and bearing load.

Study of Effect of Quenching Deformation Influenced by 17CrNiMo6 Gear Shaft of Carburization

Science.gov (United States)

Pang, Zirui; Yu, Shenjun; Xu, Jinwu

The 17CrNiMo6 steel is mainly used for the gear shaft of large modulus in many fields of heavy industry such as mining, transit, hoist, forging and so on[1]. The size of addendum circle and common normal line is changed a lot beyond the tolerance because of the long time of carburizing process and the out-of-step structural stress and thermal stress during the quenching process. And thus the posterior grinding efficiency and quality are influenced. In the paper comparison and analysis of the deformation affected by solid and hollow gear shafts were done and the methods of simulation and practice were both used. The results are as follows: the deformation of gear shaft was small before and after carburizing while that of gear shaft was large before and after quenching because of different cooling velocity, structure and hardness of each position. And the deformation of hollow was much smaller than that of solid. Therefore, if the hollow gear shaft is used, the waste of material will be decreased, and finishing cost will be reduced, and thus the technology of heat treatment will be optimized.

Rotating Shaft Tilt Angle Measurement Using an Inclinometer

Science.gov (United States)

Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Wen, Zhuoman; Liu, Shaojin; Cai, Sheng; Li, Jianrong

2015-10-01

This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

Rotating Shaft Tilt Angle Measurement Using an Inclinometer

Directory of Open Access Journals (Sweden)

Luo Jun

2015-10-01

Full Text Available This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

FRACTURE SHAFT HUMERUS: INTERLOCKING

Directory of Open Access Journals (Sweden)

Deepak Kaladagi

2014-12-01

Full Text Available BACKGROUND: The incidence of humeral fracture has significantly increased during the present years due to the population growth and road traffic, domestic, industrial, automobile accidents & disasters like tsunami, earthquakes, head-on collisions, polytrauma etc. In order to achieve a stable fixation followed by early mobilization, numerous surgical implants have been devised. PURPOSE: The purpose of this study is to analyze the results of intramedullary fixation of proximal 2/3rd humeral shaft fractures using an unreamed interlocking intramedullary nail. INTRODUCTION: In 40 skeletally matured patients with fracture shaft of humerus admitted in our hospital, we used unreamed antegrade interlocking nails. MATERIAL: We carried out a prospective analysis of 40 patients randomly selected between 2001 to 2014 who were operated at JNMC Belgaum, MMC Mysore & Navodaya Medical College, Raichur. All cases were either RTAs, Domestic, Industrial, automobile accidents & also other modes of injury. METHOD: Routine investigations with pre-anaesthetic check-up & good quality X-rays of both sides of humerus was taken. Time of surgery ranged from 5-10 days from the time of admission. Only upper 1/3rd & middle 1/3rd humeral shaft fractures were included in the study. In all the cases antegrade locked unreamed humeral nails were inserted under C-arm. Patient was placed in supine position & the shoulder was kept elevated by placing a sandbag under the scapula. In all patients incision taken from tip of acromion to 3cm over deltoid longitudinally. Postoperatively sling applied with wrist & shoulder movements started after 24 hours. All the patients ranged between the age of 21-50 years. RESULTS: Total 40 patients were operated. Maximum fracture site were in the middle third- 76%, 14% upper 1/3rd. All 40 patients achieved union. The average time of union was 8-10 weeks. All patients regained full range of movements except in few cases, where there was shoulder

Long-term brine migration through an engineered shaft seal system

International Nuclear Information System (INIS)

Fryar, D.G.; Beach, J.A.; Kelley, V.A.; Knowles, M.K.

1997-01-01

The shaft seal system for the Waste Isolation Pilot Plant (WIPP) must provide a barrier to the migration of fluids within the shafts to prevent the release of contaminants to the accessible environment. To investigate the performance of the shaft seal system, a set of fluid flow performance models was developed based upon the physical characteristics of the WIPP shaft seal system and the surrounding geologic media. This paper describes the results of a numerical model used to investigate the long-term potential for brine migration through the shaft seal system. Modeling results demonstrate that the WIPP shaft seal system will effectively limit brine migration within the repository shafts

Determining the optimal spacing of deepening of vertical mine

Energy Technology Data Exchange (ETDEWEB)

Durov, Ye.M.

1983-01-01

Light is shed on a technique for determining the optimal spacing of shafts for deepening for the examined parameters of operational and deepening operations. The presented results of studies may be used in designing new shafts, in preparing levels and in reconstruction of existing shafts with slanted and steep stratum bedding.

Procedure for determining the optimum rate of increasing shaft depth

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.

1983-03-01

Presented is an economic analysis of increasing shaft depth during mine modernization. Investigations carried out by the Yuzhgiproshakht Institute are analyzed. The investigations are aimed at determining the optimum shaft sinking rate (the rate which reduces investment to the minimum). The following factors are considered: coal output of a mine (0.9, 1.2, 1.5 and 1.8 Mt/year), depth at which the new mining level is situated (600, 800, 1200, 1400 and 1600 m), four schemes of increasing depth of 2 central shafts (rock hoisting to ground surface, rock hoisting to the existing level, rock haulage to the developed level, rock haulage to the level being developed using a large diameter borehole drilled from the new level to the shaft bottom and enlarged from shaft bottom to the new level), shaft sinking rate (10, 20, 30, 40, 50 and 60 m/month), range of increasing shaft depth (the difference between depth of the shaft before and after increasing its depth by 100, 200, 300 and 400 m). Comparative evaluations show that the optimum shaft sinking rate depends on the scheme for rock hoisting (one of 4 analyzed), range of increasing shaft depth and gas content in coal seams. The optimum shaft sinking rate ranges from 20 to 40 m/month in coal mines with low methane content and from 20 to 30 m/month in gassy coal mines. The planned coal output of a mine does not influence the optimum shaft sinking rate.

Exploratory Shaft Seismic Design Basis Working Group report

International Nuclear Information System (INIS)

Subramanian, C.V.; King, J.L.; Perkins, D.M.; Mudd, R.W.; Richardson, A.M.; Calovini, J.C.; Van Eeckhout, E.; Emerson, D.O.

1990-08-01

This report was prepared for the Yucca Mountain Project (YMP), which is managed by the US Department of Energy. The participants in the YMP are investigating the suitability of a site at Yucca Mountain, Nevada, for construction of a repository for high-level radioactive waste. An exploratory shaft facility (ESF) will be constructed to permit site characterization. The major components of the ESF are two shafts that will be used to provide access to the underground test areas for men, utilities, and ventilation. If a repository is constructed at the site, the exploratory shafts will be converted for use as intake ventilation shafts. In the context of both underground nuclear explosions (conducted at the nearby Nevada Test Site) and earthquakes, the report contains discussions of faulting potential at the site, control motions at depth, material properties of the different rock layers relevant to seismic design, the strain tensor for each of the waveforms along the shaft liners, and the method for combining the different strain components along the shaft liners. The report also describes analytic methods, assumptions used to ensure conservatism, and uncertainties in the data. The analyses show that none of the shafts' structures, systems, or components are important to public radiological safety; therefore, the shafts need only be designed to ensure worker safety, and the report recommends seismic design parameters appropriate for this purpose. 31 refs., 5 figs., 6 tabs

Automated Bearing Fault Diagnosis Using 2D Analysis of Vibration Acceleration Signals under Variable Speed Conditions

Directory of Open Access Journals (Sweden)

Sheraz Ali Khan

2016-01-01

Full Text Available Traditional fault diagnosis methods of bearings detect characteristic defect frequencies in the envelope power spectrum of the vibration signal. These defect frequencies depend upon the inherently nonstationary shaft speed. Time-frequency and subband signal analysis of vibration signals has been used to deal with random variations in speed, whereas design variations require retraining a new instance of the classifier for each operating speed. This paper presents an automated approach for fault diagnosis in bearings based upon the 2D analysis of vibration acceleration signals under variable speed conditions. Images created from the vibration signals exhibit unique textures for each fault, which show minimal variation with shaft speed. Microtexture analysis of these images is used to generate distinctive fault signatures for each fault type, which can be used to detect those faults at different speeds. A k-nearest neighbor classifier trained using fault signatures generated for one operating speed is used to detect faults at all the other operating speeds. The proposed approach is tested on the bearing fault dataset of Case Western Reserve University, and the results are compared with those of a spectrum imaging-based approach.

Hull Surface Information Retrieval and Optimization of High Speed Planing Craft

International Nuclear Information System (INIS)

Ayob, A F; Wan Nik, W B; Ray, T; Smith, W F

2012-01-01

Traditional approach on ship design involve the use of a method which takes a form that was earlier called the 'general design diagram' and is now known as the 'design spiral' – an iterative ship design process that allows for an increase in complexity and precision across the design cycle. Several advancements have been made towards the design spiral, however inefficient for handling complex simultaneous design changes, especially when later variable changes affect the ship's performance characteristics evaluated in earlier stages. Reviewed in this paper are several advancements in high speed planing craft design in preliminary design stage. An optimization framework for high speed planing craft is discussed which consist of surface information retrieval module, a suite of state-of-the-art optimization algorithms and standard naval architectural performance estimation tools. A summary of the implementation of the proposed hull surface information retrieval and several case studies are presented to demonstrate the capabilities of the framework.

Optimizing Ship Speed to Minimize Total Fuel Consumption with Multiple Time Windows

Directory of Open Access Journals (Sweden)

Jae-Gon Kim

2016-01-01

Full Text Available We study the ship speed optimization problem with the objective of minimizing the total fuel consumption. We consider multiple time windows for each port call as constraints and formulate the problem as a nonlinear mixed integer program. We derive intrinsic properties of the problem and develop an exact algorithm based on the properties. Computational experiments show that the suggested algorithm is very efficient in finding an optimal solution.

Structural Modifications for Torsional Vibration Control of Shafting Systems Based on Torsional Receptances

Directory of Open Access Journals (Sweden)

Zihao Liu

2016-01-01

Full Text Available Torsional vibration of shafts is a very important problem in engineering, in particular in ship engines and aeroengines. Due to their high levels of integration and complexity, it is hard to get their accurate structural data or accurate modal data. This lack of data is unhelpful to vibration control in the form of structural modifications. Besides, many parts in shaft systems are not allowed to be modified such as rotary inertia of a pump or an engine, which is designed for achieving certain functions. This paper presents a strategy for torsional vibration control of shaft systems in the form of structural modifications based on receptances, which does not need analytical or modal models of the systems under investigation. It only needs the torsional receptances of the system, which can be obtained by testing simple auxiliary structure attached to relevant locations of the shaft system and using the finite element model (FEM of the simple structure. An optimization problem is constructed to determine the required structural modifications, based on the actual requirements of modal frequencies and mode shapes. A numerical experiment is set up and the influence of several system parameters is analysed. Several scenarios of constraints in practice are considered. The numerical simulation results demonstrate the effectiveness of this method and its feasibility in solving torsional vibration problems in practice.

Storage shaft definitive closure plug and method

International Nuclear Information System (INIS)

Dardaine, M.

1992-01-01

A definitive closure plug system for radioactive waste storage at any deepness, is presented. The inherent weight of the closure materials is used to set in the plug: these materials display an inclined sliding surface in such a way that when the closure material rests on a stable surface of the shaft storage materials, the relative sliding of the different materials tends to spread them towards the shaft internal wall so as to completely occlude the shaft

Salt Repository Project shaft design guide: Revision 0

International Nuclear Information System (INIS)

1987-12-01

The Salt Repository Project (SRP) Shaft Design Guide (SDG) and the accompanying SRP Input to Seismic Design define the basic approach for developing appropriate shaft designs for a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. The SDG is based on current mining industry standards and practices enhanced to meet the special needs of an underground nuclear waste repository. It provides a common approach for design of both the exploratory and repository shafts. The SDG defines shaft lining and material concepts and presents methods for calculating the loads and displacements that will be imposed on lining structures. It also presents the methodology and formulae for sizing lining components. The SDG directs the shaft designer to sources of geoscience and seismic design data for the Deaf Smith County, Texas repository site. In addition, the SDG describes methods for confirming shaft lining design by means of computer analysis, and it discusses performance monitoring needs that must be considered in the design. 113 refs., 18 figs., 14 tabs

Effect of wind speed and solar irradiation on the optimization of a PV-Wind-Battery system to supply a telecommunications station

Energy Technology Data Exchange (ETDEWEB)

Dufo-Lopez, Rodolfo; Bernal-Agustin, Jose L.; Lujano, Juan; Zubi, Ghassan [Zaragoza Univ. (Spain). Electrical Engineerign Dept.

2010-07-01

This paper shows the optimization of a PV-Wind hybrid system with batteries storage to supply the electrical power to a small telecommunications station. The load demanded by the station is 100 W continuously. We have considered 6 different wind speed profiles, from 2 m/s average speed (low wind speed in many places in Spain) to 8 m/s average (very high wind speed, in few places in Spain) and 3 different irradiation profiles, from the lowest average daily irradiation in Spain, about 2.5 kWh/m{sup 2}/day, to the highest one in Spain, about 5 kWh/m{sup 2}/day. Therefore we have considered 6 x 3 = 18 combinations of wind speed and irradiation profiles. For each combination of wind speed and irradiation profiles, we have optimized the PV-Wind-Battery system to supply the power demand, considering some different PV panels, wind turbines and batteries. We have also considered in the optimization non-hybrid systems (PV-Battery systems and Wind-Battery systems). The simulation of the system performance has been done hourly. The optimal system for each combination of wind speed and irradiation is the one which can supply the whole demand of the telecommunications station with the lowest Net Present Cost of the system. Simulation and optimization has been done using HOGA (Hybrid Optimization by Genetic Algorithms) software, developed by some of the authors. The results show that, with actual prices of PV panels and wind turbines, in 13 of the 18 combinations of wind speed and irradiation profiles the optimal system is a hybrid system (it includes PV panels, wind turbine and batteries). In the other 5 combinations (the ones with lowest wind speed and/or highest irradiation), the optimal system is PV-Battery, i.e., without wind turbine. We conclude that, in most of the places in Spain, the optimal system to supply the demand of a communications station (with continous demand profile) is a hybrid system (PV-Wind-Batteries) instead of a PV-Batteries system or a Wind

Increasing shaft depth with rock hoisting to the surface. [USSR

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.

1982-06-01

Schemes of shaft construction with increasing shaft depth depend on: shaft depth, shaft diameter, types of hoisting systems, schemes of shaft reinforcement. Investigations carried out in underground coal mines in the USSR show that waste rock haulage to the surface by an independent hoisting system is most economical. Installation of this system depends on the existing hoisting scheme. When one of the operating cages or skips can be removed without a negative influence on mine operation the system of rock waste hoisting is used. The hoisting bucket used for rock removal from the shaft bottom moves in the shaft section from which one of the cages or skips has been removed. Examples of using this scheme in Donbass, Kuzbass and other coal basins are given. Economic aspects of waste material hoisting to the surface are analyzed. The system is economical when the remaining hoisting system can accept additional loads after removal of a cage or skip from the shaft. Investigations show that use of a bucket with a capacity from 2.5 to 3.0 m/sup 3/ for waste rock removal from the shaft being modernized and deepened is most economical.

Parametric studies on floating pad journal bearing for high speed cryogenic turboexpanders

Science.gov (United States)

Jain, A.; Jadhav, M. M.; Karimulla, S.; Chakravarty, A.

2017-12-01

Most modern medium and large capacity helium liquefaction/refrigeration plants employ high speed cryogenic turboexpanders in their refrigeration/liquefaction cycles as active cooling devices. The operating speed of these turboexpanders is in the range of 3000-5000 Hz and hence specialized types of bearings are required. Floating pad journal bearing, which is a special type of tilting pad journal bearing, where mechanical pivots are absent and pads are fully suspended in gas, can be a good solution for stable operation of these high speed compact rotors. The pads are separated from shaft as well as from housing by fluid film between them, and both these sides of pad are interconnected by a network of feed holes. The work presented in this article aims to characterize floating pad journal bearings through parametric studies. The steady state performance characteristics of the bearing are represented by load capacity, stiffness coefficients and heat generation rate of the bearing. The geometrical parameters such as bearing clearances, preload of pads, etc. are varied and performance characteristics of the floating pad journal bearing are studied and presented. The dependence of stiffness coefficients on rotational speed of shaft is also analyzed.

Ipsilateral humeral neck and shaft fractures

Directory of Open Access Journals (Sweden)

Zhu Bin

2017-01-01

Full Text Available Background/Aim. Fractures of the proximal humerus or shaft are common, however, ipsilateral neck and shaft humerus fracture is a rare phenomenon. This combination injury is challenging for orthopaedic surgeons because of its complex treatment options at present. The purpose of this study was to review a series of ipsilateral humeral neck and shaft fractures to study the fracture pattern, complications and treatment outcomes of each treatment options used. Methods. A total of six patients (four female and two male with the average age of 42.8 years (range: 36–49 years was collected and reviewed retrospectively. Two of them were treated with double plates and four with antegrade intramedullary nail. According to the Neer’s classification, all proximal fractures were two-part surgical neck fractures. All humeral shaft fractures were located at the middle of one third. Five fractures were simple transverse (A3, one fragmented wedge fracture (B3. One patient had associated radial nerve palsy. Results. All surgical neck fractures except one united uneventfully in the average time span of 8.7 weeks. Four humeral shaft fractures healed in near anatomic alignment. The remaining two patients had the nonunion with no radiological signs of fracture healing. The average University of California, Los Angeles End-Results (UCLA score was 23.1. On the contrary, the average American Shoulder and Elbow Surgeon's (ASES score was 73.3. The patients treated with antegrade intramedullary nails presented 70.5 points. The ASES scores were 79 in the double plates group. Conclusions. Ipsilateral humeral shaft and neck fracture is extremely rare. Both antegrade intramedullar nailing and double plates result in healing of fractures. However the risk of complication is lower in the double plating group.

Optimization of rhombic drive mechanism used in beta-type Stirling engine based on dimensionless analysis

International Nuclear Information System (INIS)

Cheng, Chin-Hsiang; Yang, Hang-Suin

2014-01-01

In the present study, optimization of rhombic drive mechanism used in a beta-type Stirling engine is performed based on a dimensionless theoretical model toward maximization of shaft work output. Displacements of the piston and the displacer with the rhombic drive mechanism and variations of volumes and pressure in the chambers of the engine are firstly expressed in dimensionless form. Secondly, Schmidt analysis is incorporated with Senft's shaft work theory to build a dimensionless thermodynamic model, which is employed to yield the dimensionless shaft work. The dimensionless model is verified with experimental data. It is found that the relative error between the experimental and the theoretical data in dimensionless shaft work is lower than 5.2%. This model is also employed to investigate the effects of the influential geometric parameters on the shaft work, and the optimization of these parameters is attempted. Eventually, design charts that help design the optimal geometry of the rhombic drive mechanism are presented in this report. - Highlights: • Specifically dealing with optimization of rhombic-drive mechanism used in Stirling engine based on dimensionless model. • Propose design charts that help determine the optimal geometric parameters of the rhombic drive mechanism. • Complete study of influential factors affecting the shaft work output

Construction features of the Exploratory Shaft at Yucca Mountain

International Nuclear Information System (INIS)

Adair, G.W.; Fiore, J.N.

1984-01-01

The Exploratory Shaft (ES) at Yucca Mountain is planned to be constructed during 1985 and 1986 as part of the detailed site characterization for one of three sites which may be selected as candidates for location of a high-level radioactive waste repository. Conventional mining methods will be used for the shaft sinking phase of the ES project. The ES will be comprised of surface support facilities, a 1,480-foot-deep circular shaft lined with concrete to a finished inside diameter of 12 feet, lateral excavations and test installations extending up to 200 feet from the shaft, and long lateral borings extending up to 2,300 feet from the shaft. The estimated time for sinking the shaft to a total depth of about 1,480 feet and completing the lateral excavations and borings is about two years. The major underground development planned for the primary test level at a depth of 1,200 feet consists of the equivalent of 1,150 feet of 15- by 15-foot drift. The total volume of rock to be removed from the shaft proper and the lateral excavations totals about 1/2 million cubic feet. Construction equipment for the shaft and underground excavation phases consists of conventional mine hoisting equipment, shot hole and rock bolt drilling jumbos, mucking machines, and hauling machines. The desire to maintain relatively uniform and even walls in selected shaft and drift intervals will require that controlled blasting techniques be employed. Such techniques generally classified as ''smooth blasting'' are commonly used for excavation in the construction industry

System design for shaft safety and productivity

Energy Technology Data Exchange (ETDEWEB)

Owen, D.; Parsons, R.; Ward, R.

1988-03-01

The aim of this paper is to describe the process of designing a system to improve safety and productivity in shafts. The objectives and constraints for the design were set out in official reports following a shaft accident at Markham Colliery in 1973. The problems to be solved were: to enable the shaftsmen to transfer the existing statutory code of signals efficiently from, or on top of, a conveyance anywhere in the shaft to the winding engineman and banksman at the surface: to detect the existence of slack rope or to detect that conditions have arisen that slack rope could be created and transmit this information to where action can be taken; and to allow conversations between winding engineman, banksman and shaftsman making allowances for the high level of acoustic noise in shafts. The approach adopted for slack rope monitoring was to monitor the tension in the cage suspension gear, thus measuring a first order effect. The three problems have a common element: information must be transferred through the shaft. This particular problem was solved with guided radio, using the winding rope as the transmission medium. The radio signal is coupled into the winding rope by means of fixed toroid encircling it at the cage and fixed magnetic antennas at the surface. The design of a digital transmission system for signalling and tension data is discussed. The 'top down' modular approach used in the design enabled full advantage to be taken of the opportunities for building a more reliable, safer and flexible system presented by technologies new to the shaft environment. The resultant system, the Safecom Shaft Signalling Communication and Winder Safety Monitoring System type S100, is in regular use at over 20 installations. 3 refs., 4 figs., 1 tab.

Optimal pacing strategy: from theoretical modelling to reality in 1500-m speed skating.

Science.gov (United States)

Hettinga, F J; De Koning, J J; Schmidt, L J I; Wind, N A C; Macintosh, B R; Foster, C

2011-01-01

Athletes are trained to choose the pace which is perceived to be correct during a specific effort, such as the 1500-m speed skating competition. The purpose of the present study was to "override" self-paced (SP) performance by instructing athletes to execute a theoretically optimal pacing profile. Seven national-level speed-skaters performed a SP 1500-m which was analysed by obtaining velocity (every 100 m) and body position (every 200 m) with video to calculate total mechanical power output. Together with gross efficiency and aerobic kinetics, obtained in separate trials, data were used to calculate aerobic and anaerobic power output profiles. An energy flow model was applied to SP, simulating a range of pacing strategies, and a theoretically optimal pacing profile was imposed in a second race (IM). Final time for IM was ∼2 s slower than SP. Total power distribution per lap differed, with a higher power over the first 300 m for IM (637.0 (49.4) vs 612.5 (50.0) W). Anaerobic parameters did not differ. The faster first lap resulted in a higher aerodynamic drag coefficient and perhaps a less effective push-off. Experienced athletes have a well-developed performance template, and changing pacing strategy towards a theoretically optimal fast start protocol had negative consequences on speed-skating technique and did not result in better performance.

Dual stator winding variable speed asynchronous generator: optimal design and experiments

International Nuclear Information System (INIS)

Tutelea, L N; Deaconu, S I; Popa, G N

2015-01-01

In the present paper is carried out a theoretical and experimental study of dual stator winding squirrel cage asynchronous generator (DSWA) behavior in the presence of saturation regime (non-sinusoidal) due to the variable speed operation. The main aims are the determination of the relations of calculating the equivalent parameters of the machine windings to optimal design using a Matlab code. Issue is limited to three phase range of double stator winding cage-induction generator of small sized powers, the most currently used in the small adjustable speed wind or hydro power plants. The tests were carried out using three-phase asynchronous generator having rated power of 6 [kVA]. (paper)

Exploratory Shaft Facility design basis study report

International Nuclear Information System (INIS)

Langstaff, A.L.

1987-01-01

The Design Basis Study is a scoping/sizing study that evaluated the items concerning the Exploratory Shaft Facility Design including design basis values for water and methane inflow; flexibility of the design to support potential changes in program direction; cost and schedule impacts that could result if the design were changed to comply with gassy mine regulations; and cost, schedule, advantages and disadvantages of a larger second shaft. Recommendations are proposed concerning water and methane inflow values, facility layout, second shaft size, ventilation, and gassy mine requirements. 75 refs., 3 figs., 7 tabs

Rotation speed measurement for turbine governor: torsion filtering by using Kalman filter

International Nuclear Information System (INIS)

Houry, M.P.; Bourles, H.

1995-11-01

The rotation speed of a turbogenerator is disturbed by its shaft torsion. Obtaining a filtered measure of this sped a problem of a great practical importance for turbine governor. A good filtering of this speed must meet two requirements: it must cut frequencies of the shaft torsion oscillation and it must not reduce or delay the signal in the pass-band. i.e. at lower frequencies. At Electricite de France, the speed measure is used to set in motion the fast valving system as quickly as possible, after a short circuit close to the unit (to contribute to the stability) or after an islanding (to quickly reach a balance with the house load). It is difficult to satisfy these two requirements by using conventional filtering methods. The standard solution consists in a first order filter: at Electricite de France, its time constant is equal to 80 ms; We have decided to improve this filtering by designing a new filter which cuts the frequencies of the shaft torsion oscillation without reducing the bandwidth of the speed measure. If one uses conventional methods to obtain a band-stop filter (for instance a Butterworth, a Chebyshev or an elliptic band-stop filter),it is easy to obtain the desired magnitude but not a phase near zero in the whole pass-band. Therefore, we have chosen to design the filter by using Kalman's theory. The measurement noise is modeled as a colored one, generated by a very lightly damped system driven by a white noise. The resulting Kalman filter is an effective band-stop filter, whose phase nicely remains near zero in the whole pass-band. (authors). 13 refs., 12 figs

Design Procedure for High-Speed PM Motors Aided by Optimization Algorithms

Directory of Open Access Journals (Sweden)

Francesco Cupertino

2018-02-01

Full Text Available This paper considers the electromagnetic and structural co-design of superficial permanent magnet synchronous machines for high-speed applications, with the aid of a Pareto optimization procedure. The aim of this work is to present a design procedure for the afore-mentioned machines that relies on the combined used of optimization algorithms and finite element analysis. The proposed approach allows easy analysis of the results and a lowering of the computational burden. The proposed design method is presented through a practical example starting from the specifications of an aeronautical actuator. The design procedure is based on static finite element simulations for electromagnetic analysis and on analytical formulas for structural design. The final results are validated through detailed transient finite element analysis to verify both electromagnetic and structural performance. The step-by-step presentation of the proposed design methodology allows the reader to easily adapt it to different specifications. Finally, a comparison between a distributed-winding (24 slots and a concentrated-winding (6 slots machine is presented demonstrating the advantages of the former winding arrangement for high-speed applications.

Diagnostics of a crack in a load coupling of a gas turbine using the machine model and the analysis of the shaft vibrations

Science.gov (United States)

Pennacchi, Paolo; Vania, Andrea

2008-07-01

The diagnostics of malfunctions that can cause catastrophic failures has to be made in early stage in the industrial environment. Often flexible couplings are employed in industrial rotating machines when gearboxes and heavy thermal gradients are present. The hot and cold alignment of these couplings can be very different. Severe misalignments can generate cracks in the stub shafts, which can propagate in operating condition. Owing to the flexural flexibility of the load coupling, the shaft vibrations may be not noticeably affected by some typical symptoms that usually point out the presence of a crack, like twice per revolution harmonics in the vibration spectrum. Anyhow, suitable diagnostic strategies can detect clear fault symptoms, while model-based methods can confirm the occurrence of the shaft bow induced by the progressive yielding of a load coupling due to a crack. This paper shows as a model-based diagnostic methodology would have allowed a crack in a load coupling of a gas turbine to be identified before a serious failure happened by means of the shaft vibration analysis under operating conditions and rated speed. Finally, the vibrations caused by the shaft bow due to the propagation of a crack in the stub shaft of the coupling have been simulated using suitable equivalent excitations, the magnitude and phase of which have been estimated by means of a model-based identification method.

Optimization of metallic microheaters for high-speed reconfigurable silicon photonics.

Science.gov (United States)

Atabaki, A H; Shah Hosseini, E; Eftekhar, A A; Yegnanarayanan, S; Adibi, A

2010-08-16

The strong thermooptic effect in silicon enables low-power and low-loss reconfiguration of large-scale silicon photonics. Thermal reconfiguration through the integration of metallic microheaters has been one of the more widely used reconfiguration techniques in silicon photonics. In this paper, structural and material optimizations are carried out through heat transport modeling to improve the reconfiguration speed of such devices, and the results are experimentally verified. Around 4 micros reconfiguration time are shown for the optimized structures. Moreover, sub-microsecond reconfiguration time is experimentally demonstrated through the pulsed excitation of the microheaters. The limitation of this pulsed excitation scheme is also discussed through an accurate system-level model developed for the microheater response.

Ipsilateral femoral neck and shaft fractures: An overlooked association

International Nuclear Information System (INIS)

Daffner, R.H.; Riemer, B.L.; Butterfield, S.L.

1991-01-01

A total of 304 patients with injuries to the femoral shaft and ipsilateral hip presented between 1984 and 1990. Some 253 of them suffered fractures of the femoral shaft and dislocated hips or fractures of the acetabulum, and 51 of these sustained fractures of the femoral shaft and neck or trochanteric region. All of the trochanteric injuries were demonstrated on the initial radiographs. However, in 11 of the patients with combined femoral shaft and neck fractures, the diagnosis was delayed by as much as 4 weeks. This delay related to the fact that these fractures tended not to separate in the initial evaluation period and that there was external rotation of the proximal femoral fragment due to the femoral shaft fracture. (orig./GDG)

Ipsilateral femoral neck and shaft fractures: An overlooked association

Energy Technology Data Exchange (ETDEWEB)

Daffner, R.H. (Dept. of Diagnostic Radiology, Allegheny General Hospital, Pittsburgh, PA (USA) Medical Coll. of Pennsylvania, Pittsburgh, PA (USA)); Riemer, B.L.; Butterfield, S.L. (Dept. of Orthopedic Surgery, Allegheny General Hospital, Pittsburgh, PA (USA) Medical Coll. of Pennsylvania, Pittsburgh, PA (USA))

1991-05-01

A total of 304 patients with injuries to the femoral shaft and ipsilateral hip presented between 1984 and 1990. Some 253 of them suffered fractures of the femoral shaft and dislocated hips or fractures of the acetabulum, and 51 of these sustained fractures of the femoral shaft and neck or trochanteric region. All of the trochanteric injuries were demonstrated on the initial radiographs. However, in 11 of the patients with combined femoral shaft and neck fractures, the diagnosis was delayed by as much as 4 weeks. This delay related to the fact that these fractures tended not to separate in the initial evaluation period and that there was external rotation of the proximal femoral fragment due to the femoral shaft fracture. (orig./GDG).

Spiral groove seal. [for hydraulic rotating shaft

Science.gov (United States)

Ludwig, L. P. (Inventor)

1973-01-01

Mating flat surfaces inhibit leakage of a fluid around a stationary shaft. A spiral groove pattern produces a pumping action toward the fluid when the shaft rotates which prevents leakage while a generated hydraulic lifting force separates the mating surfaces to minimize wear.

Dynamic analysis of cross shaft type universal joint with clearance

International Nuclear Information System (INIS)

Lu, Jian Wei; Wang, Gong Cheng; Chen, Hao; Vakakis, Alexander F.; Bergman, Lawrence A.

2013-01-01

Cross shaft type universal joint is widely used in ground vehicles to transfer torque between two intersecting axes, and its transmission feature can make a great contribution to NVH performance of the vehicle. We looked at the assembling clearance at cross shaft neck, and presented a dynamic model of cross shaft type universal joint with clearance at cross shaft neck. Two-state model is applied to describe the contact force between the cross shaft and driving joint fork based on Hertz theorem, and lumped mass method is applied to build up the dynamic model of the universal joint. Based on this model, numerical analysis is carried out to discuss the transmission feature of the universal joint with clearance at cross shaft neck, and the influence of clearance on the dynamic behavior of the system is evaluated with numerical results based on time history, power spectrum, and phase portrait. The method and conclusions presented are helpful to improvement of the transmission feature of cross shaft type universal joint.

Shaft siting decision report: Final report

International Nuclear Information System (INIS)

1985-11-01

The purpose of this study is to identify and establish relative guidelines to be used for siting of repository shafts. Weights were determined for the significant factors which impact the selection of shaft locations for a nuclear waste repository in salt. The study identified a total of 45 factors. A panel of experienced mining people utilized the Kepner-Tregoe (K-T) Decision Analysis Process to perform a structured evaluation of each significant shaft siting factor. The evaluation determined that 22 of the factors were absolute constraints and that the other 23 factors were desirable characteristics. The group established the relative weights for each of the 23 desirable characteristics by using a paired comparison method. 49 refs., 2 figs., 5 tabs

Thermoconvective flow velocity in a high-speed magnetofluid seal after it has stopped

Science.gov (United States)

Krakov, M. S.; Nikiforov, I. V.

2012-09-01

Convective flow is investigated in the high-speed (linear velocity of the shaft seal is more than 1 m/s) magnetofluid shaft seal after it has been stopped. Magnetic fluid is preliminarily heated due to viscous friction in the moving seal. After the shaft has been stopped, nonuniform heated fluid remains under the action of a high-gradient magnetic field. Numerical analysis has revealed that in this situation, intense thermomagnetic convection is initiated. The velocity of magnetic fluid depends on its viscosity. For the fluid with viscosity of 2 × 10-4 m2/s the maximum flow velocity within the volume of magnetic fluid with a characteristic size of 1 mm can attain a value of 10 m/s.

A coupled mechanical/hydrologic model for WIPP shaft seals

International Nuclear Information System (INIS)

Ehgartner, B.

