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Sample records for blade optimisation projects

  1. Noise aspects at aerodynamic blade optimisation projects

    International Nuclear Information System (INIS)

    The Netherlands Energy Research Foundation (ECN) has often been involved in industrial projects, in which blade geometries are created automatic by means of numerical optimisation. Usually, these projects aim at the determination of the aerodynamic optimal wind turbine blade, i.e. the goal is to design a blade which is optimal with regard to energy yield. In other cases, blades have been designed which are optimal with regard to cost of generated energy. However, it is obvious that the wind turbine blade designs which result from these optimisations, are not necessarily optimal with regard to noise emission. In this paper an example is shown of an aerodynamic blade optimisation, using the ECN-program PVOPT. PVOPT calculates the optimal wind turbine blade geometry such that the maximum energy yield is obtained. Using the aerodynamic optimal blade design as a basis, the possibilities of noise reduction are investigated. 11 figs., 8 refs

  2. Noise aspects at aerodynamic blade optimisation projects

    Energy Technology Data Exchange (ETDEWEB)

    Schepers, J.G. [Netherlands Energy Research Foundation, Petten (Netherlands)

    1997-12-31

    This paper shows an example of an aerodynamic blade optimisation, using the program PVOPT. PVOPT calculates the optimal wind turbine blade geometry such that the maximum energy yield is obtained. Using the aerodynamic optimal blade design as a basis, the possibilities of noise reduction are investigated. The aerodynamic optimised geometry from PVOPT is the `real` optimum (up to the latest decimal). The most important conclusion from this study is, that it is worthwhile to investigate the behaviour of the objective function (in the present case the energy yield) around the optimum: If the optimum is flat, there is a possibility to apply modifications to the optimum configuration with only a limited loss in energy yield. It is obvious that the modified configurations emits a different (and possibly lower) noise level. In the BLADOPT program (the successor of PVOPT) it will be possible to quantify the noise level and hence to assess the reduced noise emission more thoroughly. At present the most promising approaches for noise reduction are believed to be a reduction of the rotor speed (if at all possible), and a reduction of the tip angle by means of low lift profiles, or decreased twist at the outboard stations. These modifications were possible without a significant loss in energy yield. (LN)

  3. Blade Design Optimisation for Fixed-Pitch Fixed-Speed Wind Turbines

    OpenAIRE

    Lin Wang; Xinzi Tang; Xiongwei Liu

    2012-01-01

    Fixed-pitch fixed-speed (FPFS) wind turbines have some distinct advantages over other topologies for small wind turbines, particularly for low wind speed sites. The blade design of FPFS wind turbines is fundamentally different to fixed-pitch variable-speed wind turbine blade design. Theoretically, it is difficult to obtain a global mathematical solution for the blade design optimisation. Through case studies of a given baseline wind turbine and its blade airfoil, this paper aims to demonstrat...

  4. Structural optimisation of vertical-axis wind turbine composite blades based on finite element analysis and genetic algorithm

    OpenAIRE

    Wang, Lin; Kolios, Athanasios; Nishino, Takafumi; DELAFIN, Pierre-Luc; Bird, Theodore

    2016-01-01

    A wind turbine blade generally has complex structures including several layers of composite materials with shear webs, making its structure design very challenging. In this paper, a structural optimisation model for wind turbine composite blades has been developed based on a parametric FEA (finite element analysis) model and a GA (genetic algorithm) model. The optimisation model minimises the mass of composite blades with multi-criteria constraints. The number of unidirectional plies, the loc...

  5. Advanced Blade Manufacturing Project - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    POORE, ROBERT Z.

    1999-08-01

    The original scope of the project was to research improvements to the processes and materials used in the manufacture of wood-epoxy blades, conduct tests to qualify any new material or processes for use in blade design and subsequently build and test six blades using the improved processes and materials. In particular, ABM was interested in reducing blade cost and improving quality. In addition, ABM needed to find a replacement material for the mature Douglas fir used in the manufacturing process. The use of mature Douglas fir is commercially unacceptable because of its limited supply and environmental concerns associated with the use of mature timber. Unfortunately, the bankruptcy of FloWind in June 1997 and a dramatic reduction in AWT sales made it impossible for ABM to complete the full scope of work. However, sufficient research and testing were completed to identify several promising changes in the blade manufacturing process and develop a preliminary design incorporating these changes.

  6. Optimising environmental steps for the ASTRID project

    International Nuclear Information System (INIS)

    Often felt as a stress in the 90s, projects can no longer ignore the ISO environmental directives governing design. As the 4th generation reactor project, the ASTRID team has decided to go further in its approach by taking full responsibility to optimise the environmental steps within a sustainable development strategy which systematically looks to minimise the environmental impact of the project per kilowatt-hour of electricity generated. This also illustrates the importance of public acceptance, by considering the environmental requirements as a positive way of ensuring a responsible performance label. The paper describes a series of practical measures taken by the CEA as the project owner (identification of environmental requirements in the structuring documents, ecological inventory of the prospective site’s biotope, impact assessment, etc.) and by their engineering partners in their pre-conceptual studies. For example, natural resources will be optimised and minor actinides will be incinerated (radioactive waste) in the core; design options will be compared on the basis of environmental criteria for the nuclear island; and in terms of non-nuclear installations, a High Environmental Quality approach will be used to design the building housing the turbine. This paper describes the expected status of the nuclear island at the end of the pre-conceptual design phase; some reservations do remain in this paper since certain pre-conceptual design decisions will only be confirmed at the end of 2012. (author)

  7. Optimising Impact in Astronomy for Development Projects

    Science.gov (United States)

    Grant, Eli

    2015-08-01

    Positive outcomes in the fields of science education and international development are notoriously difficult to achieve. Among the challenges facing projects that use astronomy to improve education and socio-economic development is how to optimise project design in order to achieve the greatest possible benefits. Over the past century, medical scientists along with statisticians and economists have progressed an increasingly sophisticated and scientific approach to designing, testing and improving social intervention and public health education strategies. This talk offers a brief review of the history and current state of `intervention science'. A similar framework is then proposed for astronomy outreach and education projects, with applied examples given of how existing evidence can be used to inform project design, predict and estimate cost-effectiveness, minimise the risk of unintended negative consequences and increase the likelihood of target outcomes being achieved.

  8. The optimisation and analysis of a centrifugal slurry pump impeller with 2 blades

    OpenAIRE

    Mehmet Salih Cellek; Tahsin Engin

    2013-01-01

    With FLUENT, which is Computational Fluid Dynamics (CFD) software, it becomes possible to define the performance of complicated flow in turbo machines like pumps and blowers. It is not only reduced costs but also saves time. This study is aimed to optimize a commercial slurry pump impeller. Therefore, four different types of impellers were designed with using various blade angles, blade length and splitter blade on the impeller, which is the most crucial component of the pump. As a result of ...

  9. The optimisation and analysis of a centrifugal slurry pump impeller with 2 blades

    Directory of Open Access Journals (Sweden)

    Mehmet Salih Cellek

    2013-08-01

    Full Text Available With FLUENT, which is Computational Fluid Dynamics (CFD software, it becomes possible to define the performance of complicated flow in turbo machines like pumps and blowers. It is not only reduced costs but also saves time. This study is aimed to optimize a commercial slurry pump impeller. Therefore, four different types of impellers were designed with using various blade angles, blade length and splitter blade on the impeller, which is the most crucial component of the pump. As a result of analysis it was seen that every impeller affected on the pump performance at different flow rate.

  10. blades

    Directory of Open Access Journals (Sweden)

    Shashishekara S. Talya

    1999-01-01

    Full Text Available Design optimization of a gas turbine blade geometry for effective film cooling toreduce the blade temperature has been done using a multiobjective optimization formulation. Three optimization formulations have been used. In the first, the average blade temperature is chosen as the objective function to be minimized. An upper bound constraint has been imposed on the maximum blade temperature. In the second, the maximum blade temperature is chosen as the objective function to be minimized with an upper bound constraint on the average blade temperature. In the third formulation, the blade average and maximum temperatures are chosen as objective functions. Shape optimization is performed using geometric parameters associated with film cooling and blade external shape. A quasi-three-dimensional Navier–Stokes solver for turbomachinery flows is used to solve for the flow field external to the blade with appropriate modifications to incorporate the effect of film cooling. The heat transfer analysis for temperature distribution within the blade is performed by solving the heat diffusion equation using the finite element method. The multiobjective Kreisselmeier–Steinhauser function approach has been used in conjunction with an approximate analysis technique for optimization. The results obtained using both formulations are compared with reference geometry. All three formulations yield significant reductions in blade temperature with the multiobjective formulation yielding largest reduction in blade temperature.

  11. Optimisation of a stator blade using response surface method in a single-stage transonic axial compressor

    Energy Technology Data Exchange (ETDEWEB)

    Jang, C-M. [Korea Institute of Construction Technology, Daehwa-dong, Goyang-Si (Korea). Fire and Engineering Services Research Department; Kim, K-Y. [Inha University, Incheon (Korea). Department of Mechanical Engineering

    2005-12-15

    This article describes the shape optimization of a stator blade in a single-stage transonic axial compressor. The blade optimization has been performed using response surface method and three-dimensional Navier-Stokes analysis. Thin-layer approximation is introduced to the Navier-Stokes equations, and an explicit Runge-Kutta scheme is used to solve the governing equations. Two geometric design variables of the stator blade, which are used to define a stacking line, are introduced to increase an adiabatic efficiency. D-optimal design is employed to reduce the number of evaluation points for response surface. With the optimization of the stator blade, the adiabatic efficiency is successfully improved when compared with that of the reference shape of the stator with straight stacking line. Positive stacking line, which bends on blade pressure side, effectively suppresses the flow separation on the blade suction surface of the stator. (author)

  12. Engineered wood wind turbine blades : final report : design project MECH 4020

    Energy Technology Data Exchange (ETDEWEB)

    Beck, J.; Donaldson, M.; Mader, C.; Myatt, E.; Rent, J.; Sandler, A. [Group 8 (Canada)

    2005-04-11

    A project to redesign a wind turbine blade for manufacturing out of engineered wood was presented. The aim of the Aeolus Blades design project was to reduce typical manufacturing costs of $3000 for wind turbine blades to $1000 per blade using cheaper materials and less intensive manufacturing processes. The wooden blades were designed to meet the same design standards as typical wind turbine blades. The project also aimed to reduce startup costs for wind turbine applications in remote locations as well as for the residential sector. Baseline stiffness data were obtained through a series of benchmark tests on existing fiberglass and carbon fiber blades. Wooden billets were used to re-orient veneer planes and avoid interlaminar shear stress. The blades were produced from 2 machined billets. The wood blade was tested experimentally, and compared to the benchmark data and a series of finite element analyses (FEA). Results indicated that the laminated veneer lumber (LVL) was not stiff enough to support design wind pressure loads of up to 5000 Pa. Carbon fiber strips were inserted onto the outer surfaces of the blade. Results of further tests showed that overall stiffness compared to carbon fiber and fiberglass blades. Total tip deflection predicted by the FEA was within 1.5 per cent of the measured tests. The results of an economic analysis showed that the wood blades could be produced for approximately $1000 each in a 50-blade batch manufacturing run. It was concluded that engineered wood is a suitable material for wind turbine blades. 20 refs., 8 tabs., 75 figs.

  13. Blade System Design Study. Part II, final project report (GEC).

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Dayton A. (DNV Global Energy Concepts Inc., Seattle, WA)

    2009-05-01

    As part of the U.S. Department of Energy's Low Wind Speed Turbine program, Global Energy Concepts LLC (GEC)1 has studied alternative composite materials for wind turbine blades in the multi-megawatt size range. This work in one of the Blade System Design Studies (BSDS) funded through Sandia National Laboratories. The BSDS program was conducted in two phases. In the Part I BSDS, GEC assessed candidate innovations in composite materials, manufacturing processes, and structural configurations. GEC also made recommendations for testing composite coupons, details, assemblies, and blade substructures to be carried out in the Part II study (BSDS-II). The BSDS-II contract period began in May 2003, and testing was initiated in June 2004. The current report summarizes the results from the BSDS-II test program. Composite materials evaluated include carbon fiber in both pre-impregnated and vacuum-assisted resin transfer molding (VARTM) forms. Initial thin-coupon static testing included a wide range of parameters, including variation in manufacturer, fiber tow size, fabric architecture, and resin type. A smaller set of these materials and process types was also evaluated in thin-coupon fatigue testing, and in ply-drop and ply-transition panels. The majority of materials used epoxy resin, with vinyl ester (VE) resin also used for selected cases. Late in the project, testing of unidirectional fiberglass was added to provide an updated baseline against which to evaluate the carbon material performance. Numerous unidirectional carbon fabrics were considered for evaluation with VARTM infusion. All but one fabric style considered suffered either from poor infusibility or waviness of fibers combined with poor compaction. The exception was a triaxial carbon-fiberglass fabric produced by SAERTEX. This fabric became the primary choice for infused articles throughout the test program. The generally positive results obtained in this program for the SAERTEX material have led to its

  14. Sweep-twist adaptive rotor blade : final project report.

    Energy Technology Data Exchange (ETDEWEB)

    Ashwill, Thomas D.

    2010-02-01

    Knight & Carver was contracted by Sandia National Laboratories to develop a Sweep Twist Adaptive Rotor (STAR) blade that reduced operating loads, thereby allowing a larger, more productive rotor. The blade design used outer blade sweep to create twist coupling without angled fiber. Knight & Carver successfully designed, fabricated, tested and evaluated STAR prototype blades. Through laboratory and field tests, Knight & Carver showed the STAR blade met the engineering design criteria and economic goals for the program. A STAR prototype was successfully tested in Tehachapi during 2008 and a large data set was collected to support engineering and commercial development of the technology. This report documents the methodology used to develop the STAR blade design and reviews the approach used for laboratory and field testing. The effort demonstrated that STAR technology can provide significantly greater energy capture without higher operating loads on the turbine.

  15. Measurement of Rotorcraft Blade Deformation Using Projection Moiré Interferometry

    Directory of Open Access Journals (Sweden)

    Gary A. Fleming

    2000-01-01

    Full Text Available Projection Moiré Interferometry (PMI has been used to obtain near instantaneous, quantitative blade deformation measurements of a generic rotorcraft model at several test conditions. These laser-based measurements provide quantitative, whole field, dynamic blade deformation profiles conditionally sampled as a function of rotor azimuth. The instantaneous nature of the measurements permits computation of the mean and unsteady blade deformation, blade bending, and twist. The PMI method is presented, and the image processing steps required to obtain quantitative deformation profiles from PMI interferograms are described. Experimental results are provided which show blade bending, twist, and unsteady motion. This initial proof-of-concept test has demonstrated the capability of PMI to acquire accurate, full field rotorcraft blade deformation data.

  16. A STUDY ON OPTIMISATION OF RESOURCES FOR MULTIPLE PROJECTS BY USING PRIMAVERA

    OpenAIRE

    B. S. K. REDDY; SK. NAGARAJU; MD. SALMAN

    2015-01-01

    Resources play vital role in construction projects. The performance of construction industry depends chiefly on how best the resources are managed. Optimisation play pivotal role in resource management, but task is highly haphazard and chaotic under the influence of complexities and vastness. Management always looks for optimum utility of resources available with them. Hence, the project management has got important place especially in resource allocation and smooth functioning with alloca...

  17. A STUDY ON OPTIMISATION OF RESOURCES FOR MULTIPLE PROJECTS BY USING PRIMAVERA

    Directory of Open Access Journals (Sweden)

    B. S. K. REDDY

    2015-02-01

    Full Text Available Resources play vital role in construction projects. The performance of construction industry depends chiefly on how best the resources are managed. Optimisation play pivotal role in resource management, but task is highly haphazard and chaotic under the influence of complexities and vastness. Management always looks for optimum utility of resources available with them. Hence, the project management has got important place especially in resource allocation and smooth functioning with allocated budget. To achieve these goals and to exercise enhance optimisation certain tools are used for resource allocation optimally. Present work illustrates resource optimisation exercises on two ongoing projects in Dubai, UAE. Resource demands of project A & B are individually levelled and observed cumulative requirement is 17475. In other option demands of projects A & B are aggregated and then together levelled, the necessary resource observed is 16490. Comparison of individually levelled and then combined option with aggregated and then levelled clearly indicates reduction in demand of resources by 5.65% in later option, which could be best considered for economy.

  18. Evaluation of Aeroelastically Tailored Small Wind Turbine Blades Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Dayton A.

    2005-09-29

    Evaluation of Aeroelastically Tailored Small Wind Turbine Blades Final Report Global Energy Concepts, LLC (GEC) has performed a conceptual design study concerning aeroelastic tailoring of small wind turbine blades. The primary objectives were to evaluate ways that blade/rotor geometry could be used to enable cost-of-energy reductions by enhancing energy capture while constraining or mitigating blade costs, system loads, and related component costs. This work builds on insights developed in ongoing adaptive-blade programs but with a focus on application to small turbine systems with isotropic blade material properties and with combined blade sweep and pre-bending/pre-curving to achieve the desired twist coupling. Specific goals of this project are to: (A) Evaluate and quantify the extent to which rotor geometry can be used to realize load-mitigating small wind turbine rotors. Primary aspects of the load mitigation are: (1) Improved overspeed safety affected by blades twisting toward stall in response to speed increases. (2) Reduced fatigue loading affected by blade twisting toward feather in response to turbulent gusts. (B) Illustrate trade-offs and design sensitivities for this concept. (C) Provide the technical basis for small wind turbine manufacturers to evaluate this concept and commercialize if the technology appears favorable. The SolidWorks code was used to rapidly develop solid models of blade with varying shapes and material properties. Finite element analyses (FEA) were performed using the COSMOS code modeling with tip-loads and centripetal accelerations. This tool set was used to investigate the potential for aeroelastic tailoring with combined planform sweep and pre-curve. An extensive matrix of design variables was investigated, including aerodynamic design, magnitude and shape of planform sweep, magnitude and shape of blade pre-curve, material stiffness, and rotor diameter. The FEA simulations resulted in substantial insights into the structural

  19. ACCURATE KAP METER CALIBRATION AS A PREREQUISITE FOR OPTIMISATION IN PROJECTION RADIOGRAPHY.

    Science.gov (United States)

    Malusek, A; Sandborg, M; Carlsson, G Alm

    2016-06-01

    Modern X-ray units register the air kerma-area product, PKA, with a built-in KAP meter. Some KAP meters show an energy-dependent bias comparable with the maximum uncertainty articulated by the IEC (25 %), adversely affecting dose-optimisation processes. To correct for the bias, a reference KAP meter calibrated at a standards laboratory and two calibration methods described here can be used to achieve an uncertainty of standards laboratory, Q0, to any beam quality, Q, in the clinic. Alternatively, beam quality corrections are measured with an energy-independent dosemeter via a reference beam quality in the clinic, Q1, to beam quality, Q Biases up to 35 % of built-in KAP meter readings were noted. Energy-dependent calibration factors are needed for unbiased PKA Accurate KAP meter calibration as a prerequisite for optimisation in projection radiography. PMID:26743261

  20. The Development and Hover Test Application of a Projection Moire Interferometry Blade Displacement Measurement System

    Science.gov (United States)

    Sekula, Martin K.

    2012-01-01

    Projection moir interferometry (PMI) was employed to measure blade deflections during a hover test of a generic model-scale rotor in the NASA Langley 14x22 subsonic wind tunnel s hover facility. PMI was one of several optical measurement techniques tasked to acquire deflection and flow visualization data for a rotor at several distinct heights above a ground plane. Two of the main objectives of this test were to demonstrate that multiple optical measurement techniques can be used simultaneously to acquire data and to identify and address deficiencies in the techniques. Several PMI-specific technical challenges needed to be addressed during the test and in post-processing of the data. These challenges included developing an efficient and accurate calibration method for an extremely large (65 inch) height range; automating the analysis of the large amount of data acquired during the test; and developing a method to determinate the absolute displacement of rotor blades without a required anchor point measurement. The results indicate that the use of a single-camera/single-projector approach for the large height range reduced the accuracy of the PMI system compared to PMI systems designed for smaller height ranges. The lack of the anchor point measurement (due to a technical issue with one of the other measurement techniques) limited the ability of the PMI system to correctly measure blade displacements to only one of the three rotor heights tested. The new calibration technique reduced the data required by 80 percent while new post-processing algorithms successfully automated the process of locating rotor blades in images, determining the blade quarter chord location, and calculating the blade root and blade tip heights above the ground plane.

  1. SIROCCO. Silent rotors by acoustic optimisation

    Energy Technology Data Exchange (ETDEWEB)

    Schepers, J.G.; Curvers, A. [ECN Wind Energy, Petten (Netherlands); Oerlemans, S. [National Aerospace Laboratory NLR, Amsterdam (Netherlands); Braun, K.; Lutz, T.; Herrig, A.; Wuerz, W. [University of Stuttgart, Stuttgart (Germany); Matesanz, A.; Garcillan, L. [Gamesa Eolica, Madrid (Spain); Fisher, M.; Koegler, K.; Maeder, T. [GE Wind Energy/GE Global Research (United States)

    2007-07-15

    In this paper the results from the European 5th Framework project 'SIROCCO' are described. The project started in January 2003 and will end in August 2007. The main aim of the SIROCCO project is to reduce wind-turbine aerodynamic noise significantly while maintaining the aerodynamic performance. This is achieved by designing new acoustically and aerodynamically optimised airfoils for the outer part of the blade. The project focussed primarily on reducing trailing edge noise, which was broadly believed to be the dominant noise mechanism of modern wind turbines.

  2. Design of 9-meter carbon-fiberglass prototype blades : CX-100 and TX-100 : final project report.

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Derek (TPI Composites, Inc., Warren, RI)

    2007-09-01

    TPI Composites, Inc. (TPI), Global Energy Concepts, LLC (GEC), and MDZ Consulting (MDZ) have collaborated on a project to design, manufacture, and test prototype carbon-fiberglass hybrid wind turbine blades of 9-m length. The project, funded by Sandia National Laboratories, involves prototype blades in both conventional (unidirectional spar fibers running along the blade span) and ''adaptive'' (carbon fibers in off-axis orientation to achieve bend-twist-coupling) configurations. After manufacture, laboratory testing is being conducted to determine the static and fatigue strength of the prototypes, in conjunction with field testing to evaluate the performance under operational conditions.

  3. THE PERFORMANCE OF THE PROJECT COALITION IN THE UK CONSTRUCTION INDUSTRY A CONCEPTUAL OPTIMISATION MODEL

    Directory of Open Access Journals (Sweden)

    David G. Proverbs

    2000-01-01

    Full Text Available The UK construction industry has long been criticised for engendering adversarial relationships among project participants. The nature of interrelationships ultimately determines overall project performance%2C in terms of finished product%2C and levels of performance and satisfaction for the participants. To investigate these interrelationships%2C the performance and satisfaction of each individual participant must be considered. Better understanding of the interrelationships should help reduce adversarialsm and improve the performance and satisfaction of each participant. The possible interrelationships that may exist are discussed based on %91soft knowledge%92 approaches%2C i.e. psychology%2C organisational behaviour and sociology. It is concluded that the performance of each participant is interdependent and essential towards project performance. Two levels of satisfaction%2C which determine the quality of working relationships between participants%2C are postulated. The first level of satisfaction %28i.e. satisfaction on achieving organisational objectives%29 is%2C to some extent%2C dependent on the second level of satisfaction %28i.e. satisfaction on the performance of the other participants%29. Therefore%2C within the construction project coalition%2C each participant has to be satisfied with the performance of the other participants if harmonious working relationships are to be sustained. Based on these%2C a conceptual model for optimising the relationships between main participants of the project coalition is presented. Abstract in Bahasa Indonesia : Coalition+participants%2C+Interrelationships%2C+Performance%2C+Satisfaction+

  4. Blade Vibration Measurement System for Characterization of Closely Spaced Modes and Mistuning Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There are several ongoing challenges in non-contacting blade vibration and stress measurement systems that can address closely spaced modes and blade-to-blade...

  5. Defining a quantitative framework for evaluation and optimisation of the environmental impacts of mega-event projects

    OpenAIRE

    Parkes, O.; Lettieri, P.; Bogle, I. D.

    2016-01-01

    This paper presents a novel quantitative methodology for the evaluation and optimisation of the environmental impacts of the whole life cycle of a mega-event project: construction and staging the event and post-event site redevelopment and operation. Within the proposed framework, a mathematical model has been developed that takes into account greenhouse gas (GHG) emissions resulting from use of transportation fuel, energy, water and construction materials used at all stages of the mega-event...

  6. Vibration Reduction Methods and Techniques for Rotorcraft Utilizing On-Blade Active Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Rotor blades adapted for vibration control have the added benefit of extended blade and rotor life, as well as improved passenger comfort. Approaches that have been...

  7. Optimised conveying

    Energy Technology Data Exchange (ETDEWEB)

    Keller, M. [ContiTech Conveyor Belt Group (Germany)

    2004-01-01

    The paper illustrates how conveyor belts with optimised energy consumption can cut costs. It describes the project undertaken by ContiTech Conveyor Belt Group to increase the rated capacity of the conveying system at PT Kaltim Prima Coal's Eastern Kalimantan mine from 2400 tph to 3300 tph. The steel-cored conveyor belt, 27 km long, was supplied in 27 individual units and spliced onsite. The number of splices was minimised by using oval reels which reduced installation time. 2 figs.

  8. Rotorcraft On-Blade Pressure and Strain Measurements Using Wireless Optical Sensor System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Experimental measurements of rotor blades are important for understanding the aerodynamics and dynamics of a rotorcraft. This understanding can help in solving...

  9. Defining a quantitative framework for evaluation and optimisation of the environmental impacts of mega-event projects.

    Science.gov (United States)

    Parkes, Olga; Lettieri, Paola; Bogle, I David L

    2016-02-01

    This paper presents a novel quantitative methodology for the evaluation and optimisation of the environmental impacts of the whole life cycle of a mega-event project: construction and staging the event and post-event site redevelopment and operation. Within the proposed framework, a mathematical model has been developed that takes into account greenhouse gas (GHG) emissions resulting from use of transportation fuel, energy, water and construction materials used at all stages of the mega-event project. The model is applied to a case study - the London Olympic Park. Three potential post-event site design scenarios of the Park have been developed: Business as Usual (BAU), Commercial World (CW) and High Rise High Density (HRHD). A quantitative summary of results demonstrates that the highest GHG emissions associated with the actual event are almost negligible compared to those associated with the legacy phase. The highest share of emissions in the legacy phase is attributed to embodied emissions from construction materials (almost 50% for the BAU and HRHD scenarios) and emissions resulting from the transportation of residents, visitors and employees to/from the site (almost 60% for the CW scenario). The BAU scenario is the one with the lowest GHG emissions compared to the other scenarios. The results also demonstrate how post-event site design scenarios can be optimised to minimise the GHG emissions. The overall outcomes illustrate how the proposed framework can be used to support decision making process for mega-event projects planning. PMID:26686076

  10. French Project PLUSPAC: Development of a hydrogen storage unit for an optimisation of stationary FC systems; Safety of metal hydrides

    International Nuclear Information System (INIS)

    One of the objectives of the French project PLUSPAC (Local Production and hydrogen Storage Unit for an optimisation of Fuel Cell stationary systems), coordinated by the Energy Research Centre of Veolia Environment is to evaluate the performances of hydrogen storage in metal hydrides for the energetic optimisation of a stationary fuel cell system. INERIS was in charge to assess the safety of metal hydrides as a storage mean. As very few information is available regarding the safety of intermetallic compounds developed within PLUSPAC project, experimental tests have been performed so as to get information about the reactivity of the powder (reaction with air, with water, thermal decomposition). Tests have been performed on activated (15 and 30 cycles) and no activated powders, and also on an other intermetallic compound, which is supposed to be reactive. Nevertheless, none of the tests have shown any adverse reaction, neither with air, nor with water, nor when exposed to high temperatures. Today, it appears that metal hydrides tested have a safe behaviour when exposed to air, water and high temperatures. Further tests would be necessary to investigate other materials. (authors)

  11. Enhancing the damping of wind turbine rotor blades, the DAMPBLADE project

    DEFF Research Database (Denmark)

    Chaviaropoulos, P.K.; Politis, E.S.; Lekou, D.J.;

    2006-01-01

    ’ enabling the direct prediction of aeroelastic stability and fatigue life; the development and characterization of damped composite materials; and the evaluation of new technology via the design and fabrication of damped prototype blades and their full-scale laboratory testing. After 4 years of work a 19 m...... glass/polyester damped blade was designed, manufactured and tested using the know-how acquired. Modal analysis of this blade at the testing facility of CRES showed a nearly 80% increase in the damping ratio of both the first flap and lag modes compared with the earlier, standard, design practice...

  12. Improved Attachment Design for Ceramic Turbine Blades Via Hybrid Concepts Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal presents a hybrid metal-CMC turbine blade. A SiC/SiC CMC airfoil section will be bonded to a single crystal superalloy root section in order to...

  13. Optical Method for Real-Time Turbine Blade Tip Clearance Measurement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Monitoring and controlling blade tip clearance of high pressure turbines are important for maintaining the integrity of the engine during its operating points and...

  14. High Temperature, Through the Case Eddy Current Sensor for Blade Vibration Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Preliminary results have shown that low temperature eddy current sensors can provide excellent resolution for blade tip timing, and have the ability to see ?through...

  15. OPTIMAT Blades. Reliable Optimal Use of Materials for Wind Turbine Rotor Blades. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, L.G.J. [ECN Wind Energy, Petten (Netherlands); Van Wingerde, A.M.; Nijssen, R.P.L. [Knowledge Centre Wind Trubine Materials and Constructions, Delft (Netherlands); Philippidis, T.P. [University of Patras, Patras (Greece); Broendsted, P. [Risoe National Laboratory, Roskilde (Denmark); Dutton, A.G. [Council for the Central Laboratory of Research Councils CCLRC, Chilton, Didcot (United Kingdom); Kensche, C.W. [Deutsches Zentrum fuer Luft- und Raumfahrt, Berlin (Germany)

    2006-06-15

    As the required financial investments to achieve the expansion of the installed capacity of wind turbine grow, the economical pressure on reliable and structurally optimised blades, that are fit for their designed life, will increase. Very large blades may even become practically impossible without further knowledge of the material behaviour since the dominating loads on the material are caused by the blade mass. Therefore, a sound and accurate understanding of the structural behaviour of the material under all for wind turbine applications possible loading conditions is necessary. The project aims to provide accurate design recommendations for the optimised use of materials within wind turbine rotor blades and to achieve improved reliability. The major deliverable of the project will be improved design recommendations for the next generation of rotor blades. With the accurate and reliable design recommendations resulting from this project, reliable blades with optimised use of materials can be designed. The increased reliability and weight reduction of the blades will stimulate further the offshore exploitation with large capacity wind turbines. This supports the increase in wind energy and by that helps to reach the White Paper target of 40GW of installed power by 2010. The possible reduction of the material use will lower the impact on earth's resources and environment. The reduction can result from direct weight saving and from the increased reliability which prevents the need for replacements and waste of material. To execute the research activities a consortium was formed consisting of 10 research institutes from 7 EU countries; 5 wind turbine and/or blade manufactures from 3 EU countries; and the two leading certification bodies that carry out wind turbine certification throughout the world today. Over 3000 individual tests have been carried out on epoxy GFRP coupons, with numerous technical reports being issued to analyse and understand this data. The

  16. Optimisation of small-scale hydropower using quality assurance methods - Preliminary project; Vorprojekt: Optimierung von Kleinwasserkraftwerken durch Qualitaetssicherung. Programm Kleinwasserkraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Hofer, S.; Staubli, T.

    2006-11-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of a preliminary project that examined how quality assurance methods can be used in the optimisation of small-scale hydropower projects. The aim of the project, to use existing know-how, experience and synergies, is examined. Discrepancies in quality and their effects on production prices were determined in interviews. The paper describes best-practice guidelines for the quality assurance of small-scale hydro schemes. A flow chart describes the various steps that have to be taken in the project and realisation work. Information collected from planners and from interviews made with them are presented along with further information obtained from literature. The results of interviews concerning planning work, putting to tender and the construction stages of these hydro schemes are presented and commented on. Similarly, the operational phase of such power plant is also examined, including questions on operation and guarantees. The aims of the follow-up main project - the definition of a tool and guidelines for ensuring quality - are briefly reviewed.

  17. Simulation of Flexible Mechanisms in a Rotating Blade for Smart-Blade Applications

    OpenAIRE

    Paternoster, A.R.A.; Loendersloot, R.; Boer; Akkerman, R.

    2012-01-01

    The active Gurney flap technology is investigated to improve the performance of rotorblades by allowing helicopter blades to further control the lift unbalance that rises at high speed and by damping vibration loads on the rotor hub. This technology needs validation by wind tunnel testing of a scaled model blade under rotational loading. An optimised geometry of a flexible actuation system has been designed to provide motion for the deployment of the Gurney flap for a Mach-scale model blade [...

  18. Moving towards Optimising Demand-Led Learning: The 2005-2007 ECUANET Leonardo Da Vinci Project

    Science.gov (United States)

    Dealtry, Richard; Howard, Keith

    2008-01-01

    Purpose: The purpose of this paper is to present the key project learning points and outcomes as a guideline for the future quality management of demand-led learning and development. Design/methodology/approach: The research methodology was based upon a corporate university blueprint architecture and browser toolkit developed by a member of the…

  19. Blade lock for a rotor disk and rotor blade assembly

    Science.gov (United States)

    Moore, Jerry H. (Inventor)

    1992-01-01

    A rotor disk 18 and rotor blade 26 assembly is disclosed having a blade lock 66 which retains the rotor blade against axial movement in an axially extending blade retention slot 58. Various construction details are developed which shield the dead rim region D.sub.d and shift at least a portion of the loads associated with the locking device from the dead rim. In one detailed embodiment, a projection 68 from the live rim D.sub.1 of the disk 18 is adapted by slots 86 to receive blade locks 66.

  20. Blades and discs in gas turbines. Behaviour of material and components. Project department A-C. Final report; Schaufeln und Scheiben in Gasturbinen. Werkstoff- und Bauteilverhalten. Projektbereiche A bis C. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The special research area 339 `Blades and discs in gas turbines, behaviour of material and components` was carried on from 1988 to the end of 1196. This final report deals with the work in the years 1994, 1995 and 1996. In the project area A `Development of material` manufacturing processes both for metallic and ceramic high temperature materials were developed, tested and optimised. In the area of optimising casting structure, it was shown that the making grains finer up to the medium temperature range can be a suitable means for significantly raising the resistance to LCF loading with nearly unchanged heat and creep strength properties. Another main point was the characterisation and optimisation of sprayed ceramic layers on metallic substrates (heat insulating layers) and compound ceramic materials. In project area B `Material behaviour` the mechanisms were studied, which, particularly in metallic high temperature materials such as nickel-based superalloys, lead to failure of the material under thermo-mechanical stresses. In project area C `Component design`, on the one hand models for estimating service life for metallic high temperature materials under different thermo-mechanical stresses were developed. [Deutsch] Der Sonderforschungsbereich 339, `Schaufeln und Scheiben in Gasturbinen - Werkstoff- und Bauteilverhalten` wurde von 1988 bis Ende 1996 gefoerdert. Dieser Abschlussbericht behandelt die Arbeiten der Jahre 1994, 1995 und 1996. Im Projektbereich A `Werkstoffentwicklung` wurden Herstellungsverfahren sowohl fuer metallische als auch fuer keramische Hochtemperaturwerkstoffe entwickelt, erprobt und optimiert. Auf dem Gebiet der Gussgefuegeoptimierung konnte gezeigt werden, dass die Kornfeinung bis in den mittleren Temperaturbereich ein geeignetes Mittel sein kann, um den Widerstand gegen LCF-Belastung bei annaehernd unveraenderten Warm- und Kriechfestigkeitseigenschaften signifikant zu erhoehen. Einen weiteren Schwerpunkt bildete die Charakterisierung und

  1. A Global Optimisation Toolbox for Massively Parallel Engineering Optimisation

    CERN Document Server

    Biscani, Francesco; Yam, Chit Hong

    2010-01-01

    A software platform for global optimisation, called PaGMO, has been developed within the Advanced Concepts Team (ACT) at the European Space Agency, and was recently released as an open-source project. PaGMO is built to tackle high-dimensional global optimisation problems, and it has been successfully used to find solutions to real-life engineering problems among which the preliminary design of interplanetary spacecraft trajectories - both chemical (including multiple flybys and deep-space maneuvers) and low-thrust (limited, at the moment, to single phase trajectories), the inverse design of nano-structured radiators and the design of non-reactive controllers for planetary rovers. Featuring an arsenal of global and local optimisation algorithms (including genetic algorithms, differential evolution, simulated annealing, particle swarm optimisation, compass search, improved harmony search, and various interfaces to libraries for local optimisation such as SNOPT, IPOPT, GSL and NLopt), PaGMO is at its core a C++ ...

  2. Optimisation of the energy potential of low-CO2 gas turbines by using large monocrystal turbine blades. Final report; Optimierung des Energiepotentials fuer CO{sub 2}-arme Gasturbinen durch grosse Einkristall-Turbinenschaufeln. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Grossmann, J.

    2002-07-01

    Apart from the experimental identification and assessment of process characteristics during industrial-scale application of the so-called liquid metal cooling (LPC) process, the project focused on the characterisation of monocrystalline, directionally solidified materials and components. This involved the construction and commissioning of appropriate production and test aggregates, i.e. the LMC casting system and a Laue orientation testing unit, as well as the modification of a vacuum heat treatment furnace to meet the specific requirement of glow annealing of monocrystalline, directionally solidified turbine blades. [German] Das Ziel des Forschungsvorhabens (Laufzeit: 01. Juli 1997 bis 31. Dezember 2001) 'Optimierung des Energiepotentials fuer CO{sub 2}-arme Gasturbinen durch grosse Einkristall-Turbinenschaufeln' lag neben der experimentellen Bestimmung und Bewertung von Verfahrens- und Prozesskennwerten bei der industriellen Umsetzung des sogenannten Liquid-Metal-Cooling-Verfahrens (LMC) in der Eigenschaftscharakterisierung von einkristallin-gerichtet erstarrten Proben und Bauteilen, die mittels dieser neuartigen Giesstechnologie dargestellt wurden. Grundvoraussetzung fuer die umfassende Bearbeitung der o.g. Arbeitsinhalte war die Konstruktion und Inbetriebnahme der notwendigen Fertigungs- und Pruefaggregate, d.h. der LMC-Giessanlage und einer Laue-Orientierungspruefeinrichtung bzw. der Abstimmung eines Vakuum-Waermebehandlungsofens auf die spezifischen Anforderungen der Loesungsgluehung einkristallin-gerichtet erstarrter Turbinenlaufschaufeln. (orig.)

  3. Blade Vibration Measurement System for Characterization of Closely Spaced Modes and Mistuning Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Phase I project successfully demonstrated that the advanced non-contacting stress measurement system (NSMS) was able to address closely spaced modes and...

  4. The project and technical study on the track of vertical axis linkage abrasive belt grinding of turbine blade

    International Nuclear Information System (INIS)

    A method of CNC turbine blade profile abrasive belt grinding is introduced based on optimum grinding effect, where the direction of the axis of trolley wheel is consistent with that of minimum principal curvature on the contact point of turbine blade. And the cutter location path is determined, and then the NC code is derived from post-processing. A virtual machine model is built in VERICUT software to simulate actual grinding process and applied in practice, which yielded satisfactory results. (authors)

  5. Experimental Blade Research

    DEFF Research Database (Denmark)

    Eder, Martin Alexander; Branner, Kim; Berring, Peter;

    This report is a summary of the results obtained in the project: Experimental Blade Research – phase 2 (EBR2). The project was supported by the Danish Energy Authority through the 2010 Energy Technology Development and Demonstration Program (EUDP 2010-II) and has journal no. 64011-0006. The proje...... has been running from spring 2011 to the end of 2014. Being a summary report, this report only contains a collection of the research topics and the major results. For more details, see the publications listed at the end of this report.......This report is a summary of the results obtained in the project: Experimental Blade Research – phase 2 (EBR2). The project was supported by the Danish Energy Authority through the 2010 Energy Technology Development and Demonstration Program (EUDP 2010-II) and has journal no. 64011-0006. The project...

  6. Low-Noise Rotorcraft Blades

    Science.gov (United States)

    Brooks, Thomas F.

    1994-01-01

    Blades of helicopter rotors, tilt rotors, and like reshaped to reduce noise, according to proposal. Planform features combination of rearward and forward sweep. Forward sweep over large outer portion of blade constitutes primary noise-reduction feature. Relieves some of compressive effect in tip region, with consequent reduction of noise from compressive sources. Performance at high advance ratio improved. Cabin vibration and loading noise reduced by load-averaging effect of double-sweep planform. Aft-swept section provides balancing of aerodynamic and other dynamic forces on blade along 1/4-chord line of straight inboard section and along projection of line to outermost blade radius. Possible for hub-hinge forces and moments to remain within practical bounds. Provides stabilizing blade forces and moments to counteract any instability caused by forward sweep.

  7. An Innovative Technique for Evaluating the Integrity and Durability of Wind Turbine Blade Composites - Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [ORNL; Ren, Fei [ORNL; Tan, Ting [ORNL; Mandell, John [Montana State University; Agastra, Pancasatya [Montana State University

    2011-11-01

    To build increasingly larger, lightweight, and robust wind turbine blades for improved power output and cost efficiency, durability of the blade, largely resulting from its structural composites selection and aerodynamic shape design, is of paramount concern. The safe/reliable operation of structural components depends critically on the selection of materials that are resistant to damage and failure in the expected service environment. An effective surveillance program is also necessary to monitor the degradation of the materials in the course of service. Composite materials having high specific strength/stiffness are desirable for the construction of wind turbines. However, most high-strength materials tend to exhibit low fracture toughness. That is why the fracture toughness of the composite materials under consideration for the manufacture of the next generation of wind turbines deserves special attention. In order to achieve the above we have proposed to develop an innovative technology, based on spiral notch torsion test (SNTT) methodology, to effectively investigate the material performance of turbine blade composites. SNTT approach was successfully demonstrated and extended to both epoxy and glass fiber composite materials for wind turbine blades during the performance period. In addition to typical Mode I failure mechanism, the mixed-mode failure mechanism induced by the wind turbine service environments and/or the material mismatch of the composite materials was also effectively investigated using SNTT approach. The SNTT results indicate that the proposed protocol not only provides significant advance in understanding the composite failure mechanism, but also can be readily utilized to assist the development of new turbine blade composites.