1991-06-01

Effective sealing of the Waste Isolation Pilot Plant (WIPP) shafts will be required to isolate defense-generated transuranic wastes from the accessible environment. Shafts penetrate water-bearing hard rock formations before entering a massive creeping-salt formation (Salado) where the WIPP is located. Short and long-term seals are planned for the shafts. Short-term seals, a composite of concrete and bentonite, will primarily be located in the hard rock formations separating the water-bearing zones from the Salado Formation. These seals will limit water flow to the underlying long-term seals in the Salado. The long-term seals will consist of lengthly segments of initially unsaturated crushed salt. Creep closure of the shaft will consolidate unsaturated crushed salt, thereby reducing its permeability. However, water passing through the upper short-term seals and brine inherent to the salt host rock itself will eventually saturate the crushed salt and consolidation could be inhibited. Before saturating, portions of the crushed salt in the shafts are expected to consolidate to a permeability equivalent to the salt host rock, thereby effectively isolating the waste from the overlying water-bearing formations. A phenomenological model is developed for the coupled mechanical/hydrologic behavior of sealed WIPP shafts. The model couples creep closure of the shaft, crushed salt consolidation, and the associated reduction in permeability with Darcy's law for saturated fluid flow to predict the overall permeability of the shaft seal system with time. 17 refs., 6 figs., 1 tab

Shaft Siting and Configuration for Flexible Operating Mode

International Nuclear Information System (INIS)

Robert Boutin

2001-01-01

The purpose of this document as stated in the ''Technical Work Plan for Subsurface Design Section FY 01 Work Activities'' (CRWMS M and O 2001a, pg. 14) is to review and evaluate the most current concepts for shaft siting and configuration. The locations of the shaft sites will be evaluated in reference to the overall subsurface ventilation layout shown in Figure 1. The scope will include discussions on pad size requirements, shaft construction components such as collars, shaft stations, sumps, ground support and linings, head frames, fan ducting and facility equipping. In addition to these, shaft excavation methodologies and integration with the overall subsurface construction schedule will be described. The Technical Work Plan (TWP), (CRWMS M and O 2001a), for this document has been prepared in accordance with AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering and Regulatory Compliance Activities''. This document will be prepared in accordance with AP-3.10Q, ''Analysis and Models''. This document contributes to Site Recommendation (SR). The intended use of this document is to provide an analysis for shaft siting and configuration criteria for subsequent construction. This document identifies preliminary design concepts that should not be used for procurement, fabrication, or construction

A Two-Disk Extended Jeffcott Rotor Model Distinguishing a Shaft Crack from Other Rotating Asymmetries

Directory of Open Access Journals (Sweden)

Xi Wu

2008-01-01

Full Text Available A mathematical model of a cracked rotor and an asymmetric rotor with two disks representing a turbine and a generator is utilized to study the vibrations due to imbalance and side load. Nonlinearities typically related with a “breathing” crack are included using a Mayes steering function. Numerical simulations demonstrate how the variations of rotor parameters affect the vibration response and the effect of coupling between torsional and lateral modes. Bode, spectrum, and orbit plots are used to show the differences between the vibration signatures associated with cracked shafts versus asymmetric shafts. Results show how nonlinear lateral-torsional coupling shifts the resonance peaks in the torsional vibration response for cracked shafts and asymmetric rotors. The resonance peaks shift depending on the ratio of the lateral-to-torsional natural frequencies with the peak responses occurring at noninteger values of the lateral natural frequency. When the general nonlinear models used in this study are constrained to reduce to linear torsional vibration, the peak responses occur at commonly reported integer ratios. Full spectrum analyses of the X and Y vibrations reveal distinct vibration characteristics of both cracked and asymmetric rotors including reverse vibration components. Critical speeds and vibration orders predicted using the models presented herein include and extend diagnostic indicators commonly reported.

Humeral Shaft Fracture: Intramedullary Nailing.

Science.gov (United States)

Konda, Sanjit R; Saleh, Hesham; Fisher, Nina; Egol, Kenneth A

2017-08-01

This video demonstrates the technique of intramedullary nailing for a humeral shaft fracture. The patient is a 30-year-old man who sustained a gunshot wound to his right arm. The patient was indicated for humeral nailing given the comminuted nature of the diaphysis and to allow for minimal skin incisions. Other relative indications include soft-tissue compromise about the arm precluding a large surgical exposure. This video presents a case of a comminuted humeral shaft fracture treated with an intramedullary nail. Anatomic reduction and stable fixation was obtained with this technique. This case demonstrates a soft-tissue sparing technique of humeral shaft fixation using a humeral intramedullary nail. The technique is easy to perform and has significant benefits in minimizing surgical exposure, decreasing operative time, and decreasing blood loss. In the correct clinical setting, humeral nailing provides an expeditious form of fixation that restores length, alignment, and rotation of the fracture humeral diaphysis.

Large shaft development test plan

International Nuclear Information System (INIS)

Krug, A.D.

1984-03-01

This test plan proposes the conduct of a large shaft development test at the Hanford site in support of the repository development program. The purpose and objective of the test plan is to obtain the information necessary to establish feasibility and to predict the performance of the drilling system used to drill large diameter shafts. The test plan is based upon drilling a 20 ft diameter shaft to a depth of 1,000 feet. The test plan specifies series of tests to evaluate the performance of the downhole assembly, the performance of the rig, and the ability of the system to cope with geologic hazards. The quality of the hole produced will also be determined. This test plan is considered to be preliminary in that it was prepared as input for the decision to determine if development testing is required in this area. Should the decision be made to proceed with development testing, this test plan shall be updated and revised. 6 refs., 2 figs., 3 tabs

Exploratory shaft liner corrosion estimate

International Nuclear Information System (INIS)

Duncan, D.R.

1985-10-01

An estimate of expected corrosion degradation during the 100-year design life of the Exploratory Shaft (ES) is presented. The basis for the estimate is a brief literature survey of corrosion data, in addition to data taken by the Basalt Waste Isolation Project. The scope of the study is expected corrosion environment of the ES, the corrosion modes of general corrosion, pitting and crevice corrosion, dissimilar metal corrosion, and environmentally assisted cracking. The expected internal and external environment of the shaft liner is described in detail and estimated effects of each corrosion mode are given. The maximum amount of general corrosion degradation was estimated to be 70 mils at the exterior and 48 mils at the interior, at the shaft bottom. Corrosion at welds or mechanical joints could be significant, dependent on design. After a final determination of corrosion allowance has been established by the project it will be added to the design criteria. 10 refs., 6 figs., 5 tabs

Rotating Shaft Tilt Angle Measurement Using an Inclinometer

OpenAIRE

Luo Jun; Wang Zhiqian; Shen Chengwu; Wen Zhuoman; Liu Shaojin; Cai Sheng; Li Jianrong

2015-01-01

This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendic...

30 CFR 77.1911 - Ventilation of slopes and shafts.

Science.gov (United States)

2010-07-01

... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Slope and Shaft Sinking § 77.1911 Ventilation of slopes and shafts. (a) All slopes and... connected to the slope or shaft opening with fireproof air ducts; (3) Designed to permit the reversal of the...

Modeling, Simulation and Control of Matrix Convert for Variable Speed Wind Turbine System

Directory of Open Access Journals (Sweden)

M. Alizadeh Moghadam

2015-09-01

Full Text Available This paper presents modeling, simulation and control of matrix converter (MC for variable speed wind turbine (VSWT system including permanent magnet synchronous generator (PMSG. At a given wind velocity, the power available from a wind turbine is a function of its shaft speed. In order to track maximum power, the MC adjusts the PMSG shaft speed.The proposed control system allowing independent control maximum power point tracking (MPPT of generator side and regulate reactive power of grid side for the operation of the VSWT system. The MPPT is implemented by a new control system. This control system is based on control of zero d-axis current (ZDC. The ZDC control can be realized by transfer the three-phase stator current in the stationary reference frame into d-and q-axis components in the synchronous reference frame. Also this paper is presented, a novel control strategy to regulate the reactive power supplied by a variable speed wind energy conversion system. This control strategy is based on voltage oriented control (VOC. The simulation results based on Simulink/Matlab software show that the controllers can extract maximum power and regulate reactive power under varying wind velocities.

Spiral groove seal. [for rotating shaft

Science.gov (United States)

Ludwig, L. P.; Strom, T. N. (Inventor)

1974-01-01

Mating flat surfaces inhibit leakage of a fluid around a stationary shaft. A spiral groove produces a pumping action toward the fluid when the shaft rotates. This prevents leakage while a generated hydraulic lifting force separates the mating surfaces to minimize wear. Provision is made for placing these spiral grooves in communication with the fluid to accelerate the generation of the hydraulic lifting force.

Improving transition between power optimization and power limitation of variable speed/variable pitch wind turbines

Energy Technology Data Exchange (ETDEWEB)

Hansen, A D; Bindner, H [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark); Rebsdorf, A [Vestas Wind Systems A/S, Lem (Denmark)

1999-03-01

The paper summarises and describes the main results of a recently performed study of improving the transition between power optimization and power limitation for variable speed/variable pitch wind turbines. The results show that the capability of varying the generator speed also can be exploited in the transition stage to improve the quality of the generated power. (au)

Documentation and verification of the SHAFT code

International Nuclear Information System (INIS)

St John, C.M.

1991-12-01

The SHAFT code incorporates equations to compute stresses in a shaft liner when the rock through which a shaft passes is subject to known three-dimensional states of stress or strain. The deformation modes considered are hoop deformation, axial deformation, and shear on a plane normal to the shaft axis. Interaction between the liner and the soil and rock is considered, and it is assumed that the liner is in place before loading is applied. This code is intended to be used interactively but creates a permanent record complete with necessary quality assurance information. The code has been carefully verified for the case of generalized plane strain, in which an arbitrary axial strain can be defined. It may also be used for plane stress analysis. Output is given in the form of stresses at selected sample points in the linear and the rock and a simple graphical representation of the distribution of stress through the liner. 12 figs., 13 tabs

Incidence and epidemiology of tibial shaft fractures

DEFF Research Database (Denmark)

Larsen, Peter; Elsøe, Rasmus; Hansen, Sandra Hope

2015-01-01

Introduction: The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large....... The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have...... frequency of fractures while participating in sports activities and walking. Women present the highest frequency of fractures while walking and during indoor activities. Conclusion: This study shows an incidence of 16.9/100,000/year for tibial shaft fractures. AO-type 42-A1 was the most common fracture type...

Residual torsional properties of composite shafts subjected to impact loadings

International Nuclear Information System (INIS)

Sevkat, Ercan; Tumer, Hikmet

2013-01-01

Highlights: • Impact loading reduces the torsional strength of composite shaft. • Impact energy level determines the severity of torsional strength reduction. • Hybrid composite shafts can be manufactured by mixing two types of filament. • Maximum torque capacity of shafts can be estimated using finite element method. - Abstract: This paper presents an experimental and numerical study to investigate residual torsional properties of composite shafts subjected to impact loadings. E-glass/epoxy, carbon/epoxy and E-glass–carbon/epoxy hybrid composite shafts were manufactured by filament winding method. Composite shafts were impacted at 5, 10, 20 and 40 J energy levels. Force–time and energy–time histories of impact tests were recorded. One composite shaft with no impact, and four composite shafts with impact damage, five in total, were tested under torsion. Torque-twisting angle relations for each test were obtained. Reduction at maximum torque and maximum twisting angle induced by impact loadings were calculated. While 5 J impact did not cause significant reduction at maximum torque and maximum twisting angle, remaining impact loadings caused 34–67% reduction at maximum torque, and 30–61% reduction at maximum twisting angle. Reductions increased with increasing energy levels and varied depending on the material of composite shafts. The 3-D finite element (FE) software, Abaqus, incorporated with an elastic orthotropic model, was then used to simulate the torsion tests. Good agreement between experimental and numerical results was achieved

Eddy Current Sensing of Torque in Rotating Shafts

Science.gov (United States)

Varonis, Orestes J.; Ida, Nathan

2013-12-01

The noncontact torque sensing in machine shafts is addressed based on the stress induced in a press-fitted magnetoelastic sleeve on the shaft and eddy current sensing of the changes of electrical conductivity and magnetic permeability due to the presence of stress. The eddy current probe uses dual drive, dual sensing coils whose purpose is increased sensitivity to torque and decreased sensitivity to variations in distance between probe and shaft (liftoff). A mechanism of keeping the distance constant is also employed. Both the probe and the magnetoelastic sleeve are evaluated for performance using a standard eddy current instrument. An eddy current instrument is also used to drive the coils and analyze the torque data. The method and sensor described are general and adaptable to a variety of applications. The sensor is suitable for static and rotating shafts, is independent of shaft diameter and operational over a large range of torques. The torque sensor uses a differential eddy current measurement resulting in cancellation of common mode effects including temperature and vibrations.

Assessment of shaft safety and management system of controlling engineering information

Energy Technology Data Exchange (ETDEWEB)

Liu Rui-xin; Xu Yan-chun [Yanzhou Mining Group Ltd., Zoucheng (China)

2008-02-15

Evaluating shaft safety and establishing a system for controlling engineering information is very important because more than 90 shafts in thick alluvial areas suddenly have shaft wall fracturing or breaking problems and there are more than a few hundred shafts of similar geologic conditions. Taking shaft control in the Yangzhou Coal Mining Group as an example, an assessment and management system and related software were established. This system includes basic information of the mine, measurement results and analysis, and functions of empirical and theoretical forecasting and finite element analysis, which are confirmed to be very effective for guiding shaft well control engineering in practice. 8 refs., 3 figs., 2 tabs.

Gear Design Effects on the Performance of High Speed Helical Gear Trains as Used in Aerospace Drive Systems

Science.gov (United States)

Handschuh, R.; Kilmain, C.; Ehinger, R.; Sinusas, E.

2013-01-01

The performance of high-speed helical gear trains is of particular importance for tiltrotor aircraft drive systems. These drive systems are used to provide speed reduction / torque multiplication from the gas turbine output shaft and provide the necessary offset between these parallel shafts in the aircraft. Four different design configurations have been tested in the NASA Glenn Research Center, High Speed Helical Gear Train Test Facility. The design configurations included the current aircraft design, current design with isotropic superfinished gear surfaces, double helical design (inward and outward pumping), increased pitch (finer teeth), and an increased helix angle. All designs were tested at multiple input shaft speeds (up to 15,000 rpm) and applied power (up to 5,000 hp). Also two lubrication, system-related, variables were tested: oil inlet temperature (160 to 250 degF) and lubricating jet pressure (60 to 80 psig). Experimental data recorded from these tests included power loss of the helical system under study, the temperature increase of the lubricant from inlet to outlet of the drive system and fling off temperatures (radially and axially). Also, all gear systems were tested with and without shrouds around the gears. The empirical data resulting from this study will be useful to the design of future helical gear train systems anticipated for next generation rotorcraft drive systems.

Outline and results of study on excavation response of rock mass around shaft in shaft excavation effects project

International Nuclear Information System (INIS)

Sugihara, Kozo; Matsui, Hiroya; Sato, Toshinori

1993-01-01

A shaft, with a diameter of 6 m and a depth of 150 m, has been newly excavated in sedimentary rock and excavation response of rock mass around the shaft has been measured and analyzed. Excavation response has been evaluated based on the results of measurement of rock mass movement, such as displacement and strain, and change of rock property, such as deformability and permeability. This study indicates that rock property has been changed with in about 1 m from the shaft wall, and rock mass movement and property change has been influenced by rock facies, fracture and re-distributed stress. The relation between property change and these factors is remained to be evaluated in future study. (author)

DC Control Effort Minimized for Magnetic-Bearing-Supported Shaft

Science.gov (United States)

Brown, Gerald V.

2001-01-01

A magnetic-bearing-supported shaft may have a number of concentricity and alignment problems. One of these involves the relationship of the position sensors, the centerline of the backup bearings, and the magnetic center of the magnetic bearings. For magnetic bearings with permanent magnet biasing, the average control current for a given control axis that is not bearing the shaft weight will be minimized if the shaft is centered, on average over a revolution, at the magnetic center of the bearings. That position may not yield zero sensor output or center the shaft in the backup bearing clearance. The desired shaft position that gives zero average current can be achieved if a simple additional term is added to the control law. Suppose that the instantaneous control currents from each bearing are available from measurements and can be input into the control computer. If each control current is integrated with a very small rate of accumulation and the result is added to the control output, the shaft will gradually move to a position where the control current averages to zero over many revolutions. This will occur regardless of any offsets of the position sensor inputs. At that position, the average control effort is minimized in comparison to other possible locations of the shaft. Nonlinearities of the magnetic bearing are minimized at that location as well.

Designing the optimal bit: balancing energetic cost, speed and reliability.

Science.gov (United States)

Deshpande, Abhishek; Gopalkrishnan, Manoj; Ouldridge, Thomas E; Jones, Nick S

2017-08-01

We consider the challenge of operating a reliable bit that can be rapidly erased. We find that both erasing and reliability times are non-monotonic in the underlying friction, leading to a trade-off between erasing speed and bit reliability. Fast erasure is possible at the expense of low reliability at moderate friction, and high reliability comes at the expense of slow erasure in the underdamped and overdamped limits. Within a given class of bit parameters and control strategies, we define 'optimal' designs of bits that meet the desired reliability and erasing time requirements with the lowest operational work cost. We find that optimal designs always saturate the bound on the erasing time requirement, but can exceed the required reliability time if critically damped. The non-trivial geometry of the reliability and erasing time scales allows us to exclude large regions of parameter space as suboptimal. We find that optimal designs are either critically damped or close to critical damping under the erasing procedure.

A review of drilled shaft sealing for the Basalt Waste Isolation Project

International Nuclear Information System (INIS)

1981-01-01

Questions have been raised concerning the ability of the drillers of the exploratory shaft for the Basalt Waste Isolation program to develop an effective seal against water inflow down the annular space between the shaft casing and shaft wall into the mined chambers. We understand the need for shaft integrity and the concern of those responsible for the shaft planning. The purpose of this report is to give documentation to allay the fears of those who may have questions remaining in their minds concerning the prospects for a dry shaft. Included in this report are discussions of five projects where shaft sealing was effective in drilled shafts and one project where the material which is recommended for the exploratory shaft was used effectively in a conventional shaft. Also discussed is the recommended multitier approach toward shaft sealing which will, if adopted, use all of the current state of the art techniques to assure the watertightness of the shaft. It should be pointed out that none of the projects described here used all of the safeguards which are recommended in this program. If any of the materials and procedures recommended here are omitted, then of course the possibility increases for water migration through the casing-borehole annulus. It is our considered opinion that if the program recommended is adopted there will be no water inflow into the shaft, but if we are wrong or if, through human error, the program is not executed correctly, that we have devices and procedures available to us which will facilitate remedial work to perfect seal in the shaft. 4 refs., 3 figs., 1 tab

Measurement of instantaneous rotational speed using double-sine-varying-density fringe pattern

Science.gov (United States)

Zhong, Jianfeng; Zhong, Shuncong; Zhang, Qiukun; Peng, Zhike

2018-03-01

Fast and accurate rotational speed measurement is required both for condition monitoring and faults diagnose of rotating machineries. A vision- and fringe pattern-based rotational speed measurement system was proposed to measure the instantaneous rotational speed (IRS) with high accuracy and reliability. A special double-sine-varying-density fringe pattern (DSVD-FP) was designed and pasted around the shaft surface completely and worked as primary angular sensor. The rotational angle could be correctly obtained from the left and right fringe period densities (FPDs) of the DSVD-FP image sequence recorded by a high-speed camera. The instantaneous angular speed (IAS) between two adjacent frames could be calculated from the real-time rotational angle curves, thus, the IRS also could be obtained accurately and efficiently. Both the measurement principle and system design of the novel method have been presented. The influence factors on the sensing characteristics and measurement accuracy of the novel system, including the spectral centrobaric correction method (SCCM) on the FPD calculation, the noise sources introduce by the image sensor, the exposure time and the vibration of the shaft, were investigated through simulations and experiments. The sampling rate of the high speed camera could be up to 5000 Hz, thus, the measurement becomes very fast and the change in rotational speed was sensed within 0.2 ms. The experimental results for different IRS measurements and characterization of the response property of a servo motor demonstrated the high accuracy and fast measurement of the proposed technique, making it attractive for condition monitoring and faults diagnosis of rotating machineries.

RELAP/FRAP-T6 analysis of seized and sheared shaft accidents

International Nuclear Information System (INIS)

Bollinger, J.S.; Ito, T.; Peeler, G.B.

1984-01-01

Argonne National Laboratory (ANL) performed audit calculations of a Reactor Coolant Pump (RCP) seized/sheared shaft transient for the Westinghouse Seabrook Plant using RELAP5/MOD 1.5 (Cycle 32) and FRAP-T6. The objective was to determine the effect of time of loss of offsite power and other single component failures on the peak clad temperature. The RCP shaft seizure event was modeled in RELAP5 by using the pump model shaft stop option. In modeling the sheared shaft failure, the faulted pump was replaced with a branch component having no flow losses. In general, the RELAP5-predicted system response for the seized shaft transient was very comparable to the results presented in the Seabrook FSAR, although the Reactor Coolant System (RCS) pressure response was somewhat different. The RELAP5 sheared-shaft analysis results were very similar to those for the seized shaft

Speed Estimation in Geared Wind Turbines Using the Maximum Correlation Coefficient

DEFF Research Database (Denmark)

Skrimpas, Georgios Alexandros; Marhadi, Kun S.; Jensen, Bogi Bech

2015-01-01

to overcome the above mentioned issues. The high speed stage shaft angular velocity is calculated based on the maximum correlation coefficient between the 1 st gear mesh frequency of the last gearbox stage and a pure sinus tone of known frequency and phase. The proposed algorithm utilizes vibration signals...

Transient Model Validation of Fixed-Speed Induction Generator Using Wind Farm Measurements

DEFF Research Database (Denmark)

Rogdakis, Georgios; Garcia-Valle, Rodrigo; Arana Aristi, Iván

2012-01-01

In this paper, an electromagnetic transient model for fixed-speed wind turbines equipped with induction generators is developed and implemented in PSCAD/EMTDC. The model is comprised by: an induction generator, aerodynamic rotor, and a two-mass representation of the shaft system. Model validation...

Construction features of the exploratory shaft at Yucca Mountain

International Nuclear Information System (INIS)

Adair, G.W.; Fiore, J.N.

1984-01-01

The Exploratory Shaft (ES) at Yucca Mountain is planned to be constructed during 1985 and 1986 as part of the detailed site characterization for one of three sites which may be selected as candidates for location of a high-level radioactive waste repository. Conventional mining methods will be used for the shaft sinking phase of the ES project. The ES will be comprised of surface support facilities, a 1480-ft-deep circular shaft lined with concrete to a finished inside diameter of 12 ft, lateral excavations and test installations extending up to 200 ft from the shaft, and long lateral borings extending up to 2300 ft from the shaft. The estimated time for sinking the shaft to a total depth of about 1480 ft and completing the lateral excavations and borings is about two years. The major underground development planned for the primary test level at a depth of 1200 ft consists of the equivalent of 1150 ft of 15- by 15-ft drift. The total volume of rock to be removed from the shaft proper and the lateral excavations totals about 1/2 million cubic feet. Construction equipment for the shaft and underground excavation phases consists of conventional mine hoisting equipment, shot hole and rock bolt drilling jumbos, mucking machines, and hauling machines. The desire to maintain relatively uniform and even walls in selected shaft and drift intervals will require that controlled blasting techniques be employed. Certain lateral boring operations associated with tests to be conducted in the underground development may pose some unusual problems or require specialized equipment. One of the operations is boring and lining a 30-in.-diam by 600-ft-long horizontal hole with a boring machine being developed under the direction of Sandia National Laboratories. Another special operation is coring long lateral holes (500 to 2000 ft) with minimum use of liquid circulating fluids. 8 figures

DECOVALEX II project. Nirex RCF Shaft Excavation Task 1C - Coupled hydro-mechanical effects of shaft sinking within Sector 7

International Nuclear Information System (INIS)

Hakami, H.

1999-12-01

Within the framework for an international co-operation in the field of geohydrological and mechanical processes associated with radioactive waste disposal deep in rock masses (DECOVALEX II), the present work involved a number of numerical investigations in order to gain an understanding of the consequences a shaft sinking at Sellafield, England, may bring about. Research groups from five countries approached the modelling of the shaft sinking in the rock mass in question with different numerical methods. Both continuum as well as discontinuum representations of the rock mass were made. Itasca chose the code FLAC 3D , a three dimensional finite difference based computer code to carry out the numerical analyses necessary. As a first approach, an equivalent material model was chosen where discontinuities at all levels assumed to have smeared out in a rock matrix, to produce a theoretical material that would behave elasto-plastically under loading. By selecting the Mohr-Coulomb failure criterion, numerical analyses were carried out that depicted the perturbations in stress and deformational field, the shaft sinking would produce. The sinking of the shaft disturbs the flow regime of the rock mass. By presuming a number of assumptions, the approximate discharge into selected sections of the shaft were computed. Also, by numerically 'monitoring' the pore pressure drawdowns in two boreholes in close vicinity of the shaft the effect of the shaft sinking on the flow was evaluated. Having evaluated the outcome of the first series of the numerical analyses, improvements were made in the model set-up, by introducing three major flow zones with enhanced porosity and permeability in a grid that was otherwise a low conductive medium with very low porosity. A new set of flow analyses were carried out that typified the effect of the added flow zones on the general characteristics of flow in the rock mass in question. Also, by introducing a new failure criterion emerged from both

DECOVALEX II project. Nirex RCF Shaft Excavation Task 1C - Coupled hydro-mechanical effects of shaft sinking within Sector 7

Energy Technology Data Exchange (ETDEWEB)

Hakami, H. [Itasca Geomekanik AB, Stockholm (Sweden)

1999-12-01

Within the framework for an international co-operation in the field of geohydrological and mechanical processes associated with radioactive waste disposal deep in rock masses (DECOVALEX II), the present work involved a number of numerical investigations in order to gain an understanding of the consequences a shaft sinking at Sellafield, England, may bring about. Research groups from five countries approached the modelling of the shaft sinking in the rock mass in question with different numerical methods. Both continuum as well as discontinuum representations of the rock mass were made. Itasca chose the code FLAC{sup 3D}, a three dimensional finite difference based computer code to carry out the numerical analyses necessary. As a first approach, an equivalent material model was chosen where discontinuities at all levels assumed to have smeared out in a rock matrix, to produce a theoretical material that would behave elasto-plastically under loading. By selecting the Mohr-Coulomb failure criterion, numerical analyses were carried out that depicted the perturbations in stress and deformational field, the shaft sinking would produce. The sinking of the shaft disturbs the flow regime of the rock mass. By presuming a number of assumptions, the approximate discharge into selected sections of the shaft were computed. Also, by numerically 'monitoring' the pore pressure drawdowns in two boreholes in close vicinity of the shaft the effect of the shaft sinking on the flow was evaluated. Having evaluated the outcome of the first series of the numerical analyses, improvements were made in the model set-up, by introducing three major flow zones with enhanced porosity and permeability in a grid that was otherwise a low conductive medium with very low porosity. A new set of flow analyses were carried out that typified the effect of the added flow zones on the general characteristics of flow in the rock mass in question. Also, by introducing a new failure criterion emerged

Analysis of hydraulic bearing effect for vertical-shaft pump

International Nuclear Information System (INIS)

Narabayashi, Tadashi; Mawatari, Katsuhiko; Uchida, Ken; Iikura, Takahiko; Hayakawa, Kiyoshi

1999-01-01

In inner-rotating non coaxial cylinders, axial flow causes a hydraulic being effect by which the inner cylinder is put at the center of the axis of the outer cylinder, because of the pressure distribution along the surface of the inner cylinder. When the rotating speed becomes higher, whirl force is generated by the pressure distribution in the narrow gap side. Therefore, pocket-type hydraulic being was added between the rotor and the wearing, based on an experiment and flow analysis. The pockets suck a part of discharged water of a pump and pressurize a water along the rotational direction in the pocket. The pressurized water enhance the hydraulic being effect. The analysis results showed good agreement with the experiments, and the analysis method for the hydraulic being for vertical-shaft pump was established. (author)

Inventory-transportation integrated optimization for maintenance spare parts of high-speed trains

Science.gov (United States)

Wang, Jiaxi; Wang, Huasheng; Wang, Zhongkai; Li, Jian; Lin, Ruixi; Xiao, Jie; Wu, Jianping

2017-01-01

This paper presents a 0–1 programming model aimed at obtaining the optimal inventory policy and transportation mode for maintenance spare parts of high-speed trains. To obtain the model parameters for occasionally-replaced spare parts, a demand estimation method based on the maintenance strategies of China’s high-speed railway system is proposed. In addition, we analyse the shortage time using PERT, and then calculate the unit time shortage cost from the viewpoint of train operation revenue. Finally, a real-world case study from Shanghai Depot is conducted to demonstrate our method. Computational results offer an effective and efficient decision support for inventory managers. PMID:28472097

Design and Delivery of HMT Half-Shaft Prototype

Science.gov (United States)

2012-11-01

spindle welded to the outer joint output is ease of Design  and Delivery of HMT Half‐ Shaft  Prototype    24    assembly. Flange 1 contains threaded... spindle , and splined shafts . Also, the spindle of the production design is splined to match the splines of the hub internals. 2.2. Analysis The...inner-joint (Figure 33). Design  and Delivery of HMT Half‐ Shaft  Prototype    27      Figure 33: FBD of Flange/ Spindle Applying Newton’s Laws to the

Optimal Speed Control for Cruising

DEFF Research Database (Denmark)

Blanke, M.

1994-01-01

With small profit margins in merchant shipping and more than eighty percent of sailing time being cross ocean voyages, speed control is crucial for vessel profitability......With small profit margins in merchant shipping and more than eighty percent of sailing time being cross ocean voyages, speed control is crucial for vessel profitability...

Study on Manufacturing Process of Hollow Main Shaft by Open Die Forging

International Nuclear Information System (INIS)

Kwon, Yong Chul; Kang, Jong Hun; Kim, Sang Sik

2016-01-01

The main shaft is one of the key components connecting the rotor hub and gear box of a wind power generator. Typically, main shafts are manufactured by open die forging method. However, the main shaft for large MW class wind generators is designed to be hollow in order to reduce the weight. Additionally, the main shafts are manufactured by a casting process. This study aims to develop a manufacturing process for hollow main shafts by the open die forging method. The design of a forging process for a solid main shaft and hollow shaft was prepared by an open die forging process design scheme. Finite element analyses were performed to obtain the flow stress by a hot compression test at different temperature and strain rates. The control parameters of each forging process, such as temperature and effective strain, were obtained and compared to predict the suitability of the hollow main shaft forging process. Finally, high productivity reflecting material utilization ratio, internal quality, shape, and dimension was verified by the prototypes manufactured by the proposed forging process for hollow main shafts

Study on Manufacturing Process of Hollow Main Shaft by Open Die Forging

Energy Technology Data Exchange (ETDEWEB)

Kwon, Yong Chul [Gyeongnam Technopark, Changwon (Korea, Republic of); Kang, Jong Hun [Jungwon Univ., Goisan (Korea, Republic of); Kim, Sang Sik [Gyeongsang Natiional Univ., Jinju (Korea, Republic of)

2016-02-15

The main shaft is one of the key components connecting the rotor hub and gear box of a wind power generator. Typically, main shafts are manufactured by open die forging method. However, the main shaft for large MW class wind generators is designed to be hollow in order to reduce the weight. Additionally, the main shafts are manufactured by a casting process. This study aims to develop a manufacturing process for hollow main shafts by the open die forging method. The design of a forging process for a solid main shaft and hollow shaft was prepared by an open die forging process design scheme. Finite element analyses were performed to obtain the flow stress by a hot compression test at different temperature and strain rates. The control parameters of each forging process, such as temperature and effective strain, were obtained and compared to predict the suitability of the hollow main shaft forging process. Finally, high productivity reflecting material utilization ratio, internal quality, shape, and dimension was verified by the prototypes manufactured by the proposed forging process for hollow main shafts.

Proceedings of the conference on shaft drilling technology

International Nuclear Information System (INIS)

Anon.

1990-01-01

This book contains the following topics, Market analysis, World-wide operations, Innovative drilling and boring, Raise boring, Shaft lining and fittings, Entry considerations for the Yucca Mountain exploratory shaft facility for potential Radioactive Waste Disposal, Drilling rigs in the coal industry

High Efficiency Jobsite Detection of Wind Turbine Main Shaft%风机主轴的现场高效检测

Institute of Scientific and Technical Information of China (English)

郭君渝; 石小兵

2014-01-01

采用先进的专业检测工具对风机主轴进行现场检测。通过优化检测手段，创新检测方法，有效提高风机主轴的现场检测效率。%Jobsite inspection has been conducted on wind turbine main shaft by advanced and professional detec-tion tool.Though implementing of detection means optimization and detection method innovation, jobsite detection effi-ciency of wind turbine main shaft has been improved effectively.

Performances Comparison for a Rotating Shaft Suspended by 4-Axis Radial Active Magnetic Bearings via -Synthesis, Loop-Shaping Design, and Sub(∞with Uncertainties

Directory of Open Access Journals (Sweden)

G. Barbaraci

2011-01-01

Full Text Available The control systems applied on active magnetic bearing are several. A perfect levitation is characterized by maintaining the operating point condition that is characterized by the center of stator coincident with the geometric center of shaft. The first controller implemented for this purpose is PID controller that is characterized by an algorithm that leads the amplifier to produce control current until the operating point condition is not reached, this is obtained by an integration operator. The effect of an integrator is essential but not necessary for a centered levitation for example in the robust control characterized by a dynamic model depended on plant of system so that it depends on angular speed as LQR controller does. In LQR there is not integrator so there is not a perfectly centered section of shaft with center of stator. On contrary PID controller does not depend on angular speed and it can be easily implemented according some simple rules. Predictive control is another interesting controller characterized by a multiple controller operating in different condition in order to get the minimum of cost function, but also in this case the angular speed is introduce for the same reason discussed before.