  8. Evaluation tool for selection and optimisation of hydrogen demonstration projects. Application to a decentralized renewable hydrogen system

    International Nuclear Information System (INIS)

    As part of the International Energy Agency Hydrogen Implementing Agreement, an evaluation tool to assist in the design, operation and optimisation of hydrogen demonstration facilities is under development. Using commercially available flowsheet simulation software (ASPEN- Plus) as the integrating platform, this tool is designed to provide system developers with a comprehensive data base or library of component models and an integrating platform through which these models may be linked. By combining several energy system components a conceptual design of a integrated hydrogen energy system can be made. As a part of the tool and connected to the library are design guidelines which can help finding the optimal configuration in the design process. The component categories considered include: production, storage, transport, distribution and end use. Many component models have already been included in the initial test platform. The use of the tool will be illustrated by presenting the results of a specific sample system that has been designed and assessed with use of the tool. The system considered is a decentralized renewable hydrogen system in which the hydrogen is produced by biomass gasification or pyrolysis, the produced hydrogen is transported through a pipeline or with a tank truck. The storage options that are considered are liquid hydrogen and compressed gas. The hydrogen is dispensed through a refueling station. Several options for integration are conceivable; i.e. storage of the hydrogen can take place centrally or district heat of a gasification unit can be used to generate electricity for liquefaction, etc. With use of the tool several configurations with different components and various integration options have been examined. Both the results of the modeling effort and an assessment of the evaluation tool will be presented. 5 refs

  9. Optimisation of water chemistry to ensure reliable water reactor fuel performance at high burnup and in ageing plant (FUWAC): an International Atomic Energy Agency coordinated research project

    International Nuclear Information System (INIS)

    The IAEA project 'Optimisation of Water Chemistry to ensure Reliable Water Reactor Fuel Performance at High Burnup and in Aging Plant' (FUWAC) was initiated with the objectives of monitoring, maintaining and optimising water chemistry regimes in primary circuits of water cooled power reactors, taking into account high burnup operation, mixed cores and plant aging, including following issues and remedies. This report provides some highlights of the work undertaken by the project participants. Clad oxidation studies have been undertaken and include operational data from the South Ukraine WWER where no corrosion problems have been seen on either Westinghouse ZIRLO™ or Russian alloy E110 fuel cladding. Work on the Russian alloy E110 showed that potassium in the coolant is preferable to lithium for mitigating fuel cladding oxidation. Studies on crud behaviour in PWR have shown a dependence on crud thickness and pHT. The nature and mechanisms for boron deposition in fuel cladding cruds have been investigated which is the root cause of crud induced power shifts (CIPS). Operational experience at French PWRs shows no difference in the CIPS behaviour between units with Alloy 600 or 690 steam generators, whilst Korean experience provides information on the Ni/Fe ratio on fuel cladding crud and the occurrence of CIPS. Coolant additions have been studied, for example in BWR units using zinc addition, crud is more tenacious. Zinc is also added to PWR units, mainly for dose rate control and in some cases for PWSCC mitigation of Alloy 600. At low levels there has been no clear evidence of any effect of zinc on CIPS, but there is a benefit on fuel oxidation. It is suggested that zinc addition should be considered where there is SG replacement or fuel core management modification. One possibility for the elimination of fuel crud is decontamination. Such an operation is time consuming, expensive, includes several risks of corrosion and induces a large quantity of

  10. Wind Turbine Blade Design

    OpenAIRE

    Richard J. Crossley; Peter J. Schubel

    2012-01-01

    A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection ...

  11. Survey of international dose monitoring programmes for radiation workers. WP1 in the project OMINEX- (Optimisation of Monitoring for Internal Exposure)

    International Nuclear Information System (INIS)

    Monitoring of the workforce in the nuclear industries is carried out primarily in order to demonstrate compliance with European Union Basic Safety Standards for the protection of the health of workers against the dangers arising from ionizing radiation. There is however no compilation of information on internal dose monitoring programmes currently in use in the EU countries. Surveys were therefore carried out in which organisations were asked to provide information on the design of their internal dose monitoring programmes and on the costs of these programmes. Information was requested from both EU countries and Associated States. Databases for storage and reporting of all information gained were constructed, and results from the surveys compiled. This work was carried out within the EC 5th Framework Programme project OMINEX (Optimisation of Monitoring for Internal Exposure), which aims to provide advice and guidance on designing and implementing internal dose monitoring programmes in the workplace in such a way that best use is made of available resources, while minimising costs. This paper gives the results of the survey of the design of internal dose monitoring programmes. A major conclusion is that, particularly for the actinides, a wide range of approaches to monitoring are in use. There is no consensus on primary monitoring methods. All organisations monitor workers to assess individual doses for entry onto a legal dose record. Cumulative distributions show that most organisations aim to assess doses down to 0.1 - 0.5 mSv. (orig.)

  12. Storage of compressed air - Optimisation and measurement of an existing project example; Druckluftspeicherung: Optimierung / Ausmessung bestehendes Projektmuster

    Energy Technology Data Exchange (ETDEWEB)

    Brueckmann, P. [Brueckmann Elektronik, Davos Dorf (Switzerland); Cyphelly, I. [Cyphelly and Cie, Les Brenets (Switzerland)

    2007-06-15

    This short final report for the Swiss Federal Office of Energy (SFOE) deals with an additional project that augmented an earlier report on a compressed-air energy storage system. First tests are reported on that revealed that the chosen heat exchanger fulfils the thermal expectations with substantial reserves. Certain effects concerning the liquid piston system are described which showed that further development of the test infrastructure were required. This project was launched to further examine these problems. Difficulties with the liquids available which prohibited the intended exact series of measurements are commented on. The authors note that independent investigations by the Austrian company LINDE came to the same conclusions, thus confirming the function of the heat exchanger.

  13. Optimisation-based clearance

    OpenAIRE

    Varga, Andras

    2002-01-01

    The basic feature of the optimisation-based clearance approach is to reformulate the clearance problems as equivalent minimum distance problems for which ”anti”-optimisation is performed to determine the worst-case parameter combination/ flight condition leading to worst performance. The basic requirements for the applicability of the optimisation-based approach are the availability of suitable parametric models describing the overall nonlinear dynamics of the augmented aircraft and of accomp...

  14. Heteroscedastic Treed Bayesian Optimisation

    OpenAIRE

    Assael, John-Alexander M.; Wang, Ziyu; Shahriari, Bobak; De Freitas, Nando

    2014-01-01

    Optimising black-box functions is important in many disciplines, such as tuning machine learning models, robotics, finance and mining exploration. Bayesian optimisation is a state-of-the-art technique for the global optimisation of black-box functions which are expensive to evaluate. At the core of this approach is a Gaussian process prior that captures our belief about the distribution over functions. However, in many cases a single Gaussian process is not flexible enough to capture non-stat...

  15. Applied modal analysis of wind turbine blades

    DEFF Research Database (Denmark)

    Pedersen, H.B.; Kristensen, O.J.D.

    2003-01-01

    In this project modal analysis has been used to determine the natural frequencies, damping and the mode shapes for wind turbine blades. Different methods to measure the position and adjust the direction of the measuring points are discussed. Differentequipment for mounting the accelerometers are...... unloaded wind turbine blade. During this campaign the modal analysis are performed on ablade mounted in a horizontal and a vertical position respectively. Finally the results obtained from modal analysis carried out on a wind turbine blade are compared with results obtained from the Stig Øyes blade_EV1...

  16. Blade Vibration Measurement System

    Science.gov (United States)

    Platt, Michael J.

    2014-01-01

    The Phase I project successfully demonstrated that an advanced noncontacting stress measurement system (NSMS) could improve classification of blade vibration response in terms of mistuning and closely spaced modes. The Phase II work confirmed the microwave sensor design process, modified the sensor so it is compatible as an upgrade to existing NSMS, and improved and finalized the NSMS software. The result will be stand-alone radar/tip timing radar signal conditioning for current conventional NSMS users (as an upgrade) and new users. The hybrid system will use frequency data and relative mode vibration levels from the radar sensor to provide substantially superior capabilities over current blade-vibration measurement technology. This frequency data, coupled with a reduced number of tip timing probes, will result in a system capable of detecting complex blade vibrations that would confound traditional NSMS systems. The hardware and software package was validated on a compressor rig at Mechanical Solutions, Inc. (MSI). Finally, the hybrid radar/tip timing NSMS software package and associated sensor hardware will be installed for use in the NASA Glenn spin pit test facility.

  17. Turbine blade cooling: the blade temperature distribution

    Energy Technology Data Exchange (ETDEWEB)

    Horlock, J. [Cambridge University (United Kingdom). Whittle Laboratory; Torbidoni, L. [Ansaldo Energia, Genoa (Italy)

    2006-07-01

    Air cooling of high-temperature gas turbines is a standard practice; the air first cools the blading by internal convection and then by external film cooling, after ejection through holes and slots in the blade surface. In some 'conventional' analyses of turbine blade cooling, a 'standard blade' is invoked, which has a uniform blade temperature equal to the average temperature of the real blade, and estimates are made of the cooling flow required to hold the standard blade temperature to a limit set by material considerations. However, early analytical work by Ainley (for convective cooling of thin-walled blades) showed that both the coolant and blade temperatures should increase along the blade span. The current paper develops Ainley's original analysis to allow for finite blade wall thickness and thermal barrier coatings, film cooling, and variation in the mainstream gas temperature along the span. This new analysis should enable more accurate estimates to be made of cooling air flow requirements. (author)

  18. Ultimate Strength of Wind Turbine Blades under Multiaxial Loading

    DEFF Research Database (Denmark)

    Haselbach, Philipp Ulrich

    Modern wind turbine rotor blades are sophisticated lightweight structures, optimised towards achieving the best compromise between aerodynamic and structural design as well as a cost efficient manufacturing processes. They are usually designed for a lifetime of minimum 20 years, where they must...

  19. Wind Turbine Blade Design

    Directory of Open Access Journals (Sweden)

    Richard J. Crossley

    2012-09-01

    Full Text Available A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

  20. Computer Based Optimisation Rutines

    DEFF Research Database (Denmark)

    Dragsted, Birgitte; Olsen, Flemmming Ove

    1996-01-01

    In this paper the need for optimisation methods for the laser cutting process has been identified as three different situations. Demands on the optimisation methods for these situations are presented, and one method for each situation is suggested. The adaptation and implementation of the methods...

  1. Use of evidence-based practices in pregnancy and childbirth: South East Asia Optimising Reproductive and Child Health in Developing Countries project.

    Directory of Open Access Journals (Sweden)

    M Laopaiboon

    Full Text Available BACKGROUND: The burden of mortality and morbidity related to pregnancy and childbirth remains concentrated in developing countries. SEA-ORCHID (South East Asia Optimising Reproductive and Child Health In Developing countries is evaluating whether a multifaceted intervention to strengthen capacity for research synthesis, evidence-based care and knowledge implementation improves adoption of best clinical practice recommendations leading to better health for mothers and babies. In this study we assessed current practices in perinatal health care in four South East Asian countries and determined whether they were aligned with best practice recommendations. METHODOLOGY/PRINCIPAL FINDINGS: We completed an audit of 9550 medical records of women and their 9665 infants at nine hospitals; two in each of Indonesia, Malaysia and The Philippines, and three in Thailand between January-December 2005. We compared actual clinical practices with best practice recommendations selected from the Cochrane Library and the World Health Organization Reproductive Health Library. Evidence-based components of the active management of the third stage of labour and appropriately treating eclampsia with magnesium sulphate were universally practiced in all hospitals. Appropriate antibiotic prophylaxis for caesarean section, a beneficial form of care, was practiced in less than 5% of cases in most hospitals. Use of the unnecessary practices of enema in labour ranged from 1% to 61% and rates of episiotomy for vaginal birth ranged from 31% to 95%. Other appropriate practices were commonly performed to varying degrees between countries and also between hospitals within the same country. CONCLUSIONS/SIGNIFICANCE: Whilst some perinatal health care practices audited were consistent with best available evidence, several were not. We conclude that recording of clinical practices should be an essential step to improve quality of care. Based on these findings, the SEA-ORCHID project team

  2. Experimental Blade Research - phase 2

    DEFF Research Database (Denmark)

    Eder, Martin Alexander; Branner, Kim; Berring, Peter;

    This report is a summary of the results obtained in the project: Experimental Blade Research – phase 2 (EBR2). The project was supported by the Danish Energy Authority through the 2010 Energy Technology Development and Demonstration Program (EUDP 2010-II) and has journal no. 64011-0006. The proje...... has been running from spring 2011 to the end of 2014. Being a summary report, this report only contains a collection of the research topics and the major results. For more details, see the publications listed at the end of this report.......This report is a summary of the results obtained in the project: Experimental Blade Research – phase 2 (EBR2). The project was supported by the Danish Energy Authority through the 2010 Energy Technology Development and Demonstration Program (EUDP 2010-II) and has journal no. 64011-0006. The project...

  3. Mechatronic System Design Based On An Optimisation Approach

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Pedersen, Henrik Clemmensen; Hansen, Michael Rygaard

    The envisaged objective of this paper project is to extend the current state of the art regarding the design of complex mechatronic systems utilizing an optimisation approach. We propose to investigate a novel framework for mechatronic system design. The novelty and originality being the use of...... optimisation techniques. The methods used to optimise/design within the classical disciplines will be identified and extended to mechatronic system design....

  4. Massachusetts Large Blade Test Facility Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Rahul Yarala; Rob Priore

    2011-09-02

    Project Objective: The Massachusetts Clean Energy Center (CEC) will design, construct, and ultimately have responsibility for the operation of the Large Wind Turbine Blade Test Facility, which is an advanced blade testing facility capable of testing wind turbine blades up to at least 90 meters in length on three test stands. Background: Wind turbine blade testing is required to meet international design standards, and is a critical factor in maintaining high levels of reliability and mitigating the technical and financial risk of deploying massproduced wind turbine models. Testing is also needed to identify specific blade design issues that may contribute to reduced wind turbine reliability and performance. Testing is also required to optimize aerodynamics, structural performance, encourage new technologies and materials development making wind even more competitive. The objective of this project is to accelerate the design and construction of a large wind blade testing facility capable of testing blades with minimum queue times at a reasonable cost. This testing facility will encourage and provide the opportunity for the U.S wind industry to conduct more rigorous testing of blades to improve wind turbine reliability.

  5. BLADED IMPELLER FOR TURBOBLOWERS

    Science.gov (United States)

    Baumann, K.

    1949-10-01

    A means is given of holding open-sided impeller blades in a turbo-rotor. Two half blades, with dovetail roots of sufficient weight to contain the center of gravity, are fitted into slots cut in the rotor so as to form the desired angle between the blade faces. The adjoining edges of the half blades are welded to form one solid blade that is securely locked an the rotor. This design permits the manufacture of a V shaped impeller blade without the need of machining the entire V shaped contour from a single blank, and furthermore provides excellent locking characteristics for attachment to the rotor.

  6. Further dual purpose evolutionary optimization of small wind turbine blades

    International Nuclear Information System (INIS)

    Much work has been done to maximise the power extraction of wind turbine blades. However, small wind turbines are also required to be self starting and whilst blades designed for maximum power extraction can be optimised analytically, these blades often have poor starting performance. The numeric method of Differential Evolution is used here to maximise for both power and starting performance. Standard blade element theory is used to calculate the power coefficient, and a modified blade element method for starting time. The chord and twist of each blade element make up the genes for evolution. Starting times can be improved by a factor of 20 with only a small reduction in power coefficient. With the introduction of the tip speed ratio as an additional gene, up to 10% improvement in power coefficient was achieved. A second study was done in another case where analytical optimisation is not possible; the inclusion of tip losses. The inclusion resulted in only a small increase in the optimum chord in the tip region which becomes less noticeable at lower tip speed ratios

  7. Optimisation of load control

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, P. [VTT Energy, Espoo (Finland)

    1998-08-01

    Electricity cannot be stored in large quantities. That is why the electricity supply and consumption are always almost equal in large power supply systems. If this balance were disturbed beyond stability, the system or a part of it would collapse until a new stable equilibrium is reached. The balance between supply and consumption is mainly maintained by controlling the power production, but also the electricity consumption or, in other words, the load is controlled. Controlling the load of the power supply system is important, if easily controllable power production capacity is limited. Temporary shortage of capacity causes high peaks in the energy price in the electricity market. Load control either reduces the electricity consumption during peak consumption and peak price or moves electricity consumption to some other time. The project Optimisation of Load Control is a part of the EDISON research program for distribution automation. The following areas were studied: Optimization of space heating and ventilation, when electricity price is time variable, load control model in power purchase optimization, optimization of direct load control sequences, interaction between load control optimization and power purchase optimization, literature on load control, optimization methods and field tests and response models of direct load control and the effects of the electricity market deregulation on load control. An overview of the main results is given in this chapter

  8. Optimisation of load control

    International Nuclear Information System (INIS)

    Electricity cannot be stored in large quantities. That is why the electricity supply and consumption are always almost equal in large power supply systems. If this balance were disturbed beyond stability, the system or a part of it would collapse until a new stable equilibrium is reached. The balance between supply and consumption is mainly maintained by controlling the power production, but also the electricity consumption or, in other words, the load is controlled. Controlling the load of the power supply system is important, if easily controllable power production capacity is limited. Temporary shortage of capacity causes high peaks in the energy price in the electricity market. Load control either reduces the electricity consumption during peak consumption and peak price or moves electricity consumption to some other time. The project Optimisation of Load Control is a part of the EDISON research program for distribution automation. The following areas were studied: Optimization of space heating and ventilation, when electricity price is time variable, load control model in power purchase optimization, optimization of direct load control sequences, interaction between load control optimization and power purchase optimization, literature on load control, optimization methods and field tests and response models of direct load control and the effects of the electricity market deregulation on load control. An overview of the main results is given in this chapter

  9. Blades and disks in gas turbines. Material and component behaviour. Project department D. Final report; Schaufeln und Scheiben in Gasturbinen. Werkstoff- und Bauteilverhalten. Projektbereich D. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The Special Research Department No. 339, ``Disks and Blades in Gas Turbines - Material and Component Characteristics`` received financial support from 1988 through 1996. This final report discusses activities of the years 1994, 1995, and 1996. Project group D, ``Production and Quality Assurance``, investigated rotors and blades. Grinding techniques were developed and optimized for nickel base materials, and the effects of grinding on the marginal zones was investigated, including an analysis of intrinsic stresses induced by machining. In the field of ceramics, separation and production of reinforced ceramics was investigated, and techniques for vacuum soldering of ceramic/ceramic and ceramic/metal compounds for high-temperature applications were developed. In the framework of a part-project carried out at HMI, neutron diffraction was used for nondestructive analysis of volume intrinsic stresses near the joint both on model geometries and on the joint between metal shaft and ceramic rotor. The development and application of computerized tomography for testing of ceramic rotors and joints was an important contribution to quality assurance. (orig./MM) [Deutsch] Der Sonderforschungsbereich 339 `Schaufeln und Scheiben in Gasturbinen - Werkstoff- und Bauteilverhalten` wurde von 1988 bis Ende 1996 gefoerdert. Der vorliegende Abschlussbericht behandelt vor allem die Arbeiten der Jahre 1994, 1995 und 1996. Am Bauteil Rotor und Schaufel orientierten sich die Arbeiten des Projektbereichs D `Fertigung und Qualitaetssicherung`. Zum einen wurden hier Schleifverfahren fuer Nickelbasis-Werkstoffe entwickelt und optimiert und der Einfluss der Schleifbearbeitung auf die Randzoneneigenschaften studiert. Zur Randzonencharakterisierung gehoerte insbesondere auch die Analyse bearbeitungsinduzierter Eigenspannungen. Auf der Seite der Keramiken wurde zum einen die trennende Fertigung verstaerkter Keramiken untersucht. Zum anderen wurden Techniken fuer das Hochvakuumloeten von Keramik

  10. Blade Vibration Measurement System for Unducted Fans

    Science.gov (United States)

    Marscher, William

    2014-01-01

    With propulsion research programs focused on new levels of efficiency and noise reduction, two avenues for advanced gas turbine technology are emerging: the geared turbofan and ultrahigh bypass ratio fan engines. Both of these candidates are being pursued as collaborative research projects between NASA and the engine manufacturers. The high bypass concept from GE Aviation is an unducted fan that features a bypass ratio of over 30 along with the accompanying benefits in fuel efficiency. This project improved the test and measurement capabilities of the unducted fan blade dynamic response. In the course of this project, Mechanical Solutions, Inc. (MSI) collaborated with GE Aviation to (1) define the requirements for fan blade measurements; (2) leverage MSI's radar-based system for compressor and turbine blade monitoring; and (3) develop, validate, and deliver a noncontacting blade vibration measurement system for unducted fans.

  11. Turbomachine blade reinforcement

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Crespo, Andres Jose

    2016-09-06

    Embodiments of the present disclosure include a system having a turbomachine blade segment including a blade and a mounting segment coupled to the blade, wherein the mounting segment has a plurality of reinforcement pins laterally extending at least partially through a neck of the mounting segment.

  12. Wind Turbine Blade

    DEFF Research Database (Denmark)

    2010-01-01

    The invention relates to a blade for a wind turbine, particularly to a blade that may be produced by an advanced manufacturing process for producing a blade with high quality structural components. Particularly, the structural components, which are preferably manufactured from fibre reinforced...

  13. Ecological and economic optimisation of existing and future biogas plants. First project results; Oekologische und oekonomische Optimierung von bestehenden und zukuenftigen Biogasanlagen. Erste Projektergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, Regine [ifeu-Institut fuer Energie- und Umweltforschung GmbH, Heidelberg (Germany); Graweloh, Katharina; Buecker, Christin; Bruegging, Elmar; Wetter, Christof [Fachhochschule Muenster, Steinfurt (Germany). Fachbereich Energie - Gebaeude - Umwelt; Sonnleitner, Matthias; Haering, Georg; Zoerner, Wilfried [Hochschule Ingolstadt (Germany). Kompetenzfeld Erneuerbare Energien

    2009-07-01

    First analyses of biogas plants shows that even economically sound biogas plants have substantial potential for improvement in many respects. Conspicuous deficits begging improvement are to be seen in the area of measuring and control technology and thus in the control and optimisation of the entire process, and further in the general control of the plant. From an ecological viewpoint a reduction in the number of methane emission sources is needed. This would automatically increase biogas yield.

  14. Use of Evidence-Based Practices in Pregnancy and Childbirth: South East Asia Optimising Reproductive and Child Health in Developing Countries Project

    OpenAIRE

    ,

    2008-01-01

    Background The burden of mortality and morbidity related to pregnancy and childbirth remains concentrated in developing countries. SEA-ORCHID (South East Asia Optimising Reproductive and Child Health In Developing countries) is evaluating whether a multifaceted intervention to strengthen capacity for research synthesis, evidence-based care and knowledge implementation improves adoption of best clinical practice recommendations leading to better health for mothers and babies. In this study we ...

  15. Innovative design approaches for large wind turbine blades : final report.

    Energy Technology Data Exchange (ETDEWEB)

    2004-05-01

    The goal of the Blade System Design Study (BSDS) was investigation and evaluation of design and manufacturing issues for wind turbine blades in the one to ten megawatt size range. A series of analysis tasks were completed in support of the design effort. We began with a parametric scaling study to assess blade structure using current technology. This was followed by an economic study of the cost to manufacture, transport and install large blades. Subsequently we identified several innovative design approaches that showed potential for overcoming fundamental physical and manufacturing constraints. The final stage of the project was used to develop several preliminary 50m blade designs. The key design impacts identified in this study are: (1) blade cross-sections, (2) alternative materials, (3) IEC design class, and (4) root attachment. The results show that thick blade cross-sections can provide a large reduction in blade weight, while maintaining high aerodynamic performance. Increasing blade thickness for inboard sections is a key method for improving structural efficiency and reducing blade weight. Carbon/glass hybrid blades were found to provide good improvements in blade weight, stiffness, and deflection when used in the main structural elements of the blade. The addition of carbon resulted in modest cost increases and provided significant benefits, particularly with respect to deflection. The change in design loads between IEC classes is quite significant. Optimized blades should be designed for each IEC design class. A significant portion of blade weight is related to the root buildup and metal hardware for typical root attachment designs. The results show that increasing the number of blade fasteners has a positive effect on total weight, because it reduces the required root laminate thickness.

  16. Blade system design studies volume II : preliminary blade designs and recommended test matrix.

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Dayton A. (Global Energy Concepts, LLC, Kirkland, WA)

    2004-06-01

    As part of the U.S. Department of Energy's Wind Partnerships for Advanced Component Technologies (WindPACT) program, Global Energy Concepts, LLC is performing a Blade System Design Study (BSDS) concerning innovations in materials, processes and structural configurations for application to wind turbine blades in the multi-megawatt range. The BSDS Volume I project report addresses issues and constraints identified to scaling conventional blade designs to the megawatt size range, and evaluated candidate materials, manufacturing and design innovations for overcoming and improving large blade economics. The current report (Volume II), presents additional discussion of materials and manufacturing issues for large blades, including a summary of current trends in commercial blade manufacturing. Specifications are then developed to guide the preliminary design of MW-scale blades. Using preliminary design calculations for a 3.0 MW blade, parametric analyses are performed to quantify the potential benefits in stiffness and decreased gravity loading by replacement of a baseline fiberglass spar with carbon-fiberglass hybrid material. Complete preliminary designs are then presented for 3.0 MW and 5.0 MW blades that incorporate fiberglass-to-carbon transitions at mid-span. Based on analysis of these designs, technical issues are identified and discussed. Finally, recommendations are made for composites testing under Part I1 of the BSDS, and the initial planned test matrix for that program is presented.

  17. Model of turbine blades bundles

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    Prague : Institute of Thermomechanics, Academy of Sciences of the Czech Republic, v. v. i., 2013 - (Zolotarev, I.), s. 467-477 ISBN 978-80-87012-47-5. ISSN 1805-8256. [Engineering Mechanics 2013 /19./. Svratka (CZ), 13.05.2013-16.05.2013] R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : free and forced vibrations * eigenmodes * mathematical model * bundle of blades Subject RIV: BI - Acoustics

  18. Model of turbine blades bundles

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    Praha : Insitute of Thermomechanics ASCR, v. v. i., 2013 - (Zolotarev, I.). s. 125-126 ISBN 978-80-87012-46-8. ISSN 1805-8248. [Engineering Mechanics 2013 /19./. 13.05.2013-16.05.2013, Svratka] R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : free and forced vibrations * eigenmodes * bundle of blades Subject RIV: BI - Acoustics

  19. Blade by Blade Tip Clearance Measurement

    OpenAIRE

    A. G. Sheard

    2011-01-01

    This paper describes a capacitance-based tip clearance measurement system which engineers have used in the most demanding turbine test applications. The capacitance probe has survived extended use in a major European gas turbine manufacturer's high-temperature demonstrator unit, where it functioned reliably at a turbine entry temperature in excess of 1800 degrees Kelvin. This paper explores blade by blade tip clearance measurement techniques and examines probe performance under laboratory con...

  20. Rotor blade dynamic design

    Science.gov (United States)

    Pritchard, Jocelyn I.; Adelman, Howard M.; Mantay, Wayne R.

    1989-01-01

    The rotor dynamic design considerations are essentially limitations on the vibratory response of the blades which in turn limit the dynamic excitation of the fuselage by forces and moments transmitted to the hub. Quantities which are associated with the blade response and which are subject to design constraints are discussed. These include blade frequencies, vertical and inplane hub shear, rolling and pitching moments, and aeroelastic stability margin.

  1. Shape Optimization of Wind Turbine Blades

    DEFF Research Database (Denmark)

    Wang, Xudong; Shen, Wen Zhong; Zhu, Wei Jun; Sørensen, Jens Nørkær; Chen, Jin

    2009-01-01

    This paper presents a design tool for optimizing wind turbine blades. The design model is based on an aerodynamic/aero-elastic code that includes the structural dynamics of the blades and the Blade Element Momentum (BEM) theory. To model the main aero-elastic behaviour of a real wind turbine, the...... rotor. The design variables used in the current study are the blade shape parameters, including chord, twist and relative thickness. To validate the implementation of the aerodynamic/aero-elastic model, the computed aerodynamic results are compared to experimental data for the experimental rotor used in...... the European Commision-sponsored project Model Experiments in Controlled Conditions, (MEXICO) and the computed aero-elastic results are examined against the FLEX code for flow post the Tjereborg 2 MW rotor. To illustrate the optimization technique, three wind turbine rotors of different sizes (the...

  2. Ultimate Strength of Wind Turbine Blades under Multiaxial Loading

    OpenAIRE

    Haselbach, Philipp Ulrich; Branner, Kim; Berggreen, Christian; Bitsche, Robert

    2015-01-01

    Modern wind turbine rotor blades are sophisticated lightweight structures, optimised towards achieving the best compromise between aerodynamic and structural design as well as a cost efficient manufacturing processes. They are usually designed for a lifetime of minimum 20 years, where they must endure a variety of weather conditions including uncontrollable, extreme winds without developing damage and fracture.The trend in the development of wind turbines is towards larger, more efficient win...

  3. A Long-Period Grating Sensor for Wind Turbine Blades

    DEFF Research Database (Denmark)

    Glavind, Lars

    blade material, where a suitable process and recoating material were investigated. The sensor was implemented and tested on a full scale wind turbine blade placed on a test rig. This first prototype has demonstrated the capability of the sensor for wind turbine blade monitoring, particular the......This PhD project concerns the applied research for providing a novel sensor for measurements on wind turbine blades, based on Long-Period Gratings. The idea is based on the utilization of a special asymmetrical optical fibre with Long-Period Gratings for directional sensitive bend sensing. The...... project involves the processes from feasibility study of fibre grating technology to full scale test on a wind turbine blade. The project has involved the design and manufacturing of a D-shape optical fibre. The project includes the process of embedding the optical fibre directly into the wind turbine...

  4. Optimising costs in WLCG operations

    CERN Document Server

    Pradillo, Mar; Flix, Josep; Forti, Alessandra; Sciabà, Andrea

    2015-01-01

    The Worldwide LHC Computing Grid project (WLCG) provides the computing and storage resources required by the LHC collaborations to store, process and analyse the 50 Petabytes of data annually generated by the LHC. The WLCG operations are coordinated by a distributed team of managers and experts and performed by people at all participating sites and from all the experiments. Several improvements in the WLCG infrastructure have been implemented during the first long LHC shutdown to prepare for the increasing needs of the experiments during Run2 and beyond. However, constraints in funding will affect not only the computing resources but also the available effort for operations. This paper presents the results of a detailed investigation on the allocation of the effort in the different areas of WLCG operations, identifies the most important sources of inefficiency and proposes viable strategies for optimising the operational cost, taking into account the current trends in the evolution of the computing infrastruc...

  5. Fluid Mechanics Optimising Organic Synthesis

    Science.gov (United States)

    Leivadarou, Evgenia; Dalziel, Stuart

    2015-11-01

    The Vortex Fluidic Device (VFD) is a new ``green'' approach in the synthesis of organic chemicals with many industrial applications in biodiesel generation, cosmetics, protein folding and pharmaceutical production. The VFD is a rapidly rotating tube that can operate with a jet feeding drops of liquid reactants to the base of the tube. The aim of this project is to explain the fluid mechanics of the VFD that influence the rate of reactions. The reaction rate is intimately related to the intense shearing that promotes collision between reactant molecules. In the VFD, the highest shears are found at the bottom of the tube in the Rayleigh and the Ekman layer and at the walls in the Stewardson layers. As a step towards optimising the performance of the VFD we present experiments conducted in order to establish the minimum drop volume and maximum rotation rate for maximum axisymmetric spreading without fingering instability. PhD candidate, Department of Applied Mathematics and Theoretical Physics.

  6. Optimisation of radiation protection

    International Nuclear Information System (INIS)

    Optimisation of radiation protection is one of the key elements in the current radiation protection philosophy. The present system of dose limitation was issued in 1977 by the International Commission on Radiological Protection (ICRP) and includes, in addition to the requirements of justification of practices and limitation of individual doses, the requirement that all exposures be kept as low as is reasonably achievable, taking social and economic factors into account. This last principle is usually referred to as optimisation of radiation protection, or the ALARA principle. The NEA Committee on Radiation Protection and Public Health (CRPPH) organised an ad hoc meeting, in liaison with the NEA committees on the safety of nuclear installations and radioactive waste management. Separate abstracts were prepared for individual papers presented at the meeting

  7. Repair welding of cracked steam turbine blades

    International Nuclear Information System (INIS)

    The procedure for repair welding of cracked steam turbine blades made of martensitic stainless steels has been developed using the gas tungsten arc welding process. Weld repair procedures were developed using both ER316L austenitic stainless steel filler wire and ER410 martensitic stainless steel filler wire. The repair welding procedure with austenitic filler wire was developed to avoid preheating of the blade as also hydrogen induced cold cracking, and involved evaluation of three different austenitic filler wires, viz. ER309L, ER316L and ERNiCr-3. The overall development of the repair welding procedure included selection of welding consumables (for austenitic filler metal), optimisation of post weld heat treatment parameters, selection of suitable method for local pre-heating and post-weld heat treatment (PWHT) of the blades, determination of mechanical properties of weldments in as-welded and PWHT conditions, and microstructural examination. After various trials using different procedures, the procedure of local PWHT using electrical resistance heating on the top surface of the weldment and monitoring the temperature by placing a thermocouple at the bottom of the weld, was found to give the most satisfactory results. A similar procedure was used for preheating while using ER410 filler metal. Mechanical testing of weldments before and after PWHT involved tensile tests at room temperature, face and root bend tests, and microhardness measurements across the fusion line and heat affected zone. During procedure qualification, mock-ups and actual repair welding, dye penetrant testing was used at different stages and where ever possible radiography was carried out. These procedures were developed for repair welding of cracked blades in the low-pressure (LP) steam turbines of Indian nuclear power plants. The procedure with ER316 L filler wire has so far been applied for repair welding of 2 cracked blades (made of AISI 410 SS) of LP steam turbines, while the procedure

  8. Repair welding of cracked steam turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Bhaduri, A.K.; Gill, T.P.S.; Albert, S.K.; Shanmugam, K.; Iyer, D.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)]|[Nuclear Power Corp., Mumbai (India)

    1999-07-01

    The procedure for repair welding of cracked steam turbine blades made of martensitic stainless steels has been developed using the gas tungsten arc welding process. Weld repair procedures were developed using both ER316L austenitic stainless steel filler wire and ER410 martensitic stainless steel filler wire. The repair welding procedure with austenitic filler wire was developed to avoid preheating of the blade as also hydrogen induced cold cracking, and involved evaluation of three different austenitic filler wires, viz. ER309L, ER316L and ERNiCr-3. The overall development of the repair welding procedure included selection of welding consumables (for austenitic filler metal), optimisation of post weld heat treatment parameters, selection of suitable method for local pre-heating and post-weld heat treatment (PWHT) of the blades, determination of mechanical properties of weldments in as-welded and PWHT conditions, and microstructural examination. After various trials using different procedures, the procedure of local PWHT using electrical resistance heating on the top surface of the weldment and monitoring the temperature by placing a thermocouple at the bottom of the weld, was found to give the most satisfactory results. A similar procedure was used for preheating while using ER410 filler metal. Mechanical testing of weldments before and after PWHT involved tensile tests at room temperature, face and root bend tests, and microhardness measurements across the fusion line and heat affected zone. During procedure qualification, mock-ups and actual repair welding, dye penetrant testing was used at different stages and where ever possible radiography was carried out. These procedures were developed for repair welding of cracked blades in the low-pressure (LP) steam turbines of Indian nuclear power plants. The procedure with ER316 L filler wire has so far been applied for repair welding of 2 cracked blades (made of AISI 410 SS) of LP steam turbines, while the procedure

  9. Eddy current turbocharger blade speed detection

    Energy Technology Data Exchange (ETDEWEB)

    Rickman, J. Jr.

    1982-09-01

    A commercially available magnetic reluctance sensor is used to determine the angular velocity of turbocharger impeller blades from outside the aluminum housing. Eddy currents are induced in the aluminum blades by blade motion through the magnetic field projected by an externally mounted samarium-cobalt permanent magnet. Experiments show that secondary eddy currents and associated ac magnetic fields generated in the aluminum housing provide the prime excitation for a sensor coil located outside the housing. The coil output voltage spectrum shows a strongly peaked structure with peak locations at multiples of the blade passage frequency in the range 1-10 kHz. The sensor output signal decreases with increasing frequency above 2 kHz because of increasingly effective attenuation by the housing. Test results show that a circuit designed to track the blade signal gives an analog voltage output proportional to the frequency of blade passage over the operating range of the Cummins VT-903 and Detroit 8V-71T turbocharged diesel engines. Suggestions are made for the design of a sensor appropriate for both magnetic reluctance and eddy current sensing applications.

  10. Optimisation in radiotherapy II: Programmed and inversion optimisation algorithms

    International Nuclear Information System (INIS)

    This is the second article in a three part examination of optimisation in radiotherapy. The previous article established the bases of optimisation in radiotherapy, and the formulation of the optimisation problem. This paper outlines several algorithms that have been used in radiotherapy, for searching for the best irradiation strategy within the full set of possible strategies. Two principle classes of algorithm are considered - those associated with mathematical programming which employ specific search techniques, linear programming type searches or artificial intelligence - and those which seek to perform a numerical inversion of the optimisation problem, finishing with deterministic iterative inversion. (author)

  11. Optimisation in radiotherapy. II: Programmed and inversion optimisation algorithms.

    Science.gov (United States)

    Ebert, M

    1997-12-01

    This is the second article in a three part examination of optimisation in radiotherapy. The previous article established the bases of optimisation in radiotherapy, and the formulation of the optimisation problem. This paper outlines several algorithms that have been used in radiotherapy, for searching for the best irradiation strategy within the full set of possible strategies. Two principle classes of algorithm are considered--those associated with mathematical programming which employ specific search techniques, linear programming-type searches or artificial intelligence--and those which seek to perform a numerical inversion of the optimisation problem, finishing with deterministic iterative inversion. PMID:9503694

  12. Optimizing the Tip Section Profiles of a Steam Turbine Blading

    Czech Academy of Sciences Publication Activity Database

    Dvořák, Rudolf; Šafařík, P.; Luxa, Martin; Šimurda, David

    Hamburg, 2013. [ASME 2013 Turbine Blade Tip Symposium and Course Week. Hamburg (DE), 30.09.2013-03.10.2013] R&D Projects: GA TA ČR(CZ) TA03020277 Institutional support: RVO:61388998 Keywords : tip section * blade cascade * optimization * supersonic flow Subject RIV: BK - Fluid Dynamics

  13. ATLAS software configuration and build tool optimisation

    International Nuclear Information System (INIS)

    ATLAS software code base is over 6 million lines organised in about 2000 packages. It makes use of some 100 external software packages, is developed by more than 400 developers and used by more than 2500 physicists from over 200 universities and laboratories in 6 continents. To meet the challenge of configuration and building of this software, the Configuration Management Tool (CMT) is used. CMT expects each package to describe its build targets, build and environment setup parameters, dependencies on other packages in a text file called requirements, and each project (group of packages) to describe its policies and dependencies on other projects in a text project file. Based on the effective set of configuration parameters read from the requirements files of dependent packages and project files, CMT commands build the packages, generate the environment for their use, or query the packages. The main focus was on build time performance that was optimised within several approaches: reduction of the number of reads of requirements files that are now read once per package by a CMT build command that generates cached requirements files for subsequent CMT build commands; introduction of more fine-grained build parallelism at package task level, i.e., dependent applications and libraries are compiled in parallel; code optimisation of CMT commands used for build; introduction of package level build parallelism, i. e., parallelise the build of independent packages. By default, CMT launches NUMBER-OF-PROCESSORS build commands in parallel. The other focus was on CMT commands optimisation in general that made them approximately 2 times faster. CMT can generate a cached requirements file for the environment setup command, which is especially useful for deployment on distributed file systems like AFS or CERN VMFS. The use of parallelism, caching and code optimisation significantly-by several times-reduced software build time, environment setup time, increased the efficiency of

  14. Optimisation of Wheelset Maintenance: Current Research Activities

    OpenAIRE

    Bevan, Adam; Molyneux-Berry, Paul

    2014-01-01

    Recent research projects relating to wheelset damage and maintenance practices includes: - Influence of changes in material properties on observed damage - Optimisation of wheelset maintenance to reduce whole-system costs - Investigating the influence of route and vehicle design and maintenance policy on wheel tread damage - Assessment of alternative wheel profiles, considering both whole-system costs and running safety - Categorisation of wheel damage mechanisms to im...

  15. Recent results in characterisation and modeling of composites for wind turbine blades

    NARCIS (Netherlands)

    Nijssen, R.P.L.; Westphal, T.; Lahuerta Calahorra, F.; Van Delft, D.R.V.

    2013-01-01

    Wind turbine rotor blades are large structures which are designed to withstand extreme loading at low cost. Material and structural characterisation through modeling combined with tests are continuously developed to enable further design optimisation, larger rotors and new design concepts. This pape

  16. Optimisation and common sense

    International Nuclear Information System (INIS)

    This note builds on recent articles about the development of new ICRP recommendations by supporting the use of common sense in optimisation; use of an additional criterion relating to technology-based principles is suggested to support utility- and equity-based criteria. This is taken forward by use of authoritative good practice safety precautions and a need to consider safety in an integrated manner. It is noted that use of common sense in ALARP or ALARA decisions is liable to rely on access to information and training. (author)

  17. Optimisation of Microstrip Antenna

    Directory of Open Access Journals (Sweden)

    H. El Hamchary

    1996-04-01

    Full Text Available When choosing the most appropriate microstrip antenna configuration for particular applications, the kind of excitation of the radiating element is an essential factor that requires careful considerations. For controlling the distribution of energy of the linear or planar array of elements and for coupling energy to the individual elements, a wide variety of feed mechanisms are available. In this paper, the coaxial antenna feeding is assumed and the best (optimised feeding is found. Then, antenna characteristics such as radiation pattern, return loss, input impedance, and VSWR are obtained.

  18. Multiple piece turbine rotor blade

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Russell B; Fedock, John A

    2013-05-21

    A multiple piece turbine rotor blade with a shell having an airfoil shape and secured between a spar and a platform with the spar including a tip end piece. a snap ring fits around the spar and abuts against the spar tip end piece on a top side and abuts against a shell on the bottom side so that the centrifugal loads from the shell is passed through the snap ring and into the spar and not through a tip cap dovetail slot and projection structure.

  19. Blade attachment assembly

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  20. Optimisation of tree path pipe network with nonlinear optimisation method

    OpenAIRE

    Doberšek, Danijela; Goričanec, Darko

    2009-01-01

    Optimisation of tree path pipe network with nonlinear optimisation method correspondance: Corresponding author. Tel.: +00386 2 22 07 761; fax: +00386 2 22 94 476. (Dobersek, D.) (Dobersek, D.) Faculty of Chemistry and Chemical Engineering--> , University of Maribor--> , Smetanova ul. 17--> , 2000 Maribor--> - SLOVENIA (Dobersek, D.) Faculty of Chemistry and Chemical Engineerin...

  1. Blade Testing Trends (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Desmond, M.

    2014-08-01

    As an invited guest speaker, Michael Desmond presented on NREL's NWTC structural testing methods and capabilities at the 2014 Sandia Blade Workshop held on August 26-28, 2014 in Albuquerque, NM. Although dynamometer and field testing capabilities were mentioned, the presentation focused primarily on wind turbine blade testing, including descriptions and capabilities for accredited certification testing, historical methodology and technology deployment, and current research and development activities.

  2. Methodological proposal for the design of the turbine blades of wind of horizontal axis

    International Nuclear Information System (INIS)

    A methodology is developed to estimate the chord distribution airfoil and blade twist along the radius of the blade by using axial and angular moment conservation equations, blade element theory and optimization processes. This methodology takes into account the concept related with getting wind power for different chord blade values and selecting one that facilitates to get the maximum value for wind power. This work is based on project wind energy market in Colombia: operation, risk and expansion possibilities

  3. Smart actuation mechanisms for helicopter blades: design case for a mach-scaled model blade

    NARCIS (Netherlands)

    Paternoster, A.R.A.