Health monitoring system for transmission shafts based on adaptive parameter identification

Science.gov (United States)

Souflas, I.; Pezouvanis, A.; Ebrahimi, K. M.

2018-05-01

A health monitoring system for a transmission shaft is proposed. The solution is based on the real-time identification of the physical characteristics of the transmission shaft i.e. stiffness and damping coefficients, by using a physical oriented model and linear recursive identification. The efficacy of the suggested condition monitoring system is demonstrated on a prototype transient engine testing facility equipped with a transmission shaft capable of varying its physical properties. Simulation studies reveal that coupling shaft faults can be detected and isolated using the proposed condition monitoring system. Besides, the performance of various recursive identification algorithms is addressed. The results of this work recommend that the health status of engine dynamometer shafts can be monitored using a simple lumped-parameter shaft model and a linear recursive identification algorithm which makes the concept practically viable.

High-Speed Train Stop-Schedule Optimization Based on Passenger Travel Convenience

OpenAIRE

Dingjun Chen; Shaoquan Ni; Chang’an Xu; Hongxia Lv; Simin Wang

2016-01-01

The stop-schedules for passenger trains are important to the operation planning of high-speed trains, and they decide the quality of passenger service and the transportation efficiency. This paper analyzes the specific manifestation of passenger travel convenience and proposes the concepts of interstation accessibility and degree of accessibility. In consideration of both the economic benefits of railway corporations and the travel convenience of passengers, a multitarget optimization model i...

Improving the Response of a Wheel Speed Sensor by Using a RLS Lattice Algorithm

Directory of Open Access Journals (Sweden)

Wilmar Hernandez

2006-02-01

Full Text Available Among the complete family of sensors for automotive safety, consumer andindustrial application, speed sensors stand out as one of the most important. Actually, speedsensors have the diversity to be used in a broad range of applications. In today’s automotiveindustry, such sensors are used in the antilock braking system, the traction control systemand the electronic stability program. Also, typical applications are cam and crank shaftposition/speed and wheel and turbo shaft speed measurement. In addition, they are used tocontrol a variety of functions, including fuel injection, ignition timing in engines, and so on.However, some types of speed sensors cannot respond to very low speeds for differentreasons. What is more, the main reason why such sensors are not good at detecting very lowspeeds is that they are more susceptible to noise when the speed of the target is low. In short,they suffer from noise and generally only work at medium to high speeds. This is one of thedrawbacks of the inductive (magnetic reluctance speed sensors and is the case under study.Furthermore, there are other speed sensors like the differential Hall Effect sensors that arerelatively immune to interference and noise, but they cannot detect static fields. This limitstheir operations to speeds which give a switching frequency greater than a minimumoperating frequency. In short, this research is focused on improving the performance of avariable reluctance speed sensor placed in a car under performance tests by using arecursive least-squares (RLS lattice algorithm. Such an algorithm is situated in an adaptivenoise canceller and carries out an optimal estimation of the relevant signal coming from thesensor, which is buried in a broad-band noise background where we have little knowledgeof the noise characteristics. The experimental results are satisfactory and show a significantimprovement in the signal-to-noise ratio at the system output.

Designing shafts for handling high-level radioactive wastes in mined geologic repositories

International Nuclear Information System (INIS)

Hambley, D.F.; Morris, J.R.

1988-01-01

Waste package conceptual designs developed in the United States by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management are the basis for specifying the dimensions and weights of the waste package and transfer cask combinations to be hoisted in the waste handling shafts in mined geologic repositories for high-level radioactive waste. The hoist, conveyance, counterweight, and hoist ropes are then sized. Also taken into consideration are overwind and underwind arrestors and safety features required by the U.S. Nuclear Regulatory Commission. Other design features such as braking systems, chairing system design, and hoisting speed are considered in specifying waste hoisting system parameters for example repository sites

Feasibility of a Simple Small Wind Turbine with Variable-Speed Regulation Made of Commercial Components

Directory of Open Access Journals (Sweden)

Jesús Peláez Vara

2013-07-01

Full Text Available The aim of this study was to propose and evaluate a very small wind turbine (VSWT that competes with commercial grid-connected VSWTs in terms of simplicity, robustness and price. Its main components are a squirrel-cage induction generator (SCIG driven by a frequency converter. The system has a direct-drive shaft, and may be constructed with commercial equipment. Simulation of the wind turbine effect is done with a motor. A control program regulates the variable-speed of rotation through three operational modes: (i to drive the turbine to its optimum operation point; (ii to limit its maximum rotational speed; and (iii to limit the maximum power it generates. Two tests were performed, in order to evaluate the dynamic response of this system under variable wind speeds. The tests demonstrate that the system operates at the optimum operational point of the turbine, and within the set limits of maximum rotational speed and maximum generated power. The drop in performance in relation to its nominal value is about 75%, when operating at 50% of the nominal power. In summary, this VSWT with its proposed control program is feasible and reliable for operating direct-shaft grid-connected VSWTs.

Optimal swimming speed in head currents and effects on distance movement of winter-migrating fish.

Directory of Open Access Journals (Sweden)

Jakob Brodersen

Full Text Available Migration is a commonly described phenomenon in nature that is often caused by spatial and temporal differences in habitat quality. However, as migration requires energy, the timing of migration may depend not only on differences in habitat quality, but also on temporal variation in migration costs. Such variation can, for instance, arise from changes in wind or current velocity for migrating birds and fish, respectively. Whereas behavioural responses of birds to such changing environmental conditions have been relatively well described, this is not the case for fish, although fish migrations are both ecologically and economically important. We here use passive and active telemetry to study how winter migrating roach regulate swimming speed and distance travelled per day in response to variations in head current velocity. Furthermore, we provide theoretical predictions on optimal swimming speeds in head currents and relate these to our empirical results. We show that fish migrate farther on days with low current velocity, but travel at a greater ground speed on days with high current velocity. The latter result agrees with our predictions on optimal swimming speed in head currents, but disagrees with previously reported predictions suggesting that fish ground speed should not change with head current velocity. We suggest that this difference is due to different assumptions on fish swimming energetics. We conclude that fish are able to adjust both swimming speed and timing of swimming activity during migration to changes in head current velocity in order to minimize energy use.

Real-time monitoring of wind turbine generator shaft alignment using laser measurement.

OpenAIRE

Mankowski, O.; Wang, Q.

2013-01-01

Shaft Misalignment is one of the most common sources of trouble of wind turbine drive train when rigid couplings connect the shafts. Ideal alignment of the shaft is difficult to be obtained and the couplings attached to the shaft may present angular or parallel misalignment defined also as lateral and axially misalignment. Despite misalignment is often observed in the practice, there are relatively few studies on wind turbine shaft misalignment in the literature and their results are sometime...

Mine-shaft conveyance monitoring

Energy Technology Data Exchange (ETDEWEB)

Beus, M.J.; Ruff, T.M.; Iverson, S.; McCoy, W.G. [National Institute for Occupational Safety and Health, Spokane, WA (USA). Spokane Research Laboratory

2000-10-01

Monitoring conveyance position and wire rope load directly from the skip or cage top offers several significant safety and production advantages. The Spokane Research Laboratory (SRL) of the National Institute for Occupational Safety and Health (NIOSH) developed a shaft conveyance monitoring system (SCMS). This system consists of position and guide-displacement sensors, a maintenance-free battery power supply and a new sensor, which is mounted on the wire rope with a Crosby Clip, to measure hoist-rope tension. A radio data link transmits sensor output to the hoist room. A state-of-the-art automated hoisting test facility was also constructed to test the concept in a controlled laboratory setting. Field tests are now underway at the SRL hoisting research facility and in deep mine shafts in northern Idaho. 4 refs., 5 figs.

Performance of meta power rotor shaft torque meter

DEFF Research Database (Denmark)

Schmidt Paulsen, U.

2002-01-01

The present report describes the novel experimental facility in detecting shaft torque in the transmission system (main rotor shaft, exit stage of gearbox) of a wind turbine, the results and the perspectives in using this concept. The measurements arecompared with measurements, based on existing ...

WIPP air-intake shaft disturbed-rock zone study

International Nuclear Information System (INIS)

Dale, T.; Hurtado, L.D.

1996-01-01

The disturbed-rock zone surrounding the air-intake shaft at the Waste Isolation Pilot Plant (WIPP) site was investigated to determine the extent and the permeability of the disturbed-rock zone as a function of radial distance from the 6.1 m diameter shaft, at different elevations within the Salado. Gas- and brine-permeability tests were performed in the bedded halite of the Salado formation at two levels within the air-intake shaft. The gas- and brine-permeability test results demonstrated that the radial distance to an undisturbed formation permeability of 1 x 10 -21 m 2 was less than 3.0 m

Conceptual design of shaft seals for a nuclear waste disposal vault

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-04-01

The concept of a disposal vault in the Canadian Shield for the effective isolation of nuclear fuel wastes is being assessed as part of the Canadian Nuclear Fuel Waste Management Program. The vault would be accessed from the surface by a number of shafts, which would likely penetrate the vault environment and intersect significant rock fractures and thereby form preferential pathways for the migration of radionuclides from the disposal area to the biosphere. Golder Associates were retained to conduct a conceptual design study of sealing and backfilling the shafts. The first volume of this report reviews current shaft sinking and lining technologies, and recommends the preferred construction methods for the shafts. Factors that could affect the design of a shaft seal system are reviewed, and a conceptual shaft seal is proposed. The second volume addresses the performance assessment of a shaft seal system. While there are no specific performance criteria against which to compare the anticipated containment characteristics of the shaft seal system proposed, the methodology developed for the performance assessment of the reference design should enable the design to be modified to meet performance criteria as they are developed. The report estimates that it will cost $133.7 million in 1986 Canadian dollars to seal three reference shafts, including $18 million for labour and equipment, $103.4 million for backfill and sealing materials, $9.5 million for project indirect costs, and $2.8 million project management. (author). 53 refs., 36 tabs., 43 figs.

Conceptual design of shaft seals for a nuclear waste disposal vault

International Nuclear Information System (INIS)

1993-04-01

The concept of a disposal vault in the Canadian Shield for the effective isolation of nuclear fuel wastes is being assessed as part of the Canadian Nuclear Fuel Waste Management Program. The vault would be accessed from the surface by a number of shafts, which would likely penetrate the vault environment and intersect significant rock fractures and thereby form preferential pathways for the migration of radionuclides from the disposal area to the biosphere. Golder Associates were retained to conduct a conceptual design study of sealing and backfilling the shafts. The first volume of this report reviews current shaft sinking and lining technologies, and recommends the preferred construction methods for the shafts. Factors that could affect the design of a shaft seal system are reviewed, and a conceptual shaft seal is proposed. The second volume addresses the performance assessment of a shaft seal system. While there are no specific performance criteria against which to compare the anticipated containment characteristics of the shaft seal system proposed, the methodology developed for the performance assessment of the reference design should enable the design to be modified to meet performance criteria as they are developed. The report estimates that it will cost $133.7 million in 1986 Canadian dollars to seal three reference shafts, including $18 million for labour and equipment, $103.4 million for backfill and sealing materials, $9.5 million for project indirect costs, and $2.8 million project management. (author). 53 refs., 36 tabs., 43 figs

Finite element analysis of relative shaft vibrations of two-pole induction motors with static rotor eccentricity

Energy Technology Data Exchange (ETDEWEB)

Werner, Ulrich [Siemens AG, Nuernberg (Germany). Industry, Drive Technologies, Large Drives, Industry Development

2010-03-15

The paper shows a computational methodology for calculating the relative shaft vibrations in the sleeve bearings of two-pole induction machines regarding excitation due to an electromagnetic force, which is caused by static rotor eccentricity. For a worst case calculation concerning the height of exciting magnetic force electromagnetic field damping effects and magnetic resistance concerning the homopolar flux are neglected. The calculated magnetic force, acting on the rotor core with double supply frequency in direction of the smallest air gap, is implemented into a finite element rotor dynamic model. With this model the influence of the rotor speed as well as influence of the direction of the magnetic force on the relative shaft displacements can be analyzed. Therefore the paper shows a computational methodology to check, whether the rotor-bearing design is sensitive for electromagnetic excitations due to static rotor eccentricity and prepares therefore the possibility to introduce improvements during the design phase of the induction motor. (orig.)

Grinding Method and Error Analysis of Eccentric Shaft Parts

Science.gov (United States)

Wang, Zhiming; Han, Qiushi; Li, Qiguang; Peng, Baoying; Li, Weihua

2017-12-01

RV reducer and various mechanical transmission parts are widely used in eccentric shaft parts, The demand of precision grinding technology for eccentric shaft parts now, In this paper, the model of X-C linkage relation of eccentric shaft grinding is studied; By inversion method, the contour curve of the wheel envelope is deduced, and the distance from the center of eccentric circle is constant. The simulation software of eccentric shaft grinding is developed, the correctness of the model is proved, the influence of the X-axis feed error, the C-axis feed error and the wheel radius error on the grinding process is analyzed, and the corresponding error calculation model is proposed. The simulation analysis is carried out to provide the basis for the contour error compensation.

On two speed optimization problems for ships that sail in and out of emission control areas

DEFF Research Database (Denmark)

Fagerholt, Kjetil; Psaraftis, Harilaos N.

2015-01-01

This paper deals with two speed optimization problems for ships that sail in and out of Emission Control Areas (ECAs) with strict limits on sulfur emissions. For ships crossing in and out of ECAs, such as deep-sea vessels, one of the common options for complying with these limits is to burn heavy...... fuel oil (HFO) outside the ECA and switch to low-sulfur fuel such as marine gas oil (MGO) inside the ECA. As the prices of these two fuels are generally very different, so may be the speeds that the ship will sail at outside and inside the ECA. The first optimization problem examined by the paper...

Thermodynamic and economic optimization of LNG mixed refrigerant processes

International Nuclear Information System (INIS)

Wang, Mengyu; Khalilpour, Rajab; Abbas, Ali

2014-01-01

Highlights: • We study performance and cost optimization of C3MR and DMR processes. • A new economic objective function is proposed to reduce both compression work and equipment size. • The comparison of C3MR and DMR processes is based on process configuration, performance, and cost. - Abstract: Natural gas liquefaction processes are energy and cost intensive. This paper performs thermodynamic and economic optimization of the mid-scale mixed refrigerant cycles including propane precooled mixed refrigerant (C3MR) and dual mixed refrigerant (DMR) processes. Four different objective functions in this study are selected: total shaft work consumption, total cost investment (TCI), total annualized cost (TAC), and total capital cost of compressors and main cryogenic exchangers (MCHEs). Total cost investment (TCI) is a function of two key variables: shaft work (W) and overall heat transfer coefficient and area (UA) of MCHEs. It is proposed for reducing energy consumption and simultaneously minimizing total capital expenditure (CAPEX) and operating expenditure (OPEX). Total shaft work objective function can result in a 44.5% reduction of shaft work for C3MR and a 48.6% reduction for DMR compared to their baseline values, but infinitely high UA of MCHEs. Optimal results show that total capital cost of compressors and MCHEs is more suitable than other objective functions for the objective of reducing both shaft work and UA. It reduces 14.5% of specific power for C3MR and 26.7% for DMR when achieving the relatively lower UA values than their baseline values. In addition, TCI and TAC can also reduce a certain amount of total shaft work at a finite increased UA

Optimal pacing strategy: From theoretical modeling to reality in 1500m speed skating

NARCIS (Netherlands)

Hettinga, F.J.; de Koning, J.J.; Schmidt, L.J.I.; Wind, N.A.C.; McIntosh, B.; Foster, C.

2011-01-01

Purpose: Athletes are trained to choose the pace which is perceived to be correct during a specific effort, such as the 1500-m speed skating competition. The purpose of the present study was to "override" self-paced (SP) performance by instructing athletes to execute a theoretically optimal pacing

Optimal pacing strategy : from theoretical modelling to reality in 1500-m speed skating

NARCIS (Netherlands)

Hettinga, F. J.; De Koning, J. J.; Schmidt, L. J. I.; Wind, N. A. C.; MacIntosh, B. R.; Foster, C.

Purpose Athletes are trained to choose the pace which is perceived to be correct during a specific effort, such as the 1500-m speed skating competition. The purpose of the present study was to "override" self-paced (SP) performance by instructing athletes to execute a theoretically optimal pacing

Recent quality of ultra large rotor shafts

International Nuclear Information System (INIS)

Suzuki, Akira; Kinoshita, Shushi; Morita, Kikuo; Kikuchi, Hideo; Takada, Masayoshi

1983-01-01

Large size and high quality are required for rotor shafts accompanying recent trend of thermal and nuclear power generation toward large capacity. As for the low pressure rotor shafts for large capacity turbines, the disks and a shaft tend to be made into one body instead of conventional shrink fit construction, because of the experience of rotor accidents and the improvement of reliability. Therefore the ingots required become more and more large, and excellent production techniques are required for steel making, forging and heat treatment. Kobe Steel Ltd. have made about 20 large generator shafts from 420 t and 500 t ingots, and confirmed their stable high quality. Also a one-body low pressure rotor of 2600 mm diameter was made for trial, and its quality was examined. It was confirmed that the effect of forging and heat treatment was given sufficiently, and the production techniques for super-large one-body rotors were established. In steel making, vacuum degassing was applied twice to decrease hydrogen content, and VV restriction forging and pre-stage treatment were carried out. The properties of large rotors are reported. (Kako, I.)

TNX/HLW Long Shaft Pumps 1995-2000

International Nuclear Information System (INIS)

VanPelt, B.

2002-01-01

Problems with long shaft pumps are becoming clearer due to increased use, better instrumentation, more analysis, and increased testing activity. The problems are with reliability and not with hydraulic performance. The root cause of reliability problems is usually excessive vibration caused by design. The outlook for satisfactory pumps is improved as understanding of problems increases. Promising developments are emerging such as the tilt pad bearing. Alternative configurations, such as gas filled columns and submerged motor pumps, will require development. Continued development, in general, should be expected due to changing technology and industry changes. This report describes thirteen distinct pump programs starting with leakage of original mixer pumps in the 1980s and ending with the testing of tilt pad bearings now in progress. Eight of the programs occurred from 1996 to 2000. All involve long shaft pumps; all involve testing at TNX; and all involve a problem of some kind. The co mmon technical issue among the activities is vibration and shaft (or rotor) instability due to journal bearings. In every case, excessive shaft vibration is a reasonable and probable explanation for some or all of the problems

Development of a magnetic fluid shaft seal for an axial-flow blood pump.

Science.gov (United States)

Sekine, Kazumitsu; Mitamura, Yoshinori; Murabayashi, Shun; Nishimura, Ikuya; Yozu, Ryouhei; Kim, Dong-Wook

2003-10-01

A rotating impeller in a rotary blood pump requires a supporting system in blood, such as a pivot bearing or magnetic suspension. To solve potential problems such as abrasive wear and complexity of a supporting system, a magnetic fluid seal was developed for use in an axial-flow blood pump. Sealing pressures at motor speeds of up to 8,000 rpm were measured with the seal immersed in water or bovine blood. The sealing pressure was about 200 mm Hg in water and blood. The calculated theoretical sealing pressure was about 230 mm Hg. The seal remained perfect for 743 days in a static condition and for 180+ days (ongoing test) at a motor speed of 7,000 rpm. Results of measurement of cell growth activity indicated that the magnetic fluid has no negative cytological effects. The specially designed magnetic fluid shaft seal is useful for an axial-flow blood pump.

New endoscope shaft for endoscopic transsphenoidal pituitary surgery.

NARCIS (Netherlands)

Lindert, E.J. van; Grotenhuis, J.A.

2005-01-01

OBJECTIVE: To describe a new endoscope shaft developed for suction-aspiration during endoscopic transsphenoidal pituitary surgery. METHODS: A custom-made shaft for a Wolf endoscope (Richard Wolf GmbH, Knittlingen, Germany) was developed with a height of 10 mm and a width of 5 mm, allowing an

Improved circumferential shaft seal

Science.gov (United States)

Ludwig, L. P.; Strom, T. N.

1974-01-01

Comparative tests of modified and unmodified carbon ring seals showed that addition of helical grooves to conventional segmented carbon ring seals reduced leakage significantly. Modified seal was insensitive to shaft runout and to flooding by lubricant.

Torsional Vibration of a Shafting System under Electrical Disturbances

Directory of Open Access Journals (Sweden)

Ling Xiang

2012-01-01

Full Text Available Torsional vibration responses of a nonlinear shafting system are studied by a modified Riccati torsional transfer matrix combining with the Newmark-β method. Firstly, the system is modeled as a chain consisting of an elastic spring with concentrated mass points, from which a multi-segment lumped mass model is established. Secondly, accumulated errors are eliminated from the eigenfrequencies and responses of the system's torsional vibration by this newly developed procedure. The incremental transfer matrix method, combining the modified Riccati torsional transfer matrix with Newmark-β method, is further applied to solve the dynamical equations for the torsional vibration of the nonlinear shafting system. Lastly, the shafting system of a turbine-generator is employed as an illustrating example, and simulation analysis has been performed on the transient responses of the shaft's torsional vibrations during typical power network disturbances, such as three-phase short circuit, two-phase short circuit and asynchronous juxtaposition. The results validate the present method and are instructive for the design of a turbo-generator shaft.

The effect of texture on the shaft surface on the sealing performance of radial lip seals

Science.gov (United States)

Guo, Fei; Jia, XiaoHong; Gao, Zhi; Wang, YuMing

2014-07-01

On the basis of elastohydrodynamic model, the present study numerically analyzes the effect of various microdimple texture shapes, namely, circular, square, oriented isosceles triangular, on the pumping rate and the friction torque of radial lip seals, and determines the microdimple texture shape that can produce positive pumping rate. The area ratio, depth and shape dimension of a single texture are the most important geometric parameters which influence the tribological performance. According to the selected texture shape, parameter analysis is conducted to determine the optimal combination for the above three parameters. Simultaneously, the simulated performances of radial lip seal with texture on the shaft surface are compared with those of the conventional lip seal without any texture on the shaft surface.

FIXTURING DEVICE FOR DRILLING A STRAIGHT SHAFT

Directory of Open Access Journals (Sweden)

SUSAC, Florin

2017-05-01

Full Text Available The paper presents a fixturing device used for machining by drilling a straight shaft. The shaft was manufactured on EMCO CONCEPT TURN 55 CNC. The blank used was a bar with circular cross-section. The orientation and fixing scheme of the part and the orientation elements for fixturing device are presented as they were drawn in Autodesk Inventor and AutoCAD software.

Speed Optimization in Liner Shipping Network Design

DEFF Research Database (Denmark)

Brouer, Berit Dangaard; Karsten, Christian Vad; Pisinger, David

In the Liner Shipping Network Design Problem (LSNDP) services sail at a given speed throughout a round trip. In reality most services operate with a speed differentiated head- and back-haul, or even individual speeds on every sailing between two ports. The speed of a service is decisive...

A compound structure of ELM based on feature selection and parameter optimization using hybrid backtracking search algorithm for wind speed forecasting

International Nuclear Information System (INIS)

Zhang, Chu; Zhou, Jianzhong; Li, Chaoshun; Fu, Wenlong; Peng, Tian

2017-01-01

Highlights: • A novel hybrid approach is proposed for wind speed forecasting. • The variational mode decomposition (VMD) is optimized to decompose the original wind speed series. • The input matrix and parameters of ELM are optimized simultaneously by using a hybrid BSA. • Results show that OVMD-HBSA-ELM achieves better performance in terms of prediction accuracy. - Abstract: Reliable wind speed forecasting is essential for wind power integration in wind power generation system. The purpose of paper is to develop a novel hybrid model for short-term wind speed forecasting and demonstrates its efficiency. In the proposed model, a compound structure of extreme learning machine (ELM) based on feature selection and parameter optimization using hybrid backtracking search algorithm (HBSA) is employed as the predictor. The real-valued BSA (RBSA) is exploited to search for the optimal combination of weights and bias of ELM while the binary-valued BSA (BBSA) is exploited as a feature selection method applying on the candidate inputs predefined by partial autocorrelation function (PACF) values to reconstruct the input-matrix. Due to the volatility and randomness of wind speed signal, an optimized variational mode decomposition (OVMD) is employed to eliminate the redundant noises. The parameters of the proposed OVMD are determined according to the center frequencies of the decomposed modes and the residual evaluation index (REI). The wind speed signal is decomposed into a few modes via OVMD. The aggregation of the forecasting results of these modes constructs the final forecasting result of the proposed model. The proposed hybrid model has been applied on the mean half-hour wind speed observation data from two wind farms in Inner Mongolia, China and 10-min wind speed data from the Sotavento Galicia wind farm are studied as an additional case. Parallel experiments have been designed to compare with the proposed model. Results obtained from this study indicate that the

Waste and dust utilisation in shaft furnaces

Energy Technology Data Exchange (ETDEWEB)

Senk, D.; Babich, A.; Gudenau, H.W. [Rhein Westfal TH Aachen, Aachen (Germany)

2005-07-01

Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilised e.g. in agglomeration processes (sintering, pelletising or briquetting) and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverised coal (PC) has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

Deep shaft high rate aerobic digestion: laboratory and pilot plant performance

Energy Technology Data Exchange (ETDEWEB)

Tran, F; Gannon, D

1981-01-01

The Deep Shaft is essentially an air-lift reactor, sunk deep in the ground (100-160 m); the resulting high hydrostatic pressure together with very efficient mixing in the shaft provide extremely high O transfer efficiencies (O.T.E.) of less than or equal to 90% vs. 4-20% in other aerators. This high O.T.E. suggests real potential for Deep-Shaft technology in the aerobic digestion of sludges and animal wastes: with conventional aerobic digesters an O.T.E. over 8% is extremely difficult to achieve. Laboratory and pilot plant Deep-Shaft aerobic digester studies carried out at Eco-Research's Pointe Claire, Quebec laboratories, and at the Paris, Ontario pilot Deep-Shaft digester are described.

Forced sustained swimming exercise at optimal speed enhances growth of juvenile yellowtail kingfish (Seriola lalandi).

Science.gov (United States)

Palstra, Arjan P; Mes, Daan; Kusters, Kasper; Roques, Jonathan A C; Flik, Gert; Kloet, Kees; Blonk, Robbert J W

2014-01-01

Swimming exercise at optimal speed may optimize growth performance of yellowtail kingfish in a recirculating aquaculture system. Therefore, optimal swimming speeds (U opt in m s(-1) or body lengths s(-1), BL s(-1)) were assessed and then applied to determine the effects of long-term forced and sustained swimming at U opt on growth performance of juvenile yellowtail kingfish. U opt was quantified in Blazka-type swim-tunnels for 145, 206, and 311 mm juveniles resulting in values of: (1) 0.70 m s(-1) or 4.83 BL s(-1), (2) 0.82 m s(-1) or 3.25 BL s(-1), and (3) 0.85 m s(-1) or 2.73 BL s(-1). Combined with literature data from larger fish, a relation of U opt (BL s(-1)) = 234.07(BL)(-0.779) (R (2) = 0.9909) was established for this species. Yellowtail kingfish, either forced to perform sustained swimming exercise at an optimal speed of 2.46 BL s(-1) ("swimmers") or allowed to perform spontaneous activity at low water flow ("resters") in a newly designed 3600 L oval flume (with flow created by an impeller driven by an electric motor), were then compared. At the start of the experiment, ten fish were sampled representing the initial condition. After 18 days, swimmers (n = 23) showed a 92% greater increase in BL and 46% greater increase in BW as compared to resters (n = 23). As both groups were fed equal rations, feed conversion ratio (FCR) for swimmers was 1.21 vs. 1.74 for resters. Doppler ultrasound imaging showed a statistically significant higher blood flow (31%) in the ventral aorta of swimmers vs. resters (44 ± 3 vs. 34 ± 3 mL min(-1), respectively, under anesthesia). Thus, growth performance can be rapidly improved by optimal swimming, without larger feed investments.

Anti-wear additive content in fully synthetic PAO and PAG base oils and its effect on electrostatic and tribological phenomena in a rotating shaft-oil-lip seal system

Science.gov (United States)

Gajewski, Juliusz B.; Głogowski, Marek J.

2013-03-01

The paper presents the results of experiments on electrostatic and tribological aspects of different anti-wear additive's contents when an additive is blended with different fully synthetic (poly-α-olefin) and PAG (polyalkylene glycol) base oils in a rotating shaft-oil and oil-lip seal interfacial system. The experimental results are the relationships of electric potential induced in a lip seal's stiffening ring to angular velocity of a rotating metal shaft and to temperature of the oils tested. The braking torque of a shaft is measured with a torquemeter sensor connected directly with a microprocessor-based system for controlling the rotational speed and for measuring the shaft's braking torque and oil temperature. The beneficial and promising results are obtained for PAG when an external DC electric field is applied to the system and the braking torque is then reduced for a certain combination of the base oil and additive's contents. On the basis of the former and present research results an analysis is made to permit one to show how the type of the oils and additives tested can affect both interfaces: rotating shaft-oil and oil-lip of the lip seal and especially the braking torque.

Water striders adjust leg movement speed to optimize takeoff velocity for their morphology

Science.gov (United States)

Yang, Eunjin; Son, Jae Hak; Lee, Sang-Im; Jablonski, Piotr G.; Kim, Ho-Young

2016-12-01

Water striders are water-walking insects that can jump upwards from the water surface. Quick jumps allow striders to avoid sudden dangers such as predators' attacks, and therefore their jumping is expected to be shaped by natural selection for optimal performance. Related species with different morphological constraints could require different jumping mechanics to successfully avoid predation. Here we show that jumping striders tune their leg rotation speed to reach the maximum jumping speed that water surface allows. We find that the leg stroke speeds of water strider species with different leg morphologies correspond to mathematically calculated morphology-specific optima that maximize vertical takeoff velocity by fully exploiting the capillary force of water. These results improve the understanding of correlated evolution between morphology and leg movements in small jumping insects, and provide a theoretical basis to develop biomimetic technology in semi-aquatic environments.

Optimization of Friction Stir Welding Tool Advance Speed via Monte-Carlo Simulation of the Friction Stir Welding Process.

Science.gov (United States)

Fraser, Kirk A; St-Georges, Lyne; Kiss, Laszlo I

2014-04-30

Recognition of the friction stir welding process is growing in the aeronautical and aero-space industries. To make the process more available to the structural fabrication industry (buildings and bridges), being able to model the process to determine the highest speed of advance possible that will not cause unwanted welding defects is desirable. A numerical solution to the transient two-dimensional heat diffusion equation for the friction stir welding process is presented. A non-linear heat generation term based on an arbitrary piecewise linear model of friction as a function of temperature is used. The solution is used to solve for the temperature distribution in the Al 6061-T6 work pieces. The finite difference solution of the non-linear problem is used to perform a Monte-Carlo simulation (MCS). A polynomial response surface (maximum welding temperature as a function of advancing and rotational speed) is constructed from the MCS results. The response surface is used to determine the optimum tool speed of advance and rotational speed. The exterior penalty method is used to find the highest speed of advance and the associated rotational speed of the tool for the FSW process considered. We show that good agreement with experimental optimization work is possible with this simplified model. Using our approach an optimal weld pitch of 0.52 mm/rev is obtained for 3.18 mm thick AA6061-T6 plate. Our method provides an estimate of the optimal welding parameters in less than 30 min of calculation time.

Analysis and Speed Ripple Mitigation of a Space Vector Pulse Width Modulation-Based Permanent Magnet Synchronous Motor with a Particle Swarm Optimization Algorithm

Directory of Open Access Journals (Sweden)

Xing Liu

2016-11-01

Full Text Available A method is proposed for reducing speed ripple of permanent magnet synchronous motors (PMSMs controlled by space vector pulse width modulation (SVPWM. A flux graph and mathematics are used to analyze the speed ripple characteristics of the PMSM. Analysis indicates that the 6P (P refers to pole pairs of the PMSM time harmonic of rotor mechanical speed is the main harmonic component in the SVPWM control PMSM system. To reduce PMSM speed ripple, harmonics are superposed on a SVPWM reference signal. A particle swarm optimization (PSO algorithm is proposed to determine the optimal phase and multiplier coefficient of the superposed harmonics. The results of a Fourier decomposition and an optimized simulation model verified the accuracy of the analysis as well as the effectiveness of the speed ripple reduction methods, respectively.

Reactor coolant pump shaft seal stability during station blackout

International Nuclear Information System (INIS)

Rhodes, D.B.; Hill, R.C.; Wensel, R.G.

1987-05-01

Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries

Reactor coolant pump shaft seal stability during station blackout

Energy Technology Data Exchange (ETDEWEB)

Rhodes, D B; Hill, R C; Wensel, R G

1987-05-01

Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries.

Gear-shaft linkage, especially for nuclear reactor coolant pumps

International Nuclear Information System (INIS)

Delaunois, T.; Lefevre, R.

1990-01-01

The pump comprises: - inlet and outlet channels for the pumped fluid - a rotating shaft - a gear wheel mounted on the shaft by an axial locking nut which can support the axial hydraulic force - a thermal barrier above the gear wheel. A hydrostatic bearing fitted to the exterior surround of the gear wheel, the gear shaft linkage is made by at least a centering and locating device having a cylindrical span and an axial stop and another independent device which can take up the torque [fr

Classical Measurement Methods and Laser Scanning Usage in Shaft Hoist Assembly Inventory

Science.gov (United States)

Jaśkowski, Wojciech; Lipecki, Tomasz; Matwij, Wojciech; Jabłoński, Mateusz

2018-03-01

The shaft hoist assembly is the base of underground mining plant. Its efficiency and correct operation is subject to restrictive legal regulations and is controlled on a daily visual assessment by shaft crew and energomechanics. In addition, in the regular interval, the shaft hoist assembly is subject to a thorough inventory, which includes the determination of the geometrical relationships between the hoisting machine, the headframe and the shaft with its housing. Inventory measurements for shaft and headframe are used for years of conventional geodetic methods including mechanical or laser plumbing and tachymetric surveys. Additional precision levelling is also used for measuring shafts of hoisting machines and rope pulleys. Continuous modernization of measuring technology makes it possible to implement the further methods to the above mentioned purposes. The comparison of the accuracy and the economics of performing measurements based on many years of experience with comprehensive inventory of shaft hoist assembly using various research techniques was made and detailed in the article.

Classical Measurement Methods and Laser Scanning Usage in Shaft Hoist Assembly Inventory

Directory of Open Access Journals (Sweden)

Jaśkowski Wojciech

2018-01-01

Full Text Available The shaft hoist assembly is the base of underground mining plant. Its efficiency and correct operation is subject to restrictive legal regulations and is controlled on a daily visual assessment by shaft crew and energomechanics. In addition, in the regular interval, the shaft hoist assembly is subject to a thorough inventory, which includes the determination of the geometrical relationships between the hoisting machine, the headframe and the shaft with its housing. Inventory measurements for shaft and headframe are used for years of conventional geodetic methods including mechanical or laser plumbing and tachymetric surveys. Additional precision levelling is also used for measuring shafts of hoisting machines and rope pulleys. Continuous modernization of measuring technology makes it possible to implement the further methods to the above mentioned purposes. The comparison of the accuracy and the economics of performing measurements based on many years of experience with comprehensive inventory of shaft hoist assembly using various research techniques was made and detailed in the article.

Measuring Torque and Temperature in a Rotating Shaft Using Commercial SAW Sensors.

Science.gov (United States)

Silva, Diogo; Mendes, Joana C; Pereira, António B; Gégot, François; Alves, Luís N

2017-07-02

Real-time monitoring of torque in a rotating shaft is not easy to implement with technologies such as optic fiber sensors or strain gages. Surface acoustic wave (SAW) sensors are wireless and passive and can be used to monitor strain in moving parts. Commercial solutions (sensors, antennas and interrogation unit) can easily be purchased from some companies; however, they are not customized and may not meet the specificity of the measurements. In order to evaluate the adequacy of commercial off-the-shelf (COTS) solutions, temperature and strain sensors fabricated by SENSeOR (Besançon, France) were mounted on a load cell. The sensors were calibrated using a thermal chamber and a universal testing machine. The load cell was then assembled together with a steel shaft that rotated at different speeds inside an oven. The commercial antennas were replaced with an RF (radio frequency) coupler and the sensors were interrogated with the commercial interrogation unit. The influence of rotation in the accuracy on the measurements, as well as the adequacy of the sensors structure, was evaluated. It can be concluded that SAW sensors can be used to measure temperature or torque in a rotating environment; however, some customization of the components is required in order to overcome the limitations posed by COTS sensing solutions.

Technical report on prototype intelligent network flow optimization (INFLO) dynamic speed harmonization and queue warning.

Science.gov (United States)

2015-06-01

This Technical Report on Prototype Intelligent Network Flow Optimization (INFLO) Dynamic Speed Harmonization and : Queue Warning is the final report for the project. It describes the prototyping, acceptance testing and small-scale : demonstration of ...

Structural Design Optimization of Doubly-Fed Induction Generators Using GeneratorSE

Energy Technology Data Exchange (ETDEWEB)

Sethuraman, Latha [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Fingersh, Lee J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Arthurs, Claire [Georgia Institute of Technology

2017-11-13

A wind turbine with a larger rotor swept area can generate more electricity, however, this increases costs disproportionately for manufacturing, transportation, and installation. This poster presents analytical models for optimizing doubly-fed induction generators (DFIGs), with the objective of reducing the costs and mass of wind turbine drivetrains. The structural design for the induction machine includes models for the casing, stator, rotor, and high-speed shaft developed within the DFIG module in the National Renewable Energy Laboratory's wind turbine sizing tool, GeneratorSE. The mechanical integrity of the machine is verified by examining stresses, structural deflections, and modal properties. The optimization results are then validated using finite element analysis (FEA). The results suggest that our analytical model correlates with the FEA in some areas, such as radial deflection, differing by less than 20 percent. But the analytical model requires further development for axial deflections, torsional deflections, and stress calculations.

Method of lining a vertical mine shaft with concrete

Science.gov (United States)

Eklund, James D.; Halter, Joseph M.; Rasmussen, Donald E.; Sullivan, Robert G.; Moffat, Robert B.

1981-01-01

The apparatus includes a cylindrical retainer form spaced inwardly of the wall of the shaft by the desired thickness of the liner to be poured and having overlapping edges which seal against concrete flow but permit the form to be contracted to a smaller circumference after the liner has hardened and is self-supporting. A curb ring extends downwardly and outwardly toward the shaft wall from the bottom of the retainer form to define the bottom surface of each poured liner section. An inflatable toroid forms a seal between the curb ring and the shaft wall. A form support gripper ring having gripper shoes laterally extendable under hydraulic power to engage the shaft wall supports the retainer form, curb ring and liner until the newly poured liner section becomes self-supporting. Adjusting hydraulic cylinders permit the curb ring and retainer form to be properly aligned relative to the form support gripper ring. After a liner section is self-supporting, an advancing system advances the retainer form, curb ring and form support gripper ring toward a shaft boring machine above which the liner is being formed. The advancing system also provides correct horizontal alignment of the form support gripper ring.

Exploratory shaft conceptual design report: Permian Basin

International Nuclear Information System (INIS)

1983-07-01

This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Permian Basin locatd in the western part of Texas. Conceptualized designs for other possible locations (Paradox Basin in Utah and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

Exploratory shaft conceptual design report: Paradox Basin

International Nuclear Information System (INIS)

1983-07-01

This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Paradox Basin located in the southeastern part of Utah. Conceptualized designs for other possible locations (Permian Basin in Texas and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in-situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

10 CFR 60.134 - Design of seals for shafts and boreholes.

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Design of seals for shafts and boreholes. 60.134 Section....134 Design of seals for shafts and boreholes. (a) General design criterion. Seals for shafts and... closure. (b) Selection of materials and placement methods. Materials and placement methods for seals shall...

Improvement of the Torque-Speed Performance and Drive Efficiency in an SRM Using an Optimal Torque Sharing Function

Directory of Open Access Journals (Sweden)

Wei Ye

2018-05-01

Full Text Available In this paper, by evaluating the extreme value of the qth-power current, a torque sharing function (TSF family for reducing the torque ripples in the switched reluctance motor (SRM is proposed. The optimization criteria of the TSF has two secondary objectives, including the maximization of the torque-speed range and the minimization of copper loss. The evaluation indices in terms of the peak phase current, the rms (root mean square phase current, and the torque ripple factor are compared between the proposed TSF family and four conventional TSFs including linear, sinusoidal, exponential, and cubic TSFs. An optimization objective function that combines the maximum absolute value of the rate-of-change of the flux linkage (MAV-RCFL and the qth-power of current is proposed and a weighting factor is used to balance the influence of the two optimization objectives. An optimal TSF can be easily obtained by solving the optimization problem from the TSF family. The proposed TSF is validated by using simulations and experiments with a three-phase 6/4 SRM with 7.5 kW, 3000 rpm, and 270 V DC-link voltage. The dynamic simulation model is implemented in Matlab/Simulink. The results demonstrate the validity and superiority of the proposed control method; the optimal TSF provides better torque-speed performance, and a better reduction in copper loss and torque ripples at high speed, as compared to conventional TSFs.

Proposed design procedure for transmission shafting under fatigue loading

Science.gov (United States)

Loewenthal, S. H.

1978-01-01

The B106 American National Standards Committee is currently preparing a new standard for the design of transmission shafting. A design procedure, proposed for use in the new standard, for computing the diameter of rotating solid steel shafts under combined cyclic bending and steady torsion is presented. The formula is based on an elliptical variation of endurance strength with torque exhibited by combined stress fatigue data. Fatigue factors are cited to correct specimen bending endurance strength data for use in the shaft formula. A design example illustrates how the method is to be applied.

Device for selectively securing an object to a shaft

International Nuclear Information System (INIS)

Calizano, F.; Chauvel, M.

1984-01-01

A magnetic tape reel is secured to a reel drive motor shaft by a device including a hub secured to the shaft, a plurality of shoes, and actuating means for thrusting the shoes against the reel and for releasing them from contact with the reel. The securing device includes a cam mounted on the shaft in combination with a locking device including the cam periphery. The locking device thrusts the shoes against the object and is operated by rotation of the motor. The cam is immobilized in rotation while the shoes are locked

Air intake shaft performance tests (Shaft 5): In situ data report (May 1988--July 1995). Waste Isolation Pilot Plant (WIPP) Thermal/Structural Interactions Program

International Nuclear Information System (INIS)

Munson, D.E.; Baird, G.T.; Jones, R.L.

1995-07-01

Data are presented from the Air Intake Shaft Test, an in situ test fielded at the Waste Isolation Pilot Plant (WIPP). The construction of this shaft, well after the initial three access shafts, presented an unusual opportunity to obtain valuable detailed data on the mechanical response of a shaft for application to seal design. These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. Construction of the test began in December 1987; gage data in this report cover the period from May 1988 through July 1995, with the bulk of the data obtained after obtaining access in November, 1989 and from the heavily instrumented period after remote gage installation between May, 1990, and October, 1991

Air intake shaft performance tests (Shaft 5): In situ data report (May 1988--July 1995). Waste Isolation Pilot Plant (WIPP) Thermal/Structural Interactions Program

Energy Technology Data Exchange (ETDEWEB)

Munson, D.E. [Sandia National Labs., Albuquerque, NM (United States). Repository Isolation Systems Dept.; Hoag, D.L.; Ball, J.R. [RE/SPEC Inc., Albuquerque, NM (United States); Baird, G.T.; Jones, R.L. [Tech Reps, Inc., Albuquerque, NM (United States)

1995-07-01

Data are presented from the Air Intake Shaft Test, an in situ test fielded at the Waste Isolation Pilot Plant (WIPP). The construction of this shaft, well after the initial three access shafts, presented an unusual opportunity to obtain valuable detailed data on the mechanical response of a shaft for application to seal design. These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. Construction of the test began in December 1987; gage data in this report cover the period from May 1988 through July 1995, with the bulk of the data obtained after obtaining access in November, 1989 and from the heavily instrumented period after remote gage installation between May, 1990, and October, 1991.

Indirect sensorless speed control of a PMSG for wind application

DEFF Research Database (Denmark)

Diaz, S.A.; Silva, C.; Juliet, J.

2009-01-01

the method usually referred in the literature as indirect speed control (ISC). The principle of this method is the regulation of the generator torque as function of rotor speed such that the steady state operation is at the MPPT. This strategy normally requires the knowledge of the shaft speed to determinate...... in the whole wind generator system a sensorless scheme is proposed, thereby avoiding problems of electromagnetic interferences and failures in the position sensor. Usually, in wind drive system, the generator is not operated a very low speeds, therefore problems related to low back-emf for flux estimation...... the reference torque and rotor position for the orientation of the vector torque control of the PMSG. To achieve both, speed and position estimation, the sensorless technique based in back-emf estimation is proposed. Also in this paper, a laboratory set-up is described. The experimental bench is composed...

Optimization of spacing between explosion holes in advancing shafts of uranium mine in Saghand

International Nuclear Information System (INIS)

Nikgoftar, M. R.; Bahrami, A.; Shoja, A.

2004-01-01

Uranium mine in Saghand area can be mined and exploited using different underground methods. In order to achieve this goal, two vertical shafts each 350 m in length were sunk and equipped. In this article two methods which have been applied by Russian and China experts will be explained and then they will be compared with each other. Based on the advantages and disadvantages of the applied methods, a third method has been derived from their comparisons. This last method was found to have many advantages and was accepted as an selected method for the Saghand uranium exploitation

Simultaneous Optimization of Container Ship Sailing Speed and Container Routing with Transit Time Restrictions

DEFF Research Database (Denmark)

Karsten, Christian Vad; Røpke, Stefan; Pisinger, David

We introduce a decision support tool for liner shipping companies to optimally determine the sailing speed and needed fleet for a global network. As a novelty we incorporate cargo routing decisions with tight transit time restrictions on each container such that we get a realistic picture...

Optimization of advanced liquid natural gas-fuelled machineries for a high-speed ferry

DEFF Research Database (Denmark)

Tveitaskog, Kari Anne; Haglind, Fredrik

-based optimization routine are used. The top cycle is modeled as the aero-derivative gas turbine LM2500, while the following five options for bottoming cycles are modeled: ∙ Single pressure steam cycle ∙ Dual-pressure steam cycle ∙ ORC using Toluene as the working fluid with an intermediate oil loop ∙ ABC with inter......This report is aimed at designing and optimizing combined cycles in order to define the most suitable machinery system for the future high-speed Incat ferry operated by Mols-Linien. For this purpose, an in-house numerical simulation tool called DNA (Dynamic Network Analysis) and a genetic algorithm...

Adaptive sensorless field oriented control of PM motors including zero speed

DEFF Research Database (Denmark)

Rasmussen, Henrik; Vadstrup, P.; Børsting, H.

2004-01-01

This paper presents a simple control method for controlling permanent magnet synchronous motors (PMSM) in a wide speed range without a shaft sensor. An adaptive observer is used for estimation of the rotor position and speed of a permanent magnet synchronous motors (PMSM). The observer compensates...... for voltage offsets and permanent magnet strength variations. The adaption structure for estimating the strength of the permanent magnet is determined from a Lyapunov stability proof. The control method is made robust at zero and low speed by changing the direct vector current component to a value different...... from zero. In order to verify the applicability of the method the controller has been implemented and tested on a 800 W motor....

Experiences with the operation of a shaft-helix in connection with a special steel ring lining in the shafts Gorleben 1 and 2

International Nuclear Information System (INIS)

Tonscheidt, H.W.; Kahl, J.

1991-01-01

When sinking the Gorleben 1 shaft good reasons prevented the method of drilling and blasting to create the excavation. Considering the special conditions and after a successful test, the application of a modified helix was given preference to an impact-ripper, tested on an other freeze shaft project. A report is given on the experiences gained with respect to the following criteria: Assembly, dismantling and transport of the machine in the shaft - conveyance of electric energy - dust problems when cutting the concrete plug and the means engaged to overcome those problems - performance in the different types of rock formation - cutting the circular shape of the excavation with sufficient accuracy - matters of safety in connection with cutting, loading and lining the excavation - consumption and costs of cutters - total costs. A final assessment of the excavation system is made with respect to its possible application with for shaft-sinking projects. (orig.) [de

Grey Wolf based control for speed ripple reduction at low speed operation of PMSM drives.

Science.gov (United States)

Djerioui, Ali; Houari, Azeddine; Ait-Ahmed, Mourad; Benkhoris, Mohamed-Fouad; Chouder, Aissa; Machmoum, Mohamed

2018-03-01

Speed ripple at low speed-high torque operation of Permanent Magnet Synchronous Machine (PMSM) drives is considered as one of the major issues to be treated. The presented work proposes an efficient PMSM speed controller based on Grey Wolf (GW) algorithm to ensure a high-performance control for speed ripple reduction at low speed operation. The main idea of the proposed control algorithm is to propose a specific objective function in order to incorporate the advantage of fast optimization process of the GW optimizer. The role of GW optimizer is to find the optimal input controls that satisfy the speed tracking requirements. The synthesis methodology of the proposed control algorithm is detailed and the feasibility and performances of the proposed speed controller is confirmed by simulation and experimental results. The GW algorithm is a model-free controller and the parameters of its objective function are easy to be tuned. The GW controller is compared to PI one on real test bench. Then, the superiority of the first algorithm is highlighted. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Applying Data Clustering Feature to Speed Up Ant Colony Optimization

Directory of Open Access Journals (Sweden)

Chao-Yang Pang

2014-01-01

Full Text Available Ant colony optimization (ACO is often used to solve optimization problems, such as traveling salesman problem (TSP. When it is applied to TSP, its runtime is proportional to the squared size of problem N so as to look less efficient. The following statistical feature is observed during the authors’ long-term gene data analysis using ACO: when the data size N becomes big, local clustering appears frequently. That is, some data cluster tightly in a small area and form a class, and the correlation between different classes is weak. And this feature makes the idea of divide and rule feasible for the estimate of solution of TSP. In this paper an improved ACO algorithm is presented, which firstly divided all data into local clusters and calculated small TSP routes and then assembled a big TSP route with them. Simulation shows that the presented method improves the running speed of ACO by 200 factors under the condition that data set holds feature of local clustering.

Influence of rotational speed on the cyclic fatigue of rotary nickel-titanium endodontic instruments.

Science.gov (United States)

Lopes, Hélio P; Ferreira, Alessandra A P; Elias, Carlos N; Moreira, Edson J L; de Oliveira, Júlio C Machado; Siqueira, José F

2009-07-01

During the preparation of curved canals, rotary nickel-titanium (NiTi) instruments are subjected to cyclic fatigue, which can lead to instrument fracture. Although several factors may influence the cyclic fatigue resistance of instruments, the role of the rotational speed remains uncertain. This study was intended to evaluate the effects of rotational speed on the number of cycles to fracture of rotary NiTi instruments. ProTaper Universal instruments F3 and F4 (Maillefer SA, Ballaigues, Switzerland) were used in an artificial curved canal under rotational speeds of 300 rpm or 600 rpm. The artificial canal was made of stainless steel, with an inner diameter of 1.5 mm, total length of 20 mm, and arc at the end with a curvature radius of 6 mm. The arc length was 9.4 mm and 10.6 mm on the straight part. The number of cycles required to fracture was recorded. Fractured surfaces and the helical shafts of the fractured instruments were analyzed by scanning electron microscopy. The results showed approximately a 30% reduction in the observed number of cycles to fracture as rotational speed was increased from 300 to 600 RPM (p ductile type, and no plastic deformation was observed on the helical shaft of fractured instruments. The present findings for both F3 and F4 ProTaper instruments revealed that the increase in rotational speed significantly reduced the number of cycles to fracture.

Fractures of the shafts of the tibia and fibula

International Nuclear Information System (INIS)

Bender, C.E.; Campbell, D.C.

1985-01-01

Fractures of the shafts of the tibia and fibula are the most common long bone fractures. This chapter discusses tibial and fibular shaft fractures. Treatment of tibial and fibular fractures is similar and, therefore, reference is primarily made to the tibia. Diagnostic techniques are also evaluated

Controlled blasting and its implications for the NNWSI project exploratory shaft

International Nuclear Information System (INIS)

Van Eeckhout, E.M.

1987-09-01

This report reviews controlled blasting techniques for shaft sinking. Presplitting and smooth blasting are the techniques of principal interest. Smooth blasting is preferred for the Nevada Nuclear Waste Storage Investigations exploratory shaft. Shaft damage can be monitored visually or by peak velocity measurements and refractive techniques. Damage into the rock should be limited to 3 ft. 40 refs., 22 figs., 7 tabs

Speed controller for an alternating - current motor

International Nuclear Information System (INIS)

Bolie, V.W.

1984-01-01

A controller for a multi-phase ac motor that is subject to a large inertial load, e.g. an induction motor driving a heavy spinning rotor of a neutron chopper that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal Esub(L) having a meandering line frequency, includes a sensor which provides a feedback pulse train representative of the actual speed of the motor which is compared (by counting clock pulses between feedback pulses) with a reference clock signal in a computing unit to provide a motor control signal Esub(c). The motor control signal is a weighted linear sum of a speed error signal, a phase error signal, and a drift error signal, the magnitudes of which are recalculated and updated with each revolution of the motor shaft. The speed error signal is constant for large speed errors but highly sensitive to small speed errors. The stator windings of the motor are driven by variable-frequency power amplifiers which are controlled by the motor control signal Esub(c) via PROMs which store digital representations of sine and cosine waveforms in quadrature. (author)

Design capability of CANDU heat transport pump shafts against cracking

International Nuclear Information System (INIS)

Kumar, A.N.; Sheikh, Z.B.; Padgett, A.

1993-01-01

During 1986 three different Light Water Reactors (LWR's) in the U.S. reported either a cracked or fractured shaft on one or more of their reactor coolant (RC) pumps. The RC pumps for all these stations were supplied by Byron Jackson (BJ) Pump Company. A majority of CANDU heat transport (HT) pumps (equivalent of RC pumps) are supplied by BJ Pump Company and are similar in design to RC pumps. Hence the failure of these RC pumps in the U.S. utilities caused concern regarding the relevance of these failures to the BJ supplied CANDU HT pumps (HTP). This paper presents the results of AECL assessment to establish the capability of the HT pump shaft against cracking. Two methods were used for assessment: (a) detailed comparative design review of the HTP and RCP shafts; (b) semi-empirical analysis of the HTP shafts. The results of the AECL assessment showed significant differences in detailed design, materials, assembly and fits of various components and the control of operating parameters between the HT and RC pumps. It was concluded that because of these differences the failures similar to RC pump shafts are not likely to appear in HT pump shafts. This conclusion is further reinforced by about 140,000 hours of operating history of the longest running HT pump of comparable size to RC Pumps, without failures

Shaft Crack Identification Based on Vibration and AE Signals

Directory of Open Access Journals (Sweden)

Wenxiu Lu

2011-01-01

Full Text Available The shaft crack is one of the main serious malfunctions that often occur in rotating machinery. However, it is difficult to locate the crack and determine the depth of the crack. In this paper, the acoustic emission (AE signal and vibration response are used to diagnose the crack. The wavelet transform is applied to AE signal to decompose into a series of time-domain signals, each of which covers a specific octave frequency band. Then an improved union method based on threshold and cross-correlation method is applied to detect the location of the shaft crack. The finite element method is used to build the model of the cracked rotor, and the crack depth is identified by comparing the vibration response of experiment and simulation. The experimental results show that the AE signal is effective and convenient to locate the shaft crack, and the vibration signal is feasible to determine the depth of shaft crack.

Forced sustained swimming exercise at optimal speed enhances growth of juvenile yellowtail kingfish (Seriola lalandi

Directory of Open Access Journals (Sweden)

Arjan P. Palstra

2015-01-01

Full Text Available Swimming exercise at optimal speed may optimize growth performance of yellowtail kingfish in a recirculating aquaculture system. Therefore, optimal swimming speeds (Uopt in m s-1 or body lengths s-1, BL s-1 were assessed and then applied to determine the effects of long-term forced and sustained swimming at Uopt on growth performance of juvenile yellowtail kingfish. Uopt was quantified in Blazka-type swim-tunnels for 145 mm, 206 mm and 311 mm juveniles resulting in values of: 1 0.70 m s-1 or 4.83 BL s-1, 2 0.82 m s-1 or 3.25 BL s-1 and 3 0.85 m s-1 or 2.73 BL s-1. Combined with literature data from larger fish, a relation of Uopt (BL s-1 = 234.07(BL-0.779 (R2= 0.9909 was established for this species. Yellowtail kingfish, either forced to perform sustained swimming exercise at an optimal speed of 2.46 BL s-1 (‘swimmers’ or allowed to perform spontaneous activity at low water flow (‘resters’ in a newly designed 3,600 L oval flume (with flow created by an impeller driven by an electric motor, were then compared. At the start of the experiment, ten fish were sampled representing the initial condition. After 18 days, swimmers (n= 23 showed a 92% greater increase in BL and 46% greater increase in BW as compared to resters (n= 23. As both groups were fed equal rations, feed conversion ratio (FCR for swimmers was 1.21 vs. 1.74 for resters. Doppler ultrasound imaging showed a statistically significant higher blood flow (31% in the ventral aorta of swimmers vs. resters (44 ± 3 mL min-1 vs. 34 ± 3 mL min-1, respectively, under anesthesia. Thus growth performance can be rapidly improved by optimal swimming, without larger feed investments.

Application of hydraulically assembled shaft coupling hubs to large agitators

International Nuclear Information System (INIS)

Murray, W.E.; Anderson, T.D.; Bethmann, H.K.

1991-01-01

This paper describes the basis for and implementation of hydraulically assembled shaft coupling hubs for large tank-mounted agitators. This modification to the original design was intended to minimize maintenance personnel exposure to ionizing radiation and also provide for disassembly capability without damage to shafts or hubs. In addition to realizing these objectives, test confirmed that the modified couplings reduced agitator shaft end runouts approximately 65%, thereby reducing bearing loads and increasing service life, a significant enhancement for a nuclear facility. 5 refs

Natural Ventilation of Buildings through Light Shafts. Design-Based Solution Proposals

Science.gov (United States)

Ángel Padilla-Marcos, Miguel; Meiss, Alberto; Feijó-Muñoz, Jesús

2017-10-01

This work analyses how the built environment affects the quality of the air to be introduced into buildings from light shafts. Several factors such as urban environment and building design intervene in the ability of the light shaft to produce its air change process. Urban areas continuously pollute the air in cities which affects the human health and the environment sustainability. Poor air quality outside buildings supposes a big energy waste to promote an acceptable air quality inside buildings. That requires a large flow rate to maintain the indoor air quality which is translated to an energy efficiency term. The main objective focuses on the impact of standardized architecture design in the quality of the indoor air dependent on the air change in the light shaft. The air change capacity of the outdoor space is numbered analysed using the concept of air change efficiency (ACE). ACE is determined by the built environment, the wind conditions and the design of the building containing light shafts. This concept is comparatively evaluated inside a control domain virtually defined to obtain the mean age of the air for a known air volume. The longer the light shaft in the wind direction is, the better the ACE is compared with other options. Light shafts up to 12 metres high are the most suitable in order to obtain acceptable efficiency results. Other studied cases verify that assumption. Different simplified tools for the technicians to evaluate the design of buildings containing light shafts are proposed. Some strategies of architectural design of buildings with light shafts to be used for ventilation are presented.

Development and Simulation of a Type of Four-Shaft ECVT for a Hybrid Electric Vehicle

Directory of Open Access Journals (Sweden)

Yong Zhang

2016-02-01

Full Text Available In hybrid electric vehicles with power-split configurations, the engine can be decoupled from the wheel and operated with improved fuel economy, while the entire efficiency of the powertrain is affected by the circular electric power flow. Two planetary gear (2-PG sets with adding brakes/clutches, namely a type of four shaft elelctric continuously variable transmission (ECVT can provide multi-mode operation for the powertrain and extend the efficient area. First, a conventional 2-PG AT (Automatic Transmission architecture is investigated. By analyzing and comparing the connection and operating modes based on the kinematic relationship and lever analogy, a feasible four-shaft ECVT architecture with two brakes and two simplified versions are picked. To make a trade-off between fuel economy and configuration complexity, an instantaneous optimal control strategy based on the equivalent consumption minimization strategy (ECMS concept is then developed and employed as the unified optimization method in the simulations of three different configurations. Finally, the simulation results show that the simplified versions are suboptimal sets and the fuel economy is sacrificed by the limits of different modes. From the viewpoint of concept design, a multi-mode power-split configuration is more suitable for hybrid electric vehicles. This research applied a systematic methodology from concept design to energy management optimization, which can provide the guidelines for researchers to select a suitable multi-mode power-split hybrid powertrain.

46 CFR 171.100 - Shaft tunnels and stern tubes.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Shaft tunnels and stern tubes. 171.100 Section 171.100... PERTAINING TO VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.100 Shaft tunnels and... passengers on an international voyage. (b) The watertight seal in the bulkhead between the stern tube space...

Percutaneous Kirschner wire (K-wire) fixation for humerus shaft ...

African Journals Online (AJOL)

Background: Fractures of the humeral shaft are uncommon, representing less than 10 percent of all fractures in children. Humeral shaft fractures in children can be treated by immobilisation alone. A small number of fractures are unable to be reduced adequately or maintained in adequate alignment, and these should be ...

Walking, running, and resting under time, distance, and average speed constraints: optimality of walk–run–rest mixtures

Science.gov (United States)

Long, Leroy L.; Srinivasan, Manoj

2013-01-01

On a treadmill, humans switch from walking to running beyond a characteristic transition speed. Here, we study human choice between walking and running in a more ecological (non-treadmill) setting. We asked subjects to travel a given distance overground in a given allowed time duration. During this task, the subjects carried, and could look at, a stopwatch that counted down to zero. As expected, if the total time available were large, humans walk the whole distance. If the time available were small, humans mostly run. For an intermediate total time, humans often use a mixture of walking at a slow speed and running at a higher speed. With analytical and computational optimization, we show that using a walk–run mixture at intermediate speeds and a walk–rest mixture at the lowest average speeds is predicted by metabolic energy minimization, even with costs for transients—a consequence of non-convex energy curves. Thus, sometimes, steady locomotion may not be energy optimal, and not preferred, even in the absence of fatigue. Assuming similar non-convex energy curves, we conjecture that similar walk–run mixtures may be energetically beneficial to children following a parent and animals on long leashes. Humans and other animals might also benefit energetically from alternating between moving forward and standing still on a slow and sufficiently long treadmill. PMID:23365192

Walking, running, and resting under time, distance, and average speed constraints: optimality of walk-run-rest mixtures.

Science.gov (United States)

Long, Leroy L; Srinivasan, Manoj

2013-04-06

On a treadmill, humans switch from walking to running beyond a characteristic transition speed. Here, we study human choice between walking and running in a more ecological (non-treadmill) setting. We asked subjects to travel a given distance overground in a given allowed time duration. During this task, the subjects carried, and could look at, a stopwatch that counted down to zero. As expected, if the total time available were large, humans walk the whole distance. If the time available were small, humans mostly run. For an intermediate total time, humans often use a mixture of walking at a slow speed and running at a higher speed. With analytical and computational optimization, we show that using a walk-run mixture at intermediate speeds and a walk-rest mixture at the lowest average speeds is predicted by metabolic energy minimization, even with costs for transients-a consequence of non-convex energy curves. Thus, sometimes, steady locomotion may not be energy optimal, and not preferred, even in the absence of fatigue. Assuming similar non-convex energy curves, we conjecture that similar walk-run mixtures may be energetically beneficial to children following a parent and animals on long leashes. Humans and other animals might also benefit energetically from alternating between moving forward and standing still on a slow and sufficiently long treadmill.

Overview of Variable-Speed Power-Turbine Research

Science.gov (United States)

Welch, Gerard E.

2011-01-01

The vertical take-off and landing (VTOL) and high-speed cruise capability of the NASA Large Civil Tilt-Rotor (LCTR) notional vehicle is envisaged to enable increased throughput in the national airspace. A key challenge of the LCTR is the requirement to vary the main rotor speeds from 100% at take-off to near 50% at cruise as required to minimize mission fuel burn. The variable-speed power-turbine (VSPT), driving a fixed gear-ratio transmission, provides one approach for effecting this wide speed variation. The key aerodynamic and rotordynamic challenges of the VSPT were described in the FAP Conference presentation. The challenges include maintaining high turbine efficiency at high work factor, wide (60 deg.) of incidence variation in all blade rows due to the speed variation, and operation at low Reynolds numbers (with transitional flow). The PT -shaft of the VSPT must be designed for safe operation in the wide speed range required, and therefore poses challenges associated with rotordynamics. The technical challenges drive research activities underway at NASA. An overview of the NASA SRW VSPT research activities was provided. These activities included conceptual and preliminary aero and mechanical (rotordynamics) design of the VSPT for the LCTR application, experimental and computational research supporting the development of incidence tolerant blading, and steps toward component-level testing of a variable-speed power-turbine of relevance to the LCTR application.

New Technical Solution for Vertical Shaft Equipping Using Steel Headframe of Multifunction Purpose

Science.gov (United States)

Kassikhina, Elena; Pershin, Vladimir; Glazkov, Yurij

2017-11-01

The article reviews a novel approach to the design of steel angle headframe for vertical shafts of coal and ore mines on the basis of rational design solutions. Practice of construction of coal and ore mines provides application of various designs for steel angle headframes which are divided into separate large assembly blocks and constructive elements during assembling operations. Design of these blocks and elements, their weight and dimensions effect the chose of the method of assembling on which economic and technological indicators, as well as duration of down-time, depend on during performance of construction operations in shaft. The technical solution on equipment provision for mine vertical shaft using headframe of multifunctional purpose will allow changing the management construction of vertical shaft. The constructive design of the headgear allows application of the effective method of assembly and thus to provide improvement of the technical and economic indexes, and high calendar time rate of the shaft construction due to reduction of duration of works on equipment provision for the shaft and to refurbishment of the shaft in order to carry out horizontal mining.

A field trail for sealing abandoned mine shafts and adits with lightweight concrete

International Nuclear Information System (INIS)

Skinner, E.H.; Beckett, L.A.