    2013-01-01

    This work is part of the European project “Clean Sky”, which aims at improving the efficiency and the global transport quality of aircraft. The research, in this project, is currently focussing on active flap systems for helicopters to adapt the blade aerodynamic properties to local aerodynamic cond

  4. Mathematical Model of Two Blades System

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    2014-01-01

    Roč. 2, č. 4 (2014), s. 361-369. ISSN 2321-3558 R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : turbine blades * dry friction * vibration damping * torsion Subject RIV: BI - Acoustics

  5. Spreading granular material with a blade

    Science.gov (United States)

    Dressaire, Emilie; Singh, Vachitar; Grimaldi, Emma; Sauret, Alban

    2015-11-01

    The spreading of a complex fluid with a blade is encountered in applications that range from the bulldozing of granular material in construction projects to the coating of substrates with fluids in industrial applications. This spreading process is also present in everyday life, when we use a knife to turn a lump of peanut butter into a thin layer over our morning toast. In this study, we rely on granular media in a model experiment to describe the three-dimensional spreading of the material. Our experimental set-up allows tracking the spreading of a sandpile on a translating flat surface as the blade remains fixed. We characterize the spreading dynamics and the shape of the spread fluid layer when varying the tilt of the blade, its spacing with the surface and its speed. Our findings suggest that it is possible to tune the spreading parameters to optimize the coating.

  6. Optimiser les ressources humaines

    OpenAIRE

    Henriet, Bruno; Krohmer, Cathy

    2013-01-01

    Dans les trois organisations que nous avons étudiées, la démarche cherche d’abord à optimiser la gestion des ressources humaines pour s’assurer de l’adaptation des compétences des salariés aux besoins stratégiques de l’entreprise. La démarche est alors un moyen d’atteindre les compétences, en termes de niveau et de contenu, requises par les modèles productifs. Ce type de démarche a été observé dans trois entreprises de la région Pays de la Loire. La première, Fenêtre, est une menuiserie indus...

  7. Ecological and economic optimisation of present and future biogas plants. Project findings; Oekologische und oekonomische Optimierung von bestehenden und zukuenftigen Biogasanlagen. Projektergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, Regine [ifeu-Institut fuer Energie- und Umweltforschung GmbH, Heidelberg (Germany); Buecker, Christin; Bruegging, Elmar; Wetter, Christof [Fachhochschule Muenster, Steinfurt (Germany). Fachbereich Energie - Gebaeude - Umwelt; Haering, Georg; Sonnleitner, Matthias; Zoerner, Wilfried [Hochschule Ingolstadt (Germany). Kompetenzfeld Erneuerbare Energien

    2010-07-01

    In a research project funded by the BMU (''Oekologische und oekonomische Optimierung von bestehenden und zukuenftigen Biogasanlagen''), biogas plants are to be optimized both ecologically and economically. For this, practical solutions were developed for ten existing biogas plants each in Bavaria and Nordrhein-Westfalen. The project aimed at the development of optimization strategies with concrete technical solutions and a high potential of practical implementability.

  8. Blade dynamic stress analysis of rotating bladed disks

    Directory of Open Access Journals (Sweden)

    Kellner J.

    2007-10-01

    Full Text Available The paper deals with mathematical modelling of steady forced bladed disk vibrations and with dynamic stress calculation of the blades. The blades are considered as 1D kontinuum elastic coupled with three-dimensional elastic disk centrally clamped into rotor rotating with constant angular speed. The steady forced vibrations are generated by the aerodynamic forces acting along the blade length. By using modal synthesis method the mathematical model of the rotating bladed disk is condensed to calculate steady vibrations. Dynamic stress analysis of the blades is based on calculation of the time dependent reduced stress in blade cross-sections by using Hubert-Misses-Hencky stress hypothesis. The presented method is applied to real turbomachinery rotor with blades connected on the top with shroud.

  9. Fundamentals for remote structural health monitoring of wind turbine blades - a pre-project. Annex B - Sensors and non-destructive testing methods for damage detection in wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Lading, L.; McGugan, M.; Sendrup, P.; Rheinlaender, J.; Rusborg, J.

    2002-05-01

    This annex provides a description of the sensor schemes and the non-destructive testing (NDT) methods that have been investigated in this project. Acoustic emission and fibre optic sensors are described in some detail whereas only the key features of well-established NDT methods are presented. Estimates of the cost of different sensor systems are given and the advantages and disadvantages of the different schemes is discussed. (au)

  10. Methods for testing of geometrical down-scaled rotor blades

    DEFF Research Database (Denmark)

    Branner, Kim; Berring, Peter

    requirements for experimental facilities are very demanding and furthermore the time for performing the experimental test campaign and the cost are not well suitable for most research projects. This report deals with the advantages, disadvantages and open questions of using down-scaled testing on wind turbine......Full scale fatigue test is an important part of the development and design of wind turbine blades. Testing is also needed for the approval of the blades in order for them to be used on large wind turbines. Fatigue test of wind turbine blades was started in the beginning of the 1980s and has been...... scale MW wind turbine blade are very time consuming and expensive. For the industry that means that the tests, both static and fatigue, are not a tool in or a part of the design process. In the academic community, full scale testing of modern and future wind turbine blades are even more challenging as...

  11. Engineering Optimisation by Cuckoo Search

    CERN Document Server

    Yang, Xin-She

    2010-01-01

    A new metaheuristic optimisation algorithm, called Cuckoo Search (CS), was developed recently by Yang and Deb (2009). This paper presents a more extensive comparison study using some standard test functions and newly designed stochastic test functions. We then apply the CS algorithm to solve engineering design optimisation problems, including the design of springs and welded beam structures. The optimal solutions obtained by CS are far better than the best solutions obtained by an efficient particle swarm optimiser. We will discuss the unique search features used in CS and the implications for further research.

  12. Cooled snubber structure for turbine blades

    Science.gov (United States)

    Mayer, Clinton A; Campbell, Christian X; Whalley, Andrew; Marra, John J

    2014-04-01

    A turbine blade assembly in a turbine engine. The turbine blade assembly includes a turbine blade and a first snubber structure. The turbine blade includes an internal cooling passage containing cooling air. The first snubber structure extends outwardly from a sidewall of the turbine blade and includes a hollow interior portion that receives cooling air from the internal cooling passage of the turbine blade.

  13. Optimising prescription and titration of oxygen for adult inpatients using novel silicone wristbands: results of a pilot project at three centres.

    Science.gov (United States)

    Forster, Sarah; Smith, Sue; Daniel, Priya; Binnion, Amy; Briggs, Lucy; Evans, Rachel; Ryanna, Kimuli; Woltmann, Gerrit; Bajammal, Omar; Hodgson, David; Saini, Gauri; Scullion, Jane; Bolton, Charlotte E; Lowrey, Gillian

    2016-08-01

    Oxygen is the most commonly used drug in the acute hospital setting. Oxygen can be lifesaving but there is increasing evidence that it can cause harm if it is not given correctly. Prescription of oxygen, according to target saturations, has been advocated since 2008 but compliance remains at low levels. This paper describes a novel approach to improve oxygen prescription and titration in three acute hospital trusts using a colour-coded silicone wristband. The project ran for 3 months and covered more than 2,000 emergency admissions to hospital. Data was collected for oxygen prescription and titration rates for 270 patients during the project period. The wristbands showed an improvement in prescription and titration of oxygen in two out of three sites. The results support a wider controlled study of colour-coded wristbands to improve oxygen safety in secondary care. PMID:27481375

  14. Investigating the e-VLBI Mark 5 end systems in order to optimise data transfer rates as part of the ESLEA project

    Science.gov (United States)

    Strong, M.; Hughes-Jones, R.; Spencer, R. E.; Casey, S.; Kershaw, S.; Burgess, P.; Szomoru, A.

    We report on the development of high bandwidth data transfers for e-VLBI at Jodrell Bank Observatory as part of the ESLEA project. ESLEA is a UK project to exploit the use of switched-lightpath optical networks for various applications, including e-VLBI, HEP, High Performance Computing and e-Health. We show how the CPU power of the Jodrell Bank eVLBI Mark 5A end systems was limiting the data transfer rate to below 512 Mb/s. Both of the Jodrell Bank Mark 5A end systems have now been upgraded and can now transfer e-VLBI data to JIVE at the required data rate of 512 Mb/s.

  15. Engineering Optimisation by Cuckoo Search

    OpenAIRE

    Yang, Xin-She; Deb, Suash

    2010-01-01

    A new metaheuristic optimisation algorithm, called Cuckoo Search (CS), was developed recently by Yang and Deb (2009). This paper presents a more extensive comparison study using some standard test functions and newly designed stochastic test functions. We then apply the CS algorithm to solve engineering design optimisation problems, including the design of springs and welded beam structures. The optimal solutions obtained by CS are far better than the best solutions obtained by an efficient p...

  16. Numerical optimisation of an axial turbine; Numerische Optimierung einer Axialturbine

    Energy Technology Data Exchange (ETDEWEB)

    Welzel, B.

    1998-12-31

    The author presents a method for automatic shape optimisation of components with internal or external flow. The method combines a program for numerical calculation of frictional turbulent flow with an optimisation algorithm. Algorithms are a simplex search strategy and an evolution strategy. The shape of the component to be optimized is variable due to shape parameters modified by the algorithm. For each shape, a flow calculation is carried out on whose basis a functional value like performance, loss, lift or resistivity is calculated. For validation, the optimisation method is used in simple examples with known solutions. It is applied. It is applied to the components of a slow-running axial turbine. Components with accelerated and delayed rotationally symmetric flow and 2D blade profiles are optimized. [Deutsch] Es wird eine Methode zur automatischen Formoptimierung durchstroemter oder umstroemter Bauteile vorgestellt. Diese koppelt ein Programm zur numerischen Berechnung reibungsbehafteter turbulenter Stroemungen mit einem Optimierungsalgorithmus. Dabei kommen als Algorithmen eine Simplex-Suchstrategie und eine Evolutionsstrategie zum Einsatz. Die Form des zu optimierenden Koerpers ist durch Formparameter, die vom Algorithmus veraendert werden, variabel. Fuer jede Form wird eine Stroemungsberechnung durchgefuehrt und mit dieser ein Funktionswert wie Wirkungsgrad, Verlust, Auftrieb oder Widerstandskraft berechnet. Die Optimierungsmethode wird zur Validierung in einfachen Beispielen mit bekannter Loesung eingesetzt. Zur Anwendung kommt sie in den einzelnen Komponenten einer langsamlaeufigen Axialturbine. Es werden Bauteile mit beschleunigter und verzoegerter rotationssymmetrischer Stroemung und 2D-Schaufelprofile optimiert. (orig.)

  17. Wind turbine blade life-time assessment model for preventive planning of operation and maintenance

    DEFF Research Database (Denmark)

    Florian, Mihai; Sørensen, John Dalsgaard

    2014-01-01

    Out of the total wind turbine failure events, blade damage accounts for a substantial part, with some studies estimating it at around 23%. Current operation and maintenance (O&M) practices typically make use of corrective type maintenance as the basic approach, implying high costs for repair and......&M decisions for avoiding major failure events. The present paper presents a fracture mechanics based model for estimating the remaining life of a wind turbine blade, focusing on the crack propagation in the blades adhesive joints. A generic crack propagation model is built in Matlab based on a Paris law...... approach. The model is used within a risk-based maintenance decision framework to optimise maintenance planning for the blades lifetime....

  18. Vibrations of blades bunches

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    Brno: Brno University of Technology, 2014 - (Fuis, V.), s. 520-523 ISBN 978-80-214-4871-1. ISSN 1805-8248. [Engineering Mechanics 2014 /20./. Svratka (CZ), 12.05.2014-15.05.2014] Institutional support: RVO:61388998 Keywords : damping * dry friction * five-blades-bunch * harmonic excitation * response curve Subject RIV: BI - Acoustics

  19. Database about blade faults

    DEFF Research Database (Denmark)

    Branner, Kim; Ghadirian, Amin

    This report deals with the importance of measuring the reliability of the rotor blades and describing how they can fail. The Challenge is that very little non-confidential data is available and that the quality and detail in the data is limited....

  20. State of the Art analysis for the 'SolcelleInverter' project. Optimised design and control of inverter for photovoltaic systems: the AC-module

    Energy Technology Data Exchange (ETDEWEB)

    Baekhoej Kjaer, S.

    2002-02-01

    The 'SolcelleInverter' project starts with this state-of-the-art analysis of 27 different inverter topologies for use in photovoltaic applications. The main concern is the present status for inverters for single solar modules. Technologies for larger clusters of modules are also investigated. The possibility of combining a small decentralised and a big centralised unit is as well investigated. A series of topologies are discovered and this paper will present them. That includes solutions with and without transformers, systems for one or multiple modules, commercial solutions and solutions found in scientific papers and patents. (au)

  1. Effects of large bending deflections on blade flutter limits

    Energy Technology Data Exchange (ETDEWEB)

    Kallesoee, Bjarne Skovmose; Hartvig Hansen, Morten

    2008-04-15

    The coupling of bending and torsion due to large blade bending are assumed to have some effects of the flutter limits of wind turbines. In the present report, the aeroelastic blade model suggested by Kallesoee, which is similar to a second order model, is used to investigate the aeroelastic stability limits of the RWT blade with and without the effects of the large blade deflection. The investigation shows no significant change of the flutter limit on the rotor speed due to the blade deflection,whereas the first edgewise bending mode becomes negatively damped due to the coupling with blade torsion which causes a change of the effective direction of blade vibration. These observations are confirmed by nonlinear aeroelastic simulations using HAWC2. This work is part of the UpWind project funded by the European Commission under the contract number SES6-CT-2005-019945 which is gratefully acknowledged. This report is the deliverable D2.3 of the UpWind project. (au)

  2. BLADE sequences in transverse T2-weighted MR imaging of the cervical spine. Cut-off for artefacts?

    Energy Technology Data Exchange (ETDEWEB)

    Finkenzeller, T. [Hospital Nuremberg Sued (Germany). Inst. of Radiology and Neuroradiology; Wendl, C.M.; Stroszczynski, C.; Fellner, C. [University Hospital Regensburg (Germany). Inst. of Radiology; Lenhart, S. [Klinikum Weiden (Germany). Radiology and Neuroradiology; Schuierer, G. [Center of Neuroradiology, Regensburg (Germany). Inst. of Neuroradiology

    2015-02-15

    The BLADE (PROPELLER) technique reduces artefacts in imaging of the cervical spine in sagittal orientation, but till now failed to do so in axial orientation, because here it increased through plane CSF-flow artefacts, which spoiled the benefit of BLADE artefact reduction 'in plane'. The aim of this study was to compare a BLADE sequence with optimised measurement parameters in axial orientation to T2-TSE. Both sequences were compared in 58 patients with 31 discal, 16 bony and 11 spinal cord lesions. Image sharpness, reliability of spinal cord depiction, CSF flow artefacts and lesion detection were evaluated by 3 independent observers. Additionally the observers were asked which sequence they would prefer for diagnostic workup. Statistical evaluations were performed using sign and {sub X}2 test. BLADE was significantly superior concerning image sharpness, spinal cord depiction and overall lesion detection. BLADE was rated better for most pathologies, for bony lesions the differences compared with TSE were statistically significant. Regarding CSF-flow artefacts both sequences showed no difference. All readers preferred BLADE in side by side reading. An optimised axial T2 BLADE sequence decreases the problems of increased through plane CSF-flow artefacts in this orientation. By reducing various other artefacts it yields better image quality and has the potential to reduce the number of non-diagnostic examinations especially in uncooperative patients.

  3. BLADE sequences in transverse T2-weighted MR imaging of the cervical spine. Cut-off for artefacts?

    International Nuclear Information System (INIS)

    The BLADE (PROPELLER) technique reduces artefacts in imaging of the cervical spine in sagittal orientation, but till now failed to do so in axial orientation, because here it increased through plane CSF-flow artefacts, which spoiled the benefit of BLADE artefact reduction 'in plane'. The aim of this study was to compare a BLADE sequence with optimised measurement parameters in axial orientation to T2-TSE. Both sequences were compared in 58 patients with 31 discal, 16 bony and 11 spinal cord lesions. Image sharpness, reliability of spinal cord depiction, CSF flow artefacts and lesion detection were evaluated by 3 independent observers. Additionally the observers were asked which sequence they would prefer for diagnostic workup. Statistical evaluations were performed using sign and X2 test. BLADE was significantly superior concerning image sharpness, spinal cord depiction and overall lesion detection. BLADE was rated better for most pathologies, for bony lesions the differences compared with TSE were statistically significant. Regarding CSF-flow artefacts both sequences showed no difference. All readers preferred BLADE in side by side reading. An optimised axial T2 BLADE sequence decreases the problems of increased through plane CSF-flow artefacts in this orientation. By reducing various other artefacts it yields better image quality and has the potential to reduce the number of non-diagnostic examinations especially in uncooperative patients.

  4. Aerodynamics tests of a transonic turbine blade cascade model consisting of low number of blades

    Czech Academy of Sciences Publication Activity Database

    Šimurda, David; Luxa, Martin; Šafařík, Pavel; Synáč, J.

    Plzeň: Západočeská univerzita Plzeň, 2012, s. 1-10. [Turbostroje 2012. Plzeň (CZ), 26.09.2012-27.09.2012] R&D Projects: GA ČR(CZ) GAP101/10/1329 Institutional support: RVO:61388998 Keywords : transonic flow * flow field periodicity * turbine blade cascade Subject RIV: BK - Fluid Dynamics

  5. Selection of topologies for the PHOTONERGY{sup TM} project. Optimised design and control of inverter for photovoltaic systems: the AC-module

    Energy Technology Data Exchange (ETDEWEB)

    Baekhoej Kjaer, S.

    2002-06-01

    The PHOTONERGY{sup TM} project (also known as the former 'SolcelleInverter' project) is by this report carried into its third stage; the selection of a suitable topology for the AC-Module inverter. The selection of a suitable topology is based on State-Of-The-Art analysis a specifications and a comparison of four grid-tied inverters and nine dc/dc converters. This implies 23 possible combinations, from which nine is investigated with respect to efficiency in six working points, the number of components and to some extent also the rating of the components. The conclusion is that the target of a European efficiency of 93.7% is hard to achieve. But four of the examined, and two newly discovered, inverters are recommended for a further examination by means of estimations, calculations and simulations of: cost, complexity, robustness, efficiency and mass-production. The system-layout is also examined. The first layout implies that the PV-Module and the inverter is integrated into one unit and the second layout involves that the inverter is placed indoor. The layouts are compared with respect to cable-losses, enclosure demanding and lifetime. The conclusion is somehow ambiguous and a further investigation should be initiated in order to get a clear result. (au)

  6. KNOW-BLADE task-3.3 report. Rotor blade computations with 3D vortex generators

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, J.; Soerensen, N.N.; Reck, M. (and others)

    2005-01-01

    The present report describes the work done in work package WP3.3: Aerodynamic Accessories in 3D in the EC project KNOW-BLADE. Vortex generators (VGs) are modelled in 3D Navier-Stokes solvers and applied on the flow around an airfoil and a wind turbine blade. Three test cases have been investigated. They are: 1) A non-rotating airfoil section with VGs. 2) A rotating airfoil section with VGs. 3) A non-rotating wind turbine blade with VGs. The airfoil section was the FFA-W3-241 airfoil, which has been measured in the VELUX wind tunnel with and without VGs placed at different chord wise positions. Three of the partners have modelled the airfoil section as a thin airfoil section with symmetry boundary conditions in the span wise direction to simulate an array of VGs. The wind turbine blade is the LM19.1 blade equipped with one pair of VGs placed at radius = 8.5 m. In general all partners have successfully modelled vortex generators in 3D, which eventually generates vortices and mixes the boundary layer. A large effort has been on generating the numerical meshes since this is a relatively complex configuration and a large variation of length and time scales is present. Even though the quantitative agreement with measurements is not acceptable the effort spend in the present project indicate that it is possible to investigate the effect of vortex generators on wind turbine blades using 3D Navier-Stokes solvers. Much further work within independence of mesh resolution and time step as well as turbulence modelling has to be carried out in future projects before parametric variations can be investigated. (au)

  7. BWR control blade replacement strategies

    International Nuclear Information System (INIS)

    The reactivity control elements in a BWR, the control blades, perform three significant functions: provide shutdown margin during normal and accident operating conditions; provide overall core reactivity control; and provide axial power shaping control. As such, the blades are exposed to the core's neutron flux, resulting in irradiation of blade structural and absorber materials. Since the absorber depletes with time (if B4C is used, it also swells) and the structural components undergo various degradation mechanisms (e.g., embrittlement, corrosion), the blades have limits on their operational lifetimes. Consequently, BWR utilities have implemented strategies that aim to maximize blade lifetimes while balancing operational costs, such as extending a refuelling outage to shuffle high exposure blades. This paper examines the blade replacement strategies used by BWR utilities operating in US, Europe and Asia by assembling information related to: the utility's specific blade replacement strategy; the impact the newer blade designs and changes in core operating mode were having on those strategies; the mechanical and nuclear limits that determined those strategies; the methods employed to ensure that lifetime limits were not exceeded during operation; and blade designs used (current and replacement blades). (author)

  8. Rotor blade vortex interaction noise

    Science.gov (United States)

    Yu, Yung H.

    2000-02-01

    Blade-vortex interaction noise-generated by helicopter main rotor blades is one of the most severe noise problems and is very important both in military applications and community acceptance of rotorcraft. Research over the decades has substantially improved physical understanding of noise-generating mechanisms, and various design concepts have been investigated to control noise radiation using advanced blade planform shapes and active blade control techniques. The important parameters to control rotor blade-vortex interaction noise and vibration have been identified: blade tip vortex structures and its trajectory, blade aeroelastic deformation, and airloads. Several blade tip design concepts have been investigated for diffusing tip vortices and also for reducing noise. However, these tip shapes have not been able to substantially reduce blade-vortex interaction noise without degradation of rotor performance. Meanwhile, blade root control techniques, such as higher-harmonic pitch control (HHC) and individual blade control (IBC) concepts, have been extensively investigated for noise and vibration reduction. The HHC technique has proved the substantial blade-vortex interaction noise reduction, up to 6 dB, while vibration and low-frequency noise have been increased. Tests with IBC techniques have shown the simultaneous reduction of rotor noise and vibratory loads with 2/rev pitch control inputs. Recently, active blade control concepts with smart structures have been investigated with the emphasis on active blade twist and trailing edge flap. Smart structures technologies are very promising, but further advancements are needed to meet all the requirements of rotorcraft applications in frequency, force, and displacement.

  9. Transition Model Application on Mid-Section Turbine Blade Cascade

    Czech Academy of Sciences Publication Activity Database

    Váchová, J.; Luxa, Martin; Příhoda, Jaromír; Šimurda, David

    Lerici, 2015, s. 1-8. [International Symposium on Experimental Computational Aerothermodynamics of Internal Flows : ISAIF /12./. Lerici (IT), 13.07.2015-16.07.2015] R&D Projects: GA TA ČR(CZ) TA03020277; GA ČR GAP101/12/1271 Institutional support: RVO:61388998 Keywords : blade cascade * long turbine rotor blade * mid-section * optical methods * CFD modelling Subject RIV: BK - Fluid Dynamics

  10. Ultimate strength of a large wind turbine blade

    OpenAIRE

    Jensen, Find Mølholt; Stang, Henrik; Branner, Kim

    2009-01-01

    The present PhD project contains a study of the structural static strength of wind turbine blades loaded in flap-wise direction. A combination of experimental and numerical work has been used to address the most critical failure mechanisms and to get an understanding of the complex structural behaviour of wind turbine blades. Four failure mechanisms observed during the fullscale tests and the corresponding FE-analysis are presented. Elastic mechanisms associated with failure, such as buckling...

  11. Blade System Design Studies Volume I: Composite Technologies for Large Wind Turbine Blades

    Energy Technology Data Exchange (ETDEWEB)

    GRIFFIN, DAYTON A.; ASHWILL, THOMAS D.

    2002-07-01

    As part of the U.S. Department of Energy's Wind Partnerships for Advanced Component Technologies (WindPACT) program, Global Energy Concepts LLC (GEC) is performing a study concerning innovations in materials, processes and structural configurations for application to wind turbine blades in the multi-megawatt range. The project team for this work includes experts in all areas of wind turbine blade design, analysis, manufacture, and testing. Constraints to cost-effective scaling-up of the current commercial blade designs and manufacturing methods are identified, including self-gravity loads, transportation, and environmental considerations. A trade-off study is performed to evaluate the incremental changes in blade cost, weight, and stiffness for a wide range of composite materials, fabric types, and manufacturing processes. Fiberglass/carbon fiber hybrid blades are identified as having a promising combination of cost, weight, stiffness and fatigue resistance. Vacuum-assisted resin transfer molding, resin film infision, and pre-impregnated materials are identified as having benefits in reduced volatile emissions, higher fiber content, and improved laminate quality relative to the baseline wet lay-up process. Alternative structural designs are identified, including jointed configurations to facilitate transportation. Based on the results to date, recommendations are made for further evaluation and testing under this study to verify the predicted material and structural performance.

  12. Optimising agile development practices for the maintenance operation

    DEFF Research Database (Denmark)

    Heeager, Lise Tordrup; Rose, Jeremy

    2015-01-01

    on benefits. In an action research project at Aveva in Denmark we assisted with the optimisation of SCRUM, tailoring the standard process to the immediate needs of the developers. We draw on both theoretical and empirical learning to formulate nine heuristics for maintenance practitioners wishing to...

  13. AM1, a high-performance superalloy for single crystal turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Bachelet, E.; Lamanthe, G. (Societe Nationale d' Etude et de Construction de Moteurs d' Aviation (SNECMA), 75 - Paris (France))

    1992-05-01

    SNECMA has developed a nickel-based superalloy for the manufacture of high-performance turbine blades. The authors recall the basic principles governing the behaviour of superalloys and the steady progress made in producing turbine blades. They go on to explain the approaches used for analysis, production and heat treatment leading to the specification of AM and the optimisation of the alloy's microstructure. They describe its mechanical properties including tensile behaviour and toughness, its resistance to creep, to thermal and low cycle fatigue, and to environmental constraints. (author). 11 figs., 3 tabs.

  14. Mathematical model of two blades system

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    Gdaňsk : Szewalski Institute of Fluid-Flow Machinery PAS , 2012 - (Rzadkowski, R.), s. 199-208 ISBN 978-83-88237-61-4. [VETOMAC /8./. Gdaňsk (PL), 03.09.2012-06.09.2012] R&D Projects: GA ČR GA101/09/1166 Institutional research plan: CEZ:AV0Z20760514 Keywords : turbine blades * dry friction * vibration damping * torsion Subject RIV: BI - Acoustics

  15. TEM turbulence optimisation in stellarators

    CERN Document Server

    Proll, J H E; Xanthopoulos, P; Lazerson, S A; Faber, B J

    2015-01-01

    With the advent of neoclassically optimised stellarators, optimising stellarators for turbulent transport is an important next step. The reduction of ion-temperature-gradient-driven turbulence has been achieved via shaping of the magnetic field, and the reduction of trapped-electron mode (TEM) turbulence is adressed in the present paper. Recent analytical and numerical findings suggest TEMs are stabilised when a large fraction of trapped particles experiences favourable bounce-averaged curvature. This is the case for example in Wendelstein 7-X [C.D. Beidler $\\textit{et al}$ Fusion Technology $\\bf{17}$, 148 (1990)] and other Helias-type stellarators. Using this knowledge, a proxy function was designed to estimate the TEM dynamics, allowing optimal configurations for TEM stability to be determined with the STELLOPT [D.A. Spong $\\textit{et al}$ Nucl. Fusion $\\bf{41}$, 711 (2001)] code without extensive turbulence simulations. A first proof-of-principle optimised equilibrium stemming from the TEM-dominated stella...

  16. Snubber assembly for turbine blades

    Science.gov (United States)

    Marra, John J

    2013-09-03

    A snubber associated with a rotatable turbine blade in a turbine engine, the turbine blade including a pressure sidewall and a suction sidewall opposed from the pressure wall. The snubber assembly includes a first snubber structure associated with the pressure sidewall of the turbine blade, a second snubber structure associated with the suction sidewall of the turbine blade, and a support structure. The support structure extends through the blade and is rigidly coupled at a first end portion thereof to the first snubber structure and at a second end portion thereof to the second snubber structure. Centrifugal loads exerted by the first and second snubber structures caused by rotation thereof during operation of the engine are at least partially transferred to the support structure, such that centrifugal loads exerted on the pressure and suctions sidewalls of the turbine blade by the first and second snubber structures are reduced.

  17. High efficiency turbine blade coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Youchison, Dennis L.; Gallis, Michail A.

    2014-06-01

    The development of advanced thermal barrier coatings (TBCs) of yttria stabilized zirconia (YSZ) that exhibit lower thermal conductivity through better control of electron beam - physical vapor deposition (EB-PVD) processing is of prime interest to both the aerospace and power industries. This report summarizes the work performed under a two-year Lab-Directed Research and Development (LDRD) project (38664) to produce lower thermal conductivity, graded-layer thermal barrier coatings for turbine blades in an effort to increase the efficiency of high temperature gas turbines. This project was sponsored by the Nuclear Fuel Cycle Investment Area. Therefore, particular importance was given to the processing of the large blades required for industrial gas turbines proposed for use in the Brayton cycle of nuclear plants powered by high temperature gas-cooled reactors (HTGRs). During this modest (~1 full-time equivalent (FTE)) project, the processing technology was developed to create graded TBCs by coupling ion beam-assisted deposition (IBAD) with substrate pivoting in the alumina-YSZ system. The Electron Beam - 1200 kW (EB-1200) PVD system was used to deposit a variety of TBC coatings with micron layered microstructures and reduced thermal conductivity below 1.5 W/m.K. The use of IBAD produced fully stoichiometric coatings at a reduced substrate temperature of 600 oC and a reduced oxygen background pressure of 0.1 Pa. IBAD was also used to successfully demonstrate the transitioning of amorphous PVD-deposited alumina to the -phase alumina required as an oxygen diffusion barrier and for good adhesion to the substrate Ni2Al3 bondcoat. This process replaces the time consuming thermally grown oxide formation required before the YSZ deposition. In addition to the process technology, Direct Simulation Monte Carlo plume modeling and spectroscopic characterization of the PVD plumes were performed. The project consisted of five tasks. These included the production of layered

  18. Constructal blade shape in nanofluids

    OpenAIRE

    Bai Chao; Wang Liqiu

    2011-01-01

    Abstract Blade configuration of nanofluids has been proven to perform much better than dispersed configuration for some heat conduction systems. The analytical analysis and numerical calculation are made for the cylinder--shaped and regular-rectangular-prism--shaped building blocks of the blade-configured heat conduction systems (using nanofluids as the heat conduction media) to find the optimal cross-sectional shape for the nanoparticle blade under the same composing materials, composition r...

  19. Automatic optimisation of gamma dose rate sensor networks: The DETECT Optimisation Tool

    Science.gov (United States)

    Helle, K. B.; Müller, T. O.; Astrup, P.; Dyve, J. E.

    2014-05-01

    Fast delivery of comprehensive information on the radiological situation is essential for decision-making in nuclear emergencies. Most national radiological agencies in Europe employ gamma dose rate sensor networks to monitor radioactive pollution of the atmosphere. Sensor locations were often chosen using regular grids or according to administrative constraints. Nowadays, however, the choice can be based on more realistic risk assessment, as it is possible to simulate potential radioactive plumes. To support sensor planning, we developed the DETECT Optimisation Tool (DOT) within the scope of the EU FP 7 project DETECT. It evaluates the gamma dose rates that a proposed set of sensors might measure in an emergency and uses this information to optimise the sensor locations. The gamma dose rates are taken from a comprehensive library of simulations of atmospheric radioactive plumes from 64 source locations. These simulations cover the whole European Union, so the DOT allows evaluation and optimisation of sensor networks for all EU countries, as well as evaluation of fencing sensors around possible sources. Users can choose from seven cost functions to evaluate the capability of a given monitoring network for early detection of radioactive plumes or for the creation of dose maps. The DOT is implemented as a stand-alone easy-to-use JAVA-based application with a graphical user interface and an R backend. Users can run evaluations and optimisations, and display, store and download the results. The DOT runs on a server and can be accessed via common web browsers; it can also be installed locally.

  20. Operations based optimisation using simulation and CFD

    OpenAIRE

    Doherty, JJ; Clifton, DP; Gillan, MA; Ciampoli, F

    2007-01-01

    An initial investigation of an optimisation based approach for design across a continuous range of operating conditions is presented. The objective for this 'operations based optimisation' approach is to avoid the need to choose critical design point conditions and associated weighting factors by tackling the overall operational performance instead. The approach integrates numerical optimisation, response surface modelling, CFD and operational simulation. An optimisation test bed involving th...

  1. Lightning protection of flap system for wind turbine blades

    DEFF Research Database (Denmark)

    Candela Garolera, Anna; Madsen, Søren Find

    The aim of this PhD project was to investigate the behaviour of a Controllable Rubber Trailing Edge Flap (CRTEF) in a wind turbine blade when it is exposed to lightning discharges, and find the best technical solution to protect the CRTEF and the controlling system against lightning, based on the...... results of simulation models and high voltage tests. Wind turbines are a common target of lightning due to their height and location, and blades are the components most exposed to direct discharges. Protecting the blades against lightning is specially challenging, mainly because of the combination of...... insulating, semi-conductive and conductive materials in their structure. For this reason, the installation of a CRTEF in a blade requires a careful assessment of risks related to lightning strikes. The study of the lightning effects in the CRTEF system comprised the analysis of the discharge attachment, the...

  2. Guidelines to Interpret Results of Mechanical Blade Test

    International Nuclear Information System (INIS)

    This report shows the interpretation of full scale rotor blade test results and describes the engineering testing models and coefficients for any feasible rotor blade design, in order to accept and to certify any final manufactured blade as an allowable product, fit for use and working with a completely security during all the wind turbines lifetime. This work was carried out at the Wind Energy Division of the CIEMAT.DER and it is based on the authors technical experience in this field, after many years working on testing blades. Also, this paper contains results of the European wind turbine Standards II relevant to the European Project: JOULE III R.D. where the Wind Energy Division took part as participant too. (Author)

  3. Helicopter rotor blade design for minimum vibration

    Science.gov (United States)

    Taylor, R. B.

    1984-01-01

    The importance of blade design parameters in rotor vibratory response and the design of a minimum vibration blade based upon this understanding are examined. Various design approaches are examined for a 4 bladed articulated rotor operating at a high speed flight condition. Blade modal shaping, frequency placement, structural and aerodynamic coupling, and intermodal cancellation are investigated to systematically identify and evaluate blade design parameters that influence blade airloads, blade modal response, hub loads, and fuselage vibration. The relative contributions of the various components of blade force excitation and response to the vibratory hub loads transmitted to the fuselage are determined in order to isolate primary candidates for vibration alleviation. A blade design is achieved which reduces the predicted fuselage vibration from the baseline blade by approximately one half. Blade designs are developed that offer significant reductions in vibration (and fatigue stresses) without resorting to special vibration alleviation devices, radical blade geometries, or weight penalties.

  4. Optimised transdermal delivery of pravastatin.

    Science.gov (United States)

    Burger, Cornel; Gerber, Minja; du Preez, Jan L; du Plessis, Jeanetta

    2015-12-30

    Wiechers' programme "Formulating for Efficacy" initiated a new strategy to optimise the oil phase of topical formulations in order to achieve optimal transdermal drug delivery. This new approach uses the "Delivery Gap Theory" on any active pharmaceutical ingredients (APIs) to test if it could enhance transdermal drug delivery. The aim of the study was to formulate six different semi-solid formulations (three creams and three emulgels) with 2% pravastatin as the API in order to investigate the "Delivery Gap Principle", by determining which formulation would deliver pravastatin best to the target-site (system circulation). The three cream- and three emulgel formulations had different polarities, i.e. a formulation with polarity equal to that of the stratum corneum (optimised), a non-polar (lipophilic)- and a polar (hydrophilic)-formulation. Franz cell diffusion studies were executed over 12h and the optimised emulgel (2.578μg/cm(2)) had the highest median amount per area obtained. Tape stripping followed the diffusion studies and in the stratum corneum-epidermis, the hydrophilic emulgel (1.448μg/ml) contained the highest median pravastatin concentration and the epidermis-dermis the optimised emulgel (0.849μg/ml) depicted the highest pravastatin concentration. During this study, it was observed that when both emulgel and cream formulations were compared; the emulgels enhanced the delivery of pravastatin more than the creams. PMID:26505148

  5. Economic optimisation of flood risk management projects

    NARCIS (Netherlands)

    Tsimopoulou, V.

    2015-01-01

    The Netherlands has developed a flood risk management policy based on an economic rationale. After the flood disaster of 1953, when a large area of the south-western part of the country was flooded and more than 1800 people lost their lives, the so-called Delta Committee was installed, whose main pu

  6. Economic optimisation of flood risk management projects

    OpenAIRE

    Tsimopoulou, V.

    2015-01-01

    The Netherlands has developed a flood risk management policy based on an economic rationale. After the flood disaster of 1953, when a large area of the south-western part of the country was flooded and more than 1800 people lost their lives, the so-called Delta Committee was installed, whose main purpose was to coordinate actions towards a drastic reduction of flood risk. A key element of the Delta Committee’s recommendations, which formed the foundation of the current flood risk management p...

  7. Hot Blade Cuttings for the Building Industries

    DEFF Research Database (Denmark)

    Brander, David; Bærentzen, Jakob Andreas; Evgrafov, Anton;

    2016-01-01

    The constructions of advanced architectural designs are presently very labour intensive, time consuming, and expensive. They are therefore only applied to a few prestige projects, and it is a major challenge for the building industry to bring the costs down and thereby offer the architects more....... The project aims to reduce the amount of manual labour as well as production time by applying robots to cut expanded polystyrene (EPS) moulds for the concrete to form doubly curved surfaces. The scheme is based upon the so-called Hot Wire or Hot Blade technology where the surfaces are essentially swept out...

  8. SERI advanced wind turbine blades

    Science.gov (United States)

    Tangler, J.; Smith, B.; Jager, D.

    1992-02-01

    The primary goal of the Solar Energy Research Institute's (SERI) advanced wind turbine blades is to convert the kinetic energy in the wind into mechanical energy in an inexpensive and efficient manner. To accomplish this goal, advanced wind turbine blades have been developed by SERI that utilize unique airfoil technology. Performance characteristics of the advanced blades were verified through atmospheric testing on fixed-pitch, stall-regulated horizontal-axis wind turbines (HAWTs). Of the various wind turbine configurations, the stall-regulated HAWT dominates the market because of its simplicity and low cost. Results of the atmospheric tests show that the SERI advanced blades produce 10 percent to 30 percent more energy than conventional blades.

  9. Design of centrifugal impeller blades

    Science.gov (United States)

    Betz, A; Flugge-Lotz, I

    1939-01-01

    This paper restricts itself to radial impellers with cylindrical blades since, as Prasil has shown, the flow about an arbitrarily curved surface of revolution may be reduced to this normal form we have chosen by a relatively simple conformal transformation. This method starts from the simple hypotheses of the older centrifugal impeller theory by first assuming an impeller with an infinite number of blades. How the flow is then modified is then investigated. For the computation of flow for a finite number of blades, the approximation method as developed by Munk, Prandtl and Birnbaum, or Glauert is found suitable. The essential idea of this method is to replace the wing by a vortex sheet and compute the flow as the field of these vortices. The shape of the blades is then obtained from the condition that the flow must be along the surface of the blade.

  10. Combined Amplitude and Frequency Measurements for Non-Contacting Turbomachinery Blade Vibration

    Science.gov (United States)

    Platt, Michael J. (Inventor); Jagodnik, John J. (Inventor)

    2013-01-01

    A method and apparatus for measuring the vibration of rotating blades, such as turbines, compressors, fans, or pumps, including sensing the return signal from projected energy and/or field changes from a plurality of sensors mounted on the machine housing. One or more of the sensors has a narrow field of measurement and the data is processed to provide the referenced time of arrival of each blade, and therefore the blade tip deflection due to vibration. One or more of the sensors has a wide field of measurement, providing a time history of the approaching and receding blades, and the data is processed to provide frequency content and relative magnitudes of the active mode(s) of blade vibration. By combining the overall tip deflection magnitude with the relative magnitudes of the active modes, the total vibratory stress state of the blade can be determined.

  11. Full scale test SSP 34m blade, combined load. Data report

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Per H.; Nielsen, Magda; Jensen, Find M. (and others)

    2010-11-15

    This report is part of the research project where a 34m wind turbine blade from SSP-Technology A/S was tested in combined flap and edgewise load. The applied load is 55% of an imaginary extreme event based on the certification load of the blade. This report describes the reason for choosing the loads and the load direction and the method of applying the loads to the blade. A novel load introduction allows the blade to deform in a more realistic manner, allowing the observation of e.g. transverse shear distortion. The global and local deformation of the blade as well as the blades' respond to repeated tests has been studied and the result from these investigations are presented, including the measurements performed. (Author)

  12. Computer aided design and manufacturing of composite propfan blades for a cruise missile wind tunnel model

    Science.gov (United States)

    Thorp, Scott A.; Downey, Kevin M.

    1992-01-01

    One of the propulsion concepts being investigated for future cruise missiles is advanced unducted propfans. To support the evaluation of this technology applied to the cruise missile, a joint DOD and NASA test project was conducted to design and then test the characteristics of the propfans on a 0.55-scale, cruise missile model in a NASA wind tunnel. The configuration selected for study is a counterrotating rearward swept propfan. The forward blade row, having six blades, rotates in a counterclockwise direction, and the aft blade row, having six blades, rotates in a clockwise direction, as viewed from aft of the test model. Figures show the overall cruise missile and propfan blade configurations. The objective of this test was to evaluate propfan performance and suitability as a viable propulsion option for next generation of cruise missiles. This paper details the concurrent computer aided design, engineering, and manufacturing of the carbon fiber/epoxy propfan blades as the NASA Lewis Research Center.

  13. Isogeometric Analysis and Shape Optimisation

    DEFF Research Database (Denmark)

    Gravesen, Jens; Evgrafov, Anton; Gersborg, Allan Roulund;

    One of the attractive features of isogeometric analysis is the exact representation of the geometry. The geometry is furthermore given by a relative low number of control points and this makes isogeometric analysis an ideal basis for shape optimisation. I will describe some of the results we have...... obtained and also some of the problems we have encountered. One of these problems is that the geometry of the shape is given by the boundary alone. And, it is the parametrisation of the boundary which is changed by the optimisation procedure. But isogeometric analysis requires a parametrisation of the...... will explain how the validity of a parametrisation can be checked and we will describe various ways to parametrise a domain. We will in particular study the Winslow functional which turns out to have some desirable properties. Other problems we touch upon is clustering of boundary control points...

  14. Constrained optimisation of spatial sampling

    OpenAIRE

    Groenigen, van, M.

    1999-01-01

    AimsThis thesis aims at the development of optimal sampling strategies for geostatistical studies. Special emphasis is on the optimal use of ancillary data, such as co-related imagery, preliminary observations and historic knowledge. Although the object of all studies is the soil, the developed methodology can be used in any scientific field dealing with geostatistics.In summary, the objectives of this study were:Formulation of a range of optimisation criteria that honour a wide variety of ai...