1994-01-01

An abandoned mine shaft near Omar, in Logan County, WV, was permanently sealed through a cooperative agreement between the West Virginia Department of Commerce, Labor, and Environmental Resources, Division of Environmental Protection, and the US Bureau of Mines (USBM), Abandoned Mine Lands (AML) Program. An engineered shaft seal design was developed and demonstrated that featured lightweight concrete as a key material component at a wet density of about 45 lb/ft 3 . A reinforced concrete cap designed for 5 psi live load was placed over the shaft seal. Applicable new concrete technologies relating to a 100-yr design life were utilized to assure future integrity of the shaft seal. Waterproofing methods were included in the shaft seal design to provide protection from ambient moisture and corrosive mine waters and to increase the long-term durability of the shaft seal. All construction methods used in the field trial are fully adaptable for the mine-reclamation contractor. The USBM research objectives were to develop a broad generic design that will be widely applicable to other adit-sealing and shaft-sealing problems throughout the mining industry

ESF [Exploratory Shaft Facility] impact evaluation report: Volume 1, Final report

International Nuclear Information System (INIS)

1985-08-01

This report assesses the impacts of integrating an Exploratory Shaft Facility (ESF) with a high-level nuclear waste repository in salt. A general repository subsurface design is described which complies with the Mine Safety and Health Administration regulations for gassy metal and non-metal mines. This design is combined with the ESF into a site-specific subsurface layout with associated shafts and surface facilities for each of seven sites. An evaluation to identify integration impacts is described for two specific ESF configurations (Cases 1 and 2) for each of the seven sites. These configurations are an ESF which uses two of the full size repository shafts, and an ESF with one 10-ft and one 22-ft diameter shaft. An evaluation of an ESF configuration (Case 3) with two 12-ft diameter shafts at three of the seven sites is also described. These sites are Deaf Smith, Davis Canyon, and Richton Dome. A fourth evaluation (Case 4) for the Deaf Smith site only, addresses a ''fast track'' subsurface development plan to allow waste emplacement by 1998. A fifth evaluation (Case 5), provides site-specific ES locations, for the three sites included in Case 3, which are supportive of a shaft siting study prepared by ONWI

Waste Handling Shaft concrete liner degradation conclusions and recommendations

International Nuclear Information System (INIS)

1992-10-01

The primary function of the Waste Handling Shaft (WHS) at the Waste Isolation Pilot Plant (WIPP) is to permit the transfer of radioactive waste from the surface waste handling building to the underground storage area. It also serves as an intake shaft for small volumes of air during normal storage operations and as an emergency escape route. Part of the construction was the placement of a concrete liner and steel reinforced key in 1984. During a routine shaft inspection in May 1990, some degradation of the WHS concrete liner was observed between the depths of 800 and 900 feet below the ground surface. Detailed investigations of the liner had been carried out by Sandia National Laboratories and by Westinghouse Electric Corporation Waste Isolation Division (WID) through Lankard Materials Laboratory. Observations, reports, and data support the conclusion that the concrete degradation, resulting from attack by chemically aggressive brine, is a localized phenomena. It is the opinion of the WID that the degradation is not considered an immediate or near term concern; this is supported by technical experts. WID recommendations have been made which, when implemented, will ensure an extended liner life. Based on the current assessment of available data and the proposed shaft liner monitoring program described in this report, it is reasonable to assume that the operational life of the concrete shaft liner can safely support the 25-year life of the WIPP. Analysis of data indicates that degradation of the shaft's concrete liner is attributed to chemically aggressive brine seeping through construction joints and shrinkage cracks from behind the liner in and around the 834-foot depth. Chemical and mechanical components of concrete degradation have been identified. Chemical attack is comprised of several stages of concrete alteration. The other component, mechanical degradation, results from the expansive forces of crystals forming in the concrete pore space

Using Random Forests to Select Optimal Input Variables for Short-Term Wind Speed Forecasting Models

Directory of Open Access Journals (Sweden)

Hui Wang

2017-10-01

Full Text Available Achieving relatively high-accuracy short-term wind speed forecasting estimates is a precondition for the construction and grid-connected operation of wind power forecasting systems for wind farms. Currently, most research is focused on the structure of forecasting models and does not consider the selection of input variables, which can have significant impacts on forecasting performance. This paper presents an input variable selection method for wind speed forecasting models. The candidate input variables for various leading periods are selected and random forests (RF is employed to evaluate the importance of all variable as features. The feature subset with the best evaluation performance is selected as the optimal feature set. Then, kernel-based extreme learning machine is constructed to evaluate the performance of input variables selection based on RF. The results of the case study show that by removing the uncorrelated and redundant features, RF effectively extracts the most strongly correlated set of features from the candidate input variables. By finding the optimal feature combination to represent the original information, RF simplifies the structure of the wind speed forecasting model, shortens the training time required, and substantially improves the model’s accuracy and generalization ability, demonstrating that the input variables selected by RF are effective.

Electromagnetic shaft seal

International Nuclear Information System (INIS)

Takahashi, Kenji.

1994-01-01

As an electromagnetic shaft seal, there are disposed outwarding electromagnetic induction devices having generating power directing to an electroconductive fluid as an object of sealing, and inwarding electromagnetic induction device added coaxially. There are disposed elongate rectangular looped first coils having a predetermined inner diameter, second coils having the same shape and shifted by a predetermined pitch relative to the first coil and third coil having the same shape and shifted by a predetermined pitch relative to the second coil respectively each at a predetermined inner diameter of clearance to the outwarding electromagnetic induction devices and the inwarding electromagnetic induction device. If the inwarding electromagnetic induction device and the outwarding electromagnetic induction device are operated, they are stopped at a point that the generating power of the former is equal with the sum of the generating power of the latter and a differential pressure. When three-phase AC is charged to the first coil, the second coil and the third coil successively, a force is generated in the advancing direction of the magnetic field in the electroconductive fluid by the similar effect to that of a linear motor, and the seal is maintained at high reliability. Moreover, the limit for the rotational angle of the shaft is not caused. (N.H.)

Residual stress analysis of drive shafts after induction hardening

Energy Technology Data Exchange (ETDEWEB)

Lemos, Guilherme Vieira Braga; Rocha, Alexandre da Silva; Nunes, Rafael Menezes, E-mail: lemos_gl@yahoo.com.br [Universidade Federal do Rio Grande do Sul (UFRS), Porto Algre, RS (Brazil); Hirsch, Thomas Karl [Stiftung Institut für Werkstofftechnik (IWT), Bremen (Germany)

2014-08-15

Typically, for automotive shafts, shape distortion manifests itself in most cases after the induction hardening by an effect known as bending. The distortion results in a boost of costs, especially due to machining parts in the hardened state to fabricate its final tolerances. In the present study, residual stress measurements were carried out on automotive drive shafts made of DIN 38B3 steel. The samples were selected in consequence of their different distortion properties by an industrial manufacturing line. One tested shaft was straightened, because of the considerable dimensional variation and the other one not. Firstly, the residual stress measurements were carried out by using a portable diffractometer, in order to avoid cutting the shafts and evaluate the original state of the stresses, and afterwards a more detailed analysis was realized by a conventional stationary diffractometer. The obtained results presented an overview of the surface residual stress profiles after induction hardening and displayed the influence of the straightening process on the redistribution of residual stresses. They also indicated that the effects of the straightening in the residual stresses cannot be neglected. (author)

Interaction between clay-based shaft seal components and crystalline host rock

International Nuclear Information System (INIS)

Priyanto, D.; Dixon, D.; Man, A.

2010-01-01

Document available in extended abstract form only. The Government of Canada has accepted the Nuclear Waste Management Organization's (NWMO) recommendation of Adaptive Phased Management (APM) as the long-term management approach for Canada's used nuclear fuel. APM ultimately involves the isolation and containment of used nuclear fuel deep in a Deep Geological Repository (DGR). On completion of waste emplacement operation and during repository closure, shaft seals, comprising clay-based shaft seal components, will be installed at strategic locations, such as where significant fracture zones (FZs) are located. The primary function of a shaft seal is to limit and prevent short-circuiting of the groundwater flow regime via the shaft. Currently, at Atomic Energy of Canada Limited's Underground Research Laboratory (URL) a full-scale shaft seal is being constructed at the intersection of a low dipping thrust fault called FZ 2 as part of the overall URL decommissioning activities. Both crystalline rock and sedimentary rock are considered potentially suitable host rocks formations for a DGR. This paper presents the results of numerical simulation of a shaft seal installed in moderately to sparsely fractured crystalline rock (MFR). The shape and thickness of the shaft seal modelled for a DGR in this exercise are similar to the shaft seal at the URL, but in the modelling exercise it is given a larger diameter (i.e. 7.30 m) equal to the assumed diameter of a production shaft of a repository. The seal consists of a blended bentonite-sand (BS) component that is constrained between two massive concrete seals. Dense backfill (DBF) materials are installed above and below the concrete seals (CS). The concrete seals are keyed into the access shaft to better anchor the concrete units in place and in order to restrain the swelling of the bentonite-sand component of the seal as it hydrates. The reference geosphere in the proposed work is MFR similar to the rock conditions

Advisibility of excavating an additional central shaft to reduce duration of mine construction. [USSR

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.

1981-09-01

This paper evaluates methods of reducing duration and cost of underground black coal mine construction. A proposed scheme of coal deposit opening by a system of three mine shafts is critically analyzed. In comparison to the conventional scheme, the proposed one has one additional mine shaft in the central mine zone. The shaft, equipped with a cage hoisting system, permits the rate of mine drivage in the center of the mine to be increased. The cage hoisting system in the additional shaft is activated before the main skip shaft has been equipped and is in operation. Duration of mine construction is reduced by 6 to 10 months. Exacavation of the additional shaft costs from 2.5 to 3.5 million rubles. A further system of mine construction is also analyzed. The main shaft in the mine center is temporarily equipped with a cage hoisting system. The cage system is used for hoisting rocks removed from mine headings and main workings constructed at the bottom of the main shaft. The main shaft is equipped with skips and hoisting tower at a later stage when construction of main roadways and structures at its bottom has been completed. The proposed system permits mine construction to be reduced by 4 to 5 months without a major increase in investment.

Failure analysis of axle shaft of a fork lift

Directory of Open Access Journals (Sweden)

Souvik Das

2015-04-01

Full Text Available An axle shaft of fork lift failed at operation within 296 h of service. The shaft transmits torque from discrepancy to wheel through planetary gear arrangement. A section of fractured axle shaft made of induction-hardened steel was analyzed to determine the root cause of the failure. Optical microscopies as well as field emission gun scanning electron microscopy (FEG-SEM along with energy dispersive spectroscopy (EDS were carried out to characterize the microstructure. Hardness profile throughout the cross-section was evaluated by micro-hardness measurements. Chemical analysis indicated that the shaft was made of 42CrMo4 steel grade as per specification. Microstructural analysis and micro-hardness profile revealed that the shaft was improperly heat treated resulting in a brittle case, where crack was found to initiate from the case in a brittle mode in contrast to ductile mode within the core. This behaviour was related to differences in microstructure, which was observed to be martensitic within the case with a micro-hardness equivalent to 735 HV, and a mixture of non-homogeneous structure of pearlite and ferrite within the core with a hardness of 210 HV. The analysis suggests that the fracture initiated from the martensitic case as brittle mode due to improper heat treatment process (high hardness. Moreover the inclusions along the hot working direction i.e. in the longitudinal axis made the component more susceptible to failure.

ANALYTICAL EVALUATION OF CRACK PROPAGATION FOR BULB HYDRAULIC TURBINES SHAFTS

Directory of Open Access Journals (Sweden)

Mircea O. POPOVICU

2011-05-01

Full Text Available The Hydroelectric Power Plants uses the regenerating energy of rivers. The hydraulic Bulb turbines running with low heads are excellent alternative energy sources. The shafts of these units present themselves as massive pieces, with cylindrical shape, manufactured from low-alloyed steels. The paper analyses the fatigue cracks occurring at some turbines in the neighbourhood of the connection zone between the shaft and the turbine runner flange. To obtain the tension state in this zone ANSIS and AFGROW computing programs were used. The number of running hours until the piercing of the shaft wall is established as a useful result.

Feature selection in wind speed prediction systems based on a hybrid coral reefs optimization – Extreme learning machine approach

International Nuclear Information System (INIS)

Salcedo-Sanz, S.; Pastor-Sánchez, A.; Prieto, L.; Blanco-Aguilera, A.; García-Herrera, R.

2014-01-01

Highlights: • A novel approach for short-term wind speed prediction is presented. • The system is formed by a coral reefs optimization algorithm and an extreme learning machine. • Feature selection is carried out with the CRO to improve the ELM performance. • The method is tested in real wind farm data in USA, for the period 2007–2008. - Abstract: This paper presents a novel approach for short-term wind speed prediction based on a Coral Reefs Optimization algorithm (CRO) and an Extreme Learning Machine (ELM), using meteorological predictive variables from a physical model (the Weather Research and Forecast model, WRF). The approach is based on a Feature Selection Problem (FSP) carried out with the CRO, that must obtain a reduced number of predictive variables out of the total available from the WRF. This set of features will be the input of an ELM, that finally provides the wind speed prediction. The CRO is a novel bio-inspired approach, based on the simulation of reef formation and coral reproduction, able to obtain excellent results in optimization problems. On the other hand, the ELM is a new paradigm in neural networks’ training, that provides a robust and extremely fast training of the network. Together, these algorithms are able to successfully solve this problem of feature selection in short-term wind speed prediction. Experiments in a real wind farm in the USA show the excellent performance of the CRO–ELM approach in this FSP wind speed prediction problem

Forming of Hollow Shaft Forging From Titanium Alloy Ti6Al4V by Means of Rotary Compression

Directory of Open Access Journals (Sweden)

Tomczak J.

2015-04-01

Full Text Available This paper presents chosen results of theoretical-experimental works concerning forming of hollow shafts forgings from titanium alloys, which are applied in aviation industry. At the first stage of conducted analysis, the forging forming process was modeled by means of finite element method. Calculations were made using software Simufact Forming. On the basis of performed simulations optimal parameters of rotary compression process were determined. Next, experimental tests of forging forming in laboratory conditions were made. For the research needs, a forging aggregate, designed by the Authors, was used. Conducted research works confirmed the possibility of metal forming (by means of rotary compression of hollow shafts from hard workable titanium alloys. Numerous advantages of rotary compression process, make it attractive both for low series production (aircraft industry and for mass production (automotive industry.

Study on collapse mechanism of junction between greatly deeper shaft and horizontal drifts (Contract research)

International Nuclear Information System (INIS)

Kurosaki, Yukio; Yamachi, Hiroshi; Katsunuma, Yoshio; Nakata, Masao; Kuwahara, Hideki; Yamada, Fumitaka; Matsushita, Kiyoshi; Sato, Toshinori

2008-03-01

The Mizunami underground research laboratory is planned to consist of greatly deeper shaft and horizontal drifts. A junction space between a greatly deeper shaft and horizontal drifts forms which would take a complicated mechanical behavior during a junction excavation. However, a quantitative design method of supporting measures for a deep junction has not yet been established. This is because a conventional shaft design has been conducted based on past experience. Detail records have not been left either in what kind of collapses and deformed phenomena occurring in shaft constructions in a past. In order to examine a collapse mechanism of greatly deeper shaft junction, we have conducted literature surveys and interview studies concerned with deep shaft construction works in a past, and investigated what collapses or difficulties had been occurred in deep shaft junctions. Considering the results of investigations with reviews of intellectuals, a collapse mechanism of a super deep shaft junction depends on both a construction procedure of shaft junction and a geological condition at great depth. During a construction of a shaft junction, stress state of rock masses near junction wall would take a complicated stress path. Especially, it should be necessary to take a most careful consideration on that tangential stress acted around a shaft wall may reduce during horizontal drift excavation. On the other hand, where greatly deeper junction intersects faults and/or fractures with a large angle, a collapse called 'Take-nuke' may occur or extraordinary earth pressure acts on a concrete wall. This is the most typical difficulties during shaft construction. In order to recognize a mechanism of these phenomena and to find out a cause of collapse generation, numerical studies that can simulate a practical rock mass behavior around a shaft junction should be carry out. We demonstrate the finite difference method is most adequate for these simulations with intellectual review

Locomotor training with body weight support in SCI: EMG improvement is more optimally expressed at a low testing speed.

Science.gov (United States)

Meyns, P; Van de Crommert, H W A A; Rijken, H; van Kuppevelt, D H J M; Duysens, J

2014-12-01

Case series. To determine the optimal testing speed at which the recovery of the EMG (electromyographic) activity should be assessed during and after body weight supported (BWS) locomotor training. Tertiary hospital, Sint Maartenskliniek, Nijmegen, The Netherlands. Four participants with incomplete chronic SCI were included for BWS locomotor training; one AIS-C and three AIS-D (according to the ASIA (American Spinal Injury Association) Impairment Scale or AIS). All were at least 5 years after injury. The SCI participants were trained three times a week for a period of 6 weeks. They improved their locomotor function in terms of higher walking speed, less BWS and less assistance needed. To investigate which treadmill speed for EMG assessment reflects the functional improvement most adequately, all participants were assessed weekly using the same two speeds (0.5 and 1.5 km h(-1), referred to as low and high speed, respectively) for 6 weeks. The change in root mean square EMG (RMS EMG) was assessed in four leg muscles; biceps femoris, rectus femoris, gastrocnemius medialis and tibialis anterior. The changes in RMS EMG occurred at similar phases of the step cycle for both walking conditions, but these changes were larger when the treadmill was set at a low speed (0.5 km h(-1)). Improvement in gait is feasible with BWS treadmill training even long after injury. The EMG changes after treadmill training are more optimally expressed using a low rather than a high testing treadmill speed.

Numerically Analysed Thermal Condition of Hearth Rollers with the Water-Cooled Shaft

Directory of Open Access Journals (Sweden)

A. V. Ivanov

2016-01-01

Full Text Available Continuous furnaces with roller hearth have wide application in the steel industry. Typically, furnaces with roller hearth belong to the class of medium-temperature heat treatment furnaces, but can be used to heat the billets for rolling. In this case, the furnaces belong to the class of high temperature heating furnaces, and their efficiency depends significantly on the reliability of the roller hearth furnace. In the high temperature heating furnaces are used three types of watercooled shaft rollers, namely rollers without insulation, rollers with insulating screens placed between the barrel and the shaft, and rollers with bulk insulation. The definition of the operating conditions of rollers with water-cooled shaft greatly facilitates the choice of their design parameters when designing. In this regard, at the design stage of the furnace with roller hearth, it is important to have information about the temperature distribution in the body of the rollers at various operating conditions. The article presents the research results of the temperature field of the hearth rollers of metallurgical heating furnaces. Modeling of stationary heat exchange between the oven atmosphere and a surface of rollers, and between the cooling water and shaft was executed by finite elements method. Temperature fields in the water-cooled shaft rollers of various designs are explored. The water-cooled shaft rollers without isolation, rollers with screen and rollers with bulk insulation, placed between the barrel and the water-cooled shaft were investigated. Determined the change of the thermo-physic parameters of the coolant, the temperature change of water when flowing in a pipe and shaft, as well as the desired pressure to supply water with a specified flow rate. Heat transfer coefficients between the cooling water and the shaft were determined directly during the solution based on the specified boundary conditions. Found that the greatest heat losses occur in the

Study on high-speed cutting parameters optimization of AlMn1Cu based on neural network and genetic algorithm

Directory of Open Access Journals (Sweden)

Zhenhua Wang

2016-04-01

Full Text Available In this article, the cutting parameters optimization method for aluminum alloy AlMn1Cu in high-speed milling was studied in order to properly select the high-speed cutting parameters. First, a back propagation neural network model for predicting surface roughness of AlMn1Cu was proposed. The prediction model can improve the prediction accuracy and well work out the higher-order nonlinear relationship between surface roughness and cutting parameters. Second, considering the constraints of technical requirements on surface roughness, a mathematical model for optimizing cutting parameters based on the Bayesian neural network prediction model of surface roughness was established so as to obtain the maximum machining efficiency. The genetic algorithm adopting the homogeneous design to initialize population as well as steady-state reproduction without duplicates was also presented. The application indicates that the algorithm can effectively avoid precocity, strengthen global optimization, and increase the calculation efficiency. Finally, a case was presented on the application of the proposed cutting parameters optimization algorithm to optimize the cutting parameters.

Shaft extension design at the Underground Research Laboratory, Pinawa, Manitoba

International Nuclear Information System (INIS)

Kuzyk, G.W.; Ball, A.E.

1991-01-01

AECL Research has constructed an underground laboratory for the research and development required for the Canadian Nuclear Fuel Waste Management Program. The experimental program in the laboratory will contribute to the assessment of the feasibility and safety of nuclear fuel waste disposal deep in stable plutonic rock. In 1988, AECL extended the shaft of the Underground Research Laboratory (URL) from the existing 255 m depth to a depth of 443 m in cooperation with the United States Department of Energy. The project, which involved carrying out research activities while excavation and construction work was in progress, required careful planning. To accommodate the research programs, full-face blasting with a burn cut was used to advance the shaft. Existing facilities at the URL had to be modified to accommodate an expanded underground facility at a new depth. This paper discusses the design criteria, shaft-sinking methods and approaches used to accommodate the research work during this shaft extension project. (11 refs., 11 figs.)

Research and industrialization of near-net rolling technology used in shaft parts

Science.gov (United States)

Hu, Zhenghuan; Wang, Baoyu; Zheng, Zhenhua

2018-03-01

Shaft part rolling is an efficient and green nearnet shaping technology offering many advantages, including high production efficiency, high material utilization rate, high product quality, and excellent production environment. In this paper, the features of shaft part rolling are introduced along with the working principles of two main shaft part rolling technologies, namely, cross wedge rolling (CWR) and skew rolling (SR). In relation to this technology, some R&D achievements gained by the University of Science and Technology Beijing are summarized. Finally, the latest developments in shaft part rolling are presented, including SR steel balls, precise forming of camshaft blank by CWR, SR phosphorous copper balls at room temperature, and CWR hollow axle sleeve. Although the shaft part rolling technology has been widely used in China, it only accounts for about 15% of applicable parts at present. Nevertheless, this technology has broad application prospects.

Fatigue criterion for the design of rotating shafts under combined stress

Science.gov (United States)

Loewenthal, S. H.

1977-01-01

A revised approach to the design of transmission shafting which considers the flexure fatigue characteristics of the shaft material under combined cyclic bending and static torsion stress is presented. A fatigue failure relation, corroborated by published combined stress test data, is presented which shows an elliptical variation of reversed bending endurance strength with static torsional stress. From this elliptical failure relations, a design formula for computing the diameter of rotating solid shafts under the most common condition of loading is developed.

Design and Analysis of Drive Shaft using Kevlar/Epoxy and Glass/Epoxy as a Composite Material

Science.gov (United States)

Karthikeyan, P.; Gobinath, R.; Kumar, L. Ajith; Jenish, D. Xavier

2017-05-01

In automobile industry drive shaft is one of the most important components to transmit power form the engine to rear wheel through the differential gear. Generally steel drive shaft is used in automobile industry, nowadays they are more interested to replace steel drive shaft with that of composite drive shaft. The overall objective of this paper is to analyze the composite drive shaft using to find out the best replacement for conventional steel drive shaft. The uses of advanced composite materials such as Kevlar, Graphite, Carbon and Glass with proper resins ware resulted in remarkable achievements in automobile industry because of its greater specific strength and specific modulus, improved fatigue and corrosion resistances and reduction in energy requirements due to reduction in weight as compared to steel shaft. This paper is to presents, the modeling and analysis of drive shaft using Kevlar/Epoxy and Glass/Epoxy as a composite material and to find best replacement for conventional steel drive shafts with an Kevlar/epoxy or Glass/Epoxy resin composite drive shaft. Modeling is done using CATIA software and Analysis is carried out by using ANSYS 10.0 software for easy understanding. The composite drive shaft reduces the weight by 81.67 % for Kevlar/Epoxy and 72.66% for Glass/Epoxy when compared with conventional steel drive shaft.

Research on dynamic balancing simulation of rotary shaft based on ADAMS

Science.gov (United States)

Zheng, Weiqiang; Rui, Chengjie; Yang, Jie; Liu, Pingyi

2018-02-01

Due to the design and processing technology of rotary shaft, the mass center of it does not coincide with the rotating axis of the rotary shaft and there is an unbalanced mass. The unbalanced mass can have some disadvantages, such as the centrifugal force, the vibration and so on. Those disadvantages could reduce the accuracy and service life of the equipment.In this paper, the dynamic balance of the rotary shaft is analysed by the theory analysis combined with the dynamic simulation software. This method ensures that the rotary shaft meets the dynamic balancing requirements during the design stage. It effectively supports the structural design of the rotary shift, and provides a way of thinking and method for the design and development of the same type of products.

Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter Part I – Effect of Speed Ratio

Directory of Open Access Journals (Sweden)

Steven B. Ainley

2000-01-01

Full Text Available A torque converter was tested at four turbine/pump rotational speed ratios (0.200, 0.400, 0.600, and 0.800 all with a constant pump rotational speed in order to determine the effect of speed ratio on the torque converter pump flow field. Laser velocimetry was used to measure three components of velocity within the pump and a shaft encoder was employed to record the instantaneous pump angular position. Shaft encoder information was correlated with measured velocities to develop flow field blade-to-blade profiles and vector plots. Measurements were obtained in both the pump mid- and exit planes for all four speed ratios. Results showed large separation regions and jet/wake flows throughout the pump. The midplane flow was found to have strong counter-clockwise secondary components and the exit plane flow had strong clockwise secondary components. Mass flows were calculated from the velocity data and were found to decrease as the speed ratio was increased. Also, the vorticity and slip factors were calculated from the experimental data and are included. The mid-plane slip factors compare favorably to those for conventional centrifugal pumps but less slip was present in the exit plane than the mid-plane. Neither the slip factor nor the vorticity were seen to be strongly affected by the speed ratio. Finally, the torque core-to-shell and blade-to-blade torque distributions are presented for both planes.

METHOD OF ACHIEVING ACCURACY OF THERMO-MECHANICAL TREATMENT OF LOW-RIGIDITY SHAFTS

Directory of Open Access Journals (Sweden)

Antoni Świć

2016-03-01

Full Text Available The paper presents a method combining the processes of straightening and thermal treatment. Technological processes with axial strain were considered, for the case of heated material and without its heating. The essence of the process in the case of heated material consisted in the fact that if under tension all longitudinal forces in the first approximation are uniform - the same strains are generated. The presented technological approach, aimed at reducing the curvature of axial-symmetrical parts, is acceptable as the process of rough, preliminary machining, in the case of shafts with the ratio L/D≤100 (L – shaft length, d – shaft diameter and without a tendency of strengthening. To improve the accuracy and stability of geometric form of low-rigidity parts, a method was developed that combines the processes of straightening and heat treatment. The method consists in that axial strain – tension, is applied to the shaft during heating, and during cooling the product is fixed in a fixture, the cooling rate of the shaft being several-fold greater than that of the fixture. A device is presented for the realisation of the method of controlling the process of plastic deformation of low-rigidity shafts. In the case of the presented device and the adopted calculation scheme, a method was developed that permits the determination of the length of shaft section and of the time of its cooling.

Performance Optimization Design for a High-Speed Weak FBG Interrogation System Based on DFB Laser

Directory of Open Access Journals (Sweden)

Yiqiang Yao

2017-06-01

Full Text Available A performance optimization design for a high-speed fiber Bragg grating (FBG interrogation system based on a high-speed distributed feedback (DFB swept laser is proposed. A time-division-multiplexing sensor network with identical weak FBGs is constituted to realize high-capacity sensing. In order to further improve the multiplexing capacity, a waveform repairing algorithm is designed to extend the dynamic demodulation range of FBG sensors. It is based on the fact that the spectrum of an FBG keeps stable over a long period of time. Compared with the pre-collected spectra, the distorted spectra waveform are identified and repaired. Experimental results show that all the identical weak FBGs are distinguished and demodulated at the speed of 100 kHz with a linearity of above 0.99, and the range of dynamic demodulation is extended by 40%.

Performance Optimization Design for a High-Speed Weak FBG Interrogation System Based on DFB Laser.

Science.gov (United States)

Yao, Yiqiang; Li, Zhengying; Wang, Yiming; Liu, Siqi; Dai, Yutang; Gong, Jianmin; Wang, Lixin

2017-06-22

A performance optimization design for a high-speed fiber Bragg grating (FBG) interrogation system based on a high-speed distributed feedback (DFB) swept laser is proposed. A time-division-multiplexing sensor network with identical weak FBGs is constituted to realize high-capacity sensing. In order to further improve the multiplexing capacity, a waveform repairing algorithm is designed to extend the dynamic demodulation range of FBG sensors. It is based on the fact that the spectrum of an FBG keeps stable over a long period of time. Compared with the pre-collected spectra, the distorted spectra waveform are identified and repaired. Experimental results show that all the identical weak FBGs are distinguished and demodulated at the speed of 100 kHz with a linearity of above 0.99, and the range of dynamic demodulation is extended by 40%.

Mechanical coupling for a rotor shaft assembly of dissimilar materials

Science.gov (United States)

Shi, Jun [Glastonbury, CT; Bombara, David [New Hartford, CT; Green, Kevin E [Broad Brook, CT; Bird, Connic [Rocky Hill, CT; Holowczak, John [South Windsor, CT

2009-05-05

A mechanical coupling for coupling a ceramic disc member to a metallic shaft includes a first wedge clamp and a second wedge clamp. A fastener engages a threaded end of a tie-bolt to sandwich the ceramic disc between the wedge clamps. An axial spring is positioned between the fastener and the second wedge clamp to apply an axial preload along the longitudinal axis. Another coupling utilizes a rotor shaft end of a metallic rotor shaft as one wedge clamp. Still another coupling includes a solid ceramic rotor disc with a multiple of tie-bolts radially displaced from the longitudinal axis to exert the preload on the solid ceramic rotor disc.

Comparison of suprapatellar and infrapatellar intramedullary nailing for tibial shaft fractures: a systematic review and meta-analysis.

Science.gov (United States)

Yang, Liqing; Sun, Yuefeng; Li, Ge

2018-06-14

Optimal surgical approach for tibial shaft fractures remains controversial. We perform a meta-analysis from randomized controlled trials (RCTs) to compare the clinical efficacy and prognosis between infrapatellar and suprapatellar intramedullary nail in the treatment of tibial shaft fractures. PubMed, OVID, Embase, ScienceDirect, and Web of Science were searched up to December 2017 for comparative RCTs involving infrapatellar and suprapatellar intramedullary nail in the treatment of tibial shaft fractures. Primary outcomes were blood loss, visual analog scale (VAS) score, range of motion, Lysholm knee scores, and fluoroscopy times. Secondary outcomes were length of hospital stay and postoperative complications. We assessed statistical heterogeneity for each outcome with the use of a standard χ 2 test and the I 2 statistic. The meta-analysis was undertaken using Stata 14.0. Four RCTs involving 293 participants were included in our study. The present meta-analysis indicated that there were significant differences between infrapatellar and suprapatellar intramedullary nail regarding the total blood loss, VAS scores, Lysholm knee scores, and fluoroscopy times. Suprapatellar intramedullary nailing could significantly reduce total blood loss, postoperative knee pain, and fluoroscopy times compared to infrapatellar approach. Additionally, it was associated with an improved Lysholm knee scores. High-quality RCTs were still required for further investigation.

Design of inclined loaded drilled shafts in high-plasticity clay environment.

Science.gov (United States)

2011-05-01

Drilled shaft foundations are principally used to support many structures such as bridge piers, towers, : buildings, transmission towers, and roadway cable barriers. This research focuses on the use of drilled shafts : in the cable median barrier sys...

Shaft Excavation in Frozen Ground at Point 5

CERN Document Server

Osborne, J

2000-01-01

Construction work on the 112 MCHF civil engineering contract started at Point 5 in August 1998. The new surface buildings and underground structures are necessary to accommodate the CMS detector for the LHC Project. The principal underground works consist of two new shafts, two parallel caverns separated by a supporting pillar, and a number of small connection tunnels and service galleries. The two shafts are to be sunk through approximately 50 m of water-bearing moraine to the underlying molasse rock. From a number of possible construction methods, ground freezing of the moraine was considered to be most appropriate. The ground freezing is used to control the groundwater and to support temporarily the moraine during excavation and lining of the shafts. The aim of this paper is to present the ground-freezing technique and to discuss the advantages and disadvantages of the system in the light of its first few months of running on the Point 5 site.

Fracture Failure Analysis of Fuel Pump Transmission Shaft of Dual-Fuel Engine

Directory of Open Access Journals (Sweden)

Chen Pei-hong

2017-01-01

Full Text Available NTS6ZLCz-129 dual-fuel turbocharged and intercooled engine durability test at 1000h, fuel pump shaft fractured. Fracture analysis, chemical analysis, microstructure examination and finite element stress analysis were carried out on the fractured shaft. The analysis result showed that the shaft fracture cause is forging fold. By improving the forging process, the forging fold was solved, and the durability test can be carried out smoothly.

33 Shafts Category of Transuranic Waste Stored Below Ground within Area G

Energy Technology Data Exchange (ETDEWEB)

Hargis, Kenneth Marshall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Monk, Thomas H [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-05-22

This report compiles information to support the evaluation of alternatives and analysis of regulatory paths forward for the 33 shafts. The historical information includes a form completed by waste generators for each waste package (Reference 6) that included a waste description, estimates of Pu-239 and uranium-235 (U-235) based on an accounting technique, and calculations of mixed fission products (MFP) based on radiation measurements. A 1979 letter and questionnaire (Reference 7) provides information on waste packaging of hot cell waste and the configuration of disposal shafts as storage in the 33 Shafts was initiated. Tables of data by waste package were developed during a review of historical documents that was performed in 2005 (Reference 8). Radiological data was coupled with material-type data to estimate the initial isotopic content of each waste package and an Oak Ridge National Laboratory computer code was used to calculate 2009 decay levels. Other sources of information include a waste disposal logbook for the 33 shafts (Reference 9), reports that summarize remote-handled waste generated at the CMR facility (Reference 10) and placement of waste in the 33 shafts (Reference 11), a report on decommissioning of the LAMPRE reactor (Reference 12), interviews with an employee and manager involved in placing waste in the 33 shafts (References 13 and 14), an interview with a long-time LANL employee involved in waste operations (Reference 15), a 2002 plan for disposition of remote-handled TRU waste (Reference 16), and photographs obtained during field surveys of several shafts in 2007. The WIPP Central Characterization Project (CCP) completed an Acceptable Knowledge (AK) summary report for 16 canisters of remote-handled waste from the CMR Facility that contains information relevant to the 33 Shafts on hot-cell operations and timeline (Reference 17).

Is There an Optimal Speed for Economical Running?