  15. Optimising Comprehensibility in Interlingual Translation

    DEFF Research Database (Denmark)

    Nisbeth Jensen, Matilde

    2015-01-01

    . It is argued that Plain Language writing is a type of intralingual translation as it involves rewriting or translating a complex monolingual text into comprehensible language. Based on Plain Language literature, a comprehensibility framework is elaborated, which is subsequently exemplified through...... the functional text type of Patient Information Leaflet. Finally, the usefulness of applying the principles of Plain Language and intralingual translation for optimising comprehensibility in interlingual translation is discussed....

  16. Interpretation of optimisation in the context of a disposal facility for long-lived radioactive waste

    International Nuclear Information System (INIS)

    project P3-033 contained in the following output: R and D Technical Report P259 - Interpretation of Optimisation in the Context of a disposal Facility for Long-Lived Radioactive Waste. (author)

  17. Weight optimisation of a truck cabin by means of mathematical structural optimisation techniques; Gewichtsoptimierung eines Lkw-Fahrerhauses mit Hilfe mathematischer Strukturoptimierungsmethoden

    Energy Technology Data Exchange (ETDEWEB)

    Lautenschlager, U. [Siegen Univ. (Germany). Forschungszentrum fuer Multidisziplinaere Analysen und Angewandte Strukturoptimierung; Becker, W. [Siegen Univ. (Germany). Inst. fuer Mechanik und Regelungstechnik; Weber, C.M.; Wallraff, K. [Daimler-Chrysler AG, Stuttgart (Germany)

    1998-12-01

    In the consideration of the development potential of new lightweight concepts, the early mathematical simulation of the structural performance and the systematic numerical structural optimisation play an important role. This paper is the result of a joint project of the Daimler-Benz Truck Development Unit and the University of Siegen and describes a methodology for the optimisation of a truck cabin. A high efficiency of the optimisation procedure is attained by a well-adapted definition of the optimisation model. (orig.) [Deutsch] Bei der Beurteilung des Entwicklungspotentials neuer Leichtbaukonzepte spielt die fruehzeitige mathematische Simulation des Strukturverhaltens sowie die Einbeziehung einer systematischen numerischen Strukturoptimierung eine wichtige Rolle. Der nachfolgende Beitrag resultiert aus einem gemeinsamen Projekt zwischen der Nutzfahrzeugentwicklung der Daimler-Chrysler AG und der Universitaet-GH Siegen. Er beschreibt die Vorgehensweise bei der Optimierung eines Lkw-Fahrerhauses. (orig.)

  18. Failure analysis of turbine blades

    International Nuclear Information System (INIS)

    Two 20 MW gas turbines suffered damage in blades belonging to the 2nd. stage of the turbine after 24,000 hours of duty. From research it arises that the fuel used is not quite adequate to guarantee the blade's operating life due to the excess of SO3, C and Na existing in combustion gases which cause pitting to the former. Later, the corrosion phenomenon is presented under tension produced by working stress enhanced by pitting where Pb is its main agent. A change of fuel is recommended thus considering the blades will reach the operational life they were designed for. (Author)

  19. Rotating vibration behavior of the turbine blades with different groups of blades

    Science.gov (United States)

    Tsai, Gwo-Chung

    2004-04-01

    The rotating vibration behaviors of full cycle of 60 blades are studied in this report. The dynamic analysis of two different structures in one of which there are 10 groups of 6 blades and in the other 5 groups of 12 blades, is performed to investigate behavior deviation. In this research, the following jobs are considered: (1) collect the geometric dimensions and material properties of a single blade, (2) create the finite element model of a single blade, a group of 6 blades and 12 blades, and full cycle of 60 blades, (3) perform the vibration analyses of a single blade, a group of blades and a full circle of 60 blades, (4) perform the steady state stress analysis of the blade with different rotating speed; (5) get the Campbell diagram for the full circle of blades, and (6) make comparisons between a group of 6 blades and a group of 12 blades. The conclusions from the analyses are the following: (1) the contact elements are applied to groups of 6 and 12 blades systems and the highest stresses are observed at the location of the first neck of the blade root. These results completely agree very well with in-site observations. (2) The big differences were present in the Campbell diagram: resonant frequencies are observed in the first vibration group for the full system comprising the group of 6 blades and resonant frequencies are not found in the first vibration group of the full blade system made of the group of 12 blades. (3) The dynamic behavior of the full blade system comprised of a group of 6 blades was found much different from that of the full blade system made is of a group of 12 blades. (4) Excellent agreements for the vibration frequencies and mode shapes of a single blade and a full circle of blades are obtained between the FEA results and experimental data.

  20. Optimisation of VSC-HVDC Transmission for Wind Power Plants

    DEFF Research Database (Denmark)

    Silva, Rodrigo Da

    Connection of Wind Power Plants (WPP), typically oshore, using VSCHVDC transmission is an emerging solution with many benefits compared to the traditional AC solution, especially concerning the impact on control architecture of the wind farms and the grid. The VSC-HVDC solution is likely to meet...... more stringent grid codes than a conventional AC transmission connection. The purpose of this project is to analyse how HVDC solution, considering the voltage-source converter based technology, for grid connection of large wind power plants can be designed and optimised. By optimisation, the project...... the requirements established by the operators in the multiterminal VSC-HVDC transmission system. Moreover, the possibility in minimising the overall transmission losses can be a solution for small grids and the minimisation in the dispatch error is a new solution for power deliver maximisation. The...

  1. Optimization design of Savonius diffuser blade with moving deflector for hydrokınetıc cross flow turbıne rotor

    NARCIS (Netherlands)

    Wahjudi, B.; Soeparman, S.B.; Hoeijmakers, H.W.M.; bin Abu Bakar, Rosli; Froome, Craig

    2015-01-01

    The conventional Savonius turbine is a good concept for small size wind-renewable energy systems; unfortunately always it has low efficiency. Inspired from the Savonius Blade, this research project designed the diffuser form as compartment between S blade and Tandem Blade of Savonius to produce “jet

  2. Robust optimisation of railway crossing geometry

    Science.gov (United States)

    Wan, Chang; Markine, Valeri; Dollevoet, Rolf

    2016-05-01

    This paper presents a methodology for improving the crossing (frog) geometry through the robust optimisation approach, wherein the variability of the design parameters within a prescribed tolerance is included in the optimisation problem. Here, the crossing geometry is defined by parameterising the B-spline represented cross-sectional shape and the longitudinal height profile of the nose rail. The dynamic performance of the crossing is evaluated considering the variation of wheel profiles and track alignment. A multipoint approximation method (MAM) is applied in solving the optimisation problem of minimising the contact pressure during the wheel-rail contact and constraining the location of wheel transition at the crossing. To clarify the difference between the robust optimisation and the normal deterministic optimisation approaches, the optimisation problems are solved in both approaches. The results show that the deterministic optimum fails under slight change of the design variables; the robust optimum, however, has improved and robust performance.

  3. Spline for blade grids design

    Science.gov (United States)

    Korshunov, Andrei; Shershnev, Vladimir; Korshunova, Ksenia

    2015-08-01

    Methods of designing blades grids of power machines, such as equal thickness shape built on middle-line arc, or methods based on target stress spreading were invented long time ago, well described and still in use. Science and technology has moved far from that time and laboriousness of experimental research, which were involving unique equipment, requires development of new robust and flexible methods of design, which will determine the optimal geometry of flow passage.This investigation provides simple and universal method of designing blades, which, in comparison to the currently used methods, requires significantly less input data but still provides accurate results. The described method is purely analytical for both concave and convex sides of the blade, and therefore lets to describe the curve behavior down the flow path at any point. Compared with the blade grid designs currently used in industry, geometric parameters of the designs constructed with this method show the maximum deviation below 0.4%.

  4. Recent Filesystem Optimisations in FreeBSD

    OpenAIRE

    Dowse, Ian; Malone, David

    2002-01-01

    In this paper we summarise four recent optimisations to the FFS implementation in FreeBSD: soft updates, dirpref, vmiodir and dirhash. We then give a detailed exposition of dirhash’s implementation. Finally we study these optimisations under a variety of benchmarks and look at their interactions. Under micro-benchmarks, combinations of these optimisations can offer improvements of over two orders of magnitude. Even real-world workloads see improvements by a factor of 2–10.

  5. Structural damage identification in wind turbine blades using piezoelectric active sensing with ultrasonic validation

    Energy Technology Data Exchange (ETDEWEB)

    Claytor, Thomas N [Los Alamos National Laboratory; Ammerman, Curtt N [Los Alamos National Laboratory; Park, Gyu Hae [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Farrar, Charles R [Los Alamos National Laboratory; Atterbury, Marie K [Los Alamos National Laboratory

    2010-01-01

    This paper gives a brief overview of a new project at LANL in structural damage identification for wind turbines. This project makes use of modeling capabilities and sensing technology to understand realistic blade loading on large turbine blades, with the goal of developing the technology needed to automatically detect early damage. Several structural health monitoring (SHM) techniques using piezoelectric active materials are being investigated for the development of wireless, low power sensors that interrogate sections of the wind turbine blade using Lamb wave propagation data, frequency response functions (FRFs), and time-series analysis methods. The modeling and sensor research will be compared with extensive experimental testing, including wind tunnel experiments, load and fatigue tests, and ultrasonic scans - on small- to mid-scale turbine blades. Furthermore, this study will investigate the effect of local damage on the global response of the blade by monitoring low-frequency response changes.

  6. Materials for advanced turbine engines. Volume 1: Advanced blade tip seal system

    Science.gov (United States)

    Zelahy, J. W.; Fairbanks, N. P.

    1982-01-01

    Project 3, the subject of this technical report, was structured toward the successful engine demonstration of an improved-efficiency, long-life, tip-seal system for turbine blades. The advanced tip-seal system was designed to maintain close operating clearances between turbine blade tips and turbine shrouds and, at the same time, be resistant to environmental effects including high-temperature oxidation, hot corrosion, and thermal cycling. The turbine blade tip comprised an environmentally resistant, activated-diffussion-bonded, monocrystal superalloy combined with a thin layer of aluminium oxide abrasive particles entrapped in an electroplated NiCr matrix. The project established the tip design and joint location, characterized the single-crystal tip alloy and abrasive tip treatment, and established the manufacturing and quality-control plans required to fully process the blades. A total of 171 blades were fully manufactured, and 100 were endurance and performance engine-tested.

  7. Blade tip timing (BTT) uncertainties

    Science.gov (United States)

    Russhard, Pete

    2016-06-01

    Blade Tip Timing (BTT) is an alternative technique for characterising blade vibration in which non-contact timing probes (e.g. capacitance or optical probes), typically mounted on the engine casing (figure 1), and are used to measure the time at which a blade passes each probe. This time is compared with the time at which the blade would have passed the probe if it had been undergoing no vibration. For a number of years the aerospace industry has been sponsoring research into Blade Tip Timing technologies that have been developed as tools to obtain rotor blade tip deflections. These have been successful in demonstrating the potential of the technology, but rarely produced quantitative data, along with a demonstration of a traceable value for measurement uncertainty. BTT technologies have been developed under a cloak of secrecy by the gas turbine OEM's due to the competitive advantages it offered if it could be shown to work. BTT measurements are sensitive to many variables and there is a need to quantify the measurement uncertainty of the complete technology and to define a set of guidelines as to how BTT should be applied to different vehicles. The data shown in figure 2 was developed from US government sponsored program that bought together four different tip timing system and a gas turbine engine test. Comparisons showed that they were just capable of obtaining measurement within a +/-25% uncertainty band when compared to strain gauges even when using the same input data sets.

  8. Aerodynamic investigation of the tip section for titanium blade 54"

    Czech Academy of Sciences Publication Activity Database

    Luxa, Martin; Šimurda, David; Fořt, J.; Fürst, J.; Šafařík, P.; Synáč, J.; Rudas, B.

    Madrid: European Conference on Turbomachinery (ETC), 2015, s. 1-13. ISSN 2410-4833. [European Conference on Turbomachinery Fluid Dynamics and Thermodynamics /11./. Madrid (ES), 23.03.2015-27.03.2015] R&D Projects: GA TA ČR(CZ) TA03020277 Institutional support: RVO:61388998 Keywords : supersonic flow * tip section * long turbine blade * steam turbine Subject RIV: BK - Fluid Dynamics

  9. Influence of delayed excitation on vibrations of turbine blades couple

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    2013-01-01

    Roč. 7, č. 1 (2013), s. 39-52. ISSN 1802-680X R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : time delay * phase delay * blades couple * amplitude reduction * dry friction Subject RIV: BI - Acoustics

  10. Vibrations of turbine blades bundles model with rubber damping elements

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    2014-01-01

    Roč. 21, č. 1 (2014), s. 45-52. ISSN 1802-1484 R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : mathematical model * bundle of five blades * rubber damping elements * eigenmodes Subject RIV: BI - Acoustics http://www.engineeringmechanics.cz/obsahy.html?R=21&C=1

  11. Quantifying the benefits of a slender, high tip speed blade for large offshore wind turbiness

    Science.gov (United States)

    Blonk, Lindert; Rainey, Patrick; Langston, David A. J.; Vanni, Francesco

    2014-06-01

    An in-depth study has been completed to study the effects of slender, flexible blades in combination with high rotor speed operation on load mitigation, targeted at cost reductions of the structural components of large wind turbines, consequently lowering the levelized cost of energy. An overview of existing theory of sensitivity of turbine fatigue loading to the blade chord and rotor speed was created, and this was supplemented by a proposed theory for aboverated operation including the pitch controller. A baseline jacket-supported offshore turbine (7 MW) was defined, of which the blade was then redesigned to be more slender and flexible, at the same time increasing rotor speed. The blade redesign and optimisation process was guided by cost of energy assessments using a reduced loadset. Thereafter, a full loadset conform IEC61400-3 was calculated for both turbines. The expected support structure load reductions were affirmed, and it was shown that reductions of up to 18.5% are possible for critical load components. Cost modelling indicated that turbine and support structure CapEx could be reduced by 6%. Despite an energy production reduction of 0.44% related to the thicker airfoils used, the blade redesign led to a reduction in Cost of Energy.

  12. Quantifying the benefits of a slender, high tip speed blade for large offshore wind turbiness

    International Nuclear Information System (INIS)

    An in-depth study has been completed to study the effects of slender, flexible blades in combination with high rotor speed operation on load mitigation, targeted at cost reductions of the structural components of large wind turbines, consequently lowering the levelized cost of energy. An overview of existing theory of sensitivity of turbine fatigue loading to the blade chord and rotor speed was created, and this was supplemented by a proposed theory for aboverated operation including the pitch controller. A baseline jacket-supported offshore turbine (7 MW) was defined, of which the blade was then redesigned to be more slender and flexible, at the same time increasing rotor speed. The blade redesign and optimisation process was guided by cost of energy assessments using a reduced loadset. Thereafter, a full loadset conform IEC61400-3 was calculated for both turbines. The expected support structure load reductions were affirmed, and it was shown that reductions of up to 18.5% are possible for critical load components. Cost modelling indicated that turbine and support structure CapEx could be reduced by 6%. Despite an energy production reduction of 0.44% related to the thicker airfoils used, the blade redesign led to a reduction in Cost of Energy

  13. A morphing trailing edge flap system for wind turbine blades

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Barlas, Athanasios; Løgstrup Andersen, Tom

    2015-01-01

    no mechanical or metal parts are used. The prototypes tested in the laboratory and on a blade section in a wind tunnel in the period from 2007-2010 demonstrated the functionality and the aerodynamic performance of the flap concept. In a recent research and development project INDUFLAP from 2011......-2014 the flap system has been further developed in corporation with the industrial partners Hydratech Industries (DK) and Rehau (DE). A new trailing edge flap design with spanwise voids (channels) and with a chord of 15cm suitable for a 1m chord blade section was developed. It was then manufactured by...

  14. Ultimate strength of a large wind turbine blade

    DEFF Research Database (Denmark)

    Jensen, Find Mølholt

    2009-01-01

    behaviour of wind turbine blades. Four failure mechanisms observed during the fullscale tests and the corresponding FE-analysis are presented. Elastic mechanisms associated with failure, such as buckling, localized bending and the Brazier effect, are studied. In the thesis six different types of structural......The present PhD project contains a study of the structural static strength of wind turbine blades loaded in flap-wise direction. A combination of experimental and numerical work has been used to address the most critical failure mechanisms and to get an understanding of the complex structural...... reinforcements helping to prevent undesired structural elastic mechanisms are presented. The functionality of two of the suggested structural reinforcements was demonstrated in full-scale tests and the rest trough FE-studies. The blade design under investigation consisted of an aerodynamic airfoil and a load...

  15. Optimisation of Lilla Edet Landslide GPS Monitoring Network

    Science.gov (United States)

    Alizadeh-Khameneh, M. A.; Eshagh, M.; Sjöberg, L. E.

    2015-06-01

    Since the year 2000, some periodic investigations have been performed in the Lilla Edet region to monitor and possibly determine the landslide of the area with GPS measurements. The responsible consultant has conducted this project by setting up some stable stations for GPS receivers in the risky areas of Lilla Edet and measured the independent baselines amongst the stations according to their observation plan. Here, we optimise the existing surveying network and determine the optimal configuration of the observation plan based on different criteria.We aim to optimise the current network to become sensitive to detect 5 mm possible displacements in each net point. The network quality criteria of precision, reliability and cost are used as object functions to perform single-, bi- and multi-objective optimisation models. It has been shown in the results that the single-objective model of reliability, which is constrained to the precision, provides much higher precision than the defined criterion by preserving almost all of the observations. However, in this study, the multi-objective model can fulfil all the mentioned quality criteria of the network by 17% less measurements than the original observation plan, meaning 17%of saving time, cost and effort in the project.

  16. Large, low cost composite wind turbine blades

    Science.gov (United States)

    Gewehr, H. W.

    1979-01-01

    A woven roving E-glass tape, having all of its structural fibers oriented across the tape width was used in the manufacture of the spar for a wind turbine blade. Tests of a 150 ft composite blade show that the transverse filament tape is capable of meeting structural design requirements for wind turbine blades. Composite blades can be designed for interchangeability with steel blades in the MOD-1 wind generator system. The design, analysis, fabrication, and testing of the 150 ft blade are discussed.

  17. Dose optimisation in single plane interstitial brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Hellebust, Taran Paulsen; Honoré, Henriette H;

    2006-01-01

    BACKGROUND AND PURPOSE: Brachytherapy dose distributions can be optimised       by modulation of source dwell times. In this study dose optimisation in       single planar interstitial implants was evaluated in order to quantify the       potential benefit in patients. MATERIAL AND METHODS: In 14...

  18. An Optimisation Approach for Room Acoustics Design

    DEFF Research Database (Denmark)

    Holm-Jørgensen, Kristian; Kirkegaard, Poul Henning; Andersen, Lars

    2005-01-01

    This paper discuss on a conceptual level the value of optimisation techniques in architectural acoustics room design from a practical point of view. It is chosen to optimise one objective room acoustics design criterium estimated from the sound field inside the room. The sound field is modeled...

  19. Improved design for large wind turbine blades of fibre composites (Phase 4) - Summary report

    OpenAIRE

    Sørensen, Bent F; Toftegaard, Helmuth Langmaack; Goutianos, Stergios; Branner, Kim; Berring, Peter; Lund, E.; Wedel-Heinen, J.; Garm, J.H.

    2010-01-01

    Results are summarised for the project "Improved design for large wind turbine blades (Phase 4)", partially supported by the Danish Energy Agency under the Ministry of Climate and Energy through the EUDP journal no.: 33033-0267. The aim of the project was to develop new and better design methods for wind turbine blades, so that uncertainties associated with damage and defects can be reduced. The topics that are studied include buckling-driven delamination of flat load-carrying laminates, crac...

  20. An investigation of the dynamics of the horizontal wind turbine blades

    OpenAIRE

    Urieta Nieto, Itziar

    2015-01-01

    The aim of this project is to design, investigate and model the aerodynamic behavior and dynamics of a wind turbine blades taking into account the elasticity of the rotor blades and the steadiness of the flow. The main idea of the project is by performing the steady-state FSI (Fluid-Structure Interaction) analysis based on the obtained numerical results from two solvers: aerodynamic model for fluid and structural solver to evaluate the influence of the profile of wind turbin...

  1. Optimisation of patient and staff exposure in interventional cardiology

    International Nuclear Information System (INIS)

    The Council Directive of the European Community 97/43/Euratom (MED) deals with the health protection of individuals against dangers of ionising radiation in relation to medical exposure, and also focuses attention on some special practices (Art. 9), including interventional radiology, a technique involving high doses to the patient. The paper presents the European approach to optimisation of exposure in interventional cardiology. The DIMOND research consortium (DIMOND: Digital Imaging: Measures for Optimising Radiological Information Content and Dose) is working to develop quality criteria for cineangiographic images, to develop procedures for the classification of complexity of therapeutic and diagnostic procedures and to derive reference levels, related also to procedure complexity. DIMOND project also includes aspects of equipment characteristics and performance and content of training in radiation protection of personnel working in interventional radiology field. (author)

  2. Eyes Wide Open - Optimising Cosmological Surveys in a Crowded Market

    CERN Document Server

    Bassett, B A

    2004-01-01

    Optimising the major next-generation cosmological surveys (such as SNAP, KAOS etc...) is a key problem given our ignorance of the physics underlying cosmic acceleration and the plethora of surveys planned. We propose a Bayesian design framework which (1) maximises the discrimination power of a survey without assuming any underlying dark energy model, (2) finds the best niche survey geometry given current data and future competing experiments, (3) maximises the cross-section for serendipitous discoveries and (4) can be adapted to answer specific questions (such as `is dark energy dynamical?'). Integrated Parameter Space Optimisation (IPSO) is a design framework that integrates projected parameter errors over an entire dark energy parameter space and then extremises a figure of merit (such as Shannon entropy gain wich we show is stable to off-diagonal covariance matrix perturbations) as a function of survey parameters using analytical, grid or MCMC techniques. IPSO is thus a flexible, model-independent and scal...

  3. Rotating Camera System for Propeller and Rotor Blade Deformation Measurements

    OpenAIRE

    Boden, Fritz; Stasicki, Boleslaw; Szypula, Marek

    2015-01-01

    Within the EU project AIM² project a rotating stereoscopic camera system was designed, build and successfully flight tested in order to apply the non-intrusive Image Pattern Correlation Technique (IPCT) to 360° propeller deformation measurements. The complete system was affixed to the axis of the aircraft engine rotating together with the propeller at its full rotational speed. It enabled the direct measurement of the propeller blades shape as well as its local pitch angle under real operatin...

  4. Advanced Turbine Blade Cooling Techniques Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Gas turbine engine technology is constantly challenged to operate at higher combustor outlet temperatures. In a modern gas turbine engine, these temperatures can...

  5. Erosion Resistant Compressor Blade Repair Technologies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR program will demonstrate the use of wear resistant high strength nanocomposites in the turbine engine repair and refurbishment process. The...

  6. Conducting the rowing training using the blade passage time through the water

    Directory of Open Access Journals (Sweden)

    Doru Ciosici

    2011-06-01

    Full Text Available This present paper aims to present an original method, never before encountered in the specialised literature, of a long-time conducting (during a competition, a macro cycle the training of rowers. The method is called: The method of conducting the sportive training of rowing using the blade passage time through the water. This method consists of the using the blade passage rate through the water as an indicator of the intensity of the effort. By knowing the optimal time of passage of the blade through the water according to each type of effort desired to be achieved, the time of passage of the blade through the water will be planned according to each monocycle, so that the desired parameters will be reached until the competition. A blueprint of the projection of the time of passage of the blade through the water during the competition of an M4 team is presented in the paper.

  7. optimised observables in the MSSM

    Science.gov (United States)

    Mahmoudi, Farvah; Neshatpour, Siavash; Virto, Javier

    2014-06-01

    We provide a detailed analysis of the impact of the newly measured optimised observables in the decay by the LHCb experiment. The analysis is performed in the MSSM, both in the context of the usual constrained scenarios and in the context of a more general set-up where the SUSY partner masses are independent. We show that the global agreement of the MSSM solutions with the data is still very good. Nevertheless, especially in the constrained scenarios, the limits from are now very strong and are at the same level as the well-known constraints. We describe the implications of the measurements both on the Wilson coefficients and on the SUSY parameters.

  8. Use of blade lean in turbomachinery redesign

    Science.gov (United States)

    Moore, John; Moore, Joan G.; Lupi, Alex

    1993-07-01

    Blade lean is used to improve the uniformity of exit flow distributions from turbomachinery blading. In turbines, it has been used to control secondary flows by tailoring blade turning to reduce flow overturning and underturning and to create more uniform loss distributions from hub to shroud. In the present study, the Pump Consortium centrifugal impeller has been redesigned using blade lean. The flow at the exit of the baseline impeller had large blade-to-blade variations, creating a highly unsteady flow for the downstream diffuser. Blade lean is used to redesign the flow to move the high loss fluid from the suction side to the hub, significantly reducing blade-toblade variations at the exit.

  9. Optimising code generation with haggies

    Science.gov (United States)

    Reiter, T.

    2010-07-01

    This article describes haggies, a program for the generation of optimised programs for the efficient numerical evaluation of mathematical expressions. It uses a multivariate Horner-scheme and Common Subexpression Elimination to reduce the overall number of operations. The package can serve as a back-end for virtually any general purpose computer algebra program. Built-in type inference that allows to deal with non-standard data types in strongly typed languages and a very flexible, pattern-based output specification ensure that haggies can produce code for a large variety of programming languages. We currently use haggies as part of an automated package for the calculation of one-loop scattering amplitudes in quantum field theories. The examples in this articles, however, demonstrate that its use is not restricted to the field of high energy physics. Program summaryProgram title: haggies Catalogue identifier: AEGF_v1_0 Program summary: URL: http://cpc.cs.qub.ac.uk/summaries/AEGF_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU GPL v3 No. of lines in distributed program, including test data, etc.: 56 220 No. of bytes in distributed program, including test data, etc.: 579 010 Distribution format: tar.gz Programming language: Java, JavaCC Computer: Any system that runs the Java Virtual Machine Operating system: Any system that runs the Java Virtual Machine RAM: Determined by the size of the problem Classification: 4.14, 5, 6.2, 6.5, 11.1 Nature of problem: Generation of optimised programs for the evaluation of possibly large algebraic expressions Solution method: Java implementation Running time: Determined by the size of the problem

  10. Forward sweep, low noise rotor blade

    Science.gov (United States)

    Brooks, Thomas F. (Inventor)

    1996-01-01

    A forward-swept, low-noise rotor blade includes an inboard section, an aft-swept section and a forward-swept outboard section. The rotor blade reduces the noise of rotorcraft, including both standard helicopters and advanced systems such as tiltrotors. The primary noise reduction feature is the forward sweep of the planform over a large portion of the outer blade radius. The rotor blade also includes an aft-swept section. The purpose of the aft-swept region is to provide a partial balance to pitching moments produced by the outboard forward-swept portion of the blade. The rotor blade has a constant chord width; or has a chord width which decreases linearly along the entire blade span; or combines constant and decreasing chord widths, wherein the blade is of constant chord width from the blade root to a certain location on the rotor blade, then decreases linearly to the blade tip thereafter. The noise source showing maximum noise reduction is blade-vortex interaction (BVI) noise. Also reduced are thickness, noise, high speed impulsive noise, cabin vibration and loading noise.

  11. Dynamic response of active twist rotor blades

    Science.gov (United States)

    Cesnik, Carlos E. S.; Shin, Sang Joon; Wilbur, Matthew L.

    2001-02-01

    Dynamic characteristics of active twist rotor (ATR) blades are investigated analytically and experimentally in this paper. The ATR system is intended for vibration and potentially for noise reductions in helicopters through individual blade control. An aeroelastic model is developed to identify frequency response characteristics of the ATR blade with integral, generally anisotropic, strain actuators embedded in its composite construction. An ATR prototype blade was designed and manufactured to experimentally study the vibration reduction capabilities of such systems. Several bench and hover tests were conducted and those results are presented and discussed here. Selected results on sensitivity of the ATR system to collective setting (i.e. blade loading), blade rpm (i.e. centrifugal force and blade station velocity), and media density (i.e. altitude) are presented. They indicated that the twist actuation authority of the ATR blade is independent of the collective setting up to approximately 10P, and dependent on rotational speed and altitude near the torsional resonance frequency due to its dependency on the aerodynamic damping. The proposed model captures very well the physics and sensitivities to selected test parameters of the ATR system. The numerical result of the blade torsional loads show an average error of 20% in magnitude and virtually no difference in phase for the blade frequency response. Overall, the active blade model is in very good agreement with the experiments and can be used to analyze and design future active helicopter blade systems.

  12. Computer Program Aids Design Of Impeller Blades

    Science.gov (United States)

    Chen, Wei-Chung; Galazin, John V.

    1992-01-01

    Impeller blades for centrifugal turbopumps designed quickly with help of computer program. Generates blade contours and continually subjects them to evaluation. Checks physical parameters to ensure they are compatible with required performance and recycles design if criteria not met. Program written for centrifugal turbomachinery, also adapted to such axial pump components as inducer blades and stator vanes.

  13. KNOW-BLADE task-3.3 report: Rotor blade computations with 3D vortex generators

    DEFF Research Database (Denmark)

    Johansen, J.; Sørensen, Niels N.; Reck, M.; Hansen, M.O.L.; Stuermer, A.; Ramboer, J.; Hirsch, C.; Ekaterinaris, J.; Voutsinas, S.; Perivolaris, Y.

    2005-01-01

    successfully modelled vortex generators in 3D, which eventually generates vortices and mixes the boundary layer.A large effort has been on generating the numerical meshes since this is a relatively complex configuration and a large variation of length and time scales is present. Even though the quantitative...... agreement with measurements is not acceptable the effortspend in the present project indicate that it is possible to investigate the effect of vortex generators on wind turbine blades using 3D Navier-Stokes solvers. Much further work within independence of mesh resolution and time step as well as...

  14. Aerodynamic Data for Two Variants of Root Turbine Blade Sections for A 54" Turbine Rotor Blade

    Czech Academy of Sciences Publication Activity Database

    Šimurda, David; Luxa, Martin; Šafařík, P.; Synáč, J.; Rudas, B.

    Düsseldorf: ASME, 2014, V02CT38A007-V02CT38A019. (2C). ISBN 978-0-7918-4562-2. [ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. Düsseldorf (DE), 16.06.2014-20.06.2014] R&D Projects: GA TA ČR(CZ) TA03020277; GA ČR(CZ) GAP101/10/1329 Institutional support: RVO:61388998 Keywords : steam turbine * rotor * blade cascade * root section Subject RIV: BK - Fluid Dynamics

  15. COBSTRAN - COMPOSITE BLADE STRUCTURAL ANALYZER

    Science.gov (United States)

    Aiello, R. A.

    1994-01-01

    The COBSTRAN (COmposite Blade STRuctural ANalyzer) program is a pre- and post-processor that facilitates the design and analysis of composite turbofan and turboprop blades, as well as composite wind turbine blades. COBSTRAN combines composite mechanics and laminate theory with a data base of fiber and matrix properties. As a preprocessor for NASTRAN or another Finite Element Method (FEM) program, COBSTRAN generates an FEM model with anisotropic homogeneous material properties. Stress output from the FEM program is provided as input to the COBSTRAN postprocessor. The postprocessor then uses the composite mechanics and laminate theory routines to calculate individual ply stresses, strains, interply stresses, thru-the-thickness stresses and failure margins. COBSTRAN is designed to carry out the many linear analyses required to efficiently model and analyze blade-like structural components made of multilayered angle-plied fiber composites. Components made from isotropic or anisotropic homogeneous materials can also be modeled as a special case of COBSTRAN. NASTRAN MAT1 or MAT2 material cards are generated according to user supplied properties. COBSTRAN is written in FORTRAN 77 and was implemented on a CRAY X-MP with a UNICOS 5.0.12 operating system. The program requires either COSMIC NASTRAN or MSC NASTRAN as a structural analysis package. COBSTRAN was developed in 1989, and has a memory requirement of 262,066 64 bit words.

  16. Running excitation of blades bunches

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    Praha: Institute of Thermomechanics AS CR, 2014 - (Zolotarev, I.; Pešek, L.), s. 45-52 ISBN 978-80-87012-54-3. [DYMAMESI 2014. Praha (CZ), 25.11.2014-26.11.2014] Institutional support: RVO:61388998 Keywords : damping * dry friction * five-blades-bunch * delayed harmonic excitation Subject RIV: BI - Acoustics

  17. Combining simulation and multi-objective optimisation for equipment quantity optimisation in container terminals

    OpenAIRE

    Lin, Zhougeng

    2013-01-01

    This thesis proposes a combination framework to integrate simulation and multi-objective optimisation (MOO) for container terminal equipment optimisation. It addresses how the strengths of simulation and multi-objective optimisation can be integrated to find high quality solutions for multiple objectives with low computational cost. Three structures for the combination framework are proposed respectively: pre-MOO structure, integrated MOO structure and post-MOO structure. The applications of ...

  18. Turbine blade tip gap reduction system

    Science.gov (United States)

    Diakunchak, Ihor S.

    2012-09-11

    A turbine blade sealing system for reducing a gap between a tip of a turbine blade and a stationary shroud of a turbine engine. The sealing system includes a plurality of flexible seal strips extending from a pressure side of a turbine blade generally orthogonal to the turbine blade. During operation of the turbine engine, the flexible seal strips flex radially outward extending towards the stationary shroud of the turbine engine, thereby reducing the leakage of air past the turbine blades and increasing the efficiency of the turbine engine.

  19. Topology Optimisation for Coupled Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe

    This thesis deals with topology optimisation for coupled convection problems. The aim is to extend and apply topology optimisation to steady-state conjugate heat transfer problems, where the heat conduction equation governs the heat transfer in a solid and is coupled to thermal transport...... in a surrounding uid, governed by a convection-diffusion equation, where the convective velocity field is found from solving the isothermal incompressible steady-state Navier-Stokes equations. Topology optimisation is also applied to steady-state natural convection problems. The modelling is done using stabilised...... finite elements, the formulation and implementation of which was done partly during a special course as prepatory work for this thesis. The formulation is extended with a Brinkman friction term in order to facilitate the topology optimisation of fluid flow and convective cooling problems. The derived...

  20. Fatigue testing of a carbon fibre composite wind turbine blade with associated material characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, G.A.; Richardson, D.J. [Univ. of the West of England, Faculty of Engineering, Bristol (United Kingdom)

    1996-09-01

    Within the EC project JOULE 2, the University of the West of England (UWE) tested a carbon fibre reinforced epoxy (CFRE) full scale wind turbine blade together with an associated material test coupon programme. All the work was closely linked with the manufacturer Polymarine BV of the Netherlands, who designed and manufactured the blade and provided test specimens, the UWE carried out the research into the validation of the design calculations together with a check of the strength and fatigue life of the blade. (au)

  1. Model predictive control of trailing edge flaps on a wind turbine blade

    DEFF Research Database (Denmark)

    Castaignet, Damien Bruno

    with three trailing edge flaps on one blade, located on DTU’s Risø Campus in Roskilde, Denmark. This thesis is divided into three parts: the controller design, results from simulations, and results from the experiments. The trailing edge flaps controller designed for this project is based on a frequency......, in Roskilde, Denmark. One blade of the turbine was equipped with three independent trailing edge flaps. In spite of the failure of several sensors and actuators, the test of the trailing edge flaps controller described in this thesis showed a consistent flapwise blade root fatigue load reduction. An average...

  2. Methodological principles for optimising functional MRI experiments

    International Nuclear Information System (INIS)

    Functional magnetic resonance imaging (fMRI) is one of the most common methods for localising neuronal activity in the brain. Even though the sensitivity of fMRI is comparatively low, the optimisation of certain experimental parameters allows obtaining reliable results. In this article, approaches for optimising the experimental design, imaging parameters and analytic strategies will be discussed. Clinical neuroscientists and interested physicians will receive practical rules of thumb for improving the efficiency of brain imaging experiments. (orig.)

  3. User perspectives in public transport timetable optimisation

    DEFF Research Database (Denmark)

    Jensen, Jens Parbo; Nielsen, Otto Anker; Prato, Carlo Giacomo

    2014-01-01

    The present paper deals with timetable optimisation from the perspective of minimising the waiting time experienced by passengers when transferring either to or from a bus. Due to its inherent complexity, this bi-level minimisation problem is extremely difficult to solve mathematically, since tim...... applied on the large-scale public transport network in Denmark. The timetable optimisation approach yielded a yearly reduction in weighted waiting time equivalent to approximately 45 million Danish kroner (9 million USD)....

  4. Mx Magnetometry Optimisation in Unshielded Environments

    Science.gov (United States)

    Ingleby, Stuart; Griffin, Paul; Arnold, Aidan; Riis, Erling; Hunter, Dominic

    2016-05-01

    Optically pumped magnetometry in unshielded environments is potentially of great advantage in a wide range of surveying and security applications. Optimisation of OPM modulation schemes and feedback in the Mx scheme offers enhanced sensitivity through noise cancellation and decoherence suppression. The work presented demonstrates capability for software-controlled optimisation of OPM performance in ambient fields in the 0 . 5 G range. Effects on magnetometer bandwidth and sensitivity are discussed. Supported by UK National Quantum Technologies Programme.

  5. Wire topology optimisation for low power CMOS

    OpenAIRE

    Zuber, Paul

    2007-01-01

    Power optimisation has become one of the most important goals when designing integrated systems. A methodology is proposed that reduces the power consumption of a detail-routed circuit by modifying its wire topology. Its principle is a re-distribution of the local whitespace between parallel wires depending on the switching activities of the wires. The more active a wire the more space it will acquire and thus the less toggle energy is required. After optimisation, the new layout is returned...

  6. On damage diagnosis for a wind turbine blade using pattern recognition

    Science.gov (United States)

    Dervilis, N.; Choi, M.; Taylor, S. G.; Barthorpe, R. J.; Park, G.; Farrar, C. R.; Worden, K.

    2014-03-01

    With the increased interest in implementation of wind turbine power plants in remote areas, structural health monitoring (SHM) will be one of the key cards in the efficient establishment of wind turbines in the energy arena. Detection of blade damage at an early stage is a critical problem, as blade failure can lead to a catastrophic outcome for the entire wind turbine system. Experimental measurements from vibration analysis were extracted from a 9 m CX-100 blade by researchers at Los Alamos National Laboratory (LANL) throughout a full-scale fatigue test conducted at the National Renewable Energy Laboratory (NREL) and National Wind Technology Center (NWTC). The blade was harmonically excited at its first natural frequency using a Universal Resonant EXcitation (UREX) system. In the current study, machine learning algorithms based on Artificial Neural Networks (ANNs), including an Auto-Associative Neural Network (AANN) based on a standard ANN form and a novel approach to auto-association with Radial Basis Functions (RBFs) networks are used, which are optimised for fast and efficient runs. This paper introduces such pattern recognition methods into the wind energy field and attempts to address the effectiveness of such methods by combining vibration response data with novelty detection techniques.

  7. Multi-objective optimisation of web business processes

    OpenAIRE

    Tiwari, Ashutosh; Turner, Christopher; Ball, Peter D.; Vergidis, Kostas

    2010-01-01

    This paper proposes an approach for the optimisation of web business processes using multi-objective evolutionary computing. Business process optimisation is considered as the problem of constructing feasible business process designs with optimum attribute values such as duration and cost. This optimisation framework involves the application of a series of Evolutionary Multi-objective Optimisation Algorithms (EMOAs) in an attempt to generate a series of diverse optimised bus...

  8. Challenges in real world optimisation using evolutionary computing

    OpenAIRE

    Tiwari, Ashutosh; Roy, Rajkumar

    2004-01-01

    Challenges in real world optimisation using evolutionary computing With rising global competition, it is becoming increasingly more important for industry to optimise its activities. However, the complexity of real-life optimisation problems has prevented industry from exploiting the potential of optimisation algorithms. Industry has therefore relied on either trial-and-error or over- simplification for dealing with its optimisation problems. This has led to the loss of oppo...

  9. Application of Resin Transfer Molding to the Manufacture of Wind Turbine Blade Substructures. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Hedley, C. W.; Ritter, W. J.; Ashwill, T.

    2001-07-26

    The U.S. has generally lacked the capability for an iterative process of detailed structural design, manufacturing, and testing at the full blade level to achieve specific structural performance, cost, and weight targets. This project examined the effects that different composites processing methods had on the performance of representative blade substructures. In addition, the results of the testing of these substructures was used to validate NuMAD, the design tool developed at Sandia National Laboratories.

  10. System optimisation for automatic wood-fired heating systems; Systemoptimierung automatischer Holzheizung - Projektphase 1

    Energy Technology Data Exchange (ETDEWEB)

    Good, J.; Nussbaumer, T. [Verenum, Zuerich (Switzerland); Jenni, A. [Ardens GmbH, Liestal (Switzerland); Buehler, R. [Umwelt und Energie, Maschwanden (Switzerland)

    2002-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of the first phase of a project that is to optimise the performance of existing automatic wood-fired heating systems in the range 330 kW to 1 MW from the ecological and economical points of view. The report presents the results of an initial phase of the project in which five selected installations were optimised in order to be able to assess the potential for optimisation in general. The study looks at the efficiency of the plant as far as heat generation and distribution are concerned. The report presents details on various factors measured such as operating hours, heat distribution, control strategies, fuel-quality requirements, integration in heating systems and safety aspects and compares power delivered with rated power. The authors consider the potential for optimisation to be high and suggest optimisation targets concerning consumer density in district heating schemes, full-load operating hours, minimum yearly operational efficiency and the control of heating power.

  11. Multiple piece turbine rotor blade

    Energy Technology Data Exchange (ETDEWEB)

    Kimmel, Keith D.; Plank, William L.

    2016-07-19

    A spar and shell turbine rotor blade with a spar and a tip cap formed as a single piece, the spar includes a bottom end with dovetail or fir tree slots that engage with slots on a top end of a root section, and a platform includes an opening on a top surface for insertion of the spar in which a shell made from an exotic high temperature resistant material is secured between the tip cap and the platform. The spar is tapered to form thinner walls at the tip end to further reduce the weight and therefore a pulling force due to blade rotation. The spar and tip cap piece is made from a NiAL material to further reduce the weight and the pulling force.

  12. Aerodynamic Research on the Midsection of a Long Turbine Blade

    Czech Academy of Sciences Publication Activity Database

    Šimurda, David; Luxa, Martin; Šafařík, Pavel; Synáč, J.

    Gdansk: Instytut Maszyn Przeplywowych PAN, 2008 - (Doerffer, P.; Szwaba, R.), s. 147-148 ISBN 978-83-88237-41-6. [Krajowa Konferencja Mechaniki Plynów /18./. Jastrzebia Góra (PL), 21.09.2008-25.09.2008] R&D Projects: GA ČR GA101/07/1508 Institutional research plan: CEZ:AV0Z20760514 Keywords : high speed aerodynamics * blade cascade * experiment Subject RIV: BK - Fluid Dynamics

  13. Aerodynamic Research on the Midsection of a Long Turbine Blade

    Czech Academy of Sciences Publication Activity Database

    Šimurda, David; Luxa, Martin; Šafařík, Pavel; Synáč, J.

    2008-01-01

    Roč. 12, 3-4 (2008), s. 135-145. ISSN 1428-6394. [Polish National Conference of Fluid Mechanics /18./. Jastrzebia Góra, 21.09.2008-25.09.2008] R&D Projects: GA ČR GA101/07/1508 Institutional research plan: CEZ:AV0Z20760514 Keywords : high speed aerodynamics * blade cascade * experiment Subject RIV: BK - Fluid Dynamics

  14. Vibration analysis of compressor blade tip-rubbing

    OpenAIRE

    Arzina, Dina

    2011-01-01

    There has been a significant increase in air traffic volume, particularly over the past twenty years. In order to cope with this increase in demand, it has been necessary to increase the efficiency of aircraft engines. Over the years, this has been achieved by reducing the clearance between blade tips and the engine casing. As a consequence of the reduced clearance, tip-rubbing frequently occurs in the engine during operation. The primary aim of this project is to address the vibrations in...

  15. Imposed rubber elements for bladed wheel vibration suppression

    Czech Academy of Sciences Publication Activity Database

    Pešek, Luděk; Půst, Ladislav; Bula, Vítězslav; Cibulka, Jan

    Lisbon : APMTAC, 2013 - (Dimitrovová, Z.; Goncalves, R.), s. 1-10 ISBN 978-989-96264-4-7. [International Conference on Vibration Problems 2013 /11./. Lisbon (PT), 09.09.2013-12.09.2013] R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : blade * vibration * damping * rubber * thermo-mechanical characteristics Subject RIV: BI - Acoustics

  16. Non-contact methods of sensing vibrations of turbine blades

    Czech Academy of Sciences Publication Activity Database

    Procházka, Pavel; Vaněk, František

    London: Institution of Mechanical Engineers, 2012, s. 221-231. ISBN 978-0-85709-452-0. [International conference on Vibrations in Rotating Machinery /10./. London (GB), 11.09.2012-13.09.2012] R&D Projects: GA TA ČR(CZ) TA02020728 Institutional research plan: CEZ:AV0Z20760514 Keywords : steam turbine * blade vibrations * monitoring system Subject RIV: BI - Acoustics

  17. High Speed Aerodynamic Research on Root Blade Cascade

    Czech Academy of Sciences Publication Activity Database

    Luxa, Martin; Synáč, J.; Šafařík, Pavel; Šimurda, David

    Praha: ÚT AV ČR, v. v. i., 2007 - (Příhoda, J.; Kozel, K.), s. 111-114 ISBN 978-80-87012-04-8. [Conference TOPICAL PROBLEMS OF FLUID MECHANICS 2007. Praha (CZ), 28.02.2007-02.03.2007] R&D Projects: GA ČR GA101/07/1508 Institutional research plan: CEZ:AV0Z20760514 Keywords : root blade cascade * transsonic flow * aerodynamic research Subject RIV: BK - Fluid Dynamics

  18. Stochastic optimisation of water allocation on a global scale

    Science.gov (United States)

    Schmitz, Oliver; Straatsma, Menno; Karssenberg, Derek; Bierkens, Marc F. P.

    2014-05-01

    Climate change, increasing population and further economic developments are expected to increase water scarcity for many regions of the world. Optimal water management strategies are required to minimise the water gap between water supply and domestic, industrial and agricultural water demand. A crucial aspect of water allocation is the spatial scale of optimisation. Blue water supply peaks at the upstream parts of large catchments, whereas demands are often largest at the industrialised downstream parts. Two extremes exist in water allocation: (i) 'First come, first serve,' which allows the upstream water demands to be fulfilled without considerations of downstream demands, and (ii) 'All for one, one for all' that satisfies water allocation over the whole catchment. In practice, water treaties govern intermediate solutions. The objective of this study is to determine the effect of these two end members on water allocation optimisation with respect to water scarcity. We conduct this study on a global scale with the year 2100 as temporal horizon. Water supply is calculated using the hydrological model PCR-GLOBWB, operating at a 5 arcminutes resolution and a daily time step. PCR-GLOBWB is forced with temperature and precipitation fields from the Hadgem2-ES global circulation model that participated in the latest coupled model intercomparison project (CMIP5). Water demands are calculated for representative concentration pathway 6.0 (RCP 6.0) and shared socio-economic pathway scenario 2 (SSP2). To enable the fast computation of the optimisation, we developed a hydrologically correct network of 1800 basin segments with an average size of 100 000 square kilometres. The maximum number of nodes in a network was 140 for the Amazon Basin. Water demands and supplies are aggregated to cubic kilometres per month per segment. A new open source implementation of the water allocation is developed for the stochastic optimisation of the water allocation. We apply a Genetic Algorithm

  19. Cyclic Structural Analyses of SSME Turbine Blades

    Science.gov (United States)

    Kaufman, A.; Manderscheid, J. M.

    1985-01-01

    The problems of calculating the structural response of high-temperature space propulsion components such as turbine blades for the fuel turbopump are addressed. The first high-pressure-stage fuel turbine blade (HPFTB) in the liquid-hydrogen turbopump of the space shuttle main engine (SSME) was selected for this study. In the past these blades have cracked in the blade shank region and at the airfoil leading edge adjacent to the platform. To achieve the necessary durability, these blades are currently being cast by using directional solidification. Single-crystal alloys are also being investigated for future SSME applications. The study evaluated the utility of advanced structural analysis methods in assessing the low-cycle fatigue lives of these anisotropic components. The turbine blade airfoil of the high-pressure stage of the SSME fuel turbopump was analyzed because it has a history of rapid crack initiation.

  20. Diagnostic methods of a bladed disc mode shape evaluation used for shrouded blades in steam turbines

    Science.gov (United States)

    Strnad, Jaromir; Liska, Jindrich

    2015-11-01

    This paper deals with advanced methods for the evaluation of a bladed disc behavior in terms of the wheel vibration and blade service time consumption. These methods are developed as parts of the noncontact vibration monitoring system of the steam turbine shrouded blades. The proposed methods utilize the time-frequency processing (cross spectra) and the method using least squares to analyse the data from the optical and magnetoresistive sensors, which are mounted in the stator radially above the rotor blades. Fundamentally, the blade vibrations are detected during the blade passages under the sensors and the following signal processing, which covers also the proposed methods, leads to the estimation of the blade residual service life. The prototype system implementing above mentioned techniques was installed into the last stage of the new steam turbine (LP part). The methods for bladed disc mode shape evaluation were successfully verified on the signals, which were obtained during the commission operation of the turbine.

  1. Optimisation of Investment Resources at Small Enterprises

    Directory of Open Access Journals (Sweden)

    Shvets Iryna B.

    2014-03-01

    Full Text Available The goal of the article lies in the study of the process of optimisation of the structure of investment resources, development of criteria and stages of optimisation of volumes of investment resources for small enterprises by types of economic activity. The article characterises the process of transformation of investment resources into assets and liabilities of the balances of small enterprises and conducts calculation of the structure of sources of formation of investment resources in Ukraine at small enterprises by types of economic activity in 2011. On the basis of the conducted analysis of the structure of investment resources of small enterprises the article forms main groups of criteria of optimisation in the context of individual small enterprises by types of economic activity. The article offers an algorithm and step-by-step scheme of optimisation of investment resources at small enterprises in the form of a multi-stage process of management of investment resources in the context of increase of their mobility and rate of transformation of existing resources into investments. The prospect of further studies in this direction is development of a structural and logic scheme of optimisation of volumes of investment resources at small enterprises.

  2. Fluttering Analysis in Wind Turbine Blade

    OpenAIRE

    Elangovan, Prabaharan

    2012-01-01

    The wind turbine blades often subjected by a phenomenon fluttering which leads to a structural damage. Therefore, it is necessary for design engineers to predict the fluttering behavior while designing the blades. The main scope of the thesis is to analyze and study the fluttering behavior by conducting structural analysis, modal analysis, Aeroelastic stability analysis and FSI of standard wind turbine blade. The analysis is carried out in ANSYS work bench and the preliminary results shows th...

  3. Dynamic Response of Flexible Wind Turbine Blade

    OpenAIRE

    Yu-qiao Zheng; Rong-zhen ZHAO; Hong liu

    2013-01-01

    Aiming at the non-stationary and stall flutter problems of wind turbine blade caused by transient load fluctuations, the dynamic properties of wind turbine were studied, the blade was simplify to a cantilever beam in case of the action of shear deformation and cross section rotating effect were considered in this analysis, equations of the blade were established based on D'Alemberts' principle and the principle of virtual displacement. The dynamic response of the wind turbine was solved by us...

  4. Experiments on sound radiation from propeller blades

    Science.gov (United States)

    Verhulst, K.; Debruijn, A.

    1981-08-01

    The effect of blade damping and air bubbles on cavitation noise radiation, and the damping effect of an antisinging edge were studied. Completely flat cunial and aluminum blades were used. One cunial blade had a viscoelastic sandwich layer. Cavitation was simulated by steam injection. The antisinging edge and viscoelastic layer have little effect. Aluminum reduces total sound power. When the distance of the bubble screen to the steam injection source is less than half a wavelength, radiated sound power is greatly reduced.

  5. Topology optimisation of manufacturable microstructural details without length scale separation using a spectral coarse basis preconditioner

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Lazarov, Boyan Stefanov

    2015-01-01

    homogenisation approach. The approach takes boundary conditions into account and ensures connected andmacroscopically optimised microstructures regardless of the difference in micro- and macroscopic length scales. This results in microstruc-tures tailored for specific applications rather than specific properties.Manufacturability...... leading to massive savings in computational cost. The density-based topology optimisation approach combined with a Heaviside projection filter and a stochastic robust formulation is used on various problems, with both periodic and layered microstructures. The presented approach is shown to allow for the...

  6. Anisotropic beam model for analysis and design of passive controlled wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Branner, K.; Blasques, J.P.; Kim, T.; Fedorov, V.A.; Berring, P.; Bitsche, R.D.; Berggreen, C.

    2012-02-15

    The main objective of the project was, through theoretical and experimental research, to develop and validate a fully coupled, general beam element that can be used for advanced and rapid analysis of wind turbine blades. This is fully achieved in the project and the beam element has even been implemented in the aeroelastic code HAWC2. It has also been demonstrated through a parametric study in the project that a promising possibility with the tool is to reduce fatigue loads through structural couplings. More work is needed before these possibilities are fully explored and blades with structural couplings can be put into production. A cross section analysis tool BECAS (BEam Cross section Analysis Software) has been developed and validated in the project. BECAS is able to predict all geometrical and material induced couplings. This tool has obtained great interest from both industry and academia. The developed fully coupled beam element and cross section analysis tool has been validated against both numerical calculations and experimental measurements. Numerical validation has been performed against beam type calculations including Variational Asymptotical Beam Section Analysis (VABS) and detailed shell and solid finite element analyses. Experimental validation included specially designed beams with built-in couplings, a full-scale blade section originally without couplings, which subsequently was modified with extra composite layers in order to obtain measurable couplings. Both static testing and dynamic modal analysis tests have been performed. The results from the project now make it possible to use structural couplings in an intelligent manner for the design of future wind turbine blades. The developed beam element is especially developed for wind turbine blades and can be used for modeling blades with initial curvature (pre-bending), initial twist and taper. Finally, it have been studied what size of structural couplings can be obtained in current and future

  7. The BLADE Program as a diagnostic tool for turbine blade failures

    International Nuclear Information System (INIS)

    The EPRI BLADE Program has been developed by Stress Technology as a tool which will allow utility engineers undertake sophisticated studies of multiple blade designs with a minimum of training or expertise in finite element modeling or life prediction. A case study is presented where BLADE is used to assist in diagnosing the cause of an L-1 blade failure, and to assess the replacement options available through the manufacturer

  8. Reducing the burden on the environment by optimising gas transmission

    International Nuclear Information System (INIS)

    As part of the close cooperation in the gas industry between Russia and Germany over more than 25 years, Gazprom and Ruhrgas have intensified work on joint projects in various technical fields. The objective is to make use of the expertise both companies can draw on to mitigate the environmental impact of gas transmission systems and enhance their technical and economic efficiency. Optimising transmission system operation has a large environmental potential, allowing energy requirements for gas transportation and hence emissions to be significantly reduced. Gazprom and Ruhrgas intend to use their international experience to optimise the operation of Gazprom's transmission system, which comprises some 150,000 km of pipeline. In a first step, the Gazprom subsidiary Volgotransgaz, the all-Russian Scientific Research Institute of Natural Gases and Gas Technology (VNIIGAZ), Ruhrgas AG and the Ruhrgas affiliate LIWACOM Informationstechnik GmbH will together start on a 5,000 km sub-system operated by Volgotransgaz. Considerable savings are expected. The experience gained on this project is to be used in a second step for the whole of the Gazprom pipeline system. (au)

  9. Study of Wear of Pitched Blade Impellers

    OpenAIRE

    I. Fořt; F. Ambros; J. Medek

    2000-01-01

    A study was made of the erosion of blades of pitched blade impellers in a suspension of solid particles in a liquid under a turbulent regime of flow of an agitated charge. The wear of the impeller is described by an analytical approximation in exponential form, and the influence of the pitch angle on the impeller blade wear was studied experimentally. It follows from the results of the experiments made that the wear rate of the pitched blade impellers increases linearly with the decreasing pi...

  10. Impeller blade design method for centrifugal compressors

    Science.gov (United States)

    Jansen, W.; Kirschner, A. M.

    1974-01-01

    The design of a centrifugal impeller with blades that are aerodynamically efficient, easy to manufacture, and mechanically sound is discussed. The blade design method described here satisfies the first two criteria and with a judicious choice of certain variables will also satisfy stress considerations. The blade shape is generated by specifying surface velocity distributions and consists of straight-line elements that connect points at hub and shroud. The method may be used to design radially elemented and backward-swept blades. The background, a brief account of the theory, and a sample design are described.

  11. Structural tailoring of engine blades (STAEBL)

    Science.gov (United States)

    Brown, K. W.; Pratt, T. K.; Chamis, C. C.

    1983-01-01

    Mathematical optimization is applied to the design of gas turbine fan blades. The automated procedure replaces the current manual process which requires experience and intuition on the part of the designer to achieve successful blade designs. The optimization procedure that is developed utilizes the COPES/CONMIN optimization code. Approximate vibration and stress analyses are used for the optimization process. Analysis recalibrations are achieved through the application of more detailed, refined analysis. Optimizations of a hollow titanium fan blade with composite inlays and of a superhybrid composite blade are demonstrated.

  12. Free-form design of rotor blades

    International Nuclear Information System (INIS)

    This work investigates an integrated free-form approach for the design of rotor blades, where airfoil shapes are treated as unknowns. This leads to the simultaneous optimization of the chord, twist and structural design variables, together with the airfoil shapes along the blade. As airfoils are automatically tailored to the evolution of the blade, this process results in a better exploration of the solution space and relieves the user from the burden of up-front choices, leading to better final designs. The proposed approach is demonstrated by sizing a 2 MW wind turbine blade

  13. Development of a Gas Dynamic and Thermodynamic Simulation Model of the Lontra Blade Compressor™

    Science.gov (United States)

    Karlovsky, Jerome

    2015-08-01

    The Lontra Blade Compressor™ is a patented double acting, internally compressing, positive displacement rotary compressor of innovative design. The Blade Compressor is in production for waste-water treatment, and will soon be launched for a range of applications at higher pressure ratios. In order to aid the design and development process, a thermodynamic and gas dynamic simulation program has been written in house. The software has been successfully used to optimise geometries and running conditions of current designs, and is also being used to evaluate future designs for different applications and markets. The simulation code has three main elements. A positive displacement chamber model, a leakage model and a gas dynamic model to simulate gas flow through ports and to track pressure waves in the inlet and outlet pipes. All three of these models are interlinked in order to track mass and energy flows within the system. A correlation study has been carried out to verify the software. The main correlation markers used were mass flow, chamber pressure, pressure wave tracking in the outlet pipe, and volumetric efficiency. It will be shown that excellent correlation has been achieved between measured and simulated data. Mass flow predictions were to within 2% of measured data, and the timings and magnitudes of all major gas dynamic effects were well replicated. The simulation will be further developed in the near future to help with the optimisation of exhaust and inlet silencers.

  14. Structural Testing of the Blade Reliability Collaborative Effect of Defect Wind Turbine Blades

    Energy Technology Data Exchange (ETDEWEB)

    Desmond, M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hughes, S. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Paquette, J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-06-08

    Two 8.3-meter (m) wind turbine blades intentionally constructed with manufacturing flaws were tested to failure at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) south of Boulder, Colorado. Two blades were tested; one blade was manufactured with a fiberglass spar cap and the second blade was manufactured with a carbon fiber spar cap. Test loading primarily consisted of flap fatigue loading of the blades, with one quasi-static ultimate load case applied to the carbon fiber spar cap blade. Results of the test program were intended to provide the full-scale test data needed for validation of model and coupon test results of the effect of defects in wind turbine blade composite materials. Testing was part of the Blade Reliability Collaborative (BRC) led by Sandia National Laboratories (SNL). The BRC seeks to develop a deeper understanding of the causes of unexpected blade failures (Paquette 2012), and to develop methods to enable blades to survive to their expected operational lifetime. Recent work in the BRC includes examining and characterizing flaws and defects known to exist in wind turbine blades from manufacturing processes (Riddle et al. 2011). Recent results from reliability databases show that wind turbine rotor blades continue to be a leading contributor to turbine downtime (Paquette 2012).

  15. The Effect of Mounting Vortex Generators on the DTU 10MW Reference Wind Turbine Blade

    Science.gov (United States)

    Skrzypiński, Witold; Gaunaa, Mac; Bak, Christian

    2014-06-01

    The aim of the current work is to analyze possible advantages of mounting Vortex Generators (VG's) on a wind turbine blade. Specifically, the project aims at investigating at which radial sections of the DTU 10 MW Reference Wind Turbine blade it is most beneficial to mount the VG's in order to increase the Annual Energy Production (AEP) under realistic conditions. The present analysis was carried out in several steps: (1) The clean two dimensional airfoil characteristics were first modified to emulate the effect of all possible combinations of VG's (1% high at suction side x/c=0.2-0.25) and two Leading Edge Roughness (LER) values along the whole blade span. (2) The combinations from Step 1, including the clean case were subsequently modified to take into account three dimensional effects. (3) BEM computations were carried out to determine the aerodynamic rotor performance using each of the datasets from Step 2 along the whole blade span for all wind speeds in the turbine control scheme. (4) Employing the assumption of radial independence between sections of the blades, and using the results of the BEM computations described in Step 3, it is possible to determine for each radial position independently whether it is beneficial to install VG's in the smooth and LER cases, respectively. The results indicated that surface roughness that corresponds to degradation of the power curve may to some extent be mitigated by installation of VG's. The present results also indicated that the optimal VG configuration in terms of maximizing AEP depends on the degree of severity of the LER. This is because, depending on the condition of blade surface, installation of VG's on an incorrect blade span or installation of VG's too far out on the blade may cause loss in AEP. The results also indicated that the worse condition of the blade surface, the more gain may be obtained from the installation of VG's.

  16. Topology Optimisation for Coupled Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Andreasen, Casper Schousboe; Aage, Niels;

    in the solid are [3-6]. The developed methodology is applied to several two-dimensional solid-fluid thermal interaction problems, such as cooling of electronic components and heat exchangers, as well as to the design of micropumping devices based on natural convection effects. The implementation utilises......The work focuses on applying topology optimisation to forced and natural convection problems in fluid dynamics and conjugate (fluid-structure) heat transfer. To the authors' knowledge, topology optimisation has not yet been applied to natural convection flow problems in the published literature...... and the current work is thus seen as contributing new results to the field. In the literature, most works on the topology optimisation of weakly coupled convection-diffusion problems focus on the temperature distribution of the fluid, but a selection of notable exceptions also focusing on the temperature...

  17. The Effect of Mounting Vortex Generators on the DTU 10MW Reference Wind Turbine Blade

    DEFF Research Database (Denmark)

    Skrzypinski, Witold Robert; Gaunaa, Mac; Bak, Christian

    2014-01-01

    The aim of the current work is to analyze possible advantages of mounting Vortex Generators (VG's) on a wind turbine blade. Specifically, the project aims at investigating at which radial sections of the DTU 10 MW Reference Wind Turbine blade it is most beneficial to mount the VG's in order to...... datasets from Step 2 along the whole blade span for all wind speeds in the turbine control scheme. (4) Employing the assumption of radial independence between sections of the blades, and using the results of the BEM computations described in Step 3, it is possible to determine for each radial position...... independently whether it is beneficial to install VG's in the smooth and LER cases, respectively. The results indicated that surface roughness that corresponds to degradation of the power curve may to some extent be mitigated by installation of VG's. The present results also indicated that the optimal VG...

  18. Implementation of a Biaxial Resonant Fatigue Test Method on a Large Wind Turbine Blade

    Energy Technology Data Exchange (ETDEWEB)

    Snowberg, D.; Dana, S.; Hughes, S.; Berling, P.

    2014-09-01

    A biaxial resonant test method was utilized to simultaneously fatigue test a wind turbine blade in the flap and edge (lead-lag) direction. Biaxial resonant blade fatigue testing is an accelerated life test method utilizing oscillating masses on the blade; each mass is independently oscillated at the respective flap and edge blade resonant frequency. The flap and edge resonant frequency were not controlled, nor were they constant for this demonstrated test method. This biaxial resonant test method presented surmountable challenges in test setup simulation, control and data processing. Biaxial resonant testing has the potential to complete test projects faster than single-axis testing. The load modulation during a biaxial resonant test may necessitate periodic load application above targets or higher applied test cycles.

  19. Energy saving in a deep well pump with splitter blade

    Energy Technology Data Exchange (ETDEWEB)

    Goelcue, Mustafa [Department of Mechanical Education, Pamukkale University, 20017 Kinikli, Denizli (Turkey)]. E-mail: mgolcu@pamukkale.edu.tr; Pancar, Yasar [Department of Mechanical Engineering, Osman Gazi University, 26480 Eskisehir (Turkey); Sekmen, Yakup [Karabuk Vocational Collage, Zonguldak Karaelmas University, 78100 Karabuk (Turkey)

    2006-03-15

    Design parameters, like blade number, blade outlet angle and impeller outlet diameter, affect pump performance and energy consumption. Deep well pumps with splitter blades (DWPwsb) are manufactured to achieve energy saving and improve efficiency. Splitter blades are generally located at the centerline of the main blades. Blade number and blade discharge angle should be conveniently determined when splitter blades are used on the impellers. In this study, impellers having different numbers of blades (z = 5, 6, 7) with and without splitter blades (35%, 60% and 80% of the main blade length) were tested in a deep well pump. Tests have been conducted on a total of 12 impellers, and the characteristics of deep well pumps without splitter blade (DWPwosb) and DWPwsb were obtained experimentally. These results show that splitter blades cause negative effects on pump performance in impellers with blade numbers of 6 and 7. When the splitter blade is added to the impeller with the blade number of 5, the efficiency increases with flow up to 10 l/s flow rate, after which it decreases as the splitter blade length increases. The highest efficiency and the lowest energy consumption were obtained in DWPwsb with 80% of the main blade length. At the best efficiency point (b.e.p), an energy saving of 6.6% and an improvement of 1.14% in efficiency were achieved. An analysis of the additional cost of the splitter blade and the application in an agricultural area were performed.

  20. Optimisation in radiotherapy I. Defining the problem

    International Nuclear Information System (INIS)

    Optimisation in radiotherapy should incorporate a very wide set of variables, including the combinations of dose due to external beam radiotherapy, brachytherapy, internally administered radionuclides and the effects of chemotherapy, surgery, hyperthermia, other biological and chemical defenses, alternative treatment techniques, lifestyle and mental state of the patient, the economics of cancer treatment and consideration of tolerable levels of adverse effects and palliation. A full treatment optimisation would consider the influence and covariance of all these variables and any future techniques, as well as the complex constraints imposed by the biological systems being irradiated. This series of reviews concentrates on optimisation of radiotherapy through the treatment planning component of the treatment process - an area of radiotherapy research that has received a great deal of attention as the attached lists of references will testify. It hopes to provide the medical physics and engineering community (and hopefully the clinical community) with a background into the mathematical bases for the manipulation of radiation for clinical benefit. It also examines the potential benefits of research into these techniques in the light of recent approaches to optimisation in radiotherapy, and provides pointers to more concise accounts in the literature. In this first article, the incentive for radiotherapy optimisation research is established, and the actual radiotherapy optimisation problem (in terms of the manipulation of degrees of freedom in radiation delivery) is defined. The degrees of freedom associated with radiotherapy treatment are identified, and it is shown how these degrees of freedom translate into the mathematical parameters of the problem, including the dose distributions they produce. The constraints and objectives of the problem are also discussed from both physical and radiobiological perspectives. (author)

  1. Topology optimisation of natural convection problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Aage, Niels; Andreasen, Casper Schousboe;

    2014-01-01

    This paper demonstrates the application of the density-based topology optimisation approach for the design of heat sinks and micropumps based on natural convection effects. The problems are modelled under the assumptions of steady-state laminar flow using the incompressible Navier-Stokes equations...... coupled to the convection-diffusion equation through the Boussinesq approximation. In order to facilitate topology optimisation, the Brinkman approach is taken to penalise velocities inside the solid domain and the effective thermal conductivity is interpolated in order to accommodate differences in...

  2. Bat Algorithm for Multi-objective Optimisation

    CERN Document Server

    Yang, Xin-She

    2012-01-01

    Engineering optimization is typically multiobjective and multidisciplinary with complex constraints, and the solution of such complex problems requires efficient optimization algorithms. Recently, Xin-She Yang proposed a bat-inspired algorithm for solving nonlinear, global optimisation problems. In this paper, we extend this algorithm to solve multiobjective optimisation problems. The proposed multiobjective bat algorithm (MOBA) is first validated against a subset of test functions, and then applied to solve multiobjective design problems such as welded beam design. Simulation results suggest that the proposed algorithm works efficiently.

  3. [Process optimisation: from theory to practical implementation].

    Science.gov (United States)

    Töpfer, Armin

    2010-01-01

    Today process optimisation is an indispensable approach to mastering the current challenges of modern health care management. The objective is to design business processes free of defects and free of waste as well as their monitoring and controlling with meaningful test statistics. Based on the identification of essential key performance indicators, key success factors and value cash generators two basic approaches to process optimisation, which are well-established and widely used in the industry, are now being implemented in the health care sector as well: Lean Management and Six Sigma. PMID:20951951

  4. Self-optimising control of sewer systems

    DEFF Research Database (Denmark)

    Mauricio Iglesias, Miguel; Montero-Castro, Ignacio; Mollerup, Ane Loft;

    The design of sewer system control is a complex task given the large size of the sewer networks, the transient dynamics of the water flows and the stochastic nature of rainfall. This contribution presents a generic methodology for the design of a self-optimising controller in sewer systems. The...... definition of an optimal performance was carried out by through a two-stage optimisation (stochastic and deterministic) to take into account both the overflow during the current rain event as well as the expected overflow, given the probability of a future rain event. The methodology is successfully applied...

  5. Optimisation of interventional cardiology procedures; Optimisation des procedures en cardiologie interventionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Bar, Olivier [SELARL, Cardiologie Interventionnelle Imagerie Cardiaque - CIIC, 8, place de la Cathedrale - 37042 Tours (France)

    2011-07-15

    Radiation-guided procedures in interventional cardiology include diagnostic and/or therapeutic procedures, primarily coronary catheterization and coronary angioplasty. Application of the principles of radiation protection and the use of optimised procedures are contributing to dose reduction while maintaining the radiological image quality necessary for performance of the procedures. The mandatory training in patient radiation protection and technical training in the use of radiology devices mean that implementing continuous optimisation of procedures is possible in practice. This optimisation approach is the basis of patient radiation protection; when associated with the wearing of protective equipment it also contributes to the radiation protection of the cardiologists. (author)

  6. Robotic Hot-Blade Cutting

    DEFF Research Database (Denmark)

    Søndergaard, Asbjørn; Feringa, Jelle; Nørbjerg, Toke Bjerge;

    2016-01-01

    This paper presents a novel method for cost-effective, robotic production of double curved formwork in Expanded Polystyrene (EPS) for in situ and prefabricated concrete construction. A rationalization and segmentation procedure is developed, which allows for the transliteration of double curved...... NURBS surfaces to Euler elastica surface segments, while respecting various constraints of production. An 18 axis, tri-robot system approximates double curved NURBS surfaces by means of an elastically deformed and heated blade, mounted on the flanges of two manipulators. Re-orienting or translating...

  7. KNOW-BLADE task-4 report: Navier-Stokes aeroelasticity

    DEFF Research Database (Denmark)

    Politis, E.S.; Nikolaou, I.G.; Chaviaropoulos, P.K.;

    2004-01-01

    wind turbine blade have been combined with 2D and 3D unsteady Navier-Stokes solvers. The relative disadvantage of the quasi-3D approach (where the elastic solver is coupled with a 2D Navier-Stokes solver) isits inability to model induced flow. The lack of a validation test case did not allow for......The problem of the aeroelastic stability of wind turbine blades is addressed in this report by advancing the aerodynamic modelling in the beam element type codes from the engineering-type empirical models to unsteady, 2D or 3D, Navier-Stokes solvers. Inthis project, structural models for the full...... in damping with the increase of wind speeds and in a minimum value for the damping for wind speedaround 15~m/s. The eigenvalue analyses resulted in steeper distributions for this mode. The agreement in aerodynamic damping decrease with the increase of wind speed is also observed in the distributions...

  8. Structural Analysis of Basalt Fiber Reinforced Plastic Wind Turbine Blade

    OpenAIRE

    Mengal Ali Nawaz; Karuppanan Saravanan; Wahab Azmi Abdul

    2014-01-01

    In this study, Basalt fiber reinforced plastic (BFRP) wind turbine blade was analyzed and compared with Glass fiber reinforced plastic blade (GFRP). Finite element analysis (FEA) of blade was carried out using ANSYS. Data for FEA was obtained by using rule of mixture. The shell element in ANSYS was used to simulate the wind turbine blade and to conduct its strength analysis. The structural analysis and comparison of blade deformations proved that BFRP wind turbine blade has better strength co...

  9. Pressure Pulsation Signal Analysis for Centrifugal Compressor Blade Crack Determination

    OpenAIRE

    Hongkun Li; Xuefeng Zhang; Xiaowen Zhang; Shuhua Yang; Fujian Xu

    2014-01-01

    Blade is a key piece of component for centrifugal compressor. But blade crack could usually occur as blade suffers from the effect of centrifugal forces, gas pressure, friction force, and so on. It could lead to blade failure and centrifugal compressor closing down. Therefore, it is important for blade crack early warning. It is difficult to determine blade crack as the information is weak. In this research, a pressure pulsation (PP) sensor installed in vicinity to the crack area is used to d...

  10. Research on Blade Thickness Influencing Pump as Turbine

    OpenAIRE

    Sun-Sheng Yang; Chao Wang; Kai Chen; Xin Yuan

    2014-01-01

    Research on the efficiency improvement of pump as turbine (PAT) is inadequate. Blade thickness is an important geometry parameter in blade design. To explore effects of blade thickness on the influence of PAT, numerical research on three different specific speeds of PATs with different blade thickness was carried out. Their performance changes with blade thickness were presented. Besides, the variations of hydraulic loss distribution with increasing blade thickness were performed. Theoretical...

  11. TX-100 manufacturing final project report.

    Energy Technology Data Exchange (ETDEWEB)

    Ashwill, Thomas D.; Berry, Derek S. (TPI Composites, Inc., Warren, RI)

    2007-11-01

    This report details the work completed under the TX-100 blade manufacturing portion of the Carbon-Hybrid Blade Developments: Standard and Twist-Coupled Prototype project. The TX-100 blade is a 9 meter prototype blade designed with bend-twist coupling to augment the mitigation of peak loads during normal turbine operation. This structural coupling was achieved by locating off axis carbon fiber in the outboard portion of the blade skins. The report will present the tooling selection, blade production, blade instrumentation, blade shipping and adapter plate design and fabrication. The baseline blade used for this project was the ERS-100 (Revision D) wind turbine blade. The molds used for the production of the TX-100 were originally built for the production of the CX-100 blade. The same high pressure and low pressure skin molds were used to manufacture the TX-100 skins. In order to compensate for the difference in skin thickness between the CX-100 and the TX-100, however, a new TX-100 shear web plug and mold were required. Both the blade assembly fixture and the root stud insertion fixture used for the CX-100 blades could be utilized for the TX-100 blades. A production run of seven TX-100 prototype blades was undertaken at TPI Composites during the month of October, 2004. Of those seven blades, four were instrumented with strain gauges before final assembly. After production at the TPI Composites facility in Rhode Island, the blades were shipped to various test sites: two blades to the National Wind Technology Center at the National Renewable Energy Laboratory in Boulder, Colorado, two blades to Sandia National Laboratory in Albuquerque, New Mexico and three blades to the United States Department of Agriculture turbine field test facility in Bushland, Texas. An adapter plate was designed to allow the TX-100 blades to be installed on existing Micon 65/13M turbines at the USDA site. The conclusion of this program is the kick-off of the TX-100 blade testing at the three

  12. Extending Particle Swarm Optimisers with Self-Organized Criticality

    DEFF Research Database (Denmark)

    Løvbjerg, Morten; Krink, Thiemo

    Particle swarm optimisers (PSOs) show potential in function optimisation, but still have room for improvement. Self-organized criticality (SOC) can help control the PSO and add diversity. Extending the PSO with SOC seems promising reaching faster convergence and better solutions.......Particle swarm optimisers (PSOs) show potential in function optimisation, but still have room for improvement. Self-organized criticality (SOC) can help control the PSO and add diversity. Extending the PSO with SOC seems promising reaching faster convergence and better solutions....

  13. Simulation-based optimisation of complex maintenance systems

    OpenAIRE

    Alrabghi, Abdullah Omar

    2015-01-01

    There is a potential as well as a growing interest amongst researchers to utilise simulation in optimising maintenance systems. The state of the art in simulation-based optimisation of maintenance was established by systematically classifying the published literature and outlining main trends in modelling and optimising maintenance systems. In general, approaches to optimise maintenance varied significantly in the literature. Overall, these studies highlight the need for a framework that unif...

  14. Improved design for large wind turbine blades of fibre composites (Phase 4) - Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, B.F.; Toftegaard, H.; Goutanos, S. (Risoe DTU, Materials Research Div., Roskilde (Denmark)); Branner, K.; Berring, P. (Risoe DTU, Wind Energy Div., Roskilde (Denmark)); Lund, E. (Aalborg Univ., Dept. of Mechanical Engineering, Aalborg (Denmark)); Wedel-Heinen, J. (Vestas Wind System, Randers (Denmark)); Garm, J.H. (LM Wind Power, Kolding (Denmark))

    2010-06-15

    Results are summarised for the project 'Improved design for large wind turbine blades (Phase 4)', partially supported by the Danish Energy Agency under the Ministry of Climate and Energy through the EUDP journal no.: 33033-0267. The aim of the project was to develop new and better design methods for wind turbine blades, so that uncertainties associated with damage and defects can be reduced. The topics that are studied include buckling-driven delamination of flat load-carrying laminates, cracking along interfaces in material joints (fracture mechanical characterisation and modelling), cyclic crack growth with large scale bridging and the use of cohesive laws in finite element programmes for simulating wind turbine blade failure. An overview is given of the methods and the major research results of the project. The implementation of the knowledge in the industry is discussed. Finally, some ideas for future research activities are considered. (author)

  15. Improved design for large wind turbine blades of fibre composites (Phase 4) - Summary report

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Toftegaard, Helmuth Langmaack; Goutianos, Stergios;

    for wind turbine blades, so that uncertainties associated with damage and defects can be reduced. The topics that are studied include buckling-driven delamination of flat load-carrying laminates, cracking along interfaces in material joints (fracture mechanical characterisation and modelling), cyclic......Results are summarised for the project "Improved design for large wind turbine blades (Phase 4)", partially supported by the Danish Energy Agency under the Ministry of Climate and Energy through the EUDP journal no.: 33033-0267. The aim of the project was to develop new and better design methods...... crack growth with large scale bridging and the use of cohesive laws in finite element programmes for simulating wind turbine blade failure. An overview is given of the methods and the major research results of the project. The implementation of the knowledge in the industry is discussed. Finally, some...

  16. OPTIMISE - Deliverable D4.3 Report on two axis rolling, month 12

    DEFF Research Database (Denmark)

    Eriksen, Morten

    This report is one of two reports which describe de deliverables on two axis rolling in the OPTIMISE project. Most of the work in this report has also been described in the sub work package reports produced during the project. The sub work package reports are WP4.1 Two axis rolling and WP4.3 Fini...... Element Modelling of two axis rolling....

  17. Energy optimisation of domestic refrigerators

    DEFF Research Database (Denmark)

    Jakobsen, Arne; Rasmussen, Bjarne D.

    1998-01-01

    using a variable speed compressor for controlling the capacity of the refrigeration system.2) Introducing a variable speed fan for enhancing the heat transfer in the evaporator.It was the aim of the project to reduce the energy consumption of a standard refrigerator, available on the market today, by 50 %....

  18. A new type of boundary blade for steam turbines

    International Nuclear Information System (INIS)

    Long steam turbine blades are always made as massive blades cut from the solid. For a given blade material and given rotational speed of the steam turbine, the maximum permissible blade length depends on a tapering factor which expresses the ratio of the centrifugal force of the real blade, always twisted and tapered, to the centrifugal force of the theoretical cylindrical blade of the same flow cross-section. This factor can be further reduced to a considerable degree, due to a better approximation to the shape having uniform srength, if the blade is constructed as a hollow blade. (orig./LH)

  19. Study of Wear of Pitched Blade Impellers

    Directory of Open Access Journals (Sweden)

    I. Fořt

    2000-01-01

    Full Text Available A study was made of the erosion of blades of pitched blade impellers in a suspension of solid particles in a liquid under a turbulent regime of flow of an agitated charge. The wear of the impeller is described by an analytical approximation in exponential form, and the influence of the pitch angle on the impeller blade wear was studied experimentally. It follows from the results of the experiments made that the wear rate of the pitched blade impellers increases linearly with the decreasing pitch angle within the interval a Î á15°; 45° ń. The proposed form of radial profile of the leading edge of the impeller blade enables us to calculate the surface of the worn blade. This quantity significantly decreases with the length of the period when the blades are affected by the solid particles, and its values calculated according to the suggested profile of the worn blade fit fairly well with the experimentally determined values. The results of the experiments performed are valid for homogeneous distribution of solid particles in an agitated suspension.

  20. Methods for Optimisation of the Laser Cutting Process

    DEFF Research Database (Denmark)

    Dragsted, Birgitte

    . Both versions have been used for optimisations in different materials and both of them succeeded in obtaining a satisfactory quality. In addition the optimisations with the quantitative version also obtained a much higher productivity . The results of the optimisations showed that the qualitative...

  1. Les techniques d’optimisation multicritère en optimisation à deux niveaux

    OpenAIRE

    Pieume, Calice Olivier

    2011-01-01

    Cette thèse aborde l'optimisation multicritère et l'optimisation à deux niveaux. L'investigation porte principalement sur les méthodes, les applications et les liens possibles entre les deux classes d'optimisation. Premièrement, nous développons une méthode de résolution des problèmes d'optimisation linéaire multicritère. Pour ce faire, nous introduisons une nouvelle caractérisation des faces efficaces et exploitons le résultat selon lequel l'ensemble des tableaux idéaux associés aux sommets ...

  2. Optimisation of logistics processes of energy grass collection

    Science.gov (United States)

    Bányai, Tamás.

    2010-05-01

    objective function of the optimisation is the maximisation of the profit which means the maximization of the difference between revenue and cost. The objective function trades off the income of the assigned transportation demands against the logistic costs. The constraints are the followings: (1) the free capacity of the assigned transportation resource is more than the re-quested capacity of the transportation demand; the calculated arrival time of the transportation resource to the harvesting place is not later than the requested arrival time of them; (3) the calculated arrival time of the transportation demand to the processing and production facility is not later than the requested arrival time; (4) one transportation demand is assigned to one transportation resource and one resource is assigned to one transportation resource. The decision variable of the optimisation problem is the set of scheduling variables and the assignment of resources to transportation demands. The evaluation parameters of the optimised system are the followings: total costs of the collection process; utilisation of transportation resources and warehouses; efficiency of production and/or processing facilities. However the multidimensional heuristic optimisation method is based on genetic algorithm, but the routing sequence of the optimisation works on the base of an ant colony algorithm. The optimal routes are calculated by the aid of the ant colony algorithm as a subroutine of the global optimisation method and the optimal assignment is given by the genetic algorithm. One important part of the mathematical method is the sensibility analysis of the objective function, which shows the influence rate of the different input parameters. Acknowledgements This research was implemented within the frame of the project entitled "Development and operation of the Technology and Knowledge Transfer Centre of the University of Miskolc". with support by the European Union and co-funding of the European Social

  3. Design optimization for active twist rotor blades

    Science.gov (United States)

    Mok, Ji Won

    This dissertation introduces the process of optimizing active twist rotor blades in the presence of embedded anisotropic piezo-composite actuators. Optimum design of active twist blades is a complex task, since it involves a rich design space with tightly coupled design variables. The study presents the development of an optimization framework for active helicopter rotor blade cross-sectional design. This optimization framework allows for exploring a rich and highly nonlinear design space in order to optimize the active twist rotor blades. Different analytical components are combined in the framework: cross-sectional analysis (UM/VABS), an automated mesh generator, a beam solver (DYMORE), a three-dimensional local strain recovery module, and a gradient based optimizer within MATLAB. Through the mathematical optimization problem, the static twist actuation performance of a blade is maximized while satisfying a series of blade constraints. These constraints are associated with locations of the center of gravity and elastic axis, blade mass per unit span, fundamental rotating blade frequencies, and the blade strength based on local three-dimensional strain fields under worst loading conditions. Through pre-processing, limitations of the proposed process have been studied. When limitations were detected, resolution strategies were proposed. These include mesh overlapping, element distortion, trailing edge tab modeling, electrode modeling and foam implementation of the mesh generator, and the initial point sensibility of the current optimization scheme. Examples demonstrate the effectiveness of this process. Optimization studies were performed on the NASA/Army/MIT ATR blade case. Even though that design was built and shown significant impact in vibration reduction, the proposed optimization process showed that the design could be improved significantly. The second example, based on a model scale of the AH-64D Apache blade, emphasized the capability of this framework to

  4. Optimising Signalised Intersection Using Wireless Vehicle Detectors

    DEFF Research Database (Denmark)

    Adjin, Daniel Michael Okwabi; Torkudzor, Moses; Asare, Jack

    Traffic congestion on roads wastes travel times. In this paper, we developed a vehicular traffic model to optimise a signalised intersection in Accra, using wireless vehicle detectors. Traffic volume gathered was extrapolated to cover 2011 and 2016 and were analysed to obtain the peak hour traffic...

  5. Particle Swarm Optimisation with Spatial Particle Extension

    DEFF Research Database (Denmark)

    Krink, Thiemo; Vesterstrøm, Jakob Svaneborg; Riget, Jacques

    In this paper, we introduce spatial extension to particles in the PSO model in order to overcome premature convergence in iterative optimisation. The standard PSO and the new model (SEPSO) are compared w.r.t. performance on well-studied benchmark problems. We show that the SEPSO indeed managed to...