Science.gov (United States)

Black, Matthew I; Handsaker, Joseph C; Allen, Sam J; Forrester, Stephanie E; Folland, Jonathan P

2018-01-01

The influence of running speed and sex on running economy is unclear and may have been confounded by measurements of oxygen cost that do not account for known differences in substrate metabolism, across a limited range of speeds, and differences in performance standard. Therefore, this study assessed the energy cost of running over a wide range of speeds in high-level and recreational runners to investigate the effect of speed (in absolute and relative terms) and sex (men vs women of equivalent performance standard) on running economy. To determine the energy cost (kcal · kg -1  · km -1 ) of submaximal running, speed at lactate turn point (sLTP), and maximal rate of oxygen uptake, 92 healthy runners (high-level men, n = 14; high-level women, n = 10; recreational men, n = 35; recreational women, n = 33) completed a discontinuous incremental treadmill test. There were no sex-specific differences in the energy cost of running for the recreational or high-level runners when compared at absolute or relative running speeds (P > .05). The absolute and relative speed-energy cost relationships for the high-level runners demonstrated a curvilinear U shape with a nadir reflecting the most economical speed at 13 km/h or 70% sLTP. The high-level runners were more economical than the recreational runners at all absolute and relative running speeds (P running, there is no sex-specific difference, and high-level endurance runners exhibit better running economy than recreational endurance runners.

ESF [Exploratory Shaft Facility] impact evaluation report: Volume 2: Final report

International Nuclear Information System (INIS)

1985-08-01

This report assesses the impacts of integrating an Exploratory Shaft Facility (ESF) with a high-level nuclear waste repository in salt. An evaluation to identify integration impacts is described for two specific ESF configurations (Cases 1 and 2) for each of the seven sites. These configurations are an ESF which uses two of the full size repository shafts, and an ESF with one 10-ft and one 22-ft diameter shaft. An evaluation of an ESF configuration (Case 3) with two 12-ft diameter shafts at three of the seven sites is also described. These sites are Deaf Smith, Davis Canyon, and Richton Dome. A fourth evaluation (Case 4) for the Deaf Smith site only, addresses a ''fast track'' subsurface development plan to allow waste emplacement by 1998. A fifth evaluation (Case 5), provides site-specific ES locations, for the three sites included in Case 3, which are supportive of a shaft siting study prepared by ONWI. The report presents development schedules depicting construction activities and time frames commencing with receipt of the repository Construction Authorization and proceeding to initiation of emplacement operations. These schedules are site specific and are presented for each of the five cases

Low frequency torsional vibration gaps in the shaft with locally resonant structures

International Nuclear Information System (INIS)

Yu Dianlong; Liu Yaozong; Wang Gang; Cai Li; Qiu Jing

2006-01-01

The propagation of torsional wave in the shaft with periodically attached local resonators is studied with the transfer matrix theory and the finite element method. The analytical dispersion relation and the complex band structure of such a structure is presented for the first time, which indicates the existence of low frequency gaps. The effect of shaft material on the vibration attenuation in band gap is investigated. The frequency response function of the shaft with finite periodic locally resonant oscillators is simulated with finite element method, which shows large vibration attenuation in the frequency range of the gap as expected. The low frequency torsional gap in shafts provides a new idea for vibration control

A Hybrid Multi-Step Rolling Forecasting Model Based on SSA and Simulated Annealing—Adaptive Particle Swarm Optimization for Wind Speed

Directory of Open Access Journals (Sweden)

Pei Du

2016-08-01

Full Text Available With the limitations of conventional energy becoming increasing distinct, wind energy is emerging as a promising renewable energy source that plays a critical role in the modern electric and economic fields. However, how to select optimization algorithms to forecast wind speed series and improve prediction performance is still a highly challenging problem. Traditional single algorithms are widely utilized to select and optimize parameters of neural network algorithms, but these algorithms usually ignore the significance of parameter optimization, precise searching, and the application of accurate data, which results in poor forecasting performance. With the aim of overcoming the weaknesses of individual algorithms, a novel hybrid algorithm was created, which can not only easily obtain the real and effective wind speed series by using singular spectrum analysis, but also possesses stronger adaptive search and optimization capabilities than the other algorithms: it is faster, has fewer parameters, and is less expensive. For the purpose of estimating the forecasting ability of the proposed combined model, 10-min wind speed series from three wind farms in Shandong Province, eastern China, are employed as a case study. The experimental results were considerably more accurately predicted by the presented algorithm than the comparison algorithms.

Heat generation and hemolysis at the shaft seal in centrifugal blood pumps.

Science.gov (United States)

Araki, K; Taenaka, Y; Wakisaka, Y; Masuzawa, T; Tatsumi, E; Nakatani, T; Baba, Y; Yagura, A; Eya, K; Toda, K

1995-01-01

The heat and hemolysis around a shaft seal were investigated. Materials were original pumps (Nikkiso HMS-15:N-original, and 3M Delphin:D-original), vane-removed pumps (Nvane(-), Dvane(-)), and a small chamber with a shaft coiled by nichrome wire (mock pump). The original pumps were driven at 500 mmHg and 5 L/min, and vane-removed pumps were driven at the same rotation number. An electrical powers of 0, 0.5, 2, and 10 W was supplied to the mock pumps. In vitro hemolytic testing showed that hemolytic indices were 0.027 g/100 L in N-original, 0.013 in Nvane(-), 0.061 in D-original, and 0.012 in Dvane(-). Measurement of heat with a thermally insulated water chamber showed total heat within the pump of 8.62 and 10.85 W, and heat at the shaft seal of 0.87 and 0.62 W in the Nikkiso and Delphin pumps, respectively. Hemolysis and heat generation of mock pumps remained low. The results indicate that the heat generated around the shaft seal was minimal. Hemolysis at the shaft-seal was considerable but not major. Local heat did not affect hemolysis. It was concluded that the shaft-seal affected hemolysis, not by local heat but friction itself.

Long-term functional outcome following intramedullary nailing of femoral shaft fractures

NARCIS (Netherlands)

el Moumni, Mostafa; Voogd, Emma Heather; ten Duis, Henk Jan; Wendt, Klaus Wilhelm

Background: The management of femoral shaft fractures using intramedullary nailing is a popular method. The purpose of this study was to evaluate the long-term functional outcome after antegrade or retrograde intramedullary nailing of traumatic femoral shaft fractures. We further determined

Optimized Signaling Method for High-Speed Transmission Channels with Higher Order Transfer Function

Science.gov (United States)

Ševčík, Břetislav; Brančík, Lubomír; Kubíček, Michal

2017-08-01

In this paper, the selected results from testing of optimized CMOS friendly signaling method for high-speed communications over cables and printed circuit boards (PCBs) are presented and discussed. The proposed signaling scheme uses modified concept of pulse width modulated (PWM) signal which enables to better equalize significant channel losses during data high-speed transmission. Thus, the very effective signaling method to overcome losses in transmission channels with higher order transfer function, typical for long cables and multilayer PCBs, is clearly analyzed in the time and frequency domain. Experimental results of the measurements include the performance comparison of conventional PWM scheme and clearly show the great potential of the modified signaling method for use in low power CMOS friendly equalization circuits, commonly considered in modern communication standards as PCI-Express, SATA or in Multi-gigabit SerDes interconnects.

Optimization of advenced liquid natural gas-fuelled combined cycle machinery systems for a high-speed ferry

DEFF Research Database (Denmark)

Tveitaskog, Kari Anne; Haglind, Fredrik

2012-01-01

. Furthermore, practical and operational aspects of using these three machinery systems for a high-speed ferry are discussed. Two scenarios are evaluated. The first scenario evaluates the combined cycles with a given power requirement, optimizing the combined cycle while operating the gas turbine at part load...

Simulation on spread of fire smoke in the elevator shaft for a high-rise building

Directory of Open Access Journals (Sweden)

Yunchun Xia

2014-01-01

Full Text Available Spread of fire smoke in the elevator shaft of a high-rise building is influenced by many driving facts. We simulate smoke spreading in the elevator shaft, stair room, and pre-chamber with and without different supplied pressurized air. The simulation shows that smoke moves very fast in the elevator shaft. When a 12 floor high-rise building is in fire, smoke can fill up the elevator shaft in less than 1.5 min after a fire started, temperature in the elevator shaft can be higher than 187°C in 5 min, and the concentration of CO can also reach a high level. The elevator shaft has a very low visibility in less than about 100 s.

Magnetic shaft seals prevent hazardous leakage from wastewater agitators

International Nuclear Information System (INIS)

Traino, F.A.

1985-01-01

The US Department of Energy's laboratory in Miamisburg, OH, operated by Monsanto Research Corporation, processes approximately 45,000 gallons per week of low-level radioactive wastewater to meet Federal Environmental Protection Agency quality standards. Preventing the spread of radioactive contamination throughout the operating area demands effective sealing of all process piping, valves, pumps, and agitators. Rotating shafts of pumps and agitators installed a the start of operations in 1947 were sealed by stuffing glands with graphite impregnated asbestos packing. These pumps proved to be unsatisfactory. In the mid-1970's, new process pumps with mechanical seals and some with magnetic drives were installed. Later, in January 1979, new agitator shaft drives with double tandem, spring-loaded mechanical seals were installed, maintenance of these pumps was costly. The agitator drive shafts were redesigned to accommodate magnetic seals of the type successfully used in blowers and vacuum/pressure pumps in other plant locations. One inherent advantage of the magnetic seal is that it operates with a face loading as much as 50% less than a conventional spring-loaded mechanical seal. The lower loading by a predetermined uniform magnetic force contributes to long face life. Other advantages include compactness, ease of assembly with only a few parts, and insensitivity to vibration. The magnetic shaft seals installed on the agitator shafts in February 1983 are still in service without any leakage or need for maintenance. Based on current operating data and a projected five-year meantime between failures, the estimated cost benefit of the magnetic seals over spring-loaded mechanical seals over spring-loaded mechanical seals will be $640 vs $2400 respectively per seal, with 60% less downtime for maintenance

Sizing Optimization and Strength Analysis for Spread-type Gear Reducers

Directory of Open Access Journals (Sweden)

Wei-Hsuan Hsu

2014-08-01

Full Text Available A reducer is now developed towards the trend of customization service and cost-saving. In this study, a sizing program for the reducer has been developed in order to replace the manual sizing process. We aim at the total center distance of the gear reducer for optimization to reduce gear volume and weight. Also, we checked constrains such as, tooth root bending, tooth contact strength, gear shaft endangered cross-section, bearing life, gear shaft deflection, and torsion angle deformation, etc., to obtain reliable drive strength. Comparisons of sizes and weights before and after optimization confirm that the purpose for reducing production cost is achieved.

Condition monitoring of shaft of single-phase induction motor using optical sensor

Science.gov (United States)

Fulzele, Asmita G.; Arajpure, V. G.; Holay, P. P.; Patil, N. M.

2012-05-01

Transmission type of optical technique is developed to sense the condition of rotating shafts from a distance. A parallel laser beam is passed tangential over the surface of rotating shaft of a single phase induction motor and its flickering shadow is received on a photo sensor. Variations in sensor voltage output are observed on a digital storage oscilloscope. It is demonstrated that this signal carries information about shaft defects like miss alignment, play and impacts in bearings along with surface deformities. Mathematical model of signals corresponding to these shaft defects is developed. During the development and testing of the sensor, effects of reflections are investigated, sensing phenomenon is simulated, frequency response of the sensor is obtained and its performance is compared with conventional accelerometer.

Mining a coal seam with caving in a protective pillar of a mine shaft. [Poland

Energy Technology Data Exchange (ETDEWEB)

Szymura, G; Dilling, R; Kowalski, A

1984-01-01

Mining the 620 seam is evaluated (from 1.5 to 1.7 m thick at a depth of 468 m in the protective pillar of the upcast mine shaft used for ventilation, manriding and transport of materials in the Pstrowski mine in Upper Silesia). The shaft is 496 m deep, has a diameter of 3.5 m and its liners are made of bricks. Ground subsidence caused by underground mining influenced: the head frame above the shaft, residential buildings, a church, railway tracks and a river bed. A system of shortwall mining with caving was used. Deformation of shaft liners was reduced by advanced cutting of a coal block 30x30 m around the shaft. A system of timber cribbings and yielding elements was used. Design of support systems used around the shaft is shown in 3 schemes. Shaft deformation was within permissible limits. The maximum ground subsidence (0.95 m) occurred in the river area. Ground subsidence in the area of the church ranged from 0.75 to 0.81 m and in the head frame area 0.84 m. Accuracy of ground subsidence and shaft deformation forecasting was high. 4 references.

Analysis and countermeasures for the corrosion on the shaft of seawater pump

International Nuclear Information System (INIS)

Lu Hongtao; Chen Haiming

2010-01-01

The corrosion resistance of the shaft material-3Cr13 was studied through immersion test and electrochemistry test. The results indicated that 3Cr13 and the chromium plating on the shaft had poor resistance against local corrosion in seawater. And the free corrosion potential of 3Cr13 in seawater was lower than other components of the pump, this could accelerate the corrosion rate of the shaft due to galvanic corrosion. A comprehensive analysis showed that the root cause of the corrosion on the No.4 shaft was that 3Cr13 had poor resistance against local corrosion in seawater. Because of the exist of fit-up gap, galvanic corrosion effect and corrosive wear caused by sand, crevice corrosion, galvanic corrosion and wear occurred. All of these accelerated the corrosion rate of the shaft and finally caused its failure. It is suggested that the sealant should be improved and the current material 3Cr13 should be replaced by a kind of materials with better corrosion resistance. (authors)

Surface Roughness Optimization Using Taguchi Method of High Speed End Milling For Hardened Steel D2

Science.gov (United States)

Hazza Faizi Al-Hazza, Muataz; Ibrahim, Nur Asmawiyah bt; Adesta, Erry T. Y.; Khan, Ahsan Ali; Abdullah Sidek, Atiah Bt.

2017-03-01

The main challenge for any manufacturer is to achieve higher quality of their final products with maintains minimum machining time. In this research final surface roughness analysed and optimized with maximum 0.3 mm flank wear length. The experiment was investigated the effect of cutting speed, feed rate and depth of cut on the final surface roughness using D2 as a work piece hardened to 52-56 HRC, and coated carbide as cutting tool with higher cutting speed 120-240 mm/min. The experiment has been conducted using L9 design of Taguchi collection. The results have been analysed using JMP software.

The Strength Calculation of the Pump Shaft with a Worn Impeller

Directory of Open Access Journals (Sweden)

Nikolay P. Ovchinnikov

2017-12-01

Full Text Available Introduction: This paper presents the study of the impeller wear influence on stress-strain state of a centrifugal pump shaft. In agro-industrial sector, centrifugal pumps are used for watering various agricultural crops. During pumping water, a centrifugal pump impeller is usually a subject to influence of various irreversible physical-and-mechanical and physical-and-chemical processes that can result in a certain reduction in its mass. Materials and Methods: We used a comprehensive approach including the analysis of a sufficient number domestic and foreign publications on the research topic and parametric studies conducted on a laboratory-pumping unit. We had modern vibration-based diagnostic equipment, the mathematical models of loading a pump shaft and a finite-element modeling in APM Win Machine software (Beam module. Results: The comparison of the maximum equivalent dynamic stresses obtained according to the proposed method with existing methods for carrying out the checking strength calculation of a centrifugal pump shaft showed that account of the impeller wear significantly changes picture of stress-strain state shaft. Discussion and Conclusions: The amendments proposed by the author in checking strength calculation of a centrifugal pump shaft will allow estimating its stress-strain state in certain production situations.

Torsional Vibrations of a Conic Shaft with Opposite Tapers Carrying Arbitrary Concentrated Elements

Directory of Open Access Journals (Sweden)

Jia-Jang Wu

2013-01-01

Full Text Available The purpose of this paper is to present the exact solution for free torsional vibrations of a linearly tapered circular shaft carrying a number of concentrated elements. First of all, the equation of motion for free torsional vibration of a conic shaft is transformed into a Bessel equation, and, based on which, the exact displacement function in terms of Bessel functions is obtained. Next, the equations for compatibility of deformations and equilibrium of torsional moments at each attaching point (including the shaft ends between the concentrated elements and the conic shaft with positive and negative tapers are derived. From the last equations, a characteristic equation of the form is obtained. Then, the natural frequencies of the torsional shaft are determined from the determinant equation , and, corresponding to each natural frequency, the column vector for the integration constants, , is obtained from the equation . Substitution of the last integration constants into the associated displacement functions gives the corresponding mode shape of the entire conic shaft. To confirm the reliability of the presented theory, all numerical results obtained from the exact method are compared with those obtained from the conventional finite element method (FEM and good agreement is achieved.

Design considerations for sealing the shafts of a nuclear fuel waste disposal vault

International Nuclear Information System (INIS)

Mortazavi, M.H.S.; Chan, H.T.; Radhakrishna, H.S.

1985-05-01

The shafts in an underground disposal system, which constitute potential pathways between the disposal vault and the biosphere, should be effectively sealed if the system is to perform as a hydrodynamic and geochemical barrier for the safe containment of nuclear fuel waste. In the design of the shaft backfill, consideration should be given to ensure that the backfill and the backfill/rock interface remain intact. Design-related problems, including critical pathways for the transport or radionuclides, configuration of shaft backfill and its functional requirements, the state of stress in a backfilled shaft with particular emphasis on the arching and load transfer phenomenon are discussed in this report

Shaft Seal Compensates for Cold Flow

Science.gov (United States)

Myers, W. N.; Hein, L. A.

1985-01-01

Seal components easy to install. Ring seal for rotating or reciprocating shafts spring-loaded to compensate for slow yielding (cold flow) of sealing material. New seal relatively easy to install because components preassembled, then installed in one piece.

Precision electronic speed controller for an alternating-current motor

Science.gov (United States)

Bolie, V.W.

A high precision controller for an alternating-current multi-phase electrical motor that is subject to a large inertial load. The controller was developed for controlling, in a neutron chopper system, a heavy spinning rotor that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal having a meandering line frequency. The controller includes a shaft revolution sensor which provides a feedback pulse train representative of the actual speed of the motor. An internal digital timing signal generator provides a reference signal which is compared with the feedback signal in a computing unit to provide a motor control signal. The motor control signal is a weighted linear sum of a speed error voltage, a phase error voltage, and a drift error voltage, each of which is computed anew with each revolution of the motor shaft. The speed error signal is generated by a novel vernier-logic circuit which is drift-free and highly sensitive to small speed changes. The phase error is also computed by digital logic, with adjustable sensitivity around a 0 mid-scale value. The drift error signal, generated by long-term counting of the phase error, is used to compensate for any slow changes in the average friction drag on the motor. An auxillary drift-byte status sensor prevents any disruptive overflow or underflow of the drift-error counter. An adjustable clocked-delay unit is inserted between the controller and the source of the reference pulse train to permit phase alignment of the rotor to any desired offset angle. The stator windings of the motor are driven by two amplifiers which are provided with input signals having the proper quadrature relationship by an exciter unit consisting of a voltage controlled oscillator, a binary counter, a pair of read-only memories, and a pair of digital-to-analog converters.

Analysis of the Dynamic Behavior of a Rotating Composite Hollow Shaft

Directory of Open Access Journals (Sweden)

Aldemir Ap Cavalini Jr

Full Text Available Abstract In the present paper, a simplified homogenized beam theory is used in the context of a numerical investigation regarding the dynamic behavior of a rotating composite hollow shaft. For this aim, a horizontal flexible composite shaft and a rigid disc form the considered simple supported rotating system. The mathematical model of the rotor is derived from the Lagrange’s equation and the Rayleigh-Ritz method, which is obtained from the strain and kinetic energies of the disc and shaft, and the mass unbalance. In this case, a convergence procedure is carried out in terms of the vibration modes to obtain a representative model for the rotor system. Therefore, the proposed analysis is performed in both frequency and time domains, in which the frequency response functions, the unbalance responses, the Campbell diagram, and the orbits are numerically determined. Additionally, the instability threshold of the rotor system is obtained. This study illustrates the convenience of the composite hollow shafts for rotor dynamics applications.

General factors that affects the increase of population mobility and principles of optimization of high-speed passenger transportations

OpenAIRE

Momot, A.

2014-01-01

Purpose. Analyze the main factors that influence the increased mobility of the population in the transport market of Ukraine. Methods. The article uses an improved method of determining the optimal areas of high-speed passenger trains and determines the value of rational transportation of passengers in different directions of speed traffic, as well as the method of marginal income. Results. In this article we analyzed seven major factors that influence the increased mobility of the population...

Construction of full-scale shaft seals in crystalline rock

International Nuclear Information System (INIS)

Martino, J.B.; Dixon, D.A.; Onagi, D.; Kim, C-S; Holowick, B.

2011-01-01

The Underground Research Laboratory (URL) was constructed to investigate concepts related to geological disposal of used nuclear fuel. This involved investigating the rock mass by undertaking in situ experiments using a multi disciplinary technical approach. The decision was made in 2003 to close the URL. Part of the closure process involved installing seals in the access and ventilation shafts at locations where they intersected an ancient thrust fault (Fracture Zone 2 -- FZ2). FZ2 is an active hydraulic pathway in the Lac du Bonnet batholith and this feature is the dominating structural and hydrogeological feature at the URL site. Above FZ2 the groundwater has a low salinity and is dominated by surface-related processes. With increasing depth in the batholith, surface-related effects decrease and the salinity of the groundwater increases to 90 g/L total dissolved solids. The decision to install the seals was made as part of the due diligence for the site closure to ensure that the saline groundwater located at depth down strike and below the thrust fault would not enter the closed underground openings and mix with less saline shallow groundwater. The construction of each seal involved the installation of a heavily reinforced low alkalinity concrete component keyed into the surrounding rock. The concrete supported and restrained a central clay-sand component, which was capped by an unreinforced concrete component. The clay-sand component spans the exposure of the thrust fault in each shaft. This paper describes the construction of the main shaft seal and the ventilation shaft seal. The construction of the shaft seals at the URL was part of the Nuclear Legacy Liabilities Program (NLLP) being funded by Natural Resources Canada (NRCan). (author)

Construction of full-scale shaft seals in crystalline rock

Energy Technology Data Exchange (ETDEWEB)

Martino, J.B.; Dixon, D.A.; Onagi, D.; Kim, C-S; Holowick, B. [Atomic Energy of Canada Limited, Pinawa, MB (Canada)

2011-07-01

The Underground Research Laboratory (URL) was constructed to investigate concepts related to geological disposal of used nuclear fuel. This involved investigating the rock mass by undertaking in situ experiments using a multi disciplinary technical approach. The decision was made in 2003 to close the URL. Part of the closure process involved installing seals in the access and ventilation shafts at locations where they intersected an ancient thrust fault (Fracture Zone 2 -- FZ2). FZ2 is an active hydraulic pathway in the Lac du Bonnet batholith and this feature is the dominating structural and hydrogeological feature at the URL site. Above FZ2 the groundwater has a low salinity and is dominated by surface-related processes. With increasing depth in the batholith, surface-related effects decrease and the salinity of the groundwater increases to 90 g/L total dissolved solids. The decision to install the seals was made as part of the due diligence for the site closure to ensure that the saline groundwater located at depth down strike and below the thrust fault would not enter the closed underground openings and mix with less saline shallow groundwater. The construction of each seal involved the installation of a heavily reinforced low alkalinity concrete component keyed into the surrounding rock. The concrete supported and restrained a central clay-sand component, which was capped by an unreinforced concrete component. The clay-sand component spans the exposure of the thrust fault in each shaft. This paper describes the construction of the main shaft seal and the ventilation shaft seal. The construction of the shaft seals at the URL was part of the Nuclear Legacy Liabilities Program (NLLP) being funded by Natural Resources Canada (NRCan). (author)

An Evolutionary Multi-objective Approach for Speed Tuning Optimization with Energy Saving in Railway Management

OpenAIRE

Chevrier , Rémy

2010-01-01

International audience; An approach for speed tuning in railway management is presented for optimizing both travel duration and energy saving. This approach is based on a state-of-the-art evolutionary algorithm with Pareto approach. This algorithm provides a set of diversified non-dominated solutions to the decision-maker. A case study on Gonesse connection (France) is also reported and analyzed.

Magnetostrictive patch sensor system for battery-less real-time measurement of torsional vibrations of rotating shafts

Science.gov (United States)

Lee, Jun Kyu; Seung, Hong Min; Park, Chung Il; Lee, Joo Kyung; Lim, Do Hyeong; Kim, Yoon Young

2018-02-01

Real-time uninterrupted measurement for torsional vibrations of rotating shafts is crucial for permanent health monitoring. So far, strain gauge systems with telemetry units have been used for real-time monitoring. However, they have a critical disadvantage in that shaft operations must be stopped intermittently to replace telemetry unit batteries. To find an alternative method to carry out battery-less real-time measurement for torsional vibrations of rotating shafts, a magnetostrictive patch sensor system was proposed in the present study. Since the proposed sensor does not use any powered telemetry system, no battery is needed and thus there is no need to stop rotating shafts for battery replacement. The proposed sensor consists of magnetostrictive patches and small magnets tightly bonded onto a shaft. A solenoid coil is placed around the shaft to convert magnetostrictive patch deformation by shaft torsional vibration into electric voltage output. For sensor design and characterization, investigations were performed in a laboratory on relatively small-sized stationary solid shaft. A magnetostrictive patch sensor system was then designed and installed on a large rotating propulsion shaft of an LPG carrier ship in operation. Vibration signals were measured using the proposed sensor system and compared to those measured with a telemetry unit-equipped strain gauge system.

Comparison of tibial shaft ski fractures in children and adults.

Science.gov (United States)

Hamada, Tomo; Matsumoto, Kazu; Ishimaru, Daichi; Sumi, Hiroshi; Shimizu, Katsuji

2014-09-01

To examine whether child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures. Descriptive epidemiological study. Prospectively analyzed the epidemiologic factors, injury types, and injury mechanisms at Sumi Memorial Hospital. This study analyzed information obtained from 276 patients with tibial fractures sustained during skiing between 2004 and 2012. We focused on 174 ski-related tibial shaft fractures with respect to the following factors: age, gender, laterality of fracture, skill level, mechanism of fracture (fall vs collision), scene of injury (steepness of slope), snow condition, and weather. Fracture pattern was graded according to Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification and mechanical direction [external (ER) or internal rotation (IR)]. Tibial shaft fractures were the most common in both children (89.3%) and adults (47.4%). There were no significant differences in gender, side of fracture, mechanism of fracture, snow condition, or weather between children and adults. Skill levels were significantly lower in children than in adults (P differences in some of these parameters, suggesting that child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures.

Exploratory shaft conceptual design report: Gulf Interior Region salt domes

International Nuclear Information System (INIS)

1983-07-01

This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Gulf Interior Region of the United States (Louisiana and Mississippi). Conceptualized designs for other possible locations (Paradox Basin in Utah and Permian Basin in Texas) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in-situ testing of the salt. The in-situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homoqeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptural design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

Rotary compression process for producing toothed hollow shafts

Directory of Open Access Journals (Sweden)

J. Tomczak

2014-10-01

Full Text Available The paper presents the results of numerical analyses of the rotary compression process for hollow stepped shafts with herringbone teeth. The numerical simulations were performed by Finite Element Method (FEM, using commercial software package DEFORM-3D. The results of numerical modelling aimed at determining the effect of billet wall thickness on product shape and the rotary compression process are presented. The distributions of strains, temperatures, damage criterion and force parameters of the process determined in the simulations are given, too. The numerical results obtained confirm the possibility of producing hollow toothed shafts from tube billet by rotary compression methods.

Shaft sealing issue in CO2 storage sites

Science.gov (United States)

Dieudonné, A.-C.; Charlier, R.; Collin, F.

2012-04-01

Carbon capture and storage is an innovating approach to tackle climate changes through the reduction of greenhouse gas emissions. Deep saline aquifers, depleted oil and gas reservoirs and unmineable coal seams are among the most studied reservoirs. However other types of reservoir, such as abandonned coal mines, could also be used for the storage of carbon dioxide. In this case, the problem of shaft sealing appears to be particularly critical regarding to the economic, ecologic and health aspects of geological storage. The purpose of the work is to study shaft sealing in the framework of CO2 storage projects in abandoned coal mines. The problem of gas transfers around a sealing system is studied numerically using the finite elements code LAGAMINE, which has been developped for 30 years at the University of Liege. A coupled hydro-mechanical model of unsaturated geomaterials is used for the analyses. The response of the two-phase flow model is first studied through a simple synthetic problem consisting in the injection of gas in a concrete-made column. It stands out of this first modeling that the advection of the gas phase represents the main transfer mechanism of CO2 in highly unsaturated materials. Furthermore the setting of a bentonite barrier seal limits considerably the gas influx into the biosphere. A 2D axisymetric hydromechanical modeling of the Anderlues natural gas storage site is then performed. The geological and hydrogeological contexts of the site are used to define the problem, for the initial and boundary conditions, as well as the material properties. In order to reproduce stress and water saturation states in the shale before CO2 injection in the mine, different phases corresponding to the shaft sinking, the mining and the set up of the sealing system are simulated. The system efficiency is then evaluated by simulating the CO2 injection with the imposed pressure at the shaft wall. According to the modeling, the low water saturation of concrete and

The optimization of low specific speed centrifugal pump based on incomplete sensitivities

International Nuclear Information System (INIS)

Zhang, R H; Zheng, K; Shi, F X; Yao, L H

2012-01-01

In this research, the optimization method for low specific speed centrifugal pump impeller based on incomplete sensitivities was proposed. The main feature of the algorithm is that it avoids solving the flow field repeatedly in one optimization cycle in finite difference method and it avoids solving the adjoint equation in adjoint method. The blade meridional plan is considered as constant, and the blade camber line was parameterize by Taylor function. The coefficients in the Taylor function were taken as the control variable. The moment acting on the blade was considered as the objective function. With the incomplete sensitivities we can get the gradient of the objective function with respect to the control variable easily, and the blade shape can be renewed according to the inverse direction of the gradient. We will find the optimum design when the objective function is minimized. The computational cost is greatly reduced. The calculation cases show that the proposed theory and method is rotational.

A Multi-Point Method Considering the Maximum Power Point Tracking Dynamic Process for Aerodynamic Optimization of Variable-Speed Wind Turbine Blades

Directory of Open Access Journals (Sweden)

Zhiqiang Yang

2016-05-01

Full Text Available Due to the dynamic process of maximum power point tracking (MPPT caused by turbulence and large rotor inertia, variable-speed wind turbines (VSWTs cannot maintain the optimal tip speed ratio (TSR from cut-in wind speed up to the rated speed. Therefore, in order to increase the total captured wind energy, the existing aerodynamic design for VSWT blades, which only focuses on performance improvement at a single TSR, needs to be improved to a multi-point design. In this paper, based on a closed-loop system of VSWTs, including turbulent wind, rotor, drive train and MPPT controller, the distribution of operational TSR and its description based on inflow wind energy are investigated. Moreover, a multi-point method considering the MPPT dynamic process for the aerodynamic optimization of VSWT blades is proposed. In the proposed method, the distribution of operational TSR is obtained through a dynamic simulation of the closed-loop system under a specific turbulent wind, and accordingly the multiple design TSRs and the corresponding weighting coefficients in the objective function are determined. Finally, using the blade of a National Renewable Energy Laboratory (NREL 1.5 MW wind turbine as the baseline, the proposed method is compared with the conventional single-point optimization method using the commercial software Bladed. Simulation results verify the effectiveness of the proposed method.

Interaction between drilled shaft and mechanically stabilized earth (MSE) wall : project summary.

Science.gov (United States)

2015-08-31

Drilled shafts are being constructed within the reinforced zone of mechanically stabilized earth (MSE) walls (Figure 1). The drilled shafts may be subjected to horizontal loads and push against the front of the wall. Distress of MSE wall panels has b...

Wind Turbine Generator Modeling and Simulation Where Rotational Speed is the Controlled Variable

DEFF Research Database (Denmark)

Mihet-Popa, Lucian; Blaabjerg, Frede; Boldea, Ion

2004-01-01

the interaction between a wind turbine and the power system. The model is intended to simulate the behaviour of the wind turbine using induction generators both during normal operation. Sample simulation results for two induction generators (2/0.5 MW) validate the fundamental issues.......To optimise the power produced in a wind turbine, the speed of the turbine should vary with the wind speed. A simple control method is proposed that will allow an induction machine to run a turbine at its maximum power coefficient. Various types of power control strategies have been suggested...... for application in variable speed wind turbines. The usual strategy is to control the power or the torque acting on the wind turbine shafts. This paper presents an alternative control strategy, where the rotational speed is the controlled variable. The paper describes a model, which is being developed to simulate...

Ticket Fare Optimization for China’s High-Speed Railway Based on Passenger Choice Behavior

Directory of Open Access Journals (Sweden)

Jinzi Zheng

2017-01-01

Full Text Available Although China’s high-speed railway (HSR is maturing after more than ten years of construction and development, the load factor and revenue of HSR could still be improved by optimizing the ticket fare structure. Different from the present unitary and changeless fare structure, this paper explores the application of multigrade fares to China’s HSR. On the premise that only one fare grade can be offered for each origin-destination (O-D at the same time, this paper addresses the questions of how to adjust ticket price over time to maximize the revenue. First, on the basis of piecewise pricing strategy, a ticket fare optimization model is built, which could be transformed to convex program to be solved. Then, based on the analysis of passenger arrival regularity using historical ticket data of Beijing-Shanghai HSR line, several experiments are performed using the method proposed in the paper to explore the properties of the optimal multigrade fare scheme.

The detection of wind turbine shaft misalignment using temperature monitoring

OpenAIRE

Tonks, Oliver; Wang, Qing

2016-01-01

Temperature is a parameter increasingly monitored in wind turbine systems. This paper details a potential temperature monitoring technique for use on shaft couplings. Such condition monitoring methods aid fault detection in other areas of wind turbines. However, application to shaft couplings has not previously been widely researched. A novel temperature measurement technique is outlined, using an infra-red thermometer which can be applied to online condition monitoring. The method was va...