  6. Quantifying Timing Leaks and Cost Optimisation

    OpenAIRE

    Di Pierro, Alessandra; Hankin, Chris; Wiklicky, Herbert

    2008-01-01

    We develop a new notion of security against timing attacks where the attacker is able to simultaneously observe the execution time of a program and the probability of the values of low variables. We then show how to measure the security of a program with respect to this notion via a computable estimate of the timing leakage and use this estimate for cost optimisation.

  7. Optimisation of connections to a fibre network

    NARCIS (Netherlands)

    D.K. Leegwater (Dirk Klaas); J.D. de Groot

    2004-01-01

    textabstractStronger competition together with the development of new technologies have forced the Telecom Service Providers (TSP's) in the Netherlands to look for sophisticated optimisation methods to reduce the costs of their communication services especially for new areas such as the application

  8. Fusing website usability and search engine optimisation

    Directory of Open Access Journals (Sweden)

    Eugene B. Visser

    2014-03-01

    Full Text Available Background: Most websites, especially those with a commercial orientation, need a high ranking on a search engine for one or more keywords or phrases. The search engine optimisation process attempts to achieve this. Furthermore, website users expect easy navigation, interaction and transactional ability. The application of website usability principles attempts to achieve this. Ideally, designers should achieve both goals when they design websites.Objectives: This research intended to establish a relationship between search engine optimisation and website usability in order to guide the industry. The authors found a discrepancy between the perceived roles of search engines and website usability.Method: The authors designed three test websites. Each had different combinations of usability, visibility and other attributes. They recorded and analysed the conversions and financial spending on these experimental websites. Finally, they designed a model that fuses search engine optimisation and website usability.Results: Initially, it seemed that website usability and search engine optimisation complemented each other. However, some contradictions between the two, based on content, keywords and their presentation, emerged. Industry experts do not acknowledge these contradictions, although they agree on the existence of the individual elements. The new model highlights the complementary and contradictory aspects.Conclusion: The authors found no evidence of any previous empirical experimental results that could confirm or refute the role of the model. In the fast-paced world of competition between commercial websites, this adds value and originality to the websites of organisations whose websites play important roles.

  9. Statistical models of shape optimisation and evaluation

    CERN Document Server

    Davies, Rhodri; Taylor, Chris

    2008-01-01

    Addresses one of the key issues in shape modelling: that of establishing a meaningful correspondence between a set of shapesUses a novel approach to establishing correspondence by casting model-building as an optimisation problem Includes practical examples of applications for both 2D and 3D sets of shapesFull implementation details, perviously unpublished, provided

  10. Topology optimised planar photonic crystal building blocks

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Hede, K. K.; Borel, Peter Ingo; Jensen, Jakob Søndergaard; Sigmund, Ole

    A photonic crystal waveguide (PhCW) 1x4 splitter has been constructed from PhCW 60° bends1 and Y-splitters2 that have been designed individually by utilising topology optimisation3. The splitter has been fabricated in a silicon-on-insulator material (Fig. 1) and exhibits a broadband splitting for...

  11. Self-optimising control of sewer systems

    DEFF Research Database (Denmark)

    Mauricio Iglesias, Miguel; Montero-Castro, I.; Mollerup, Ane Loft;

    2013-01-01

    Self-optimising control is a useful concept to select optimal controlled variables from a set of candidate measurements in a systematic manner. In this study, use self-optimizing control tools and apply them to the specific features of sewer systems, e.g. the continuously transient dynamics, the ...

  12. Optimised Design of Transparent Optical Domains

    DEFF Research Database (Denmark)

    Hanik, N.; Caspar, C.; Schmidt, F.;

    2000-01-01

    Three different design concepts for transparent, dispersion compensated, optical WDM transmission links are optimised numerically and experimentally for 10 Gbit/s data rate per channel. It is shown that robust transparent domains of 1,500 km in diameter can be realised using simple design rutes....

  13. Ice-impact analysis of blades

    Science.gov (United States)

    Chamis, C. C.; Murthy, P. L. N.; Singhal, S. N.; Reddy, E. S.

    1994-01-01

    A computational capability is described for evaluating the ice-impact on engine blades made from composites. The ice block is modeled as an equivalent spherical object and has the velocity opposite to that of the aircraft with direction parallel to the engine axis. A finer finite element mesh is used for a portion of the blade near the impact region compared to the course mesh for the rest of the blade. The effects of ice size and velocity on the average leading edge strain are evaluated for a simulated unswept composite propfan blade. Parametric studies are performed to assess the blade structural responses due to the ice-impact at various locations along the span. It is found that: (1) for a given engine speed, a critical ice speed exists that corresponds to the maximum strain; and (2) the tip bending type frequencies increase after impact while the torsion frequencies decrease.

  14. Lightning transient analysis in wind turbine blades

    DEFF Research Database (Denmark)

    Candela Garolera, Anna; Holbøll, Joachim; Madsen, Søren Find

    2013-01-01

    The transient behavior of lightning surges in the lightning protection system of wind turbine blades has been investigated in this paper. The study is based on PSCAD models consisting of electric equivalent circuits with lumped and distributed parameters involving different lightning current...... waveforms. The aim of the PSCAD simulations is to study the voltages induced by the lightning current in the blade that may cause internal arcing. With this purpose, the phenomenon of current reflections in the lightning down conductor of the blade and the electromagnetic coupling between the down conductor...... and other internal conductive elements of the blade is studied. Finally, several methods to prevent internal arcing are discussed in order to improve the lightning protection of the blade....

  15. Failure analysis of air fan blades

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-qing; JI Zhe; CUI Yong-li; CUI Chun-zhi; SUN Zhi

    2008-01-01

    The failure of all 12 blades of an air fan was investigated by metallurgical and mechanical experiments and an examina-tion of the fracture surface. The experimental results show that the cast aluminium-silicon alloy without any modification had a number of material defects, such as coarse grains, a loose structure, a large number of shrinkage holes, a long and thin bold-pin shaped silicon-phase, poor material strength and serious brittleness. In addition, installed on the spindle without elastic conjunction,blade No. 10 vibrated and inevitably.spun off due to the large centrifugal force. Therefore, blade No. 10 first cracked at the locking handle, then broke at the root, which caused all the other 11 blades to be broken by the crack of blade No.10.

  16. Preliminary blade design using integrated computer codes

    Science.gov (United States)

    Ryan, Arve

    1988-12-01

    Loads on the root of a horizontal axis wind turbine (HAWT) rotor blade were analyzed. A design solution for the root area is presented. The loads on the blades are given by different load cases that are specified. To get a clear picture of the influence of different parameters, the whole blade is designed from scratch. This is only a preliminary design study and the blade should not be looked upon as a construction reference. The use of computer programs for the design and optimization is extensive. After the external geometry is set and the aerodynamic loads calculated, parameters like design stresses and laminate thicknesses are run through the available programs, and a blade design optimized on basis of facts and estimates used is shown.

  17. Wave-induced dynamics of flexible blades

    CERN Document Server

    Luhar, M

    2015-01-01

    We present an experimental and numerical study that describes the motion of flexible blades, scaled to be dynamically similar to natural aquatic vegetation, forced by wave-induced oscillatory flows. For the conditions tested, blade motion is governed primarily by two dimensionless variables: (i) the Cauchy number, $Ca$, which represents the ratio of the hydrodynamic forcing to the restoring force due to blade stiffness, and (ii) the ratio of the blade length to the wave orbital excursion, $L$. For flexible blades with $Ca \\gg 1$, the relationship between drag and velocity can be described by two different scaling laws at the large- and small-excursion limits. For large excursions ($L \\ll 1$), the flow resembles a unidirectional current and the scaling laws developed for steady-flow reconfiguration studies hold. For small excursions ($L \\gg 1$), the beam equations may be linearized and a different scaling law for drag applies. The experimental force measurements suggest that the small-excursion scaling applies...

  18. A Two-Bladed Concept Wind Turbine

    DEFF Research Database (Denmark)

    Kim, Taeseong

    This article shows the potential for reducing extreme loads with an innovative design of wind turbine, a partial pitch two-bladed concept turbine. The most extreme conditions to test a turbine are considered to be stand-still combined with a grid failure in which the wind comes from all directions...... from 0 to 360 degrees. All aeroelastic load simulations are done by using the aeroelastic code HAWC2. From the load comparisons between the partial pitch two-bladed turbine and a conventional three-bladed turbine it is observed that the partial pitch two-bladed turbine can reduce the extreme tower...... bottom bending moment by approximately 33% compared to the three-bladed turbine....

  19. Optimised performance of industrial high resolution computerised tomography

    International Nuclear Information System (INIS)

    -sensitivity/noise, density-sensitivity/noise, and mass attenuation-sensitivity/noise. With these measures, a method is presented that finds the optimal equipment settings, where no improvement can be made without worsening at least one other sensitivity/noise ratio. This thesis includes modelling and verification of the sharpness of the CT system in terms of the modulation transfer function, MTF. Together with the limiting perception factor and the maximised SNR the detectability limits for any specific contrasting detail in the centre of a cylindrical sample can be determined. It is also demonstrated that the model can be used to suppress beam hardening when collecting CT-data. When homogeneous samples are imaged, the model can in addition be used to make post-processing corrections for suppressing the beam hardening artefacts. Wavelet-based local tomography has been found to produce images with good accuracy from projection data only from a small region in a sample. This technique is demonstrated on thermal barrier coatings, which contain internal cracks. With optimised equipment settings and geometrical magnification of a region in the sample, wavelet-based local tomography produced high-resolution images of excellent quality. The increased resolution reveals features in the microstructure that cannot be resolved with traditional CT. This technique will be a useful tool for characterisation of the microstructure in advanced materials

  20. Experimental investigation of the flow field and power consumption characteristics of regular and fractal blade impellers in a dynamic mixer

    Science.gov (United States)

    Steiros, K.; Bruce, P. J. K.; Buxton, O. R. H.; Vassilicos, J. C.

    2015-11-01

    Experiments have been performed in an octagonal un-baffled water tank, stirred by three radial turbines with different geometry impellers: (1) regular rectangular blades; (2) single-iteration fractal blades; (3) two-iteration fractal blades. Shaft torque was monitored and the power number calculated for each case. Both impellers with fractal geometry blades exhibited a decrease of turbine power number compared to the regular one (15% decrease for single-iteration and 19% for two iterations). Phase locked PIV in the discharge region of the blades revealed that the vortices emanating from the regular blades are more coherent, have higher kinetic energy, and advect faster towards the tank's walls where they are dissipated, compared to their fractal counterparts. This suggests a strong link between vortex production and behaviour and the energy input for the different impellers. Planar PIV measurements in the bulk of the tank showed an increase of turbulence intensity of over 20% for the fractal geometry blades, suggesting higher mixing efficiency. Experiments with pressure measurements on the different geometry blade surfaces are ongoing to investigate the distribution of forces, and calculate hydrodynamic centres of pressure. The authors would like to acknowledge the financial support given by European Union FP7 Marie Curie MULTISOLVE project (Grant Agreement No. 317269).

  1. Nuclear power plant maintenance optimisation SENUF network activity

    International Nuclear Information System (INIS)

    During providing scientific and technical support to TACIS and PHARE nuclear safety programs a large amount of knowledge related to Russian design reactor systems has accumulated and led to creation of a new Network concerning Nuclear Safety in Central and Eastern Europe called ''Safety of Eastern European type Nuclear Facilities'' (SENUF). SENUF contributes to bring together all stakeholders of TACIS and PHARE: beneficiaries, end users, Eastern und Western nuclear industries, and thus, to favour fruitful technical exchanges and feedback of experience. At present the main focus of SENUF is the nuclear power plant maintenance as substantial element of plant operational safety as well as life management. A Working Group has been established on plant maintenance. One of its major tasks in 2004 is to prepare a status report on advanced strategies to optimise maintenance. Optimisation projects have an interface with the plant's overall life management program. Today, almost all plants involved in SENUF network have an explicit policy to extend their service life, thus, component ageing management, modernization and refurbishment actions became much more important. A database is also under development, which intends to help sharing the available knowledge and specific equipment and tools. (orig.)

  2. Microstructure stability: Optimisation of 263 Ni-based superalloy

    Directory of Open Access Journals (Sweden)

    Crozet Coraline

    2014-01-01

    Full Text Available To reduce CO2 emissions on coal-fired power plant, A-ultra supercritical (A-USC power plant whose steam conditions exceed 700 °C are being developed. At these elevated temperatures, the use of Ni-base superalloys becomes necessary. In this context and within the European project NextGenPower, focus is made on commercial Nimonic C-263 as a candidate material for turbine rotors. Nimonic C-263 is known to have low sensitivity to segregation, high workability and high weldability which are major properties for the manufacture of large shafts. Long-term creep strength is also required for this application and unfortunately Nimonic C-263 shows η-phase precipitation after long-time exposure between 700 °C–900 °C which is detrimental for long-term creep properties. The composition of Nimonic C-263 was thus optimised to overcome the formation of η-phase. Trial tests were made in order to study the effect of hardening contribution elements on microstructural and mechanical properties. Then, a 500 mm diameter forged rotor was made from optimised 263 alloy and shows promising properties.

  3. Repair welding of cracked steam turbine blades using austenitic and martensitic stainless-steel consumables

    International Nuclear Information System (INIS)

    The procedure for repair welding of cracked steam turbine blades made of martensitic stainless steels has been developed using the gas tungsten arc welding process. Weld repair procedures were developed using both ER 316L austenitic and ER 410 martensitic stainless-steel filler wire. The overall development of the repair welding procedure included selection of welding consumables (for austenitic filler metal), optimisation of post-weld heat treatment parameters, selection of suitable method for local pre-heating and post-weld heat treatment (PWHT) of the blades, determination of mechanical properties of weldments in as-welded and PWHT conditions, and microsturctural examination. After various trials using different procedures, the procedure of local PWHT (and preheating when using martensitic stainless-steel filler wire) using electrical resistance heating on the top surface of the weldment and monitoring the temperature by placing a thermocouple at the bottom of the weld was found to give the most satisfactory results. These procedures have been developed and/or applied for repair welding of cracked blades in steam turbines

  4. Repair welding of cracked steam turbine blades using austenitic and martensitic stainless-steel consumables

    Energy Technology Data Exchange (ETDEWEB)

    Bhaduri, A.K. E-mail: bhaduri@igcar.ernet.in; Gill, T.P.S.; Albert, S.K.; Shanmugam, K.; Iyer, D.R

    2001-06-01

    The procedure for repair welding of cracked steam turbine blades made of martensitic stainless steels has been developed using the gas tungsten arc welding process. Weld repair procedures were developed using both ER 316L austenitic and ER 410 martensitic stainless-steel filler wire. The overall development of the repair welding procedure included selection of welding consumables (for austenitic filler metal), optimisation of post-weld heat treatment parameters, selection of suitable method for local pre-heating and post-weld heat treatment (PWHT) of the blades, determination of mechanical properties of weldments in as-welded and PWHT conditions, and microsturctural examination. After various trials using different procedures, the procedure of local PWHT (and preheating when using martensitic stainless-steel filler wire) using electrical resistance heating on the top surface of the weldment and monitoring the temperature by placing a thermocouple at the bottom of the weld was found to give the most satisfactory results. These procedures have been developed and/or applied for repair welding of cracked blades in steam turbines.

  5. Crack of a first stage blade in a steam turbine

    Directory of Open Access Journals (Sweden)

    M. Nurbanasari

    2014-10-01

    Full Text Available The failure of the first stage blade in a steam turbine of 55 MW was investigated. The blade was made of 17-4 PH stainless steel and has been used for 12 years before failure. The current work aims to find out the main cause of the first stage blade failure. The methods for investigation were metallurgical analysis, chemical composition test, and hardness measurement. The result showed that there was no evidence the blade failure was due to material. The damage found on the blade namely crack on the blade root. Two locations of the crack observed at the blade root, which was at the tang and the fillet, with different failure modes. In general, the damage of the blade was started by the corrosion occurred on the blade root. The crack at the blade root tang was due to corrosion fatigue and the crack occurred at the blade root fillet owing to stress corrosion cracking.

  6. Improved design for large wind turbine blades of fibre composites (Phase 3)

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Branner, Kim; Lund, E.;

    methods for wind turbine blades, so that uncertainties associated with damage and defects can be reduced. The following topics with respect to failure modes were covered: Buckling-driven delamination of loadcarrying laminates, cracking along interfaces in material joints, implementation of cohesive laws......An overview is given of the activities of the project "Improved design for large wind turbine blades (Phase 3)", partially supported by the Danish Energy Agency under the Ministry of Climate and Energy through the EFP-grant no. 33031-0078. The project was focussed at the development of new design...

  7. Ultimate strength of a large wind turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Moelholt Jensen, Find

    2008-05-15

    The present PhD project contains a study of the structural static strength of wind turbine blades loaded in flap-wise direction. A combination of experimental and numerical work has been used to address the most critical failure mechanisms and to get an understanding of the complex structural behaviour of wind turbine blades. Four failure mechanisms observed during the fullscale tests and the corresponding FE-analysis are presented. Elastic mechanisms associated with failure, such as buckling, localized bending and the Brazier effect, are studied. Six different types of structural reinforcements helping to prevent undesired structural elastic mechanisms are presented. The functionality of two of the suggested structural reinforcements was demonstrated in full-scale tests and the rest trough FE-studies. The blade design under investigation consisted of an aerodynamic airfoil and a load carrying box girder. In total, five full-scale tests have been performed involving one complete blade and two shortened box girders. The second box girder was submitted to three independent tests covering different structural reinforcement alternatives. The advantages and disadvantages of testing a shortened load carrying box girder vs. an entire blade are discussed. Changes in the boundary conditions, loads and additional reinforcements, which were introduced in the box girder tests in order to avoid undesired structural elastic mechanisms, are presented. New and advanced measuring equipment was used in the fullscale tests to detect the critical failure mechanisms and to get an understanding of the complex structural behaviour. Traditionally, displacement sensors and strain gauges in blade tests are arranged based on an assumption of a Bernoulli-Euler beam structural response. In the present study it is shown that when following this procedure important information about distortions of the cross sections is lost. In the tests presented here, one of the aims was to measure distortion

  8. Optimisation of the Management of Higher Activity Waste in the UK - 13537

    International Nuclear Information System (INIS)

    The Upstream Optioneering project was created in the Nuclear Decommissioning Authority (UK) to support the development and implementation of significant opportunities to optimise activities across all the phases of the Higher Activity Waste management life cycle (i.e. retrieval, characterisation, conditioning, packaging, storage, transport and disposal). The objective of the Upstream Optioneering project is to work in conjunction with other functions within NDA and the waste producers to identify and deliver solutions to optimise the management of higher activity waste. Historically, optimisation may have occurred on aspects of the waste life cycle (considered here to include retrieval, conditioning, treatment, packaging, interim storage, transport to final end state, which may be geological disposal). By considering the waste life cycle as a whole, critical analysis of assumed constraints may lead to cost savings for the UK Tax Payer. For example, it may be possible to challenge the requirements for packaging wastes for disposal to deliver an optimised waste life cycle. It is likely that the challenges faced in the UK are shared in other countries. It is therefore likely that the opportunities identified may also apply elsewhere, with the potential for sharing information to enable value to be shared. (authors)

  9. Fluid-structure coupling for wind turbine blade analysis using OpenFOAM

    Science.gov (United States)

    Dose, Bastian; Herraez, Ivan; Peinke, Joachim

    2015-11-01

    Modern wind turbine rotor blades are designed increasingly large and flexible. This structural flexibility represents a problem for the field of Computational Fluid Dynamics (CFD), which is used for accurate load calculations and detailed investigations of rotor aerodynamics. As the blade geometries within CFD simulations are considered stiff, the effect of blade deformation caused by aerodynamic loads cannot be captured by the common CFD approach. Coupling the flow solver with a structural solver can overcome this restriction and enables the investigation of flexible wind turbine blades. For this purpose, a new Finite Element (FE) solver was implemented into the open source CFD code OpenFOAM. Using a beam element formulation based on the Geometrically Exact Beam Theory (GEBT), the structural model can capture geometric non-linearities such as large deformations. Coupled with CFD solvers of the OpenFOAM package, the new framework represents a powerful tool for aerodynamic investigations. In this work, we investigated the aerodynamic performance of a state of the art wind turbine. For different wind speeds, aerodynamic key parameters are evaluated and compared for both, rigid and flexible blade geometries. The present work is funded within the framework of the joint project Smart Blades (0325601D) by the German Federal Ministry for Economic Affairs and Energy (BMWi) under decision of the German Federal Parliament.

  10. Influence of pitch, twist, and taper on a blade`s performance loss due to roughness

    Energy Technology Data Exchange (ETDEWEB)

    Tangler, J.L. [National Renewable Energy Laboratory, Golden, Colorado (United States)

    1997-08-01

    The purpose of this study was to determine the influence of blade geometric parameters such as pitch, twist, and taper on a blade`s sensitivity to leading edge roughness. The approach began with an evaluation of available test data of performance degradation due to roughness effects for several rotors. In addition to airfoil geometry, this evaluation suggested that a rotor`s sensitivity to roughness was also influenced by the blade geometric parameters. Parametric studies were conducted using the PROP computer code with wind-tunnel airfoil characteristics for smooth and rough surface conditions to quantify the performance loss due to roughness for tapered and twisted blades relative to a constant-chord, non-twisted blade at several blade pitch angles. The results indicate that a constant-chord, non-twisted blade pitched toward stall will have the greatest losses due to roughness. The use of twist, taper, and positive blade pitch angles all help reduce the angle-of-attack distribution along the blade for a given wind speed and the associated performance degradation due to roughness. (au)

  11. Influence of pitch, twist, and taper on a blade`s performance loss due to roughness

    Energy Technology Data Exchange (ETDEWEB)

    Tangler, J.L. [National Renewable Energy Lab., Golden, CO (United States)

    1996-12-31

    The purpose of this study was to determine the influence of blade geometric parameters such as pitch, twist, and taper on a blade`s sensitivity to leading edge roughness. The approach began with an evaluation of available test data of performance degradation due to roughness effects for several rotors. In addition to airfoil geometry, this evaluation suggested that a rotor`s sensitivity to roughness was also influenced by the blade geometric parameters. Parametric studies were conducted using the PROP computer code with wind-tunnel airfoil characteristics for smooth and rough surface conditions to quantify the performance loss due to roughness for tapered and twisted blades relative to a constant-chord, non-twisted blade at several blade pitch angles. The results indicate that a constant-chord, non-twisted blade pitched toward stall will have the greatest losses due to roughness. The use of twist, taper, and positive blade pitch angles all help reduce the angle-of-attack distribution along the blade for a given wind speed and the associated performance degradation due to roughness. 8 refs., 6 figs.

  12. Influence of blade motion on mass flux to a model seagrass blade

    Science.gov (United States)

    Lei, Jiarui; Nepf, Heidi

    2015-11-01

    Seagrass and other freshwater macrophytes can acquire nutrients from surrounding water through their blades. While we anticipate that blade motion and reconfiguration may impact mass flux at the blade surface, this topic is an area of open discussion and research. We seek to better understand the interaction of individual blades with both unidirectional and oscillatory flows and how this interaction impacts mass flux. The degree of reconfiguration can be quantified by two dimensionless numbers, the Cauchy number, Ca, and the buoyancy parameter, B. For unidirectional currents (U) , a theoretical model for the transfer velocity (K) was constructed assuming the boundary layer on the blade surface remained laminar and developed like that over a flat plate, which predicts K ~U 0 . 5 . When the blades were bent-over, the model predicted the measured flux well; when the blades remained upright, the flux to the blade diminished relative to the model. Preliminary wave experiments show that blade motion increased with wave amplitude, and that there are two distinct regimes. In the first regime (Ca15. In this regime, the phase difference was approximately zero and the blade moved passively with the wave. NSF.

  13. Real-time optimisation of the Hoa Binh reservoir, Vietnam

    DEFF Research Database (Denmark)

    Richaud, Bertrand; Madsen, Henrik; Rosbjerg, Dan;

    2011-01-01

    -time optimisation. First, the simulation-optimisation framework is applied for optimising reservoir operating rules. Secondly, real-time and forecast information is used for on-line optimisation that focuses on short-term goals, such as flood control or hydropower generation, without compromising the deviation of...... the long-term objectives from the optimised rule curves. The method is illustrated for optimisation of the Hoa Binh reservoir in Vietnam. The approach is proven efficient to trade-off conflicting objectives. Selected by a Pareto optimisation method, the preferred optimum is able to mitigate the floods...... quality of the forecast is addressed. The results illustrate the importance of a sufficient forecast lead time to start pre-releasing water in flood situations....

  14. Blade Deterioration in a Gas Turbine Engine

    Directory of Open Access Journals (Sweden)

    W. Tabakoff

    1998-01-01

    Full Text Available A study has been conducted to predict blade erosion of gas turbine engines. The blade material erosion model is based on three dimensional particle trajectory simulation in the three-dimensional turbine flow field. The trajectories provide the special distribution of the particle impact parameters over the blade surface. A semi-empirical erosion model, derived from erosion tests of material samples at different particulate flow conditions, is used in the prediction of blade surface erosion based on the trajectory impact data. To improve the blade erosion resistance and to decrease the blade deterioration, the blades must be coated. For this purpose, an experimental study was conducted to investigate the behavior of rhodium platinum aluminide coating exposed to erosion by fly ash particles. New protective coatings are developed for erosion and thermal barrier. Chemical vapor deposition technique (CVD was used to apply the ceramic TiC coatings on INCO 718 and stainless steel 410. The erosive wear of the coated samples was investigated experimentally by exposing them to particle laden flow at velocities from 180 to 305m/s and temperatures from ambient to 538°C in a specially designed erosion wind tunnel. Both materials (INCO 718 and stainless steel 410 coated with CVD TiC showed one order of magnitude less erosion rate compared to some commercial coatings on the same substrates.

  15. Full Scale Test SSP 34m blade, edgewise loading LTT. Extreme load and PoC_InvE Data report

    DEFF Research Database (Denmark)

    Nielsen, Magda; Roczek-Sieradzan, Agnieszka; Jensen, Find Mølholt;

    edgewise direction (LTT). The blade has been submitted to thorough examination by means of strain gauges, displacement transducers and a 3D optical measuring system. This data report presents results obtained during full scale testing of the blade up to 80% Risø load, where 80% Risø load corresponds to 100......This report is the second report covering the research and demonstration project “Eksperimentel vingeforskning: Strukturelle mekanismer i nutidens og fremtidens store vinger under kombineret last”, supported by the EUDP program. A 34m wind turbine blade from SSP-Technology A/S has been tested in...

  16. Turbine blade wear and damage. An overview of advanced characterization techniques

    Energy Technology Data Exchange (ETDEWEB)

    Schlobohm, Jochen; Li, Yinan; Kaestner, Markus; Poesch, Andreas; Reithmeier, Eduard [Hannover Univ. (Germany). Inst. fuer Mess- und Regelungstechnik; Bruchwald, Oliver; Frackowiak, Wojciech; Reimche, Wilfried; Maier, Hans Juergen [Hannover Univ. (Germany). Inst. fuer Werkstoffkunde

    2016-07-01

    This paper gives an overview of four measurement techniques that allow to extensively characterize the status of a worn turbine blade. In addition to the measurement of geometry and surface properties, the condition of the two protective coatings needs to be monitored. Fringe projection was used to detect and quantify geometric variances. The technique was improved using newly developed algorithms like inverse fringe projection. A Michelson interferometer was employed to further analyze areas with geometric defects and characterize the surface morphology of the blade. Pulsed high frequency induction thermography enabled the scanning of the blade for small cracks at or close to the surface. High frequency eddy current testing was used to determine the protective layers status and their thickness.

  17. Fundamentals for remote structural health monitoring of wind turbine blades - a preproject

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Lading, L.; Sendrup, P.;

    2002-01-01

    This summary-report describes the results of a pre-project that has the aim of estab-lishing the basic technical knowledge to evaluate whether remote surveillance of the rotor blades of large off-shore wind turbines has technical and economical potential.A cost-benefit analysis was developed......-scale tests of a wind turbine blade developing damage: 1) detection of stress wave emission by acoustic emission, 2) measurement of modal shape changes byaccelerometers and 3) measurement of crack opening of adhesive joint by a fibre optics micro-bend displacement transducer that was developed in the project...... transducer was found to work well for detectingadhesive failure. Modelling work shows that damage in a wind turbine blade causes a significant change in the modal shape when the damage is in the or-der of 0.5-1 m. Rough estimates of the prices of complete sensor systems were made. The system based onacoustic...

  18. Pitched Blade Turbine Efficiency at Particle Suspension

    OpenAIRE

    D. Ceres; T. Jirout; Rieger, F.

    2010-01-01

    Mixing suspensions is a very important hydraulic operation. The pitched six-blade turbine is a widely-used axial-flow impeller. This paper deals with effect relative impeller size and particle content on theefficiency of a pitched six-blade turbine at particle suspension. Two pitched six-blade turbines were used in model measurements of just suspension impeller speed. The ratios of the vessel to agitator diameter D/d were 3 and 4.5. The measurements were carried out in a dish-bottomed vessel ...

  19. Resonant vibration control of wind turbine blades

    DEFF Research Database (Denmark)

    Svendsen, Martin Nymann; Krenk, Steen; Høgsberg, Jan Becker

    2010-01-01

    The paper deals with introduction of damping to specific vibration modes of wind turbine blades, using a resonant controller with acceleration feedback. The wind turbine blade is represented by three-dimensional, two-node finite elements in a local, rotating frame of reference. The element....... The efficiency of the resonant controller is demonstrated for a representative turbine blade exposed to turbulent wind loading. It is found that the present explicit tuning procedure yields close to optimal tuning, with very limited modal spill-over and effective reduction of the vibration amplitudes....

  20. Rotating blade vibration analysis using shells

    Science.gov (United States)

    Leissa, A. W.; Lee, J. K.; Wang, A. J.

    1981-01-01

    Shallow shell theory and the Ritz method are employed to determine the frequencies and mode shapes of turbomachinery blades having both camber and twist, rotating with non-zero angles of attack. Frequencies obtained for different degrees of shallowness and thickness are compared with results available in the literature, obtained from finite element analyses of nonrotating blades. Frequencies are also determined for a rotating blade, showing the effects of changing the (1) angular velocity of rotation, (2) disk radius and (3) angle of attack, as well as the significance of the most important body force terms.

  1. Studies of blade-vortex interaction noise reduction by rotor blade modification

    Science.gov (United States)

    Brooks, Thomas F.

    1993-01-01

    Blade-vortex interaction (BVI) noise is one of the most objectionable types of helicopter noise. This impulsive blade-slap noise can be particularly intense during low-speed landing approach and maneuvers. Over the years, a number of flight and model rotor tests have examined blade tip modification and other blade design changes to reduce this noise. Many times these tests have produced conflicting results. In the present paper, a number of these studies are reviewed in light of the current understanding of the BVI noise problem. Results from one study in particular are used to help establish the noise reduction potential and to shed light on the role of blade design. Current blade studies and some new concepts under development are also described.

  2. Numerical simulation on the aerodynamic effects of blade icing on small scale Straight-bladed VAWT

    Science.gov (United States)

    Feng, Fang; Li, Shengmao; Li, Yan; Tian, Wenqiang

    To invest the effects of blade surface icing on the aerodynamics performance of the straight-bladed vertical-axis wind turbine (SB-VAWT), wind tunnel tests were carried out on a static straight blade using a simple icing wind tunnel. Firstly, the icing situations on blade surface at some kinds of typical attack angle were observed and recorded under different cold water flow fluxes. Then the iced blade airfoils were combined into a SB-VAWT model with two blades. Numerical simulations were carried out on this model, and the static and dynamic torque coefficients of the model with and without icing were computed. Both the static and dynamic torque coefficients were decreased for the icing effects.

  3. Structural Analysis of Basalt Fiber Reinforced Plastic Wind Turbine Blade

    Directory of Open Access Journals (Sweden)

    Mengal Ali Nawaz

    2014-07-01

    Full Text Available In this study, Basalt fiber reinforced plastic (BFRP wind turbine blade was analyzed and compared with Glass fiber reinforced plastic blade (GFRP. Finite element analysis (FEA of blade was carried out using ANSYS. Data for FEA was obtained by using rule of mixture. The shell element in ANSYS was used to simulate the wind turbine blade and to conduct its strength analysis. The structural analysis and comparison of blade deformations proved that BFRP wind turbine blade has better strength compared to GFRP wind turbine blade.

  4. Haemodynamic optimisation in lower limb arterial surgery

    DEFF Research Database (Denmark)

    Bisgaard, J; Gilsaa, T; Rønholm, E; Toft, P

    2012-01-01

    BACKGROUND: Goal-directed therapy has been proposed to improve outcome in high-risk surgery patients. The aim of this study was to investigate whether individualised goal-directed therapy targeting stroke volume and oxygen delivery could reduce the number of patients with post-operative complicat......BACKGROUND: Goal-directed therapy has been proposed to improve outcome in high-risk surgery patients. The aim of this study was to investigate whether individualised goal-directed therapy targeting stroke volume and oxygen delivery could reduce the number of patients with post-operative...... index was optimised by administering 250 ml aliquots of colloid intraoperatively and during the first 6 h post-operatively. Following surgery, fluid optimisation was supplemented with dobutamine, if necessary, targeting an oxygen delivery index level ≥ 600 ml/min(/) m(2) in the intervention group...

  5. Improved Squeaky Wheel Optimisation for Driver Scheduling

    CERN Document Server

    Aickelin, Uwe; Li, Jingpeng

    2008-01-01

    This paper presents a technique called Improved Squeaky Wheel Optimisation for driver scheduling problems. It improves the original Squeaky Wheel Optimisations effectiveness and execution speed by incorporating two additional steps of Selection and Mutation which implement evolution within a single solution. In the ISWO, a cycle of Analysis-Selection-Mutation-Prioritization-Construction continues until stopping conditions are reached. The Analysis step first computes the fitness of a current solution to identify troublesome components. The Selection step then discards these troublesome components probabilistically by using the fitness measure, and the Mutation step follows to further discard a small number of components at random. After the above steps, an input solution becomes partial and thus the resulting partial solution needs to be repaired. The repair is carried out by using the Prioritization step to first produce priorities that determine an order by which the following Construction step then schedul...

  6. Energy optimisation - happy gators; Energieoptimierung - Glueckliche Krokodile

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-08-01

    Although Messrs. Wolfferts had been the servicing partner for the technical facilities of the Cologne Zoo for many years, the daughter company, Gebaeude- und Energiemanagement GmbH founded in 1997 was not satisfied: They offered an optimisation package comprising servicing and repair measures as well as tariff optimisation. The new contract was closed for the aquarium terrarium and insectarium to begin with. [German] Seit Jahren wartet die Firma Wolfferts die Heizungs-, Lueftungs- und Sanitaeranlagen im Koelner Zoo. Das war der 1997 gegruendeten Wolfferts-Tochter Gebaeude- und Energiemanagement GmbH nicht genug: Sie offerierte dem Kunden ein Optimierungspaket zunaechst fuer das Aquarium mit angeschlossenem Terrarium und Insektarium. Seither sind die laufenden Reparaturmassnahmen mit energietariflichen Optimierungen verknuepft. (orig.)

  7. Acoustic Resonator Optimisation for Airborne Particle Manipulation

    Science.gov (United States)

    Devendran, Citsabehsan; Billson, Duncan R.; Hutchins, David A.; Alan, Tuncay; Neild, Adrian

    Advances in micro-electromechanical systems (MEMS) technology and biomedical research necessitate micro-machined manipulators to capture, handle and position delicate micron-sized particles. To this end, a parallel plate acoustic resonator system has been investigated for the purposes of manipulation and entrapment of micron sized particles in air. Numerical and finite element modelling was performed to optimise the design of the layered acoustic resonator. To obtain an optimised resonator design, careful considerations of the effect of thickness and material properties are required. Furthermore, the effect of acoustic attenuation which is dependent on frequency is also considered within this study, leading to an optimum operational frequency range. Finally, experimental results demonstrated good particle levitation and capture of various particle properties and sizes ranging to as small as 14.8 μm.

  8. Fermionic orbital optimisation in tensor network states

    CERN Document Server

    Krumnow, C; Eisert, J

    2015-01-01

    Tensor network states and specifically matrix-product states have proven to be a powerful tool for simulating ground states of strongly correlated spin models. Recently, they have also been applied to interacting fermionic problems, specifically in the context of quantum chemistry. A new freedom arising in such non-local fermionic systems is the choice of orbitals, it being far from clear what choice of fermionic orbitals to make. In this work, we propose a way to overcome this challenge. We suggest a method intertwining the optimisation over matrix product states with suitable fermionic Gaussian mode transformations, hence bringing the advantages of both approaches together. The described algorithm generalises basis changes in the spirit of the Hartree-Fock methods to matrix-product states, and provides a black box tool for basis optimisations in tensor network methods.

  9. Techno-economic optimisation of energy systems

    International Nuclear Information System (INIS)

    The traditional approach currently used to assess the economic interest of energy systems is based on a defined flow-sheet. Some studies have shown that the flow-sheets corresponding to the best thermodynamic efficiencies do not necessarily lead to the best production costs. A method called techno-economic optimisation was proposed. This method aims at minimising the production cost of a given energy system, including both investment and operating costs. It was implemented using genetic algorithms. This approach was compared to the heat integration method on two different examples, thus validating its interest. Techno-economic optimisation was then applied to different energy systems dealing with hydrogen as well as electricity production. (author)

  10. Numerical and Experimental Study of Friction Damping Blade Attachments of Rotating Bladed Disks

    OpenAIRE

    Charleux, D.; Gibert, C; Thouverez, F.; Dupeux, J.

    2006-01-01

    In order to mitigate high cycle fatigue risks in bladed disks, the prediction of the vibration levels early in the design process is important. Therefore, the different sources of damping need to be modeled accurately. In this paper the impact of friction in blade attachments on forced response is investigated both numerically and experimentally. An efficient multiharmonic balance method is proposed in order to compute the forced response of bladed disks with contact and friction nonlineariti...

  11. Genetic Algorithm Optimisation for Finance and Investment

    OpenAIRE

    Robert Pereira

    2000-01-01

    This paper provides an introduction to the use of genetic algo- rithms for financial optimisation. The aim is to give the reader a basic understanding of the computational aspects of these algorithms and how they can be applied to decision making in finance and investment. Genetic algorithms are especially suitable for complex problems char- actised by large solution spaces, multiple optima, non differentiability of the objective function, and other irregular features. The mechanics of constr...

  12. Optimisation problems in wireless sensor networks

    OpenAIRE

    Suomela, Jukka

    2009-01-01

    This thesis studies optimisation problems related to modern large-scale distributed systems, such as wireless sensor networks and wireless ad-hoc networks. The concrete tasks that we use as motivating examples are the following: (i) maximising the lifetime of a battery-powered wireless sensor network, (ii) maximising the capacity of a wireless communication network, and (iii) minimising the number of sensors in a surveillance application. A sensor node consumes energy both when it is transmit...

  13. Clustering Optimisation Techniques in Mobile Networks

    OpenAIRE

    Rozaki, Eleni

    2016-01-01

    The use of mobile phones has exploded over the past years,abundantly through the introduction of smartphones and the rapidly expanding use of mobile data. This has resulted in a spiraling problem of ensuring quality of service for users of mobile networks. Hence, mobile carriers and service providers need to determine how to prioritise expansion decisions and optimise network faults to ensure customer satisfaction and optimal network performance. To assist in that decision-making process, thi...

  14. Digital Ecosystems: Optimisation by a Distributed Intelligence

    OpenAIRE

    Briscoe, G.; Wilde, P

    2007-01-01

    Can intelligence optimise Digital Ecosystems? How could a distributed intelligence interact with the ecosystem dynamics? Can the software components that are part of genetic selection be intelligent in themselves, as in an adaptive technology? We consider the effect of a distributed intelligence mechanism on the evolutionary and ecological dynamics of our Digital Ecosystem, which is the digital counterpart of a biological ecosystem for evolving software services in a distributed network. We i...

  15. Engineering optimisations in query rewriting for OBDA

    OpenAIRE

    Mora, José; Corcho, Oscar

    2013-01-01

    Ontology-based data access (OBDA) systems use ontologies to provide views over relational databases. Most of these systems work with ontologies implemented in description logic families of reduced expressiveness, what allows applying efficient query rewriting techniques for query answering. In this paper we describe a set of optimisations that are applicable with one of the most expressive families used in this context (ELHIO¬). Our resulting system exhibits a behaviour that is comparable to ...

  16. Optimisation Modelling of Efficiency of Enterprise Restructuring

    OpenAIRE

    Yefimova Hanna V.

    2014-01-01

    The article considers issues of optimisation of the use of resources directed at restructuring of a shipbuilding enterprise, which is the main prerequisite of its efficiency. Restructuring is considered as a process of complex and interconnected change in the structure of assets, liabilities, enterprise functions, initiated by dynamic environment, which is based on the strategic concept of its development and directed at increase of efficiency of its activity, which is expressed in the growth...

  17. Improved Squeaky Wheel Optimisation for Driver Scheduling

    OpenAIRE

    Aickelin, Uwe; Burke, Edmund; Li, Jingpeng

    2006-01-01

    This paper presents a technique called Improved Squeaky Wheel Optimisation (ISWO) for driver scheduling problems. It improves the original Squeaky Wheel Optimisation’s (SWO) effectiveness and execution speed by incorporating two additional steps of Selection and Mutation which implement evolution within a single solution. In the ISWO, a cycle of Analysis-Selection-Mutation-Prioritization-Construction continues until stopping conditions are reached. The Analysis step first computes the fitness...

  18. Transmit Power Optimisation in Wireless Network

    OpenAIRE

    Besnik Terziu

    2011-01-01

    Transmit power optimisation in wireless networks based on beamforming have emerged as a promising technique to enhance the spectrum efficiency of present and future wireless communication systems. The aim of this study is to minimise the access point power consumption in cellular networks while maintaining a targeted quality of service (QoS) for the mobile terminals. In this study, the targeted quality of service is delivered to a mobile station by providing a desired level of Signal to Inter...

  19. Constraint Programming and Combinatorial Optimisation in Numberjack

    OpenAIRE

    Hébrard, Emmanuel; Eoin, O'Mahony; Barry, O'Sullivan

    2010-01-01

    Python benets from a large and active programming com- munity. Numberjack is a modelling package written in Python for embed- ding constraint programming and combinatorial optimisation into larger applications. It has been designed to seamlessly and efficiently support a number of underlying combinatorial solvers. Currently, Numberjack supports three constraint programming solvers, one MIP solver, and one satisability solver -- all available as open-source software. This paper illustrates man...

  20. Fusing website usability and search engine optimisation

    OpenAIRE

    Eugene B. Visser; Melius Weideman

    2014-01-01

    Background: Most websites, especially those with a commercial orientation, need a high ranking on a search engine for one or more keywords or phrases. The search engine optimisation process attempts to achieve this. Furthermore, website users expect easy navigation, interaction and transactional ability. The application of website usability principles attempts to achieve this. Ideally, designers should achieve both goals when they design websites.Objectives: This research intended to establis...

  1. Multiple-objective sensor management and optimisation

    OpenAIRE

    Page, Scott F.

    2009-01-01

    One of the key challenges associated with exploiting modern Autonomous Vehicle technology for military surveillance tasks is the development of Sensor Management strategies which maximise the performance of the on-board Data-Fusion systems. The focus of this thesis is the development of Sensor Management algorithms which aim to optimise target tracking processes. Three principal theoretical and analytical contributions are presented which are related to the manner in which such problems are f...