Granuloma annulare localized to the shaft of the penis

DEFF Research Database (Denmark)

Trap, R; Wiebe, B

1993-01-01

A case of granuloma annulare localized to the shaft of the penis is reported. The differential diagnoses are discussed. Penile granuloma annulare is a rare disorder and it is concluded that biopsies of penile lesions are recommended to verify the correct diagnosis.......A case of granuloma annulare localized to the shaft of the penis is reported. The differential diagnoses are discussed. Penile granuloma annulare is a rare disorder and it is concluded that biopsies of penile lesions are recommended to verify the correct diagnosis....

The design of a turboshaft speed governor using modern control techniques

Science.gov (United States)

Delosreyes, G.; Gouchoe, D. R.

1986-01-01

The objectives of this program were: to verify the model of off schedule compressor variable geometry in the T700 turboshaft engine nonlinear model; to evaluate the use of the pseudo-random binary noise (PRBN) technique for obtaining engine frequency response data; and to design a high performance power turbine speed governor using modern control methods. Reduction of T700 engine test data generated at NASA-Lewis indicated that the off schedule variable geometry effects were accurate as modeled. Analysis also showed that the PRBN technique combined with the maximum likelihood model identification method produced a Bode frequency response that was as accurate as the response obtained from standard sinewave testing methods. The frequency response verified the accuracy of linear models consisting of engine partial derivatives and used for design. A power turbine governor was designed using the Linear Quadratic Regulator (LQR) method of full state feedback control. A Kalman filter observer was used to estimate helicopter main rotor blade velocity. Compared to the baseline T700 power turbine speed governor, the LQR governor reduced droop up to 25 percent for a 490 shaft horsepower transient in 0.1 sec simulating a wind gust, and up to 85 percent for a 700 shaft horsepower transient in 0.5 sec simulating a large collective pitch angle transient.

Shaft seals for final high-level radioactive waste repositories. ELSA. Pt. 1

International Nuclear Information System (INIS)

Kudla, W.; Schreiter, F.; Gruner, M.

2013-01-01

The state of the art in science and technology fir shaft seals with long-term stability is summarized regarding their applicability for high-level waste repository in Germany. The concepts and drafts for the shaft sealing systems ERAM, Asse, Konrad, the WIPP side, the RESEAL concept, the NAGRA concept and the project LASA are reviewed. The methodology of applying partial factors in a safety analysis is summarized and the applicability of this method for geotechnical sealing structures is confirmed. To establish geomechanical boundary conditions of the host rocks and clay stone the stress-strain behavior of the rock mass adjoining the shaft has to be identified including time-dependent thermo-mechanical processes. The general and special requirements for the design of shaft sealing systems, especially in salt rock and clay formations are described, derived from the safety requirements (BMU 2010). Finally general information needs were identified.

Technique to reduce the shaft torque stress at an induction machine

Directory of Open Access Journals (Sweden)

Adrian Tulbure

2005-10-01

Full Text Available For the active attenuation at load stress in the drive shaft, the control system should receive as input signal the instantaneous shaft torque value. In this context an intelligent observer for shaft tongue of mains operatea induction machine, which is able to responding by variation of LIF (Load Input Function[1] must be developed. Extensive computer simulation prove the effectiveness of the proposed solution. In order to obtain a practical validation, the stimulated regulator has been designed and tested in the Institute of Electrical Engineering in Clausthal/Germany [2]. This paper contains following parts: Developing the mathematical model, Practical realisation, Simulations and measurements, Evaluating the control solutions and Conclusions.

Application of the cylindrically guided wave technique for bolt and pump-shaft inspections

International Nuclear Information System (INIS)

Light, G.M.; Ruescher, E.H.; Bloom, E.A.; Tsai, Y.M.

1990-01-01

Southwest Research Institute (SwRI) has been working with the cylindrically guided wave technique (CGWT) since late 1982. The initial work was aimed at inspecting reactor pressure vessel hold-down studs. The CGWT was shown to be able to detect defects as small as 0.060 inch (1.5 mm) deep through metal paths up to 120 inches (304 cm) in stud bolt carbon steel. Later developments in the application of CGWT were aimed at inspecting reactor coolant pump (RCP) shafts. The RCP shafts are usually approximately 2 meters long and have changing diameters along the length, from approximately 12 cm to 23 cm in discrete steps. The pump shafts have been susceptible to small cracks and can be inspected most cost-effectively from the top of the shaft. A matrix transducer composed of six 1-inch (2.54-cm) diameter transducers along with pulsing and receiving electronics (EPRI Pump-Shaft Inspection System) was developed during 1988. A patent application for this technology has been made. This report describes the work conducted during 1989 and the results obtained

Rustler Formation in the waste handling and exhaust shafts, Waste Isolation Pilot Plant (WIPP) site, southeastern New Mexico

International Nuclear Information System (INIS)

Holt, R.M.; Powers, D.W.

1987-01-01

The Permian Rustler Formation was recently examined in detail in two shafts at the WIPP site: the waste handling shaft (waste shaft) and the exhaust shaft. Fresh exposures of the Rustler in the shafts exhibited abundant primary sedimentary structures. The abundance of primary sedimentary structures observed in the shafts is unequaled in previously described sections. Data are reported here in their stratigraphic context as an initial basis for evaluation of depositional environments of the Rustler and reevaluating the role of dissolution in the formation of the Rustler. 10 refs

Seismic fragility capacity of equipment--horizontal shaft pump test

International Nuclear Information System (INIS)

Iijima, T.; Abe, H.; Suzuki, K.

2005-01-01

The current seismic fragility capacity of horizontal shaft pump is 1.6 x 9.8 m/s 2 (1.6 g), which was decided from previous vibration tests and we believe that it must have sufficient margin. The purpose of fragility capacity test is to obtain realistic seismic fragility capacity of horizontal shaft pump by vibration tests. Reactor Building Closed Cooling Water (RCW) Pump was tested as a typical horizontal shaft pump, and then bearings and liner rings were tested as important parts to evaluate critical acceleration and dispersion. Regarding RCW pump test, no damage was found, though maximum input acceleration level was 6 x 9.8 m/s 2 (6 g). Some kinds of bearings and liner rings were tested on the element test. Input load was based on seismic motion which was same with the RCW pump test, and maximum load was equivalent to over 20 times of design seismic acceleration. There was not significant damage that caused emergency stop of pump but degradation of surface roughness was found on some kinds of bearings. It would cause reduction of pump life, but such damage on bearings occurred under large seismic load condition that was equivalent to over 10 to 20 g force. Test results show that realistic fragility capacity of horizontal shaft pump would be at least four times as higher as current value which has been used for our seismic PSA. (authors)

Space Shuttle Orbital Maneuvering Subsystem (OMS) Engine Propellant Leakage Ball-Valve Shaft Seals

Science.gov (United States)

Lueders, Kathy; Buntain, Nick; Fries, Joseph (Technical Monitor)

1999-01-01

Evidence of propellant leakage across ball-valve shaft seals has been noted during the disassembly of five flight engines and one test engine at the NASA Lyndon B. Johnson Space Center, White Sands Test Facility. Based on data collected during the disassembly of these five engines, the consequences of propellant leakage across the ball-valve shaft seals can be divided into four primary areas of concern: Damage to the ball-valve pinion shafts, damage to sleeved bearings inside the ball-valve and actuator assemblies, degradation of the synthetic rubber o-rings used in the actuator assemblies, and corrosion and degradation to the interior of the actuator assemblies. The exact time at which leakage across the ball-valve shaft seals occurs has not been determined, however, the leakage most likely occurs during engine firings when, depending on the specification used, ball-valve cavity pressures range as high as 453 to 550 psia. This potential pressure range for the ball-valve cavities greatly exceeds the acceptance leakage test pressure of 332 psia. Since redesign and replacement of the ball-valve shaft seals is unlikely, the near term solution to prevent damage that occurs from shaft-seal leakage is to implement a routine overhaul and maintenance program for engines in the fleet. Recommended repair, verification, and possible preventative maintenance measures are discussed in the paper.

Implementation of a flaw model to the fracturing around a vertical shaft

CSIR Research Space (South Africa)

Van de Steen, B

2003-04-01

Full Text Available -scale excavations. The simulated fracture pattern around a vertical shaft is compared to the fracturing around a shaft at a depth of 3400 m. The simulations suggest that wedge-shaped zones, called dog-ears, a reformed by a progressive splitting-like failure...

Machine Directional Register System Modeling for Shaft-Less Drive Gravure Printing Machines

Directory of Open Access Journals (Sweden)

Shanhui Liu

2013-01-01

Full Text Available In the latest type of gravure printing machines referred to as the shaft-less drive system, each gravure printing roller is driven by an individual servo motor, and all motors are electrically synchronized. The register error is regulated by a speed difference between the adjacent printing rollers. In order to improve the control accuracy of register system, an accurate mathematical model of the register system should be investigated for the latest machines. Therefore, the mathematical model of the machine directional register (MDR system is studied for the multicolor gravure printing machines in this paper. According to the definition of the MDR error, the model is derived, and then it is validated by the numerical simulation and experiments carried out in the experimental setup of the four-color gravure printing machines. The results show that the established MDR system model is accurate and reliable.

Control rod drive shaft latch

International Nuclear Information System (INIS)

Thorp, A.G. II.

1976-01-01

A latch mechanism is operated by differential pressure on a piston to engage the drive shaft for a control rod in a nuclear reactor, thereby preventing the control rod from being ejected from the reactor in case of failure of the control rod drive mechanism housing which is subjected to the internal pressure in the reactor vessel. 6 claims, 4 drawing figures

Load speed regulation in compliant mechanical transmission systems using feedback and feedforward control actions.

Science.gov (United States)

Raul, P R; Dwivedula, R V; Pagilla, P R

2016-07-01

The problem of controlling the load speed of a mechanical transmission system consisting of a belt-pulley and gear-pair is considered. The system is modeled as two inertia (motor and load) connected by a compliant transmission. If the transmission is assumed to be rigid, then using either the motor or load speed feedback provides the same result. However, with transmission compliance, due to belts or long shafts, the stability characteristics and performance of the closed-loop system are quite different when either motor or load speed feedback is employed. We investigate motor and load speed feedback schemes by utilizing the singular perturbation method. We propose and discuss a control scheme that utilizes both motor and load speed feedback, and design an adaptive feedforward action to reject load torque disturbances. The control algorithms are implemented on an experimental platform that is typically used in roll-to-roll manufacturing and results are shown and discussed. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Planar rotational magnetic micromotors with integrated shaft encoder and magnetic rotor levitation

Science.gov (United States)

Guckel, Henry; Christenson, T. R.; Skrobis, K. J.; Klein, J.; Karnowsky, M.

1994-01-01

Deep x-ray lithography and electroplating may be combined to form a fabrication tool for micromechanical devices with large structural heights, to 500 micron, and extreme edge acuities, less than 0.1 micron-run-out per 100 micron of height. This process concept which originated in Germany as LIGA may be further extended by adding surface micromachining. This extension permits the fabrication of precision metal and plastic parts which may be assembled into three-dimensional micromechanical components and systems. The processing tool may be used to fabricate devices from ferromagnetic material such as nickel and nickel-iron alloys. These materials when properly heat treated exhibit acceptable magnetic behavior for current to flux conversion and marginal behavior for permanent magnet applications. The tool and materials have been tested via planar, magnetic, rotational micromotor fabrication. Three phase reluctance machines of the 6:4 configuration with 280 micron diameter rotors have been tested and analyzed. Stable rotational speeds to 34,000 rpm with output torques above 10 x 10(exp -9) N-m have been obtained. The behavior is monitored with integrated shaft encoders which are photodiodes which measure the rotor response. Magnetic levitation of the rotor via reluctance forces has been achieved and has reduced frictional torque losses to less than 1 percent of the available torque. The results indicate that high speed limits of these actuators are related to torque ripple. Hysteresis motors with magnetic bearings are under consideration and will produce high speed rotational machines with excellent sensor application potential.

Expected long-term outcome after a tibial shaft fracture

DEFF Research Database (Denmark)

Faergemann, C; Frandsen, P A; Röck, N D

1999-01-01

OBJECTIVE: A prospective study of 207 laymen and professionals answered a questionnaire regarding the expectations of the long-term outcome 6 months after a unilateral tibial shaft fracture. The aim was (1) to disclose the expected outcome after unilateral tibial shaft fracture, and (2) to compare...... these expectations with the outcome measured in patients. METHODS: There were five groups of nonpatients: (1) 42 orthopedic surgeons, (2) 36 physiotherapists, (3) 42 students, (4) 49 white collar workers, and (5) 38 blue collar workers. Outcome was measured by Sickness Impact Profile (SIP). The SIP scores were...

Less invasive plate osteosynthesis in humeral shaft fractures.

Science.gov (United States)

Apivatthakakul, Theerachai; Phornphutkul, Chanakarn; Laohapoonrungsee, Anupong; Sirirungruangsarn, Yuddhasert

2009-12-01

Stable internal fixation of the humeral shaft by less invasive percutaneous plate insertion using two separate (proximal and distal) incisions, indirect reduction by closed manipulation and fixation to preserve the soft tissue and blood supply at the fracture zone. Early mobilization of the shoulder and elbow to ensure a good functional outcome. Humeral shaft fractures (classified according to AO classification as: 12-A, B, C). Humeral shaft fractures extending to the proximal or distal shaft, small or deformed medullary canal or open growth plate. Humeral shaft fractures with primary radial nerve palsy. Proximal humeral shaft fractures extending to the humeral head. Distal humeral fractures extending to the elbow joint. Two incisions proximal and distal to the fracture zone are used. A 3-cm proximal incision lies between the lateral border of the proximal part of the biceps and the medial border of the deltoid. Distally, a 3-cm incision is made along the lateral border of the biceps. The interval between biceps and brachialis is identified. The biceps is retracted medially to expose the musculocutaneous nerve. The brachialis muscle has dual innervation, the medial half being innervated by the musculocutaneous nerve and the lateral half by the radial nerve. The brachialis is split longitudinally at its midline. The musculocutaneous nerve is retracted along with the medial half of the brachialis, while the lateral half of the brachialis serves as a cushion to protect the radial nerve. A deep subbrachial tunnel is created from the distal to the proximal incision. The selected plate is tied with a suture to a hole at the tip of the tunneling instrument for pulling the plate back along the prepared track. The plate is aligned in the correct position on the anterior surface of the humerus. Traction is applied and the fracture reduced to restore alignment by image intensifier, followed by plate fixation with at least two bicortical locking screws or three bicortical

Survey and analytical studies on a 'TAKANUKE' collapse mechanism for greatly deeper shafts (Contract research)

International Nuclear Information System (INIS)

Kurosaki, Yukio; Yamachi, Hiroshi; Matsui, Hiroya

2008-09-01

Mizunami underground research laboratory (MIU) is planned to be excavated to the depth of 1000m below the ground surface and is now under construction. One of the most serious problems in a greatly deeper shaft is 'TAKANUKE' collapse caused by slip movement of large discontinuities, as we have reported in the report of 'Study on Collapse Mechanism of Junction between Greatly Deeper Shaft and Horizontal Drifts [JAEA-Research 2008-248 (2008)]'. TAKANUKE collapse has been well known among mining engineers in JAPAN. However, an occurring mechanism of the collapse has not yet been revealed and a design code for it also has not been established. In this report, we have conducted numerical studies using finite difference method in order to throw an objective light on a mechanism of TAKANUKE collapse. These studies show two different stress states in upper and lower side of a large discontinuities. In lower side, a minimum principal stress at shaft wall region drastically reduces due to shaft sinking. This might make shaft wall stability difficult in poor geological condition. Such a TAKANUKE collapse can be found in ventilation shaft projects of the ENASAN tunnel. In the another side of discontinuity, a slip movement along discontinuities takes place due to shaft sinking. This slip movement induces a typical TAKANUKE collapse, as we have reported in 2007. In order to evaluate a possibility of TAKANUKE collapse during MIU main shaft sinking, we have conducted a particle body analysis, which can estimate a brittle failure of hard rock, such as MIU construction site. A fault with a steeply dipping over 79 degree to the main shaft, discovered in a survey boring at MIU site, has a low potential of TAKANUKE collapse during shaft sinking. Beside, a fault with dip of 60 degree may easily slip in a form of TAKANUKE collapse. One CD-ROM is attached as an appendix. (J.P.N.)

Documentation and verification of the SHAFT code; Yucca Mountain Site Characterization Project

Energy Technology Data Exchange (ETDEWEB)

St.John, C.M. [Agapito (J.F.T.) and Associates, Inc., Grand Junction, CO (United States)

1991-12-01

The SHAFT code incorporates equations to compute stresses in a shaft liner when the rock through which a shaft passes is subject to known three-dimensional states of stress or strain. The deformation modes considered are hoop deformation, axial deformation, and shear on a plane normal to the shaft axis. Interaction between the liner and the soil and rock is considered, and it is assumed that the liner is in place before loading is applied. This code is intended to be used interactively but creates a permanent record complete with necessary quality assurance information. The code has been carefully verified for the case of generalized plane strain, in which an arbitrary axial strain can be defined. It may also be used for plane stress analysis. Output is given in the form of stresses at selected sample points in the linear and the rock and a simple graphical representation of the distribution of stress through the liner. 12 figs., 13 tabs.

Mechanism of magnetic liquid flowing in the magnetic liquid seal gap of reciprocating shaft

Science.gov (United States)

Li, Decai; Xu, Haiping; He, Xinzhi; Lan, Huiqing

2005-03-01

In order to solve the problems that exist in the magnetic liquid seal of reciprocating shaft, we have set up an experimental facility, which composes a camera, microscope, step-by-step motor, pin roller screw, reciprocating motion shaft, pole pieces, permanent magnet and the magnetic liquid in the seal gap. Through the optical technology and image process of the experimental facility, we have studied the magnetic liquid flow in the seal gap when the reciprocating shaft moves with different velocities and strokes. This study specially concentrates on: (1) the regular pattern of such flow; (2) the loss quantity of magnetic liquid caused by the reciprocating motion shaft; (3) the failure reasons of this magnetic liquid seal; and (4) the design of a new structure for the magnetic liquid seal of reciprocating shaft. The application indicates that the new structure is very effective in some occasions. The new structure was accepted as the state patent in 2001 and authenticated as the achievement in the scientific research in 2002.

Mechanism of magnetic liquid flowing in the magnetic liquid seal gap of reciprocating shaft

International Nuclear Information System (INIS)

Li Decai; Xu Haiping; He Xinzhi; Lan Huiqing

2005-01-01

In order to solve the problems that exist in the magnetic liquid seal of reciprocating shaft, we have set up an experimental facility, which composes a camera, microscope, step-by-step motor, pin roller screw, reciprocating motion shaft, pole pieces, permanent magnet and the magnetic liquid in the seal gap. Through the optical technology and image process of the experimental facility, we have studied the magnetic liquid flow in the seal gap when the reciprocating shaft moves with different velocities and strokes. This study specially concentrates on: (1) the regular pattern of such flow; (2) the loss quantity of magnetic liquid caused by the reciprocating motion shaft; (3) the failure reasons of this magnetic liquid seal; and (4) the design of a new structure for the magnetic liquid seal of reciprocating shaft. The application indicates that the new structure is very effective in some occasions. The new structure was accepted as the state patent in 2001 and authenticated as the achievement in the scientific research in 2002

A calculation method of the optimal distance of the long-drawn short-pressure type localfan in minebased on the principle of the jet and Suction volume

Science.gov (United States)

Fu, Shaotong

2018-01-01

In order to dilute the harmful smoke and dust of the working surface in the production of the roadway in the mine shaft, the combination of mine local ventilation is often considered when conditions permitting. However there is no definite method to determine the distance between fan and working surface. Considering the concentration of smoke, the size of working face, the ventilation time, the wind speed of the working face and the principle of suction volume, this paper analyzes the long - drawn short - pressure type of the ventilation scheme, and presents an optimal algorithm for the distance between the exhaust ventilator and the working face:{{L}}{{o}}=\\frac{{({{{v}}}{{f}}{{t}})}{{Z}}{{{S}}}{{o}}\\frac{\\exists }{{{z}}{{β }}}}{3.398{{{S}}}W\\frac{1}{{{z}}{{A}}}}. Then this paperpresentsa reference distance for different wind speed requirements of a project.

Hydro-mechanical modelling of a shaft seal in crystalline and sedimentary host rock media using COMSOL

Energy Technology Data Exchange (ETDEWEB)

Priyanto, D.G. [Atomic Energy of Canada Limited, Pinawa, MB (Canada)

2011-07-01

Shaft seals are components of the engineered barriers system considered for closure of a Deep Geological Repository (DGR). These seals would be installed in strategic locations of the shafts, where significant fracture zones (FZ) are located and would serve to limit upward flow of groundwater from the repository level towards the surface. This paper presents the results of hydro-mechanical (HM) numerical modelling exercises to evaluate the performance of a shaft seal using a finite element computer code, COMSOL. This study considered a variety of host geological media as part of generic assessments of system evolution in a variety of environments including five hypothetical sedimentary and crystalline host rock conditions. Four simulations of a shaft seal in different sedimentary rocks were completed, including: shale with isotropic permeability; shale with anisotropic permeability; limestone with isotropic permeability; and limestone with anisotropic permeability. The other simulation was a shaft seal in crystalline rock with isotropic permeability. Two different stages were considered in these HM simulations. Stages 1 and 2 simulated the groundwater flow into an open shaft and after installation of shaft sealing components, respectively. As expected, the models were able to simulate that installation of the shaft seal limits groundwater flow through the shaft. Based on the conditions and assumptions defined for the host media and fracture features examined in this study, the following conclusions can be drawn from the results of the numerical modelling exercises. A shaft that remained open for a longer time was beneficial with respect to delaying of seal saturation because it could reduce the groundwater flow rate around the fracture zone. Delaying saturation time indicates slower movement of the groundwater or other substances that may be transported with the groundwater. The core of the shaft seal (i.e., the bentonite-sand mixture (BSM)) became fully saturated

Load and resistance factor design of drilled shafts in shale for lateral loading.

Science.gov (United States)

2014-04-01

A research project involving 32 drilled shaft load tests was undertaken to establish LRFD procedures for : design of drilled shafts subjected to lateral loads. Tests were performed at two Missouri Department of : Transportation (MoDOT) geotechnical r...

SHABERTH - ANALYSIS OF A SHAFT BEARING SYSTEM (CRAY VERSION)

Science.gov (United States)

Coe, H. H.

1994-01-01

The SHABERTH computer program was developed to predict operating characteristics of bearings in a multibearing load support system. Lubricated and non-lubricated bearings can be modeled. SHABERTH calculates the loads, torques, temperatures, and fatigue life for ball and/or roller bearings on a single shaft. The program also allows for an analysis of the system reaction to the termination of lubricant supply to the bearings and other lubricated mechanical elements. SHABERTH has proven to be a valuable tool in the design and analysis of shaft bearing systems. The SHABERTH program is structured with four nested calculation schemes. The thermal scheme performs steady state and transient temperature calculations which predict system temperatures for a given operating state. The bearing dimensional equilibrium scheme uses the bearing temperatures, predicted by the temperature mapping subprograms, and the rolling element raceway load distribution, predicted by the bearing subprogram, to calculate bearing diametral clearance for a given operating state. The shaft-bearing system load equilibrium scheme calculates bearing inner ring positions relative to the respective outer rings such that the external loading applied to the shaft is brought into equilibrium by the rolling element loads which develop at each bearing inner ring for a given operating state. The bearing rolling element and cage load equilibrium scheme calculates the rolling element and cage equilibrium positions and rotational speeds based on the relative inner-outer ring positions, inertia effects, and friction conditions. The ball bearing subprograms in the current SHABERTH program have several model enhancements over similar programs. These enhancements include an elastohydrodynamic (EHD) film thickness model that accounts for thermal heating in the contact area and lubricant film starvation; a new model for traction combined with an asperity load sharing model; a model for the hydrodynamic rolling and

A shaft seal system for the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Hansen, F.D.; Ahrens, E.H.; Dennis, A.W.; Hurtado, L.D.; Knowles, M.K.; Tillerson, J.R.; Thompson, T.W.; Galbraith, D.

1996-01-01

As part of the demonstration of compliance with federal regulations, a shaft seal system has been designed for the Waste Isolation Pilot Plant. The system completely fills the 650 m shafts with components consisting of the common engineering materials, each of which possesses low permeability, longevity, and can be constructed using available technology. Design investigations couple rock mechanics and fluid flow analysis and tests of these materials within the natural geological setting, and demonstrate the effectiveness of the design

An Analysis of Variable-Speed Wind Turbine Power-Control Methods with Fluctuating Wind Speed

Directory of Open Access Journals (Sweden)

Seung-Il Moon

2013-07-01

Full Text Available Variable-speed wind turbines (VSWTs typically use a maximum power-point tracking (MPPT method to optimize wind-energy acquisition. MPPT can be implemented by regulating the rotor speed or by adjusting the active power. The former, termed speed-control mode (SCM, employs a speed controller to regulate the rotor, while the latter, termed power-control mode (PCM, uses an active power controller to optimize the power. They are fundamentally equivalent; however, since they use a different controller at the outer control loop of the machine-side converter (MSC controller, the time dependence of the control system differs depending on whether SCM or PCM is used. We have compared and analyzed the power quality and the power coefficient when these two different control modes were used in fluctuating wind speeds through computer simulations. The contrast between the two methods was larger when the wind-speed fluctuations were greater. Furthermore, we found that SCM was preferable to PCM in terms of the power coefficient, but PCM was superior in terms of power quality and system stability.

Designing vertical shafts for mines with deepening and outlet of rock to the operating level

Energy Technology Data Exchange (ETDEWEB)

Durov, Ye.M.

1983-01-01

Requirements for designing the cross sections of central shafts are examined, as well as those for determining the productivity of lifts and equipment of the shafts with a condition of use in a subsequent technological layout of their deepening with outlet of the rock to the operating level. Typical cross sections of skip and cellular shafts are given.

Bentonite as a waste isolation pilot plant shaft sealing material

International Nuclear Information System (INIS)

Daemen, J.; Ran, Chongwei

1996-12-01

Current designs of the shaft sealing system for the Waste Isolation Pilot Plant (WIPP) propose using bentonite as a primary sealing component. The shaft sealing designs anticipate that compacted bentonite sealing components can perform through the 10,000-year regulatory period and beyond. To evaluate the acceptability of bentonite as a sealing material for the WIPP, this report identifies references that deal with the properties and characteristics of bentonite that may affect its behavior in the WIPP environment. This report reviews published studies that discuss using bentonite as sealing material for nuclear waste disposal, environmental restoration, toxic and chemical waste disposal, landfill liners, and applications in the petroleum industry. This report identifies the physical and chemical properties, stability and seal construction technologies of bentonite seals in shafts, especially in a saline brine environment. This report focuses on permeability, swelling pressure, strength, stiffness, longevity, and densification properties of bentonites

Bentonite as a waste isolation pilot plant shaft sealing material

Energy Technology Data Exchange (ETDEWEB)

Daemen, J.; Ran, Chongwei [Univ. of Nevada, Reno, NV (United States)

1996-12-01

Current designs of the shaft sealing system for the Waste Isolation Pilot Plant (WIPP) propose using bentonite as a primary sealing component. The shaft sealing designs anticipate that compacted bentonite sealing components can perform through the 10,000-year regulatory period and beyond. To evaluate the acceptability of bentonite as a sealing material for the WIPP, this report identifies references that deal with the properties and characteristics of bentonite that may affect its behavior in the WIPP environment. This report reviews published studies that discuss using bentonite as sealing material for nuclear waste disposal, environmental restoration, toxic and chemical waste disposal, landfill liners, and applications in the petroleum industry. This report identifies the physical and chemical properties, stability and seal construction technologies of bentonite seals in shafts, especially in a saline brine environment. This report focuses on permeability, swelling pressure, strength, stiffness, longevity, and densification properties of bentonites.

Geologic mapping of the air intake shaft at the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Holt, R.M.; Powers, D.W.

1990-12-01

The air intake shaft (AS) was geologically mapped from the surface to the Waste Isolation Pilot Plant (WIPP) facility horizon. The entire shaft section including the Mescalero Caliche, Gatuna Formation, Santa Rosa Formation, Dewey Lake Redbeds, Rustler Formation, and Salado Formation was geologically described. The air intake shaft (AS) at the Waste Isolation Pilot Plant (WIPP) site was constructed to provide a pathway for fresh air into the underground repository and maintain the desired pressure balances for proper underground ventilation. It was up-reamed to minimize construction-related damage to the wall rock. The upper portion of the shaft was lined with slip-formed concrete, while the lower part of the shaft, from approximately 903 ft below top of concrete at the surface, was unlined. As part of WIPP site characterization activities, the AS was geologically mapped. The shaft construction method, up-reaming, created a nearly ideal surface for geologic description. Small-scale textures usually best seen on slabbed core were easily distinguished on the shaft wall, while larger scale textures not generally revealed in core were well displayed. During the mapping, newly recognized textures were interpreted in order to refine depositional and post-depositional models of the units mapped. The objectives of the geologic mapping were to: (1) provide confirmation and documentation of strata overlying the WIPP facility horizon; (2) provide detailed information of the geologic conditions in strata critical to repository sealing and operations; (3) provide technical basis for field adjustments and modification of key and aquifer seal design, based upon the observed geology; (4) provide geological data for the selection of instrument borehole locations; (5) and characterize the geology at geomechanical instrument locations to assist in data interpretation. 40 refs., 27 figs., 1 tab

Investigation on Flow-Induced Noise due to Backflow in Low Specific Speed Centrifugal Pumps

Directory of Open Access Journals (Sweden)

Qiaorui Si

2013-01-01

Full Text Available Flow-induced noise causes disturbances during the operation of centrifugal pumps and also affects their performance. The pumps often work at off-design conditions, mainly at part-load conditions, because of frequent changes in the pump device system. Consequently numerous unstable phenomena occur. In low specific speed centrifugal pumps the main disturbance is the inlet backflow, which is considered as one of the most important factors of flow-induced noise and vibration. In this study, a test rig of the flow-induced noise and vibration of the centrifugal pump was built to collect signals under various operating conditions. The three-dimensional unsteady flow of centrifugal pumps was calculated based on the Reynolds-averaged equations that resemble the shear stress transport (SST k-ω turbulence model. The results show that the blade passing frequency and shaft frequency are dominant in the spectrum of flow-induced noise, whereas the shaft component, amplitude value at shaft frequency, and peak frequencies around the shaft increase with decreasing flow. Through flow field analysis, the inlet backflow of the impeller occurs under 0.7 times the design flow. The pressure pulsation spectrum with backflow conditions validates the flow-induced noise findings. The velocity characteristics of the backflow zone at the inlet pipe were analyzed, and the dynamic characteristics of the backflow eddy during one impeller rotating period were simultaneously obtained by employing the backflow conditions. A flow visualization experiment was performed to confirm the numerical calculations.

Torsional vibration analysis in turbo-generator shaft due to mal-synchronization fault

Science.gov (United States)

Bangunde, Abhishek; Kumar, Tarun; Kumar, Rajeev; Jain, S. C.

2018-03-01

A rotor of turbo-generator shafting is many times subjected to torsional vibrations during its lifespan. The reasons behind these vibrations are three-Phase fault, two-phase fault, line to ground fault, faulty-mal synchronization etc. Sometimes these vibrations can cause complete failure of turbo-generator shafting system. To calculate moment variation during these faults on the shafting system vibration analysis is done using Finite Elements Methods to calculate mass and stiffness matrix. The electrical disturbance caused during Mal-synchronization is put on generator section, and corresponding second order equations are solved by using “Duhamel Integral”. From the moment variation plots at four sections critically loaded sections are identified.

Results from the geological surveys carried out in the Bure laboratory's shafts

International Nuclear Information System (INIS)

Rebours, Herve; Righini, Celine

2010-01-01

Document available in extended abstract form only. After the government's authorization to build and operate an underground laboratory, Andra started the investigation works in November 99 on the Meuse/Haute-Marne URL site. The Meuse/Haute-Marne URL is located at the border of the Champagne-Ardenne and Lorraine regions, on the township of Bure in the Callovo-Oxfordian clay-rich rock. On the URL site, the layer is about 135 m-thick and lies at a depth of 417 m to 552 m. The laboratory consists of two levels of experimental drifts at depths of 445 m and 490 m, respectively, with two vertical shafts crossing the 505 m-thick sedimentary cover of Kimeridgian (about 100 meters of marls and limestones), Oxfordian (about 300 meters of limestones) and Callovo-Oxfordian formations. The construction of the underground installations started in August 2000 with the sinking of the main shaft and was completed on the 27 April 2006 when it linked up with the southern drift of the laboratory. The two access shafts are sunk with a drill and blast method with steps of 2.4 to 3.1 m. A temporary support with grouted bolts and wire mesh is set immediately after the blasting and removal of the muck. The definitive concrete lining is installed about 12 to 20 m behind the face. The excavated diameter of the main shaft where the geological surveys and experiments have been undertaken is of 6 m (5 m after lining). The second shaft (auxiliary shaft for the ventilation of the URL) is sunk in a smaller diameter (5 m). The aims of the geological surveys carried out during the shaft sinking are to describe the vertical and lateral (between the two shafts) variations of the lithology, to confirm the absence of fault and the geometry of the argillaceous rocks formation. These surveys allow to characterize the natural or inducted fracturing by a sedimentary and structural follow-up of the excavation face. This follow-up was carried out every 2.4 to 3.0 meters in the shafts. During the shaft

A study on rock mass behaviour induced by shaft sinking in the Horonobe Underground Research Laboratory

International Nuclear Information System (INIS)

Tsusaka, Kimikazu; Tokiwa, Tetsuya; Inagaki, Daisuke; Hatsuyama, Yoshihiro; Koike, Masashi; Ijiri, Yuji

2012-01-01

Japan Atomic Energy Agency has been excavating three deep shafts through soft sedimentary rock in the Horonobe Underground Research Laboratory. In this paper, the authors discussed rock mass behaviour induced by a 6.5 m diameter shaft sinking. They conducted geological mapping in an excavation face and boreholes digged around the shaft wall, field measurements such as convergence measurements and monitoring of rock displacements using multi-interval borehole extensometers around a shaft at around 160 m and 220 m in depths, and three-dimensional numerical analysis which models the shaft excavation procedure such as timing of installation of support elements and setting and removal of a concrete form. As a result, it was clarified that remarkably large compressive strains occurred within about 1 m into the shaft wall in a radial direction since the rock mass behaviour was controlled by the concrete lining and that the behaviour would predominantly be induced by the fractures closing which opened significantly and propagated during excavation steps before the installation of a concrete lining and the directions where the strains occurred heavily depended on the fracture orientation around the shaft. (author)

Outcomes in closed reamed interlocking nail in fractures of shaft of femur

International Nuclear Information System (INIS)

Mohammad, T.; Sawati, A.; Ahmed, A.