  2. Numerical Investigation Of Compression Performance Of Different Blade Configuration In Co-Rotor Turbo-Propeller

    Directory of Open Access Journals (Sweden)

    Venkatesh . N

    2015-05-01

    Full Text Available This project work is to investigate the compression efficiency of different configuration of Turbo-Prop CoRotor Blade System of Subsonic Axial Flow Compressor. By this method the highly compressed air can be passed over the intake of the engine to the compressor with high mass flow rate in change of low velocity and high pressure ratio. The length of the small rotor is varied in terms of large rotor length by 25,50 & 75% . Each will have three space configuration in terms of diameter of rotor and in the percentage of 5,10,15%. A total of 12 configurations will be simulated to arrive optimum blade configuration. The blades are made in the shape of an airfoil like wing of an aircraft. The engine rotates the propeller blades, which produce lift. This lift is called thrust and moves the aircraft forward. Blades are usually made of high lift airfoil which allows more rotation to generate high pressure for engine. ANSYS- Fluent is commercial software which is robust for most of the fluid dynamic problems and it is used in this project work to evaluate the different configurations of co-rotor propeller system to arrive the best.

  3. Optimisation and symmetry in experimental radiation physics

    International Nuclear Information System (INIS)

    The present monograph is concerned with the optimisation of geometric factors in radiation physics experiments. The discussions are essentially confined to those systems in which optimisation is equivalent to symmetrical configurations of the measurement systems. They include, measurements of interaction cross section of diverse types, determination of polarisations, development of detectors with almost ideal characteristics, production of radiations with continuously variable energies and development of high efficiency spectrometers etc. The monograph is intended for use by experimental physicists investigating primary interactions of radiations with matter and associated technologies. We have illustrated the various optimisation procedures by considering the cases of the so-called ''14 MeV'' on d-t neutrons and gamma rays with energies less than 3 MeV. Developments in fusion technology are critically dependent on the availability accurate cross sections of nuclei for fast neutrons of energies at least as high as d-t neutrons. In this monograph we have discussed various techniques which can be used to improve the accuracy of such measurements and have also presented a method for generating almost monoenergetic neutrons in the 8 MeV to 13 MeV energy range which can be used to measure cross sections in this sparingly investigated region

  4. Exploration of automatic optimisation for CUDA programming

    KAUST Repository

    Al-Mouhamed, Mayez

    2014-09-16

    © 2014 Taylor & Francis. Writing optimised compute unified device architecture (CUDA) program for graphic processing units (GPUs) is complex even for experts. We present a design methodology for a restructuring tool that converts C-loops into optimised CUDA kernels based on a three-step algorithm which are loop tiling, coalesced memory access and resource optimisation. A method for finding possible loop tiling solutions with coalesced memory access is developed and a simplified algorithm for restructuring C-loops into an efficient CUDA kernel is presented. In the evaluation, we implement matrix multiply (MM), matrix transpose (M-transpose), matrix scaling (M-scaling) and matrix vector multiply (MV) using the proposed algorithm. We present the analysis of the execution time and GPU throughput for the above applications, which favourably compare to other proposals. Evaluation is carried out while scaling the problem size and running under a variety of kernel configurations. The obtained speedup is about 28-35% for M-transpose compared to NVIDIA Software Development Kit, 33% speedup for MV compared to general purpose computation on graphics processing unit compiler, and more than 80% speedup for MM and M-scaling compared to CUDA-lite.

  5. Wind wheel with a single bladed or two blade rotor arranged on a tower

    Energy Technology Data Exchange (ETDEWEB)

    Laussermair, F.; Kaiba, K.

    1980-02-14

    The invention concerns a wind wheel (impeller) with a single bladed or two blade rotor arranged on a tower. The wind speed, with which the air flows over wind wheels, is normally different over the rotor circle area. This leads to the creation of cyclic torques, which will try to turn the rotor head cyclically around the tower axis and cause torsional oscillations. It is therefore the purpose of the invention to create a wind wheel, in which the tendency of the rotor head to turn around the tower axis is reduced, without incurring losses of output. The problem of the invention is solved, by having one or more auxiliary blades in addition to the main blade or blades, which lie in the rotor plane and are cyclically adjustable around their longitudinal axis, so that their aerodynamic up thrust produces a torque around the tower axis, which practically compensates for the torque resulting from the different flow over the main blade or blades. One example of the invention achieves the adjustment of the auxiliary blades around their longitudinal axis by means of one or more levers, each of which is connected at its end to one auxiliary blade, and has a roller on its other end, which can roll around a fixed curved disc, where the roller is pressed by a spring against the curved disc.

  6. Eulerian laser Doppler vibrometry: Online blade damage identification on a multi-blade test rotor

    Science.gov (United States)

    Oberholster, A. J.; Heyns, P. S.

    2011-01-01

    Laser Doppler vibrometry enables the telemetry-free measurement of online turbomachinery blade vibration. Specifically, the Eulerian or fixed reference frame implementation of laser vibrometry provides a practical solution to the condition monitoring of rotating blades. The short data samples that are characteristic of this measurement approach do however negate the use of traditional frequency domain signal processing techniques. It is therefore necessary to employ techniques such as time domain analysis and non-harmonic Fourier analysis to obtain useful information from the blade vibration signatures. The latter analysis technique allows the calculation of phase angle trends which can be used as indicators of blade health deterioration, as has been shown in previous work for a single-blade rotor. This article presents the results from tests conducted on a five-blade axial-flow test rotor at different rotor speeds and measurement positions. With the aid of artificial neural networks, it is demonstrated that the parameters obtained from non-harmonic Fourier analysis and time domain signal processing on Eulerian laser Doppler vibrometry signals can successfully be used to identify and quantify blade damage from among healthy blades. It is also shown that the natural frequencies of individual blades can be approximated from the Eulerian signatures recorded during rotor run-up and run-down.

  7. Solar-optimized building construction. TC3: Solar-optimized new building ECOTEC 1 and 2: Construction of a new office and laboratory building in two stages, optimised according to solar, energetic and ecological aspects. Phase 1: Projecting, construction and system optimisation. Final report; Solaroptimiertes Bauen. TK 3: Solaroptimierter Neubau ECOTEC 1 und 2: Neubau eines Buero und Laborgebaeudes in zwei Bauabschnitten, optimiert nach solaren, energetischen und oekologischen Gesichtspunkten. Phase 1: Planung, Bauausfuehrung und Systemoptimierung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    The two ECOTEC buildings are constructed on the premises of Bremen university. They are identical mirror buildings with optimised solar technology and heat pumps to reduce the dependence on external energy supply. The results achieved so far are promising. [German] Im Mittelpunkt des Vorhabens stand die Errichtung der solaroptimierten Niedrigenergie-Gebaeude ECOTEC in zwei Bauabschnitten gleichem, aber spiegelverkehrtem Grundrissen auf dem Gelaende des Technologieparks der Universitaet Bremen. Das Planungskonzept sah zur Reduktion des Fremdenergiebedarfs den optimierten Einsatz und die Kopplung von Solarenergie, Waermepumpe ueber die Gebaeudeleittechnik vor. Basis fuer alle Berechnungen und Planungen war der Niedrigenergiestandard, der durch erhoehte Waermedaemmung der Gebaeudehuelle, kontrollierte Lueftung, solartechnische Module und solararchitektonische Merkmale erreicht und sogar ueberschritten wurde. Durch den gezielten Einsatz der Gebaeudeleit- und -systemtechnik wird ein energiesparender Betrieb insbesondere der Gebaeudebeheizung, der Lueftungsanlage sowie der Beleuchtung schon in der Planungsphase vorbereitet. Zusammenfassend laesst sich feststellen, dass das entwickelte Technikkonzept nach erfolgter Abstimmung mit den Nutzerbeduerfnissen geringste Energieverbraeuche bei sehr gutem Komfort bietet. (orig.)

  8. Airfoil family design for large offshore wind turbine blades

    International Nuclear Information System (INIS)

    Wind turbine blades size has scaled-up during last years due to wind turbine platform increase especially for offshore applications. The EOLIA project 2007-2010 (Spanish Goverment funded project) was focused on the design of large offshore wind turbines for deep waters. The project was managed by ACCIONA Energia and the wind turbine technology was designed by ACCIONA Windpower. The project included the design of a wind turbine airfoil family especially conceived for large offshore wind turbine blades, in the order of 5MW machine. Large offshore wind turbines suffer high extreme loads due to their size, in addition the lack of noise restrictions allow higher tip speeds. Consequently, the airfoils presented in this work are designed for high Reynolds numbers with the main goal of reducing blade loads and mantainig power production. The new airfoil family was designed in collaboration with CENER (Spanish National Renewable Energy Centre). The airfoil family was designed using a evolutionary algorithm based optimization tool with different objectives, both aerodynamic and structural, coupled with an airfoil geometry generation tool. Force coefficients of the designed airfoil were obtained using the panel code XFOIL in which the boundary layer/inviscid flow coupling is ineracted via surface transpiration model. The desing methodology includes a novel technique to define the objective functions based on normalizing the functions using weight parameters created from data of airfoils used as reference. Four airfoils have been designed, here three of them will be presented, with relative thickness of 18%, 21%, 25%, which have been verified with the in-house CFD code, Wind Multi Block WMB, and later validated with wind tunnel experiments. Some of the objectives for the designed airfoils concern the aerodynamic behavior (high efficiency and lift, high tangential coefficient, insensitivity to rough conditions, etc.), others concern the geometry (good for structural design

  9. AERODYNAMIC RESEARCH ON THE MCA – TYPE COMPRESSOR BLADE CASCADE

    Czech Academy of Sciences Publication Activity Database

    Šimurda, David; Luxa, Martin; Šafařík, P.

    Glasgow : ASME, 2010, s. 99-108. ISBN 978-0-7918-4402-1. [ASME Turbo Expo 2010. Glasgow (GB), 14.06.2010-18.06.2010] R&D Projects: GA AV ČR(CZ) IAA200760801; GA ČR(CZ) GA101/08/0623; GA ČR(CZ) GAP101/10/1329 Institutional research plan: CEZ:AV0Z20760514 Keywords : compressor blade cascade * transonic flow * aerodynamic research Subject RIV: BK - Fluid Dynamics http://www.asmeconferences.org/TE10/ConfSpecInfo.cfm

  10. Tip Cascade Aerodynamics of Turbine Stage Blades 48"

    Czech Academy of Sciences Publication Activity Database

    Synáč, J.; Rudas, B.; Šťastný, M.; Luxa, Martin; Šimurda, David; Šafařík, Pavel

    Vol. 8. Graz: Technischen Universität Graz, 2009 - (Heitmeir, F.; Martelli, F.; Manna, M.), s. 1449-1457 ISBN 978-3-85125-036-7. [Turbomachinery Fluid Dynamics and Thermodynamics /8./. Graz (AT), 23.03.2009-27.03.2009] R&D Projects: GA ČR(CZ) GA101/08/0623; GA ČR GA101/07/1508 Institutional research plan: CEZ:AV0Z20760514 Keywords : aerodynamics * tip section * blade cascade Subject RIV: BK - Fluid Dynamics

  11. Mathematical model of blades bundle with damping connections

    Czech Academy of Sciences Publication Activity Database

    Pešek, Luděk; Půst, Ladislav; Cibulka, Jan; Bula, Vítězslav

    2013-01-01

    Roč. 63, č. 3 (2013), s. 43-46. ISSN 1729-3774. [Международная научнo-техническая конференция /5./. Alušta, 24.06.2013-28.06.2013] R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : blades vibration * damping elements * rubber * mathematic models Subject RIV: BI - Acoustics

  12. Research overview on vibration damping of mistuned bladed disk assemblies

    OpenAIRE

    Zhang, Liang; Liu, Tiejian; Li, Xin; Xuyao HUO

    2016-01-01

    Bladed disk assemblies are very important parts in auto engine and gas turbine, and is widely used in practical engineering. The mistuning existing commonly in the bladed disk assemblies can destroy the vibration characteristics of the bladed disk assemblies, which is one of the reasons for the high cycle fatigue failure of bladed disk assemblies, so it is necessary to research how to reduce the vibration of the bladed disk assemblies. On the basis of the review of relevant research at home a...

  13. Helicopter Rotor Blade With Free Tip

    Science.gov (United States)

    Stroub, Robert H.; Young, Larry; Cawthorne, Matthew; Keys, Charles

    1992-01-01

    Free-tip rotor blades improve fuel efficiency and performance characteristics of helicopters. Outermost portion of blade pivots independently with respect to inboard portion about pitch axis parallel to blade axis, located forward of aerodynamic center. Centrifugal force acts on tension/torsion strap and biases tip nose-up. Airstream turns tip nose-down, other torques cause tip to "weathervane" to intermediate angular position resulting in net lift. Reduces fluctuations in lift, with two effects: flapwise vibratory loads on blade and vibratory loads on pitch-control mechanism reduced; negative lift produced by advancing fixed tip eliminated, reducing power required to achieve same overall lift. Applies to tilt rotors and tail rotors as well.

  14. Composite blade structural analyzer (COBSTRAN) user's manual

    Science.gov (United States)

    Aiello, Robert A.

    1989-01-01

    The installation and use of a computer code, COBSTRAN (COmposite Blade STRuctrual ANalyzer), developed for the design and analysis of composite turbofan and turboprop blades and also for composite wind turbine blades was described. This code combines composite mechanics and laminate theory with an internal data base of fiber and matrix properties. Inputs to the code are constituent fiber and matrix material properties, factors reflecting the fabrication process, composite geometry and blade geometry. COBSTRAN performs the micromechanics, macromechanics and laminate analyses of these fiber composites. COBSTRAN generates a NASTRAN model with equivalent anisotropic homogeneous material properties. Stress output from NASTRAN is used to calculate individual ply stresses, strains, interply stresses, thru-the-thickness stresses and failure margins. Curved panel structures may be modeled providing the curvature of a cross-section is defined by a single value function. COBSTRAN is written in FORTRAN 77.

  15. Composite Blade Structural Analyzer (COBSTRAN) demonstration manual

    Science.gov (United States)

    Aiello, Robert A.

    1989-01-01

    The input deck setup is described for a computer code, composite blade structural analyzer (COBSTRAN) which was developed for the design and analysis of composite turbofan and turboprop blades and also for composite wind turbine blades. This manual is intended for use in conjunction with the COBSTRAN user's manual. Seven demonstration problems are described with pre- and postprocessing input decks. Modeling of blades which are solid thru-the-thickness and also aircraft wing airfoils with internal spars is shown. Corresponding NASTRAN and databank input decks are also shown. Detail descriptions of each line of the pre- and post-processing decks is provided with reference to the Card Groups defined in the user's manual. A dictionary of all program variables and terms used in this manual may be found in Section 6 of the user's manual.

  16. Wireless Inductive Power Device Suppresses Blade Vibrations

    Science.gov (United States)

    Morrison, Carlos R.; Provenza, Andrew J.; Choi, Benjamin B.; Bakhle, Milind A.; Min, James B.; Stefko, George L.; Duffy, Kirsten P.; Fougers, Alan J.

    2011-01-01

    Vibration in turbomachinery can cause blade failures and leads to the use of heavier, thicker blades that result in lower aerodynamic efficiency and increased noise. Metal and/or composite fatigue in the blades of jet engines has resulted in blade destruction and loss of lives. Techniques for suppressing low-frequency blade vibration, such as gtuned circuit resistive dissipation of vibratory energy, h or simply "passive damping," can require electronics incorporating coils of unwieldy dimensions and adding unwanted weight to the rotor. Other approaches, using vibration-dampening devices or damping material, could add undesirable weight to the blades or hub, making them less efficient. A wireless inductive power device (WIPD) was designed, fabricated, and developed for use in the NASA Glenn's "Dynamic Spin Rig" (DSR) facility. The DSR is used to simulate the functionality of turbomachinery. The relatively small and lightweight device [10 lb (approx.=4.5 kg)] replaces the existing venerable and bulky slip-ring. The goal is the eventual integration of this technology into actual turbomachinery such as jet engines or electric power generators, wherein the device will facilitate the suppression of potentially destructive vibrations in fan blades. This technology obviates slip rings, which require cooling and can prove unreliable or be problematic over time. The WIPD consists of two parts: a remote element, which is positioned on the rotor and provides up to 100 W of electrical power to thin, lightweight piezoelectric patches strategically placed on/in fan blades; and a stationary base unit that wirelessly communicates with the remote unit. The base unit supplies inductive power, and also acts as an input and output corridor for wireless measurement, and active control command to the remote unit. Efficient engine operation necessitates minimal disturbance to the gas flow across the turbine blades in any effort to moderate blade vibration. This innovation makes it

  17. Attractivity and acceptance of electric-powered vehicles. Results of the project OPTUM - Optimisation of the potentials of environmental reliefs of electic-powered vehicles; Attraktivitaet und Akzeptanz von Elektroautos. Ergebnisse aus dem Projekt OPTUM - Optimierung der Umweltentlastungspotenziale von Elektrofahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, Konrad; Sunderer, Georg; Birzle-Harder, Barbara; Deffner, Jutta

    2012-07-01

    In the research project OPTUM it was analysed to what extent environmental reliefs can be gained by electric cars. For this purpose an integrated approach was pursued, taking into account both considerations on the vehicle side and interactions with the energy sector. In detail the following key questions were analysed: acceptance and attractiveness of electric vehicles, market potentials for electric vehicles, interactions with the energy sector, CO2 reduction potentials for electric mobility, economic analysis of the storage media and resource efficiency of electric mobility. In this report the results concerning the question of acceptance and attractiveness of electric vehicles are presented. In doing so, results of two empirical investigations are described which were carried out in OPTUM to determine the acceptance and attractiveness of electric vehicles. The first one is a qualitative analysis by means of focus group discussions; the second one a standardised survey among buyers of new cars. The standardised survey contained a conjoint analysis, in which the participants had to choose between conventional cars, plug-in-hybrid vehicles and all-electrical cars. The empirical analyses show: There is an enormous potential of acceptance for electric cars (plug-in-hybrids and all-electric vehicles). Depending on scenario and vehicle class, especially for all-electrical cars, a potential of acceptance exists from 12 to 25 percent. Furthermore, both empirical investigations provide indications how the potential of acceptance can be realised or even extended.

  18. Probabilistic performance analysis of eroded compressor blades

    OpenAIRE

    Kumar, A.; Nair, P.B.; Keane, A. J.; Shahpar, S.

    2005-01-01

    This paper presents a probabilistic analysis of the effect of erosion on the performance of compressor fan blades. A realistic parametric CAD model is developed to represent eroded blades. Design of Experiments (DOE) techniques are employed to generate a set of candidate points, which are combined with a parametric geometry modeling and grid generation routine to produce a hybrid mesh. A multigrid Reynolds-Averaged Navier Stokes (RANS) solver HYDRA with Spalart Allmaras turbulence model is us...

  19. Desulfurization Of Gas-Turbine Blades

    Science.gov (United States)

    Outlaw, Ronald A.

    1994-01-01

    Sulfur removed from nickel-base superalloy used to make gas-turbine blades by heating alloy and simultaneously subjecting it to sputtering by directed Ar(Sup+) ions from ion gun or from glow discharge. Reduction of sulfur content of superalloy by factor of 10 increases lifetime of turbine blade made of alloy by similar factor, because stability of protective surface oxide formed during operation of turbine increased.

  20. An empirical study on website usability elements and how they affect search engine optimisation

    Directory of Open Access Journals (Sweden)

    Eugene B. Visser

    2011-03-01

    Full Text Available The primary objective of this research project was to identify and investigate the website usability attributes which are in contradiction with search engine optimisation elements. The secondary objective was to determine if these usability attributes affect conversion. Although the literature review identifies the contradictions, experts disagree about their existence.An experiment was conducted, whereby the conversion and/or traffic ratio results of an existing control website were compared to a usability-designed version of the control website,namely the experimental website. All optimisation elements were ignored, thus implementing only usability. The results clearly show that inclusion of the usability attributes positively affect conversion,indicating that usability is a prerequisite for effective website design. Search engine optimisation is also a prerequisite for the very reason that if a website does not rank on the first page of the search engine result page for a given keyword, then that website might as well not exist. According to this empirical work, usability is in contradiction to search engine optimisation best practices. Therefore the two need to be weighed up in terms of importance towards search engines and visitors.

  1. Optimisation structurelle des systemes energetiques

    Science.gov (United States)

    Saloux, Etienne

    The development of renewable energies is growing over the last decade to face environmental issues due to the world fossil fuel consumption increase. These energies are highly involved in houses and commercial buildings and numerous systems have been proposed to meet their energy demand. Therefore, improving both efficiency and use of systems, i.e. improving energy management, appears essential to limit the ecological footprint of humanity on the planet. However, system integration yields a very complex problem to be solved due to the large number of units and theirs technology, size, working conditions and interconnections. This situation highlights the lack of systematic analysis for comparing integrated system performance and for correctly pointing out their potential. As a result, the objective of this thesis is to develop and to present such a method, in other words the structural optimization of energy systems. It will be helpful to choose the optimal equipment by identifying all the possibilities of system arrangements and for comparing their performance. Combinations have then been subjected to environmental (climate), structural (available area) and economical constrains while assessment criteria have considered both energy, economic and ecological aspects. For that reason, as well as energy and economic analyses, the exergy concept has also been applied to the equipment. Nevertheless, the high degree of complexity of integrated systems and the tedious numerical calculations make the resolution by using standard software very difficult. It is clear that the whole optimization project would be considerable and the aim is to develop models and optimization tools. First of all, an exhaustive review of energy equipment including photovoltaic panels, solar collectors, heat pumps and thermal energy storage systems, has been performed. Afterwards, energy and exergy models have been developed and tested for two specific energy scenarios: a) a solar assisted heat

  2. Sandwich materials for wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Thybo Thomsen, O. [Aalborg Univ., Dept. of Mechanical Engineering, Aalborg (Denmark)

    2006-07-01

    Wind turbine blades are being manufactured using polymer matrix composite materials (PMC), in a combination of monolithic (single skin) and sandwich composites. Present day designs are mainly based on glass fibre reinforced composites (GFRP), but for very large blades carbon fibre reinforced composites (CFRP) are being used increasingly, in addition to GFRP by several manufacturers to reduce the weight. The size of wind turbines have increased significantly over the last 25 years, and this trend is expected to continue in the future. Thus, it is anticipated that wind turbines with a rated power output in the range of 8-10 MW and a rotor diameter about 170-180 m will be developed and installed within the next 10-15 years. The paper presents an overview of current day design principles and materials technology applied for wind turbine blades, and it highlights the limitations and important design issues to be addressed for up-scaling of wind turbine blades from the current maximum length in excess of 61 m to blade lengths in the vicinity of 90 m as envisaged for future very large wind turbines. In particular, the paper discusses the potential advantages and challenges of applying sandwich type construction to a larger extent than is currently being practiced for the load carrying parts of wind turbine blades. (au)

  3. Eddy current inspection of stationary blade rings

    International Nuclear Information System (INIS)

    Stationary turbine blade rings in a US power plant have experienced chloride-induced cracking. Failure analysis determined two types of cracking mechanisms: corrosion fatigue cracking confined to the leading edge of the outer shroud; and stress corrosion cracking present all over the blade surface. Fluorescent dye penetrant is typically used to detect and size cracks. However, it requires cleaning the blade rings by sandblasting to obtain reliable inspection results. Sand blasting in turn requires sealing the lower half of the turbine housing to prevent sand from contaminating the rest of the power plant components. Furthermore, both the penetrant examination and the removal of the sand are time consuming and costly. An alternative NDE technique is desirable which requires no pre-cleaning of the blade and a quick go/no-go inspection with the capability of estimating the crack length. This paper presents an innovative eddy current technique which meets the desired objectives by incorporating the use of specially designed contoured scanners equipped with an array of pancake coils. A set of eddy current pancake coils housed in three different scanners is used to manually scan and inspect the convex side of the stationary blade rings. The pancake coils are operated in a transmit/receive mode using two separate eddy current instruments. This paper presents the inspection concept, including scanner and probe designs, and test results from the various stages of multiple blade rings

  4. Cooled gas turbine blade edge flow analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, Marcio Teixeira de [Instituto Tecnologico de Aeronautica, Divisao de Engenharia Mecanica Aeronautica ITA/IEM, Sao Jose dos Campos, SP (Brazil)], e-mail: marcio@ita.br

    2010-07-01

    The flow on the rotating blades of a turbine is unsteady due to the wake of the stator blade row upstream. This unsteadiness is a source of losses and complex flow structures on the rotor blade due to the variation on the turbulence levels and location of the boundary layer laminar to turbulent transition. Convective cooled blades often time have cooling air ejected at the trailing edge right at the blade wake. The present investigation presents an analysis of a canonical flow consistent with the flow topology found at the trailing edge of a gas turbine blade with coolant ejection. A hydrodynamic stability analysis is performed for the combined wake and jet velocity profiles given by a gaussian distribution representing the turbulent rms wake and a laminar jet superposed. The growth rate of any instability found on the flow is an indication of faster mixing, resulting in a reduction on the wake velocity defect and consequently on the complexity associated with it. The results show that increasing the Mach number or the three-dimensionality of the disturbances result in a reduction of the amplification rate. When the flow at the trailing edge is modified by a jet, the amplification rates are lower, but the range of unstable stream wise wavenumbers is larger. (author)

  5. Recent Development in Turbine Blade Film Cooling

    Directory of Open Access Journals (Sweden)

    Je-Chin Han

    2001-01-01

    Full Text Available Gas turbines are extensively used for aircraft propulsion, land-based power generation, and industrial applications. Thermal efficiency and power output of gas turbines increase with increasing turbine rotor inlet temperature (RIT. The current RIT level in advanced gas turbines is far above the .melting point of the blade material. Therefore, along with high temperature material development, a sophisticated cooling scheme must be developed for continuous safe operation of gas turbines with high performance. Gas turbine blades are cooled internally and externally. This paper focuses on external blade cooling or so-called film cooling. In film cooling, relatively cool air is injected from the inside of the blade to the outside surface which forms a protective layer between the blade surface and hot gas streams. Performance of film cooling primarily depends on the coolant to mainstream pressure ratio, temperature ratio, and film hole location and geometry under representative engine flow conditions. In the past number of years there has been considerable progress in turbine film cooling research and this paper is limited to review a few selected publications to reflect recent development in turbine blade film cooling.

  6. Atmospheric icing on large wind turbine blades

    Directory of Open Access Journals (Sweden)

    Muhammad S. Virk, Matthew C. Homola, Per J. Nicklasson

    2012-01-01

    Full Text Available A numerical study of atmospheric ice accretion on a large horizontal axis ‘NREL 5 MW’ wind turbine blade has been carried out using the computational fluid dynamics based technique. Numerical analyses were carried out at five different sections along the wind turbine blade for both rime and glaze ice conditions. Based upon the flow field calculation and the droplet collision efficiency, the rate and shape of accreted ice was simulated at different atmospheric temperatures. Results indicate that the icing is less severe near the blade root sections, where the blade profiles are larger and thicker, both in terms of local ice mass and accreted ice thickness. Change in accreted ice growth with the atmospheric temperature is significant along the blade sections from centre to tip. The research work also highlighted that the ice accretion on wind turbine blades can also be controlled by optimizing its geometric design features instead of only using the energy consuming anti icing and de-icing systems.

  7. Study of the CNGS beam and identification of muons in the Opera experiment. Optimization of the beam line from SPL-Frejus project; Etude du faisceau CNGS et identification des muons dans l'experience OPERA. Optimisation de la ligne de faisceau du projet SPL-Frejus

    Energy Technology Data Exchange (ETDEWEB)

    Cazes, A

    2004-12-15

    Neutrino oscillations are the subject of most of the experiments looking at this particle. This mechanism uses the fact that neutrinos have mass to allow the transformation from one flavour to another one. The OPERA experiment will start to take data in spring 2006. Its goal is to proof this mechanism with no ambiguity using the appearance of tau neutrinos in the CNGS beam, which is made of muon neutrinos. This thesis presents a description of neutrino beams in general, and more precisely of the CNGS beam, which is sent from CERN to Gran Sasso in Italy. The neutrino flux are recalculated, and simulations have been performed in order to study miss positioning of the beam line elements. The OPERA detector is made of bricks containing a pile of lead plates and photographic emulsion films, of two trackers and two spectrometers. The high position resolution of the emulsions (< 1 {mu}m ), allows to identify the {tau} created by the tau neutrino charged current interactions. The brick localisation is made using a scintillator array. The pattern recognition in these scintillators as well as in the spectrometers is one of the part of this thesis. Furthermore, a muon identification algorithm has been set up. It allows to reject by a factor 20 the charm background. Future of neutrino oscillation physics is the building of more and more intense neutrino beams, in order to measure the last unknown parameters ({theta}{sub 13} and {delta}{sub CP}). The project of neutrino beam from CERN to the Fr us tunnel is fully revisited in the last part of this thesis. An optimisation of all the beam line element is proposed, and allows to reach a sensitivity to {theta}{sub 13} around one degree. (author)

  8. Investigation of dry friction effect of shroud damping wire on model test bladed wheel

    Czech Academy of Sciences Publication Activity Database

    Pešek, Luděk; Půst, Ladislav; Bula, Vítězslav; Vaněk, František; Cibulka, Jan

    Portland: ASME, 2013, s. 1-7. [ASME 2013 International Design Engineering Technical Conferences&computers and Information in Engineering Conference. Portland (US), 04.08.2013-07.08.2013] R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : dry friction * damping wire * bladed wheel Subject RIV: BI - Acoustics

  9. Non-contact Measurement of Stationary Characteristics of Shrouded Steam Turbine Blades under Rotation

    Czech Academy of Sciences Publication Activity Database

    Procházka, Pavel; Vaněk, František

    Piscataway: IEEE, 2015, s. 2084-2088. ISBN 978-1-4799-6113-9. [I2MTC - International Instrumentation and Measurement Technology Conference. Pisa (IT), 11.05.2015-14.05.2015] R&D Projects: GA TA ČR TA02020728 Institutional support: RVO:61388998 Keywords : steam turbine * blade vibration * magnetoresistive sensor * stationary deflection Subject RIV: BI - Acoustics

  10. Non-contact systems for monitoring blade vibrations of steam turbines

    Czech Academy of Sciences Publication Activity Database

    Procházka, Pavel; Vaněk, František

    Leuven: KU Leuven, 2012 - (Sas, P.; Moens, D.; Jonckheere, S.), s. 3359-3372 ISBN 9789073802896. [ISMA2012-USD2012. Leuven (BE), 17.09.2012-19.09.2012] R&D Projects: GA TA ČR TA02020728 Institutional research plan: CEZ:AV0Z20760514 Keywords : steam turbines * blade vibrations * non-contact sensors Subject RIV: JB - Sensors, Measurment, Regulation

  11. FE Modeling of Blade Couple with Friction Contacts under Dynamic Loading

    Czech Academy of Sciences Publication Activity Database

    Pešek, Luděk; Půst, Ladislav; Vaněk, František; Veselý, Jan

    Guanajuato : IFToMM, 2011, s. 1-8. [World Congress in Mechanism and Machine Science /13/. Guanajuato (MX), 19.06.2011-23.06.2011] R&D Projects: GA ČR GA101/09/1166 Institutional research plan: CEZ:AV0Z20760514 Keywords : blade wheel * dynamics * contact problem * friction Subject RIV: BI - Acoustics

  12. Aerodynamic Data for Tip Section of Rotor with 52 Titanium Blades 1375 mm Long

    Czech Academy of Sciences Publication Activity Database

    Luxa, Martin; Synáč, J.; Šimurda, David; Šafařík, Pavel

    Plzeň: ZČU Plzeň, 2014. ISBN 978-80-260-6447-3. [Turbostroje 2014. Plzeň (CZ), 24.09.2014-25.09.2014] R&D Projects: GA TA ČR(CZ) TA03020277 Institutional support: RVO:61388998 Keywords : supersonic flow * long turbine rotor blade * tip section Subject RIV: BK - Fluid Dynamics

  13. Basic optimization methodology for the design of friction damping in blade shrouds

    Czech Academy of Sciences Publication Activity Database

    Hajžman, M.; Brůha, J.; Zeman, V.; Rychecký, D.; Pešek, Luděk

    Portland: ASME, 2013. [ASME 2013 International Design Engineering Technical Conferences&computers and Information in Engineering Conference. Portland (US), 04.08.2013-07.08.2013] R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : dry friction * damping * turbine blades * vibration Subject RIV: BI - Acoustics

  14. New Methods of Noncontact Sensing of Blade Vibrations and Deflections in Turbomachinery

    Czech Academy of Sciences Publication Activity Database

    Procházka, Pavel; Vaněk, František

    2014-01-01

    Roč. 63, č. 6 (2014), s. 1583-1592. ISSN 0018-9456 R&D Projects: GA TA ČR TA02020728 Institutional support: RVO:61388998 Keywords : blade vibrations * induction sensors * magnetoresistive (MR) sensors * steam turbines Subject RIV: BI - Acoustics Impact factor: 1.790, year: 2014

  15. FE Modeling of Blade Couple with Friction Contacts Under Dynamic Loading

    Czech Academy of Sciences Publication Activity Database

    Pešek, Luděk; Půst, Ladislav; Vaněk, František; Veselý, Jan

    2014-01-01

    Roč. 2, č. 3 (2014), s. 229-238. ISSN 2321-3558 R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : turbine blades * dry friction * damping Subject RIV: BI - Acoustics http://www.tvi-in.com/Journals/journaldetail.aspx?Id=201406251115146464844edeb39be66

  16. Development and Analysis of a Swept Blade Aeroelastic Model for a Small Wind Turbine (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Preus, R.; Damiani, R.; Lee, S.; Larwood, S.

    2014-06-01

    As part of the U.S. Department-of-Energy-funded Competitiveness Improvement Project, the National Renewable Energy Laboratory (NREL) developed new capabilities for aeroelastic modeling of precurved and preswept blades for small wind turbines. This presentation covers the quest for optimized rotors, computer-aided engineering tools, a case study, and summary of the results.

  17. The possibilities of tuning and optimisation of acoustic resonance properties of the human vocal tract

    Czech Academy of Sciences Publication Activity Database

    Radolf, Vojtěch; Vampola, T.

    Praha: Institute of Thermomechanics AS CR, v. v. i., 2007 - (Zolotarev, I.), s. 237-238 ISBN 978-80-87012-06-2. [Engineering Mechanics 2007: national conference with international participation. Svratka (CZ), 14.05.2007-17.05.2007] R&D Projects: GA ČR GA106/04/1025 Institutional research plan: CEZ:AV0Z20760514 Keywords : acoustics * optimisation * formant tuning Subject RIV: BI - Acoustics

  18. CCGT performance simulation and diagnostics for operations optimisation and risk management

    OpenAIRE

    Mucino, Marco

    2007-01-01

    This thesis presents a techno-economic performance simulation and diagnostics computational system for the operations optimisation and risk management of a CCGT power station. The project objective was to provide a technological solution to a business problem originated at the Manx Electricity Authority (MEA). The CCGT performance simulation program was created from the integration of existing and new performance simulation codes of the main components of a CCGT power statio...

  19. An empirical study on website usability elements and how they affect search engine optimisation

    OpenAIRE

    Eugene B. Visser; Melius Weideman

    2011-01-01

    The primary objective of this research project was to identify and investigate the website usability attributes which are in contradiction with search engine optimisation elements. The secondary objective was to determine if these usability attributes affect conversion. Although the literature review identifies the contradictions, experts disagree about their existence.An experiment was conducted, whereby the conversion and/or traffic ratio results of an existing control website were compared...

  20. Deliverable D21.11 - Results of model tests on optimised configurations

    OpenAIRE

    Falchi, Massimo; Bugalsky, Tomasz Bugalsky; Di Felice, Fabio; Aloisio, Giovanni; Pereira, Francisco; Franchi, Stefano Ildebrando; Costanzo, Marcello; Pecoraro, Andrea; Salvatore, Francesco; Grizzi, Silvano; Nicolai, Claudia, Dr.

    2013-01-01

    Results of experimental work to evaluate design solutions aimed at improving the hydrodynamic performance of state-of-art screw propeller systems are presented. The report is written in fulfilment of the STREAMLINE Project Deliverable D21.11 `Results of model tests on optimised configurations.' The work documented herein is performed in the framework of Work Package 21, Task 21.6 in which propulsion efficiency enhancements deriving from the application of CFD- based design and numerical optim...

  1. Instability of a penetrating blade

    Science.gov (United States)

    Bigoni, D.; Bosi, F.; Dal Corso, F.; Misseroni, D.

    2014-03-01

    Application of a dead compressive load at the free end of an elastic rod (the ‘blade') induces its penetration into a sliding sleeve ending with a linear elastic spring. Bifurcation and stability analysis of this simple elastic system shows a variety of unexpected behaviors: (i) an increase of buckling load at decreasing of elastic stiffness; (ii) a finite number of buckling loads for a system with infinite degrees of freedom (leading to a non-standard Sturm-Liouville problem); (iii) more than one bifurcation load associated to each bifurcation mode; (iv) a restabilization of the straight configuration after the second bifurcation load associated to the first instability mode; (v) the presence of an Eshelby-like (or configurational) force, deeply influencing stability. Only the first of these behaviors was previously known, the second and third ones disprove common beliefs, the fourth highlights a sort of ‘island of instability', and the last one shows surprising phenomena and effects on stability.

  2. Optimisation under Data Uncertainty in Wireless Communication Networks

    OpenAIRE

    Claßen, Grit

    2015-01-01

    In this thesis, we study robustness concepts of mathematical optimisation and apply these to wireless network problems which are subject to data uncertainty. Uncertainties occur quite frequently in radio networks as, for instance, the quality of the transmission signal varies or user demands fluctuate. Robust and stochastic optimisation are two methodologies to tackle such deviations already in the planning phase of the network. While stochastic optimisation is a suitable technique in case th...

  3. Share-of-Surplus Product Line Optimisation with Price Levels

    OpenAIRE

    Luo, X. G.; Z. C. Zhang; Kwong, C. K.; J. F. Tang

    2014-01-01

    Kraus and Yano (2003) established the share-of-surplus product line optimisation model and developed a heuristic procedure for this nonlinear mixed-integer optimisation model. In their model, price of a product is defined as a continuous decision variable. However, because product line optimisation is a planning process in the early stage of product development, pricing decisions usually are not very precise. In this research, a nonlinear integer programming share-of-surplus product line opti...

  4. Optimisation techniques for advanced process supervision and control

    OpenAIRE

    Abu-el-zeet, Z.H.

    2000-01-01

    This thesis is concerned with the use and development of optimisation techniques for process supervision and control. Two major areas related to optimisation are combined namely model predictive control and dynamic data reconciliation. A model predictive control scheme is implemented and used to simulate the control of a coal gasification plant. Static as well as dynamic data reconciliation techniques are developed and used in conjunction with steady-state optimisation and model predictive co...

  5. Méthodes d'optimisations de programmes bas niveau

    OpenAIRE

    Touati, Sid-Ahmed-Ali

    2010-01-01

    This manuscript is a synthesis of our research e ort since one full decade on the topic of low level code optimisation, devoted to an integration in a compiler backend or in a semi-automatic optimisation tool. At the backend level, processor characteristics are known and can be used to generate codes using the underlying hardware more effciently. We start our document by a global view on the phase ordering problem in optimising compilation. Nowadays, hundreds of compilation passes and code op...

  6. Aspects of Optimisation of Separation of Drugs by Chemometrics

    OpenAIRE

    Harang, Valérie

    2003-01-01

    Statistical experimental designs have been used for method development and optimisation of separation. Two reversed phase HPLC methods were optimised. Parameters such as the pH, the amount of tetrabutylammonium (TBA; co-ion) and the gradient slope (acetonitrile) were investigated and optimised for separation of erythromycin A and eight related compounds. In the second method, a statistical experimental design was used, where the amounts of acetonitrile and octane sulphonate (OSA; counter ion)...

  7. Optimised limit for polarimetric calibration of fully polarised SAR systems

    OpenAIRE

    Chen, J.; Guo, W; Li, Z.; Liu, W.

    2016-01-01

    The optimised limit for polarimetric calibration of fully polarised synthetic aperture radar systems is derived by establishing an error model as a function of cross-talk, channel imbalance and system noise. Compared with noise equivalent sigma zero, the polarimetric error below the optimised limit is too small to affect the signal of cross-polarised channel. Thus, polarimetric calibration could be relaxed or even ignored in this case. With the backscatter model, optimised limits for cross-ta...

  8. Method of calculating blade-to-blade plane flow in centrifugal pump

    Science.gov (United States)

    Jackson, E. D.

    1970-01-01

    Steam filament solution determines velocity distribution due to potential flow in the blade-to-blade plane of the radial impeller. This is used to determine the mass-averaged relative fluid angle, which is in turn used in an axisymmetric program to obtain steam surfaces of the assumed axisymmetric flow.

  9. Laser grooved buried contact cells optimised for linear concentration systems

    Energy Technology Data Exchange (ETDEWEB)

    Vivar, M.; Anton, I.; Sala, G. [Instituto de Energia Solar, UPM, Ciudad Universitaria S/N, 28040 Madrid (Spain); Morilla, C.; Fernandez, J.M. [BP Solar Espana, Pol. Ind. Tres Cantos, s/n Zona Oeste, 28760 Tres Cantos, Madrid (Spain)

    2010-02-15

    Laser grooved buried contact silicon solar cells can be optimised for use in linear concentration systems at low cost. Optimising the groove depth, the copper thickness and the finger pitch by using the Design of Experiments (DOE) experimental methodology can lead to a dramatic reduction of the cell series resistance. This type of cell can be optimised for each application in an industrial line with few changes. For the EUCLIDES III linear concentrator system, optimised cell efficiency metrics for 51 x 116 mm units are in the range of 18-19% at the 40 x concentration level. (author)

  10. Optimisation of sonochemical and/or sonoelectrochemical cell with the help of numerical simulation of ultrasonic intensity distribution

    Czech Academy of Sciences Publication Activity Database

    Klíma, Jiří; González-Garcia, J.; Frias-Ferrer, A.; Ludvík, Jiří; Sáez, V.; Iniesta, J.

    Hamburg : -, 2006 . s. 1. [European Sonochemistry Society Meeting /10./. 04.06.06-08.06.06, Hamburg] R&D Projects: GA MŠk 1P05OC074 Grant ostatní: Generalidad Valenciana(ES) GV05/104 Institutional research plan: CEZ:AV0Z40400503 Keywords : ultrasonic intensity distribution * cell geometry optimisation * wave equation Subject RIV: CG - Electrochemistry

  11. Bistable devices for morphing rotor blades

    Science.gov (United States)

    Johnson, Terrence

    This dissertation presents two bistable concepts for morphing rotor blades. These concepts are simple and are composed of bistable devices that act as coupling structures between an actuator and the rotor blade. Bistable or "snap-through" mechanisms have two stable equilibrium states and are a novel way to achieve large actuation output stroke at relatively modest effort for gross rotor morphing applications. This is because in addition to the large actuation stroke associated with the snap-through (relative to conventional actuator/ amplification systems) coming at relatively low actuation effort, no locking is required in either equilibrium state (since they are both stable). The first concept that is presented in this dissertation is a that is composed of a bistable twisting device that twists the tip of helicopter rotor blades. This work examines the performance of the presented bistable twisting device for rotor morphing, specifically, blade tip twist under an aerodynamic lift load. The device is analyzed using finite element analysis to predict its load carrying capability and bistable behavior. The second concept that is presented is a concept that is composed of a bistable arch for rotor blade chord extension. The bistable arch is coupled to a thin flat plate that is supported by rollers. Increasing the chord of the rotor blade is expected to generate more lift-load and improve helicopter performance. In this work, a methodology is presented to design the bistable arches for chord morphing using the finite element analysis and pseudo-rigid body model method. This work also examines the effect of different arches, arch hinge size and shape, inertial loads and rigidity on arch performance. Finally, this work shows results from an experiment that was conducted to validate the developed numerical model and demonstrates how the arch can be actuated using a Nitinol Shape Memory Alloy (SMA) wire to extend the chord of a helicopter rotor blade.