2015-01-01

Femoral shaft fracture is one of the common fractures seen in accident and emergency department of our hospital. Violent forces are required to break this and strongest of human bones. There are various treatment modalities for femoral shaft fractures in adults like traction, brace, platting, intramedullary nail (IMN), external fixators and inter locking nails. The study was done with an objective to evaluate the results of closed reamed interlocking nail in fractures of shaft of femur. Methods: A prospective study of 114 cases of femoral shaft fractures was carried out at orthopaedic unit of Ayub Teaching Hospital Abbottabad during 1 year. All these cases were treated with statically locked nails under spinal or general anaesthesia. These cases were followed up for up to one year and Results of the interlocking nail were observed in terms of union and complications. Results: Out of 114 patients, 95 underwent union in 90-150 days with a mean of 110.68 days. Ten patients had dynamization within six weeks because of obvious fracture gap in radiograph. There were 3 patients who had non-union, and 6 patients had delayed union which was treated with dynamization. Conclusion: Close reamed interlocking intramedullary nail in femoral shaft fractures is the treatment of choice. Patient rehabilitation is early, hospitalization is short, and fracture healing response is good. (author)

Functional design criteria for an exploratory shaft facility in salt: Technical report

International Nuclear Information System (INIS)

1986-11-01

The purpose of the Functional Criteria for Design is to provide technical direction for the development of detailed design criteria for the exploratory shaft facility. This will assure that the exploratory shaft facility will be designed in accordance with the current Mission Plan as well as the Nuclear Waste Policy Act and 10 CFR Part 60, which will facilitate the licensing process. The functional criteria for design are not intended to limit or constrain the designer's flexibility. The following philosophies will be incorporated in the designs: (1) The exploratory shaft will be designed to fulfill its intended purpose which is to characterize the salt site by subsurface testing; (2) the design will minimize any adverse impact which the facility may cause to the environment and any damage to the site if it should be found suitable for a repository; (3) the health and safety of the public and of the workers will be an essential factor in the design; (4) sound engineering principles and practices will be consistently employed in the design process; (5) the exploratory shaft and related surface and subsurface facilities will be designed to be economical and reliable in construction, operation, and maintenance; and (6) the exploratory shaft facility will be designed in accordance with applicable federal, state, and local regulations, as well as all applicable national consensus codes and standards

High-speed LWR transients simulation for optimizing emergency response

International Nuclear Information System (INIS)

Wulff, W.; Cheng, H.S.; Lekach, S.V.; Mallen, A.N.; Stritar, A.

1984-01-01

The purpose of computer-assisted emergency response in nuclear power plants, and the requirements for achieving such a response, are presented. An important requirement is the attainment of realistic high-speed plant simulations at the reactor site. Currently pursued development programs for plant simulations are reviewed. Five modeling principles are established and a criterion is presented for selecting numerical procedures and efficient computer hardware to achieve high-speed simulations. A newly developed technology for high-speed power plant simulation is described and results are presented. It is shown that simulation speeds ten times greater than real-time process-speeds are possible, and that plant instrumentation can be made part of the computational loop in a small, on-site minicomputer. Additional technical issues are presented which must still be resolved before the newly developed technology can be implemented in a nuclear power plant

Speed control with torque ripple reduction of switched reluctance motor by Hybrid Many Optimizing Liaison Gravitational Search technique

Directory of Open Access Journals (Sweden)

Nutan Saha

2017-06-01

Full Text Available This paper presents a control scheme for simultaneous control of the speed of Switched Reluctance Motor (SRM and minimizing the torque ripple employing Hybrid Many Optimizing Liaison Gravitational Search Algorithm (Hybrid MOLGSA technique. The control mechanism includes two controlling loops, the outer loop is governed for speed control and a current controller for the inner loop, intelligent selection of turn on and turn off angle for a 60 KW, 3-phase 6/8 SRM. It is noticed that the torque ripple coefficient, ISE of speed & current are reduced by 12.81%, 38.60%, 16.74% respectively by Hybrid MOLGSA algorithm compared to Gravitational Search Algorithm (GSA algorithm. It is also observed that the settling times for the controller using the parameter values for obtaining best values of torque ripple, Integral square error of speed and current are reduced by 51.25%, 58.04% and 59.375% by proposed Hybrid MOLGSA algorithm compared to the GSA algorithm.

Shaft flexibility effects on aeroelastic stability of a rotating bladed disk

Science.gov (United States)

Khader, Naim; Loewy, Robert

1989-01-01

A comprehensive study of Coriolis forces and shaft flexibility effects on the structural dynamics and aeroelastic stability of a rotating bladed-disk assembly attached to a cantilever, massless, flexible shaft is presented. Analyses were performed for an actual bladed-disk assembly, used as the first stage in the fan of the 'E3' engine. In the structural model, both in-plane and out-of-plane elastic deformation of the bladed-disk assembly were considered relative to their hub, in addition to rigid disk translations and rotations introduced by shaft flexibility. Besides structural coupling between blades (through the flexible disk), additional coupling is introduced through quasisteady aerodynamic loads. Rotational effects are accounted for throughout the work, and some mode shapes for the whole structure are presented at a selected rpm.

Numerical Simulation of Galvanic Corrosion Caused by Shaft Grounding Systems in Steel Ship Hulls

National Research Council Canada - National Science Library

Wang, Y

2005-01-01

The shaft grounding systems used on board HMC ships have substantially reduced the shaft-to-hull resistance and, thus, improved the performance of the shipboard impressed current cathodic protection (ICCP) system...

Reclamation of derelict land: procedure for locating abandoned mine shafts

Energy Technology Data Exchange (ETDEWEB)

1976-01-01

A procedure for locating abandoned shafts has been compiled from the experiences of those familiar with the problem. The procedure begins with a careful study of all the maps, aerial photographs and documents related to the mining activity and may include specialized surveys using geophysical, geochemical and aerial photographic methods when specific conditions are known or are likely to exist at the site. Direct methods, of either excavation, probing or drilling are required in each instance to confirm the location. Most of the methods are illustrated with case histories, and seismic and remote sensing methods are discussed in detail in appendices. Also in appendices, specific sources of information relating to mining are listed. Physical characteristics of mine shafts which are likely to have a bearing on the finding of the shaft are discussed, and an outline of the costs of the methods is presented. A glossary of mining terms used in the document and a detailed bibliography are provided.

APPLICATION OF ELECTRONIC TACHEOMETER FOR PREAND POST-CONSTRUCTION SURVEY OF ELEVATOR SHAFT

Directory of Open Access Journals (Sweden)

M. S. Nesterionok

2015-01-01

Full Text Available Floor-by-floor survey of installed elements of an elevator shaft using coordinate method and tacheometer is also inhibited by the necessity to determine device installation points for floors of every mounting horizon that leads to additional measurements due to conditions of the completed building framework and presence of a great number of situational disturbances and then it entails significant time expenditure and diminution of accuracy in the obtained results. Technical capabilities of the modern electronic tacheometer substantially simplify an accomplishment of the mission because the device can be applied not only in function of vertical projection but it can be used for preand post-construction survey of the elevator shaft with the help of advanced radiation method. While using the given method the electronic tacheometer equipped with diagonal ocular is installed over a bearing sign in the elevator pit and control points of the elevator shaft are determined with the help of specially developed portable beam deflector in the form of disc with radius r, which is fixed to a handle rod and orientated perpendicularly to a laser beam. An innovation diagram for preand post-construction survey of elevator shaft has been developed while applying this type of deflector. The diagram is characterized by high efficiency due to the fact that one tacheometer installation makes it possible to execute highly accurate, complete plane and high-level surveying of the whole elevator shaft including doorways, door sills and jambs.The paper proposes a new method for pre and post construction survey of the elevator shaft using the electronic tacheometer while applying specially developed beam deflector that ensures a geometric fixing of one or simultaneously two surveying points to spatial coordinate system where the preand post-construction survey is carried out. The method is characterized by high geometric accuracy and technological efficiency.

Measuring surface-water loss in Honouliuli Stream near the ‘Ewa Shaft, O‘ahu, Hawai‘i

Science.gov (United States)

Rosa, Sarah N.

2017-05-30

The Honolulu Board of Water Supply is currently concerned with the possibility of bacteria in the pumped water of the ‘Ewa Shaft (State well 3-2202-21). Groundwater from the ‘Ewa Shaft could potentially be used to meet future potable water needs in the ‘Ewa area on the island of O‘ahu. The source of the bacteria in the pumped water is unknown, although previous studies indicate that surface water may be lost to the subsurface near the site. The ‘Ewa Shaft consists of a vertical shaft, started near the south bank of Honouliuli Stream at an altitude of about 161 feet, and two horizontal infiltration tunnels near sea level. The shaft extracts groundwater from near the top of the freshwater lens in the Waipahu-Waiawa aquifer system within the greater Pearl Harbor Aquifer Sector, a designated Water Management Area.The surface-water losses were evaluated with continuous groundwater-level data from the ‘Ewa Shaft and a nearby monitoring well, continuous stream-discharge data from U.S. Geological Survey streamflow-gaging station 16212490 (Honouliuli Stream at H-1 Freeway near Waipahu), and seepage-run measurements in Honouliuli Stream and its tributary. During storms, discharge at the Honouliuli Stream gaging station increases and groundwater levels at ‘Ewa Shaft and a nearby monitoring well also increase. The concurrent increase in water levels at ‘Ewa Shaft and the nearby monitoring well during storms indicates that regional groundwater-level changes related to increased recharge, reduced withdrawals (due to a decrease in demand during periods of rainfall), or both may be occurring; although these data do not preclude the possibility of local recharge from Honouliuli Stream. Discharge measurements from two seepage runs indicate that surface water in the immediate area adjacent to ‘Ewa Shaft infiltrates into the streambed and may later reach the groundwater system developed by the ‘Ewa Shaft. The estimated seepage loss rates in the vicinity of �

Locomotor training with body weight support in SCI : EMG improvement is more optimally expressed at a low testing speed

NARCIS (Netherlands)

Meyns, P.; Van de Crommert, H. W. A. A.; Rijken, H.; van Kuppevelt, D. H. J. M.; Duysens, J.

2014-01-01

Study design: Case series. Objectives: To determine the optimal testing speed at which the recovery of the EMG (electromyographic) activity should be assessed during and after body weight supported (BWS) locomotor training. Setting: Tertiary hospital, Sint Maartenskliniek, Nijmegen, The Netherlands.

High speed subfractional HP-motor with permanent magnets

International Nuclear Information System (INIS)

Hanitsch, R.; Frenzel, B.

1998-01-01

During the last years an increasing demand for small permanent magnet motors can be detected, especially in the fields of medical applications. For heart assist devices there is the request to have small high speed devices operating at low voltage supply with almost no overtemperature. The design of a special hollow shaft motor for the speed range of 15000..25000 rpm and a torque of 4 to 8 mNm will be outlined. The low noise requirements and the high efficiency request lead to a design with an airgap winding. A thermal analysis is also done in order to meet the conditions given by the medical specialists. The features of the prototype will be presented and also the sensorless control strategy will be outlined. Measured and calculated data show good agreement. Focus will be on the magnetic circuit and the thermal behaviour and not on the control aspects of the motor. Specific parameters demonstrate the good quality of the drive system. (orig.)

Exploring Optimization Opportunities in Four-Point Suspension Wind Turbine Drivetrains through Integrated Design Approaches

Energy Technology Data Exchange (ETDEWEB)

Sethuraman, Latha [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Quick, Julian [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Guo, Yi [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-01-12

Drivetrain design has significant influence on the costs of wind power generation. Current industry practices usually approach the drivetrain design with loads and system requirements defined by the turbine manufacturer. Several different manufacturers are contracted to supply individual components from the low-speed shaft to the generator - each receiving separate design specifications from the turbine manufacturer. Increasingly, more integrated approaches to turbine design have shown promise for blades and towers. Yet, integrated drivetrain design is a challenging task owing to the complex physical behavior of the important load-bearing components, namely the main bearings, gearbox, and the generator. In this paper we combine two of NREL's systems engineering design tools, DriveSE and GeneratorSE, to enable a comprehensive system-level drivetrain optimization for the IEAWind reference turbine for land-based applications. We compare a more traditional design with integrated approaches employing decoupled and coupled design optimization. It is demonstrated that both approaches have the potential to realize notable mass savings with opportunities to lower the costs of energy.

Viscoelastic Characterization of Long-Eared Owl Flight Feather Shaft and the Damping Ability Analysis

Directory of Open Access Journals (Sweden)

Jia-li Gao

2014-01-01

Full Text Available Flight feather shaft of long-eared owl is characterized by a three-parameter model for linear viscoelastic solids to reveal its damping ability. Uniaxial tensile tests of the long-eared owl, pigeon, and golden eagle flight feather shaft specimens were carried out based on Instron 3345 single column material testing system, respectively, and viscoelastic response of their stress and strain was described by the standard linear solid model. Parameter fitting result obtained from the tensile tests shows that there is no significant difference in instantaneous elastic modulus for the three birds’ feather shafts, but the owl shaft has the highest viscosity, implying more obvious viscoelastic performance. Dynamic mechanical property was characterized based on the tensile testing results. Loss factor (tanδ of the owl flight feather shaft was calculated to be 1.609 ± 0.238, far greater than those of the pigeon (0.896 ± 0.082 and golden eagle (1.087 ± 0.074. It is concluded that the long-eared owl flight feather has more outstanding damping ability compared to the pigeon and golden eagle flight feather shaft. Consequently, the long-eared owl flight feathers can dissipate the vibration energy more effectively during the flying process based on the principle of damping mechanism, for the purpose of vibration attenuation and structure radiated noise reduction.

Analysis of experimental shaft seal data for high-performance turbomachines, as for Space Shuttle main engines

Science.gov (United States)

Hendricks, R. C.; Braun, M. J.; Mullen, R. L.; Burcham, R. E.; Diamond, W. A.

1985-01-01

High-pressure, high-temperature seal flow (leakage) data for nonrotating and rotating Raleigh-step and convergent-tapered-bore seals were characterized in terms of a normalized flow coefficient. The data for normalized Rayleigh-steip and nonrotating tapered-bore seals were in reasonable agreement with theory, but data for the rotating tapered-bore seals were not. The tapered-bore-seal operational clearances estimated from the flow data were significantly larger than calculated. Although clearances are influenced by wear from conical to cylindrical geometry and errors in clearance corrections, the problem was isolated to the shaft temperature - rotational speed clearance correction. The geometric changes support the use of some conical convergence in any seal. Under these conditions rotation reduced the normalized flow coefficiently by nearly 10 percent.

Analysis of experimental shaft seal data for high-performance turbomachines - As for Space Shuttle main engines

Science.gov (United States)

Hendricks, R. C.; Mullen, R. L.; Braun, M. J.; Burcham, R. E.; Diamond, W. A.

1987-01-01

High-pressure, high-temperature seal flow (leakage) data for nonrotating and rotating Raleigh-step and convergent-tapered-bore seals were characterized in terms of a normalized flow coefficient. The data for normalized Rayleigh-step and nonrotating tapered-bore seals were in reasonable agreement with theory, but data for the rotating tapered-bore seals were not. The tapered-bore-seal operational clearances estimated from the flow data were significantly larger than calculated. Although clearances are influenced by wear from conical to cylindrical geometry and errors in clearance corrections, the problem was isolated to the shaft temperature - rotational speed clearance correction. The geometric changes support the use of some conical convergence in any seal. Under these conditions rotation reduced the normalized flow coefficiently by nearly 10 percent.

Explosion-proof conservation of the Lohberg shaft 1 and 2; Explosionsfeste Konservierung der Schaechte Lohberg 1 und 2

Energy Technology Data Exchange (ETDEWEB)

Hachmann, Andreas [AHA - Andreas Hachmann, Recklinghausen (Germany). Pruefung und Abnahme

2010-03-15

In the course of closure of the former Lohberg/Osterfeld colliery backfilling of shafts 1 and 2 with concrete was envisaged according to the original plans. On the basis of a modified plan, however, the two shafts will now be maintained for drainage. Hence a suspended pack was constructed on the 3{sup rd} level for each of the two shafts. Both shafts must be explosion-proof until the water is raised. The structural steel solution described in more detail in this contribution was applied in both shafts. (orig.)

Monitoring device for shaft oscillation of reactor incorporated-type recycling pump

International Nuclear Information System (INIS)

Miyashita, Kaoru; Shibasaki, Kimiyuki.

1995-01-01

The present invention concerns monitoring of recycling pump shaft oscillation in a BWR type reactor, which monitors by separating a rotation pulse signal and a shaft oscillation waveform signal obtained in a non-contact type displacement meter. Namely, a threshold value calculation means of a separation processing section takes in original waveform data and selects the maximum value and the minimum value among them. A threshold value is calculated based on the values. An average value of the original waveform data for portions which do not exceed the threshold value is calculated. A first calculation means compares each of the original data with the threshold value, and if the original data are greater than the threshold value, they are outputted as the original data corresponding to the rotation pulse signal. When the original data are smaller than the threshold value, they are outputted as they are as a shaft oscillation waveform signal. On the other hand, a second calculation means calculates an average value for the pulse of the original waveform data corresponding to the rotation pulse signal. An average value of the original waveform data which do not exceed the threshold value are subtracted from the average value, to form the shaft oscillation waveform signal and output the same. (I.S.)

Exploratory shaft facility preliminary designs - Permian Basin

International Nuclear Information System (INIS)

1983-09-01

The purpose of the Preliminary Design Report, Permian Basin, is to provide a description of the preliminary design for an Exploratory Shaft Facility in the Permian Basin, Texas. This issue of the report describes the preliminary design for constructing the exploratory shaft using the Large Hole Drilling method of construction and outlines the preliminary design and estimates of probable construction cost. The Preliminary Design Report is prepared to complement and summarize other documents that comprise the design at the preliminary stage of completion, December 1982. Other design documents include drawings, cost estimates and schedules. The preliminary design drawing package, which includes the construction schedule drawing, depicts the descriptions in this report. For reference, a list of the drawing titles and corresponding numbers are included in the Appendix. The report is divided into three principal sections: Design Basis, Facility Description, and Construction Cost Estimate. 30 references, 13 tables

Reliability of agriculture universal joint shafts based on temperature measuring in universal joint bearing assemblies

Directory of Open Access Journals (Sweden)

Аleksandar Asonja

2015-03-01

Full Text Available This paper presents a research into reliability calculations of agriculture double universal joint shafts based on temperature measuring in cardan-type universal joint bearing assemblies. Special laboratory equipment was developed for this research which is presented in the paper. The objective of this research was to test the real life span of universal joint shafts in the laboratory and in field, to obtain the results which can be used to improve the reliability of universal joint shafts. If the presented research were used along with maintenance measures recommended in the paper and with proper use, the level of reliability of the shafts would be 2.1 times higher. The presented results of the research showed that needle bearings, i.e. bearing assemblies of the joints, are the most critical elements on universal joint shafts and are possible causes of their lower reliability. The second universal joint is the part with the lowest reliability in the observed technical system.

Experimental and numerical study of the effect of rolling parameters on shaft deformation during the longitudinal rolling process

Science.gov (United States)

Kowalik, Marek; Trzepiecinski, Tomasz

2018-05-01

This paper presents the characteristics of the process of longitudinal rolling of shafts and the geometry of the working section of forming rollers with a secant profile. In addition, the analytical formulae defining the geometry of a roller profile were determined. The experiments were carried out on shafts made of S235JR and C45 structural steels and the MSC.Marc + Mentat program was used for the numerical analysis of the rolling process based on the finite element method. The paper analyses the effect of roller geometry on the changes in value of the widening coefficient and the diameter reduction coefficient for the first forming passage. It was found that the mechanical properties of the shaft material have a slight influence on the widening coefficient. The value of the widening coefficient of the shaft increases with increase in the initial diameter of the shaft. Increasing shaft diameter causes an increase of strain gradient on the cross-section of the shaft.

A multiple ship routing and speed optimization problem under time, cost and environmental objectives

DEFF Research Database (Denmark)

Wen, M.; Pacino, Dario; Kontovas, C.A.

2017-01-01

The purpose of this paper is to investigate a multiple ship routing and speed optimization problem under time, cost and environmental objectives. A branch and price algorithm as well as a constraint programming model are developed that consider (a) fuel consumption as a function of payload, (b......) fuel price as an explicit input, (c) freight rate as an input, and (d) in-transit cargo inventory costs. The alternative objective functions are minimum total trip duration, minimum total cost and minimum emissions. Computational experience with the algorithm is reported on a variety of scenarios....

Scanning Electron Microscopic Hair Shaft Analysis in Ectodermal Dysplasia Syndromes.

Science.gov (United States)

Hirano-Ali, Stefanie A; Reed, Ashley M; Rowan, Brandon J; Sorrells, Timothy; Williams, Judith V; Pariser, David M; Hood, Antoinette F; Salkey, Kimberly

2015-01-01

The objective of the current study was to catalog hair shaft abnormalities in individuals with ectodermal dysplasia (ED) syndromes using scanning electron microscopy (SEM) and to compare the findings with those in unaffected controls. This is the second of a two-part study, the first of which used light microscopy as the modality and was previously published. Scanning electron microscopy was performed in a blinded manner on hair shafts from 65 subjects with seven types of ED syndromes and 41 unaffected control subjects. Assessment was performed along the length of the shaft and in cross section. Hair donations were collected at the 28th Annual National Family Conference held by the National Foundation for Ectodermal Dysplasia. Control subjects were recruited from a private dermatology practice and an academic children's hospital outpatient dermatology clinic. SEM identified various pathologic hair shaft abnormalities in each type of ED and in control patients. When hairs with all types of ED were grouped together and compared with those of control patients, the difference in the presence of small diameter and shallow and deep grooves was statistically significant (p < 0.05). When the EDs were separated according to subtype, statistically significant findings were also seen. SEM is a possible adjuvant tool in the diagnosis of ED syndromes. There are significant differences, with high specificity, between the hairs of individuals with ED and those of control subjects and between subtypes. © 2015 Wiley Periodicals, Inc.

Examination of reactor coolant pump shaft at Crystal River-3

International Nuclear Information System (INIS)

Hayner, G.O.; Frye, C.R.; Clary, M.D.

1987-01-01

A detailed examination was performed on a broken RCP shaft assembly. The primary fracture was located in a groove under the upper end of the hydrostatic bearing journal. Additionally, all four impeller-to-shaft bolts and one drive pin failed. Mechanical properties, bulk chemistry, hardness, and microstructure were normal for the A-286 material used for the shaft, bolts and pins. A zone of axial surface cracking was seen just above the top of the hydrostatic bearing journal. According to Yoon et.al. these cracks are caused by thermal fatigue resulting from turbulent hot and cold water mixing in this area and have a self limiting depth. The primary RCP shaft fracture was caused by high cycle fatigue. Crack initiation probably occurred during initial use of the RCP and according to Yoon was caused by a combination postulated effect of comined surface residual stresses and stress concentration in the groove area. Several combinations of effects including broken impeller bolts probably were responsible for the initial crack propagation. Fracture mechanics testing results in 550 0 F air and simulated PWR water were used to estimate the stress intensity range of the primary crack and the crack propagation time by comparison of the fracture surface features. These estimates indicated that the propagation time was probably in the range from ≅ 191 to ≅ 323 days with a maximum stress intensity level of ≅ 30 ksi √(in). (orig.)

Design of steel lined pressure tunnels and shafts - Annual report; Dimensionnement des galeries et puits blindes - Rapport annuel

Energy Technology Data Exchange (ETDEWEB)

Hachem, F.; Schleiss, A.

2009-07-01

Modern power plants are expected to operate at variable speed in a wide range of output power with improved efficiency, flexibility and safety. Therefore, the pumped-storage power generation has gained in importance since it allows storing and generating electricity to supply high peak demands by moving water back and forth between reservoirs at different elevations. A project consortium, called HydroNet (Modern Methodologies for Design, Manufacturing and Operation of Pumped-Storage Power Plant) has been created aiming to converge towards a consistent standardized methodology for design, manufacturing, operation, monitoring and control of pumped-storage power plants in order to give new impulsions in the hydropower technology and maintain the strong position of Switzerland in peak hydropower production as well as in the exportation of high-valued technology. One of the civil engineering field involved in this consortium is the design and control of pressurized shafts and tunnels with a special focus on safety. Since 1980s, no significant fundamental research has been performed aiming to integrate design with interaction between water, steel lining and rock mass. The results of these investigations stand for a crucial target in Switzerland since the collapse of the shallow buried pressure shaft of Cleuson-Dixence hydropower plant in December 2000. (authors)

Three-Dimensional Numerical Analysis of Compound Lining in Complex Underground Surge-Shaft Structure

Directory of Open Access Journals (Sweden)

Juntao Chen

2015-01-01

Full Text Available The mechanical behavior of lining structure of deep-embedded cylinder surge shaft with multifork tunnel is analyzed using three-dimensional nonlinear FEM. With the elastic-plastic constitutive relations of rock mass imported and the implicit bolt element and distributed concrete cracking model adopted, a computing method of complex surge shaft is presented for the simulation of underground excavations and concrete lining cracks. In order to reflect the interaction and initial gap between rock mass and concrete lining, a three-dimensional nonlinear interface element is adopted, which can take into account both the normal and tangential characteristics. By an actual engineering computation, the distortion characteristics and stress distribution rules of the dimensional multifork surge-shaft lining structure under different behavior are revealed. The results verify the rationality and feasibility of this computation model and method and provide a new idea and reference for the complex surge-shaft design and construction.

Reactor coolant pump shaft seal behavior during blackout conditions

International Nuclear Information System (INIS)

Mings, W.J.

1985-01-01

The United States Nuclear Regulatory Commission has classified the problem of reactor coolant pump seal failures as an unresolved safety issue. This decision was made in large part due to experimental results obtained from a research program developed to study shaft seal performance during station blackout and reported in this paper. Testing and analysis indicated a potential for pump seal failure under postulated blackout conditions leading to a loss of primary coolant with a concomitant danger of core uncovery. The work to date has not answered all the concerns regarding shaft seal failure but it has helped scope the problem and focus future research needed to completely resolve this issue

TMI-2 auxiliary building elevator shaft and pit decontamination

Energy Technology Data Exchange (ETDEWEB)

Bengel, T.G.

1986-01-01

Decontamination of the elevator pit and shaft in the auxiliary building at Three Mile Island Unit 2 (TMI-2) was performed to remove high radiation and contamination levels which prevented personnel from utilizing the elevator. The radiation and contamination levels in the TMI-2 auxiliary building elevator shaft have been reduced to the point where plant personnel are again permitted to ride in the elevator without a radiation work permit, with the exception of access to the 281-ft (basement) level. Based on the declassification and expanded use of the elevator, the task goal has been met. The tax expended 16.16 man-rem and 621 man-hours.

Optimization of mine ventilation fan speeds according to ventilation on demand and time of use tariff

International Nuclear Information System (INIS)

Chatterjee, Arnab; Zhang, Lijun; Xia, Xiaohua

2015-01-01

Highlights: • DSM techniques are applied to an underground mine ventilation network. • A minimization model is solved to find the optimal speeds of the main mine fan. • Ventilation on demand (VOD) leads to a saving of USD 213160. • The optimal mining schedule, together with VOD, leads to a saving of USD 277035. • According to a case study, a maximum of 2 540 035 kW h can be saved per year. - Abstract: In the current situation of the energy crisis, the mining industry has been identified as a promising area for application of demand side management (DSM) techniques. This paper investigates the potential for energy-cost savings and actual energy savings, by implementation of variable speed drives to ventilation fans in underground mines. In particular, ventilation on demand is considered in the study, i.e., air volume is adjusted according to the demand at varying times. Two DSM strategies, energy efficiency (EE) and load management (LM), are formulated and analysed. By modelling the network with the aid of Kirchhoff’s laws and Tellegen’s theorem, a nonlinear constrained minimization model is developed, with the objective of achieving EE. The model is also made to adhere to the fan laws, such that the fan power at its operating points is found to achieve realistic results. LM is achieved by finding the optimal starting time of the mining schedule, according to the time of use (TOU) tariff. A case study is shown to demonstrate the effects of the optimization model. The study suggests that by combining load shifting and energy efficiency techniques, an annual energy saving of 2 540 035 kW h is possible, leading to an annual cost saving of USD 277035

Numerical Study on the Tensile Behavior of 3D Four Directional Cylindrical Braided Composite Shafts

Science.gov (United States)

Zhao, Guoqi; Wang, Jiayi; Hao, Wenfeng; Liu, Yinghua; Luo, Ying

2017-10-01

The tensile behavior of 3D four directional cylindrical braided composite shafts was analyzed with the numerical method. The unit cell models for the 3D four directional cylindrical braided composite shafts with various braiding angles were constructed with ABAQUS. Hashin's failure criterion was used to analyze the tensile strength and the damage evolution of the unit cells. The influence of the braiding angle on the tensile behavior of the 3D four directional cylindrical braided composite shafts was analyzed. The numerical results showed that the tensile strength along the braiding direction increased as the braiding angle decreased. These results should play an integral role in the design of braiding composites shafts.

An Innovative Hybrid Model Based on Data Pre-Processing and Modified Optimization Algorithm and Its Application in Wind Speed Forecasting

Directory of Open Access Journals (Sweden)

Ping Jiang

2017-07-01

Full Text Available Wind speed forecasting has an unsuperseded function in the high-efficiency operation of wind farms, and is significant in wind-related engineering studies. Back-propagation (BP algorithms have been comprehensively employed to forecast time series that are nonlinear, irregular, and unstable. However, the single model usually overlooks the importance of data pre-processing and parameter optimization of the model, which results in weak forecasting performance. In this paper, a more precise and robust model that combines data pre-processing, BP neural network, and a modified artificial intelligence optimization algorithm was proposed, which succeeded in avoiding the limitations of the individual algorithm. The novel model not only improves the forecasting accuracy but also retains the advantages of the firefly algorithm (FA and overcomes the disadvantage of the FA while optimizing in the later stage. To verify the forecasting performance of the presented hybrid model, 10-min wind speed data from Penglai city, Shandong province, China, were analyzed in this study. The simulations revealed that the proposed hybrid model significantly outperforms other single metaheuristics.

An adaptive nonlinear internal-model control for the speed control of homopolar salient-pole BLDC motor

Science.gov (United States)

CheshmehBeigi, Hassan Moradi

2018-05-01

In this paper, a novel speed control method for Homopolar Brushless DC (HBLDC) motor based on the adaptive nonlinear internal-model control (ANIMC) is presented. Rotor position information is obtained online by the Hall-Effect sensors placed on the motor's shaft, and is used to calculate the accurate model and accurate inverse model of the HBLDC motor. The online inverse model of the motor is used in the controller structure. To suppress the reference ? error, the negative feedback of difference between the motor speed and its model output ? is applied in the proposed controller. An appropriate signal is the output of the controller, which drives the power switches to converge the motor speed to the constant desired speed. Simulations and experiments are carried out on a ? three-phase HBLDC motor. The proposed drive system operates well in the speed response and has good robustness with respect to the disturbances. To validate the theoretical analysis, several experimental results are discussed in this paper.

Site study plan for exploratory shaft monitoring wells, Deaf Smith County Site, Texas: Preliminary Draft

International Nuclear Information System (INIS)

1988-01-01

As part of site characterization studies, two exploratory shafts will be constructed at the Deaf Smith County site, Texas. Twelve wells at five locations have been proposed to monitor potential impacts of shaft construction on water-bearing zones in the Ogallala Formation and the Dockum Group. In addition, tests have been proposed to determine the hydraulic properties of the water-bearing zones for use in design and construction of the shafts. Samples of the Blackwater Draw Formation, Ogallala Formation, and Dockum Group will be obtained during construction of these wells. Visual indentification, laboratory testing, and in situ testing will yield data necessary for Exploratory Shaft Facility design and construction. This activity provides the earliest data on the Blackwater Drew Formation, Ogallala Formation, and Dockum Group near the exploratory shaft locations. Drilling and hydrologic testing are scheduled prior to other subsurface activity at the Exploratory Shaft Facility to establish ground-water baseline conditions. The Technical Field Services Contractor is responsible for conducting the field program of drilling and testing. Samples and data will be handled and reported in accordance with established Salt Repository Project procedures. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that the appropriate documentation is maintained. 45 refs., 11 figs., 4 tabs

Full-shipload tramp ship routing and scheduling with variable speeds

DEFF Research Database (Denmark)

Wen, M.; Røpke, Stefan; Petersen, Hanne Løhmann

2016-01-01

This paper investigates the simultaneous optimization problem of routing and sailing speed in the context of full-shipload tramp shipping. In this problem, a set of cargoes can be transported from their load to discharge ports by a fleet of heterogeneous ships of different speed ranges and load......-dependent fuel consumption. The objective is to determine which orders to serve and to find the optimal route for each ship and the optimal sailing speed on each leg of the route so that the total profit is maximized. The problem originated from a real-life challenge faced by a Danish tramp shipping company....... It is shown that speed optimization can improve the total profit by 16% on average and the fuel price has a significant effect on the average sailing speed and total profit....

Torsional analysis of 1 MW gearbox and shaft system in the Avedoere wind turbine