  12. The SNL100-01 blade : carbon design studies for the Sandia 100-meter blade.

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, Daniel Todd

    2013-02-01

    A series of design studies to investigate the effect of carbon on blade weight and performance for large blades was performed using the Sandia 100-meter All-glass Baseline Blade design as a starting point. This document provides a description of the final carbon blade design, which is termed as SNL100-01. This report includes a summary of the design modifications applied to the baseline all-glass 100-meter design and a description of the NuMAD model files that are made publicly available. This document is intended primarily to be a companion document to the distribution of the NuMAD blade model files for SNL100-01.

  13. Wind turbine blade shear web disbond detection using rotor blade operational sensing and data analysis.

    Science.gov (United States)

    Myrent, Noah; Adams, Douglas E; Griffith, D Todd

    2015-02-28

    A wind turbine blade's structural dynamic response is simulated and analysed with the goal of characterizing the presence and severity of a shear web disbond. Computer models of a 5 MW offshore utility-scale wind turbine were created to develop effective algorithms for detecting such damage. Through data analysis and with the use of blade measurements, a shear web disbond was quantified according to its length. An aerodynamic sensitivity study was conducted to ensure robustness of the detection algorithms. In all analyses, the blade's flap-wise acceleration and root-pitching moment were the clearest indicators of the presence and severity of a shear web disbond. A combination of blade and non-blade measurements was formulated into a final algorithm for the detection and quantification of the disbond. The probability of detection was 100% for the optimized wind speed ranges in laminar, 30% horizontal shear and 60% horizontal shear conditions. PMID:25583871

  14. Design and test of box girder for a large wind turbine blade

    DEFF Research Database (Denmark)

    Nielsen, Per Hørlyk; Tesauro, Angelo; Bitsche, Robert;

    This report is covering the structural design and full scale test of a box girder as a part of the project “Demonstration of new blade design using manufacturing process simulations” supported by the EUDP program. A box girder with a predetermined outer geometry was designed using new inventions......, which create an inner structure in the box girder. With a combination of advanced FEM analysis and the inventions it was possible to reduce the material thickness of the cap by up to 40%. The new design of the box girder was manufactured at SSP Technology A/S, where it was demonstrated that the...... manufacturing process could include the new inventions. Subsequently the box girder was transported to the blade test facility at DTU Wind Energy. A series of test was performed with the blade to investigate the behaviour during loading, and finally the girder was loaded to ultimate failure. The report includes...

  15. Public transport optimisation emphasising passengers’ travel behaviour

    DEFF Research Database (Denmark)

    Jensen, Jens Parbo

    the published performance measures and what passengers actually experience, a large academic contribution of the current PhD study is the explicit consideration of passengers’ travel behaviour in optimisation studies and in the performance assessment. Besides the explicit passenger focus in transit planning...... more importance to travel time certainty than travel time reductions as they associate an inherent disutility with travel time uncertainty. This disutility may broadly be interpreted as an anxiety cost for the need for having contingency plans in case of disruptions, and may be looked...

  16. Optimising end of generation of Magnox reactors

    International Nuclear Information System (INIS)

    Designing, justifying and gaining regulatory approval for optimised, terminal fuel cycles for the last 4 of the 13 strong Magnox Fleet is described, covering: - constraints set by the plant owner's integrated closure plan, opportunities for innovative fuel cycles while preserving flexibility to respond to business changes; - methods of collectively determining best options for each site; - selected strategies including lower fuel element retention and inter-reactor transfer of fuel; - the required work scope, its technical, safety case and resource challenges and how they were met; - achieving additional electricity generation worth in excess of Pound 1 b from 4 sites (a total of 8 reactors); - the keys to success. (authors)

  17. Particle swarm optimisation based video abstraction

    Directory of Open Access Journals (Sweden)

    Magda B. Fayk

    2010-04-01

    Full Text Available Video abstraction is a basic step for intelligent access to video and multimedia databases which facilitates content-based video indexing, retrieving and browsing. This paper presents a new video abstraction scheme. The proposed method relies on two stages. First, video is divided into short segments. Second, keyframes in each segment are selected using particle swarm optimisation. A group of experiments show that the proposed technique is promising in regards to selecting the most significant keyframes despite a sustainment in overhead processing.

  18. EAF steelplant optimisation using EFSOP technology

    Energy Technology Data Exchange (ETDEWEB)

    Goodfellow, H.D.; Ferro, L.; Galbiati, P.

    2005-06-01

    Most high productivity electric arc furnace (EAF) melt shops employ significant amounts of chemical energy in the melting process. Goodfellow's EFSOP technology uses continuous offgas analysis plus process monitoring to optimise the use of chemical energy in the EAF. Benefits include savings in electrical energy, gas, oxygen and carbon, which result in significant reductions in conversion costs and increased productivity. Recent results from the installation of KT injectors and EFSOP at Tamsa are presented, together with operational results from other recent North American plants. Finally, an innovative development programme based on yield improvements in EAF steelmaking via improved process modelling and control methods is described. (author)

  19. Advanced manufacturing: optimising the factories of tomorrow

    International Nuclear Information System (INIS)

    Faced with competition Patrick Philippon - Les Defis du CEA no.179 - April 2013 from the emerging countries, the competitiveness of the industrialised nations depends on the ability of their industries to innovate. This strategy necessarily entails the reorganisation and optimisation of the production systems. This is the whole challenge for 'advanced manufacturing', which relies on the new information and communication technologies. Interactive robotics, virtual reality and non-destructive testing are all technological building blocks developed by CEA, now approved within a cross-cutting programme, to meet the needs of industry and together build the factories of tomorrow. (author)

  20. Wind Turbine Load Mitigation based on Multivariable Robust Control and Blade Root Sensors

    International Nuclear Information System (INIS)

    This paper presents two H∞ multivariable robust controllers based on blade root sensors' information for individual pitch angle control. The wind turbine of 5 MW defined in the Upwind European project is the reference non-linear model used in this research work, which has been modelled in the GH Bladed 4.0 software package. The main objective of these controllers is load mitigation in different components of wind turbines during power production in the above rated control zone. The first proposed multi-input multi-output (MIMO) individual pitch H'' controller mitigates the wind effect on the tower side-to-side acceleration and reduces the asymmetrical loads which appear in the rotor due to its misalignment. The second individual pitch H'' multivariable controller mitigates the loads on the three blades reducing the wind effect on the bending flapwise and edgewise momentums in the blades. The designed H'' controllers have been validated in GH Bladed and an exhaustive analysis has been carried out to calculate fatigue load reduction on wind turbine components, as well as to analyze load mitigation in some extreme cases

  1. Successful Solutions to SSME/AT Development Turbine Blade Distress

    Science.gov (United States)

    Montgomery, Stuart K.

    1999-01-01

    As part of the High-Pressure Fuel Turbopump/Alternate Turbopump (HPFTP/AT) turbine blade development program, unique turbine blade design features were implemented to address 2nd stage turbine blade high cycle fatigue distress and improve turbine robustness. Features included the addition of platform featherseal dampers, asymmetric blade tip seal segments, gold plating of the blade attachments, and airfoil tip trailing edge modifications. Development testing shows these features have eliminated turbine blade high cycle fatigue distress and consequently these features are currently planned for incorporation to the flight configuration. Certification testing will begin in 1999. This presentation summarizes these features.

  2. Advances in wind turbine blade design and materials

    DEFF Research Database (Denmark)

    well as the requirements and challenges for composite materials used in both current and future designs of wind turbine blades. Part one outlines the challenges and developments in wind turbine blade design, including aerodynamic and aeroelastic design features, fatigue loads on wind turbine blades...... fatigue resistance of wind turbine blades. The final part of the book describes advances in wind turbine blade materials, development and testing, including biobased composites, surface protection and coatings, structural performance testing and the design, manufacture and testing of small wind turbine...... materials scientists and engineers, wind turbine blade manufacturers and maintenance technicians, scientists, researchers and academics....

  3. Rotor blade full-scale fatigue testing technology and research

    DEFF Research Database (Denmark)

    Nielsen, Per Hørlyk; Berring, Peter; Pavese, Christian; Branner, Kim

    Full scale fatigue test is an important part of the development and design of wind turbine blades. Testing is also needed for the approval of the blades in order for them to be used on large wind turbines. However, usually only one prototype blade is tested. Fatigue test of wind turbine blades was...... presented in this report giving the blade test facility operator a guide to choose the method that best fit the needs and economic constraints. The state of the art method is currently dual axis mass resonance, where the purpose of the test is to emulate the loads the blades encounter in operation....

  4. Determination of HART I Blade Structural Properties by Laboratory Testing

    Science.gov (United States)

    Jung, Sung N.; Lau, Benton H.

    2012-01-01

    The structural properties of higher harmonic Aeroacoustic Rotor Test (HART I) blades were measured using the original set of blades tested in the German-dutch wind tunnel (DNW) in 1994. the measurements include bending and torsion stiffness, geometric offsets, and mass and inertia properties of the blade. the measured properties were compared to the estimated values obtained initially from the blade manufacturer. The previously estimated blade properties showed consistently higher stiffness, up to 30 percent for the flap bending in the blade inboard root section.

  5. Single and Twisted Blades Digital Simulation and Dynamic Analysis

    Directory of Open Access Journals (Sweden)

    A. Benretem

    2016-03-01

    Full Text Available This work represents a comparative study of a numerical simulation of frequencies and fundamental modes of flapping vibration, drag and torsion of the two blades of a small wind turbine, a single one and another with optimum blade design. The objective of this study is to understand the behavior of two types of blades subjected to various canvassing. The results reveal that the various canvassing and maximum displacements are located at the end of the two blades; in fact, the results show that a single blade has higher frequencies than twisted one but does not undergo large displacements in comparison to twisted blade.

  6. Structural optimization study of composite wind turbine blade

    DEFF Research Database (Denmark)

    Chen, Jin; Shen, Wen Zhong; Wang, Quan; Pang, Xiaoping; Li, Songlin; Guo, Xiaofeng

    2013-01-01

    In this paper the initial layout of a 2. MW composite wind turbine blade is designed first. The new airfoils families are selected to design a 2. MW wind turbine blade. The finite element parametric model for the blade is established. Based on the modified Blade Element Momentum theory, a new one...... the structural design and optimization of wind turbine blades. © 2012.......-way fluid-structure interaction method is introduced. A procedure combining finite element analysis and particle swarm algorithm to optimize composite structures of the wind turbine blade is developed. The procedure proposed not only allows thickness variation but also permits the spar cap location...

  7. Further development of the swinging-blade Savonius rotor

    Science.gov (United States)

    Aldoss, T. K.; Najjar, Y. S. H.

    Savonius rotor performance is improved by allowing both downwind and upwind rotor blades to swing back through an optimum angle. This will minimize the drag on the upwind blade and maximize the drag on the down-wind blade. A combination of 50 degrees upwind blade swing angle and 13.5 degrees downwind blade swing angle have been found experimentally to be the optimum swing angles that increased the rotor maximum power coefficient to about 23.5 percent compared with 18 percent with optimum upwind blade swing alone.

  8. Methodology and Toolset for Model Verification, Hardware/Software co-simulation, Performance Optimisation and Customisable Source-code generation

    DEFF Research Database (Denmark)

    Berger, Michael Stübert; Soler, José; Yu, Hao;

    2013-01-01

    The MODUS project aims to provide a pragmatic and viable solution that will allow SMEs to substantially improve their positioning in the embedded-systems development market. The MODUS tool will provide a model verification and Hardware/Software co-simulation tool (TRIAL) and a performance...... optimisation and customisable source-code generation tool (TUNE). The concept is depicted in automated modelling and optimisation of embedded-systems development. The tool will enable model verification by guiding the selection of existing open-source model verification engines, based on the automated analysis...

  9. 3X-100 blade field test.

    Energy Technology Data Exchange (ETDEWEB)

    Zayas, Jose R.; Johnson, Wesley D.

    2008-03-01

    In support of a Work-For-Other (WFO) agreement between the Wind Energy Technology Department at Sandia National Laboratories and 3TEX, one of the three Micon 65/13M wind turbines at the USDA Agriculture Research Service (ARS) center in Bushland, Texas, has been used to test a set of 9 meter wind turbine blades, manufactured by TPI composites using the 3TEX carbon material for the spar cap. Data collected from the test has been analyzed to evaluate both the aerodynamic performance and the structural response from the blades. The blades aerodynamic and structural performance, the meteorological inflow and the wind turbine structural response has been monitored with an array of 57 instruments: 15 to characterize the blades, 13 to characterize inflow, and 15 to characterize the time-varying state of the turbine. For the test, data was sampled at a rate of 40 Hz using the ATLAS II (Accurate GPS Time-Linked Data Acquisition System) data acquisition system. The system features a time-synchronized continuous data stream and telemetered data from the turbine rotor. This paper documents the instruments and infrastructure that have been developed to monitor these blades, turbines and inflow, as well as both modeling and field testing results.

  10. Dynamic Response of Flexible Wind Turbine Blade

    Directory of Open Access Journals (Sweden)

    Yu-qiao Zheng

    2013-07-01

    Full Text Available Aiming at the non-stationary and stall flutter problems of wind turbine blade caused by transient load fluctuations, the dynamic properties of wind turbine were studied, the blade was simplify to a cantilever beam in case of the action of shear deformation and cross section rotating effect were considered in this analysis, equations of the blade were established based on D'Alemberts' principle and the principle of virtual displacement. The dynamic response of the wind turbine was solved by using the finite element method under the transient load environment. A 29.2 m rotor blade, previously reported in specialized literature, was chosen as a case study to validate dynamic behaviour predicted by a Timoshenko beam model. It is concluded that despite its simplicity, The cross-sectional shear-deformation  has great influence on  dynamic response of the blade.Dynamic model is sufficiently accurate to serve as a design tool for the recursive analyses required during design and optimization stages of wind turbines using only readily available computational tools.

  11. Modal analysis of wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G.C.; Hansen, M.H.; Baumgart, A.; Carlen, I.

    2002-02-01

    The modal analysis technique has been used to identify essential dynamic properties of wind turbine blades like natural frequencies, damping characteristics and mode shapes. Different experimental procedures have been considered, and the most appropriate of these has been selected. Although the comparison is based on measurements on a LM 19 m blade, the recommendations given are believed to be valid for other wind turbine blades as well. The reliability of the selected experimental analysis has been quantified by estimating the unsystematic variations in the experimental findings. Satisfactory results have been obtained for natural frequencies, damping characteristics and for the dominating deflection direction of the investigated mode shapes. For the secondary deflection directions, the observed experimental uncertainty may be considerable - especially for the torsional deflection. The experimental analysis of the LM 19 m blade has been compared with results from a state-of-the-art FE-modeling of the same blade. For some of the higher modes substantial discrepancies between the natural frequencies originating from the FE-modeling and the modal analysis, respectively, are observed. In general the qualitative features of measured and computed modes shapes are in good agreement. However, for the secondary deflection directions, substantial deviations in the absolute values may occur (when normalizing with respect to the primary deflection direction). Finally, suggestions of potential future improvements of the experimental procedure are discussed. (au)

  12. Individual blade pitch for yaw control

    International Nuclear Information System (INIS)

    Individual pitch control (IPC) for reducing blade loads has been investigated and proven successful in recent literature. For IPC, the multi-blade co-ordinate (MBC) transformation is used to process the blade load signals from the rotating to a stationary frame of reference. In the stationary frame of reference, the yaw error of a turbine can be appended to generate IPC actions that are able to achieve turbine yaw control for a turbine in free yaw. In this paper, IPC for yaw control is tested on a high-fidelity numerical model of a commercially produced wind turbine in free yaw. The tests show that yaw control using IPC has the distinct advantage that the yaw system loads and support structure loading are substantially reduced. However, IPC for yaw control also shows a reduction in IPC blade load reduction potential and causes a slight increase in pitch activity. Thus, the key contribution of this paper is the concept demonstration of IPC for yaw control. Further, using IPC for yaw as a tuning parameter, it is shown how the best trade-off between blade loading, pitch activity and support structure loading can be achieved for wind turbine design

  13. Optimisation of vertical axis wind turbines

    OpenAIRE

    Roynarin, Wirachai

    2004-01-01

    A practical Vertical Axis Wind Turbine (VAWTs) based on a Darrieus rotor has been designed and tested and found to be capable of self-starting at wind speeds above 4m/s. The self-start feature has been achieved by replacing the usual symmetrical aerofoil blade in the VAWT rotor and by using a concentric Savonius rotor or semi-cylinder turbine. A computer program was produced to compute the power coefficient versus tip speed ratio characteristics of a selected aerofoil profile employed in a VA...

  14. A finite element diagnostic tool for turbine blade failures

    International Nuclear Information System (INIS)

    The authors initiated the development of a diagnostic tool for evaluating the reliability of low pressure steam turbine blades. Designated BLADE (Blade Life Algorithm for Design Evaluation), the program is developed specifically for use by utility engineers to assess and correct blade failures - providing details on stresses, natural frequencies and blade life which traditionally are proprietary to the turbine blade manufacturers. Developed as a stand alone, finite element based program, BLADE requires no previous expertise in modeling or analysis of blade designs. The user is prompted to provide basic blade and root dimensions, including any applicable cover and tiewire information. The program then utilizes this information to automatically generate a complete finite element model of the blade or blade group configuration, and calculate static and dynamic stresses in the airfoil, root, tenon and cover sections of the blade. Natural frequency and mode shapes are also calculated and available to the user. To assist the utility engineer interpret this information, the static and dynamic stress components are combined with the high and low cycle material properties using the BLADE-FATIGUE program to predict the time to fatigue crack initiation, using the local strain approach

  15. Piezoelectric Vibration Damping Study for Rotating Composite Fan Blades

    Science.gov (United States)

    Min, James B.; Duffy, Kirsten P.; Choi, Benjamin B.; Provenza, Andrew J.; Kray, Nicholas

    2012-01-01

    Resonant vibrations of aircraft engine blades cause blade fatigue problems in engines, which can lead to thicker and aerodynamically lower performing blade designs, increasing engine weight, fuel burn, and maintenance costs. In order to mitigate undesirable blade vibration levels, active piezoelectric vibration control has been investigated, potentially enabling thinner blade designs for higher performing blades and minimizing blade fatigue problems. While the piezoelectric damping idea has been investigated by other researchers over the years, very little study has been done including rotational effects. The present study attempts to fill this void. The particular objectives of this study were: (a) to develop and analyze a multiphysics piezoelectric finite element composite blade model for harmonic forced vibration response analysis coupled with a tuned RLC circuit for rotating engine blade conditions, (b) to validate a numerical model with experimental test data, and (c) to achieve a cost-effective numerical modeling capability which enables simulation of rotating blades within the NASA Glenn Research Center (GRC) Dynamic Spin Rig Facility. A numerical and experimental study for rotating piezoelectric composite subscale fan blades was performed. It was also proved that the proposed numerical method is feasible and effective when applied to the rotating blade base excitation model. The experimental test and multiphysics finite element modeling technique described in this paper show that piezoelectric vibration damping can significantly reduce vibrations of aircraft engine composite fan blades.

  16. Pressure Pulsation Signal Analysis for Centrifugal Compressor Blade Crack Determination

    Directory of Open Access Journals (Sweden)

    Hongkun Li

    2014-01-01

    Full Text Available Blade is a key piece of component for centrifugal compressor. But blade crack could usually occur as blade suffers from the effect of centrifugal forces, gas pressure, friction force, and so on. It could lead to blade failure and centrifugal compressor closing down. Therefore, it is important for blade crack early warning. It is difficult to determine blade crack as the information is weak. In this research, a pressure pulsation (PP sensor installed in vicinity to the crack area is used to determine blade crack according to blade vibration transfer process analysis. As it cannot show the blade crack information clearly, signal analysis and empirical mode decomposition (EMD are investigated for feature extraction and early warning. Firstly, signal filter is carried on PP signal around blade passing frequency (BPF based on working process analysis. Then, envelope analysis is carried on to filter the BPF. In the end, EMD is carried on to determine the characteristic frequency (CF for blade crack. Dynamic strain sensor is installed on the blade to determine the crack CF. Simulation and experimental investigation are carried on to verify the effectiveness of this method. The results show that this method can be helpful for blade crack classification for centrifugal compressors.

  17. BENCHMARKING OF CT FOR PATIENT EXPOSURE OPTIMISATION.

    Science.gov (United States)

    Racine, Damien; Ryckx, Nick; Ba, Alexandre; Ott, Julien G; Bochud, François O; Verdun, Francis R

    2016-06-01

    Patient dose optimisation in computed tomography (CT) should be done using clinically relevant tasks when dealing with image quality assessments. In the present work, low-contrast detectability for an average patient morphology was assessed on 56 CT units, using a model observer applied on images acquired with two specific protocols of an anthropomorphic phantom containing spheres. Images were assessed using the channelised Hotelling observer (CHO) with dense difference of Gaussian channels. The results were computed by performing receiver operating characteristics analysis (ROC) and using the area under the ROC curve (AUC) as a figure of merit. The results showed a small disparity at a volume computed tomography dose index (CTDIvol) of 15 mGy depending on the CT units for the chosen image quality criterion. For 8-mm targets, AUCs were 0.999 ± 0.018 at 20 Hounsfield units (HU) and 0.927 ± 0.054 at 10 HU. For 5-mm targets, AUCs were 0.947 ± 0.059 and 0.702 ± 0.068 at 20 and 10 HU, respectively. The robustness of the CHO opens the way for CT protocol benchmarking and optimisation processes. PMID:26940439

  18. Ant Colony Optimisation for Backward Production Scheduling

    Directory of Open Access Journals (Sweden)

    Leandro Pereira dos Santos

    2012-01-01

    Full Text Available The main objective of a production scheduling system is to assign tasks (orders or jobs to resources and sequence them as efficiently and economically (optimised as possible. Achieving this goal is a difficult task in complex environment where capacity is usually limited. In these scenarios, finding an optimal solution—if possible—demands a large amount of computer time. For this reason, in many cases, a good solution that is quickly found is preferred. In such situations, the use of metaheuristics is an appropriate strategy. In these last two decades, some out-of-the-shelf systems have been developed using such techniques. This paper presents and analyses the development of a shop-floor scheduling system that uses ant colony optimisation (ACO in a backward scheduling problem in a manufacturing scenario with single-stage processing, parallel resources, and flexible routings. This scenario was found in a large food industry where the corresponding author worked as consultant for more than a year. This work demonstrates the applicability of this artificial intelligence technique. In fact, ACO proved to be as efficient as branch-and-bound, however, executing much faster.

  19. HVAC system optimisation-in-building section

    Energy Technology Data Exchange (ETDEWEB)

    Lu, L.; Cai, W.; Xie, L.; Li, S.; Soh, Y.C. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore (Singapore)

    2004-07-01

    This paper presents a practical method to optimise in-building section of centralised Heating, Ventilation and Air-Conditioning (HVAC) systems which consist of indoor air loops and chilled water loops. First, through component characteristic analysis, mathematical models associated with cooling loads and energy consumption for heat exchangers and energy consuming devices are established. By considering variation of cooling load of each end user, adaptive neuro-fuzzy inference system (ANFIS) is employed to model duct and pipe networks and obtain optimal differential pressure (DP) set points based on limited sensor information. A mix-integer nonlinear constraint optimization of system energy is formulated and solved by a modified genetic algorithm. The main feature of our paper is a systematic approach in optimizing the overall system energy consumption rather than that of individual component. A simulation study for a typical centralized HVAC system is provided to compare the proposed optimisation method with traditional ones. The results show that the proposed method indeed improves the system performance significantly. (author)

  20. Thermal-barrier-coated turbine blade study

    Science.gov (United States)

    Siemers, P. A.; Hillig, W. B.

    1981-01-01

    The effects of coating TBC on a CF6-50 stage 2 high-pressure turbine blade were analyzed with respect to changes in the mean bulk temperature, cooling air requirements, and high-cycle fatigue. Localized spallation was found to have a possible deleterious effect on low-cycle fatigue life. New blade design concepts were developed to take optimum advantage of TBCs. Process and material development work and rig evaluations were undertaken which identified the most promising combination as ZrO2 containing 8 w/o Y2O3 applied by air plasma spray onto a Ni22Cr-10Al-1Y bond layer. The bond layer was applied by a low-pressure, high-velocity plasma spray process onto the base alloy. During the initial startup cycles the blades experienced localized leading edge spallation caused by foreign objects.

  1. Worn blades may have caused turbine failure

    International Nuclear Information System (INIS)

    Detroit Edison Co.'s decision not to replace eighth-stage blades in low-pressure turbine number three may have caused the event that damaged the turbine, generator, and exciter at Fermi-2 on December 25, 1993. This finding is included in the February 7 report of the Nuclear Regulatory Commission's Augmented Inspection Teams (AIT). GEC Turbine Generations Ltd. of England, manufacturer of the turbine, had recommended replacing the blades during the plant's third refueling outage in September 1992. Detroit Edison chose not to do so, stating in its report, open-quotes This wear is of the same magnitude as that noticed in RF01 [refueling outage 1] and it is not necessary to record this wear since all blades will be changed in RF04 [refueling outage 4].close quotes

  2. Aerodynamics of Rotor Blades for Quadrotors

    CERN Document Server

    Bangura, Moses; Naldi, Roberto; Mahony, Robert

    2016-01-01

    In this report, we present the theory on aerodynamics of quadrotors using the well established momentum and blade element theories. From a robotics perspective, the theoretical development of the models for thrust and horizontal forces and torque (therefore power) are carried out in the body fixed frame of the quadrotor. Using momentum theory, we propose and model the existence of a horizontal force along with its associated power. Given the limitations associated with momentum theory and the inadequacy of the theory to account for the different powers represented in a proposed bond graph lead to the use of blade element theory. Using this theory, models are then developed for the different quadrotor rotor geometries and aerodynamic properties including the optimum hovering rotor used on the majority of quadrotors. Though this rotor is proven to be the most optimum rotor, we show that geometric variations are necessary for manufacturing of the blades. The geometric variations are also dictated by a desired th...

  3. Microtextured Surfaces for Turbine Blade Impingement Cooling

    Science.gov (United States)

    Fryer, Jack

    2014-01-01

    Gas turbine engine technology is constantly challenged to operate at higher combustor outlet temperatures. In a modern gas turbine engine, these temperatures can exceed the blade and disk material limits by 600 F or more, necessitating both internal and film cooling schemes in addition to the use of thermal barrier coatings. Internal convective cooling is inadequate in many blade locations, and both internal and film cooling approaches can lead to significant performance penalties in the engine. Micro Cooling Concepts, Inc., has developed a turbine blade cooling concept that provides enhanced internal impingement cooling effectiveness via the use of microstructured impingement surfaces. These surfaces significantly increase the cooling capability of the impinging flow, as compared to a conventional untextured surface. This approach can be combined with microchannel cooling and external film cooling to tailor the cooling capability per the external heating profile. The cooling system then can be optimized to minimize impact on engine performance.

  4. Methods of making wind turbine rotor blades

    Energy Technology Data Exchange (ETDEWEB)

    Livingston, Jamie T. (Pensacola, FL); Burke, Arthur H. E. (Gulf Breeze, FL); Bakhuis, Jan Willem (Nijverdal, NL); Van Breugel, Sjef (Enschede, NL); Billen, Andrew (Daarlerveen, NL)

    2008-04-01

    A method of manufacturing a root portion of a wind turbine blade includes, in an exemplary embodiment, providing an outer layer of reinforcing fibers including at least two woven mats of reinforcing fibers, providing an inner layer of reinforcing fibers including at least two woven mats of reinforcing fibers, and positioning at least two bands of reinforcing fibers between the inner and outer layers, with each band of reinforcing fibers including at least two woven mats of reinforcing fibers. The method further includes positioning a mat of randomly arranged reinforcing fibers between each pair of adjacent bands of reinforcing fibers, introducing a polymeric resin into the root potion of the wind turbine blade, infusing the resin through the outer layer, the inner layer, each band of reinforcing fibers, and each mat of random reinforcing fibers, and curing the resin to form the root portion of the wind turbine blade.

  5. Multi-objective evolutionary optimisation for product design and manufacturing

    CERN Document Server

    2011-01-01

    Presents state-of-the-art research in the area of multi-objective evolutionary optimisation for integrated product design and manufacturing Provides a comprehensive review of the literature Gives in-depth descriptions of recently developed innovative and novel methodologies, algorithms and systems in the area of modelling, simulation and optimisation

  6. Design Optimisation and Conrol of a Pilot Operated Seat Valve

    DEFF Research Database (Denmark)

    Nielsen, Brian; Andersen, Torben Ole; Hansen, Michael Rygaard

    2004-01-01

    The paper gives an approach for optimisation of the bandwidth of a pilot operated seat valve for mobile applications. Physical dimensions as well as parameters of the implemented control loop are optimised simultaneously. The frequency response of the valve varies as a function of the pressure drop...

  7. Optimising polarised neutron scattering measurements--XYZ and polarimetry analysis

    CERN Document Server

    Cussen, L D

    2002-01-01

    The analytic optimisation of neutron scattering measurements made using XYZ polarisation analysis and neutron polarimetry techniques is discussed. Expressions for the 'quality factor' and the optimum division of counting time for the XYZ technique are presented. For neutron polarimetry the optimisation is identified as analogous to that for measuring the flipping ratio and reference is made to the results already in the literature.

  8. Multi-criteria Scantling Optimisation of Cruise Ships

    OpenAIRE

    Caprace, Jean-David; Bair, Frédéric; Rigo, Philippe

    2010-01-01

    A numerical tool for the optimisation of the scantlings of a ship is extended by considering production cost, weight and moment of iner tia in the objective function. A multi-criteria optimisation of a passenger ship is conducted to illustrate the analysis process. Pareto frontiers are obtained and results are verified with Bureau Veritas rules.

  9. Computational method for the design of wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Vitale, A.J. [Instituto Argentino de Oceanografia, Camino La Carrindanga Km. 7.5, CC 804, B8000FWB Bahia Blanca (Argentina); Universidad Tecnologica Nacional Facultad Regional Bahia Blanca, GESE, 11 de Abril 461, B8000LMI Bahia Blanca (Argentina); Universidad Nacional del Sur, Dpto. de Ing. Electrica y de Computadoras, Av. Alem 1253, 8000 Bahia Blanca (Argentina); Rossi, A.P. [Universidad Tecnologica Nacional Facultad Regional Bahia Blanca, GESE, 11 de Abril 461, B8000LMI Bahia Blanca (Argentina); Universidad Nacional del Sur, Dpto. de Ing. Electrica y de Computadoras, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

    2008-07-15

    Zeus Disenador was developed to design low-power, horizontal-axis wind turbine blades, by means of an iterative algorithm. With this software, it is possible to obtain the optimum blade shape for a wind turbine to satisfy energy requirements of an electric system with optimum rotor efficiency. The number of blades, the airfoil curves and the average wind velocity can be specified by the user. The user can also request particular edge conditions for the width of the blades and for the pitch angle. Results are provided in different windows. Two- and three-dimensional graphics show the aspect of the resultant blade. Numerical results are displayed for blade length, blade surface, pitch angle variation along the blade span, rotor angular speed, rotor efficiency and rotor output power. Software verifications were made by comparing rotor power and rotor efficiency for different designs. Results were similar to those provided by commercial wind generator manufacturers. (author)

  10. Research overview on vibration damping of mistuned bladed disk assemblies

    Directory of Open Access Journals (Sweden)

    Liang ZHANG

    2016-04-01

    Full Text Available Bladed disk assemblies are very important parts in auto engine and gas turbine, and is widely used in practical engineering. The mistuning existing commonly in the bladed disk assemblies can destroy the vibration characteristics of the bladed disk assemblies, which is one of the reasons for the high cycle fatigue failure of bladed disk assemblies, so it is necessary to research how to reduce the vibration of the bladed disk assemblies. On the basis of the review of relevant research at home and abroad, the mistuning vibration mechanism of the bladed disk assemblies is introduced, and the main technical methods of the vibration damping of bladed disk assemblies are reviewed, such as artificially active mistuning, collision damping, friction damping and optimization of the blade position. Some future research directions are presented.

  11. Linearization of friction effects in vibration of two rotating blades

    Directory of Open Access Journals (Sweden)

    Hajžman M.

    2013-06-01

    Full Text Available This paper is aimed at modelling of friction effects in blade shrouding which are realized by means of friction elements placed between blades. In order to develop a methodology of modelling, two blades with one friction element in between are considered only. Flexible blades fixed to a rotating disc are discretized by FEM using 1D Rayleigh beam elements derived in rotating space as well as the friction element modelled as a rigid body. The blades and the friction element are connected through two concurrent friction planes, where the friction forces arise on the basis of centrifugal force acting on the friction element. The linearization of friction is performed using the harmonic balance method to determine equivalent damping coefficients in dependence on the amplitudes of relative slip motion between the blades and the friction element. The methodology is applied to a model of two real blades and will be extended for the whole bladed disc with shrouding.

  12. Steel fiber composites for tidal turbine blades

    OpenAIRE

    Kucera, Marko

    2011-01-01

    The last decade has seen a drastic increase in focus on several types of renewable energy, including a still increasing interest in tidal power. This method of harnessing energy and the technology required to do so are relatively new, and even though a number of prototypes have been built during the last years, none have yet emerged as a standard or definite solution. As of today, all the prototypes have based their turbine blade technology on that of wind turbines, thus producing the blades ...

  13. New airfoil sections for straight bladed turbine

    International Nuclear Information System (INIS)

    A theoretical investigation of aerodynamic performance for vertical axis Darrieus wind turbine with new airfoils sections is carried out. The blade section aerodynamics characteristics are determined from turbomachines cascade model. The model is also adapted to the vertical Darrieus turbine for the performance prediction of the machine. In order to choose appropriate value of zero-lift-drag coefficient in calculation, an analytical expression is introduced as function of chord-radius ratio and Reynolds numbers. New airfoils sections are proposed and analyzed for straight-bladed turbine

  14. Distribution of Defects in Wind Turbine Blades and Reliability Assessment of Blades Containing Defects

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Branner, Kim; Berring, Peter; Sørensen, John Dalsgaard

    2009-01-01

    In the present paper two stochastic models for the distribution of defects in wind turbine blades are proposed. The first model assumes that the individual defects are completely randomly distributed in the blade. The second model assumes that the defects occur in clusters of different size based...... on the assumption that one error in the production process tends to trigger several defects. For both models additional information about number, type and size of the defects is included as stochastic variables. The probability of failure for a wind turbine blade will not only depend on variations in...

  15. Modified cuckoo search: A new gradient free optimisation algorithm

    International Nuclear Information System (INIS)

    Highlights: → Modified cuckoo search (MCS) is a new gradient free optimisation algorithm. → MCS shows a high convergence rate, able to outperform other optimisers. → MCS is particularly strong at high dimension objective functions. → MCS performs well when applied to engineering problems. - Abstract: A new robust optimisation algorithm, which can be regarded as a modification of the recently developed cuckoo search, is presented. The modification involves the addition of information exchange between the top eggs, or the best solutions. Standard optimisation benchmarking functions are used to test the effects of these modifications and it is demonstrated that, in most cases, the modified cuckoo search performs as well as, or better than, the standard cuckoo search, a particle swarm optimiser, and a differential evolution strategy. In particular the modified cuckoo search shows a high convergence rate to the true global minimum even at high numbers of dimensions.

  16. Modified cuckoo search: A new gradient free optimisation algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Walton, S., E-mail: 512465@swansea.ac.uk [College of Engineering, Swansea University, Swansea SA2 8PP, Wales (United Kingdom); Hassan, O.; Morgan, K.; Brown, M.R. [College of Engineering, Swansea University, Swansea SA2 8PP, Wales (United Kingdom)

    2011-09-15

    Highlights: > Modified cuckoo search (MCS) is a new gradient free optimisation algorithm. > MCS shows a high convergence rate, able to outperform other optimisers. > MCS is particularly strong at high dimension objective functions. > MCS performs well when applied to engineering problems. - Abstract: A new robust optimisation algorithm, which can be regarded as a modification of the recently developed cuckoo search, is presented. The modification involves the addition of information exchange between the top eggs, or the best solutions. Standard optimisation benchmarking functions are used to test the effects of these modifications and it is demonstrated that, in most cases, the modified cuckoo search performs as well as, or better than, the standard cuckoo search, a particle swarm optimiser, and a differential evolution strategy. In particular the modified cuckoo search shows a high convergence rate to the true global minimum even at high numbers of dimensions.

  17. Premature failure of low pressure turbine blade of an aircraft

    International Nuclear Information System (INIS)

    A low pressure turbine blade failed during the ground run of an aircraft engine. The failed blade was analyzed to find out the cause of failure. The material of the blade was Udimet -500, a high strength Ni-base super alloy. Low cycle fatigue was observed during fractography. Fatigue crack was originated from an ejected grain. When the crack reached to a critical size, the blade failed under overload condition. (author)

  18. Dynamic Analysis of Wind Turbine Blades Using Radial Basis Functions

    OpenAIRE

    Ming-Hung Hsu

    2011-01-01

    Wind turbine blades play important roles in wind energy generation. The dynamic problems associated with wind turbine blades are formulated using radial basis functions. The radial basis function procedure is used to transform partial differential equations, which represent the dynamic behavior of wind turbine blades, into a discrete eigenvalue problem. Numerical results demonstrate that rotational speed significantly impacts the first frequency of a wind turbine blade. Moreover, the...

  19. Rotor blade online monitoring and fault diagnosis technology research

    DEFF Research Database (Denmark)

    Tesauro, Angelo; Pavese, Christian; Branner, Kim

    Rotor blade online monitoring and fault diagnosis technology is an important way to find blade failure mechanisms and thereby improve the blade design. Condition monitoring of rotor blades is necessary in order to ensure the safe operation of the wind turbine, make the maintenance more economical......, unbalancing of the rotor, icing and lightning. Research is done throughout the world in order to develop and improve such measurement systems. Commercial hardware and software available for the described purpose is presented in the report....

  20. Reconstruction of Vital Blade Signal from Unsteady Casing Vibration

    OpenAIRE

    Meng Hee Lim; Leong, M. S.

    2014-01-01

    Some important information pertaining to blade fault is thought to be concealed in highly unsteady casing vibration. This paper explores suitable methods to best reconstruct blade related signals from raw casing vibration, which could be used for diagnosis of blade fault. The feasibility of translation invariant wavelet transform and cycle spinning (TIWT-CS) technique in reconstruction of these signals is investigated in this paper. Subsequently, a new parameter for blade fault diagnosis, nam...

  1. Experimental Investigation On Design Of High Pressure Steam Turbine Blade

    OpenAIRE

    SUBRAMANYAM PAVULURI, DR. A. SIVA KUMAR

    2013-01-01

    The Experimental investigation on design of high pressure steam turbine blade addresses the issue of steam turbine efficiency. A specific focus on aerofoil profile for high pressure turbine blade, and it evaluates the effectiveness of certain Chromium and Nickel in resisting creep and fracture in turbine blades. The capable of thermal and chemical conditions in blade substrate from to prevent the corrosion when exposed to wet steam. The efficiency of the steam turbine is a key factor in both ...

  2. Impedance-Based Structural Health Monitoring of Wind Turbine Blades

    OpenAIRE

    Pitchford, Corey

    2007-01-01

    Wind power is a fast-growing source of non-polluting, renewable energy with vast potential. However, current wind technology must be improved before the potential of wind power can be fully realized. One of the key components in improving wind turbines is their blades. Blade failure is very costly because blade failure can damage other blades, the wind turbine itself, and possibly other wind turbines. A successful structural health monitoring (SHM) system incorporated into wind turbines c...

  3. Design and Analysis of Composite Propeller Blade for Aircraft

    OpenAIRE

    Madhusudhan BM; Dr P.V Srihari

    2014-01-01

    Fiber reinforced composites is used for twin blade propeller because of its high strength, low temperature applications. Fiber has to be oriented in the loading direction while designing the composite propeller blade. The blade geometry and design are more complex involving many controlling parameters. In the present work a methodology to design a composite propeller to analyze its strength and deformation using ANSYS software. The weight of the composite blade is reduced comp...

  4. Application of circulation controlled blades for vertical axis wind turbines

    OpenAIRE

    Velissarios Kourkoulis; Andrew Shires

    2013-01-01

    The blades of a vertical axis wind turbine (VAWT) rotor see an inconsistent angle of attack through its rotation. Consequently, VAWT blades generally use symmetrical aerofoils with a lower lift-to-drag ratio than cambered aerofoils tailored to maximise horizontal axis wind turbine rotor performance. This paper considers the feasibility of circulation controlled (CC) VAWT blades, using a tangential air jet to provide lift and therefore power augmentation. However CC blade sections require a hi...

  5. OPTIMISE - Deliverable D4.2 Deliver optimised samples made by two axis rolling to UNIVERSITY OF TWENTE, month 11

    DEFF Research Database (Denmark)

    Eriksen, Morten

    This report explains why the deliverables of optimised samples made by two axis rolling was not send to UNIVERSITY OF TWENTE.......This report explains why the deliverables of optimised samples made by two axis rolling was not send to UNIVERSITY OF TWENTE....

  6. Work management to optimise occupational radiological protection

    International Nuclear Information System (INIS)

    Although work management is no longer a new concept, continued efforts are still needed to ensure that good performance, outcomes and trends are maintained in the face of current and future challenges. The ISOE programme thus created an Expert Group on Work Management in 2007 to develop an updated report reflecting the current state of knowledge, technology and experience in the occupational radiological protection of workers at nuclear power plants. Published in 2009, the new ISOE report on Work Management to Optimise Occupational Radiological Protection in the Nuclear Power Industry provides up-to-date practical guidance on the application of work management principles. Work management measures aim at optimising occupational radiological protection in the context of the economic viability of the installation. Important factors in this respect are measures and techniques influencing i) dose and dose rate, including source- term reduction; ii) exposure, including amount of time spent in controlled areas for operations; and iii) efficiency in short- and long-term planning, worker involvement, coordination and training. Equally important due to their broad, cross-cutting nature are the motivational and organisational arrangements adopted. The responsibility for these aspects may reside in various parts of an installation's organisational structure, and thus, a multi-disciplinary approach must be recognised, accounted for and well-integrated in any work. Based on the operational experience within the ISOE programme, the following key areas of work management have been identified: - regulatory aspects; - ALARA management policy; - worker involvement and performance; - work planning and scheduling; - work preparation; - work implementation; - work assessment and feedback; - ensuring continuous improvement. The details of each of these areas are elaborated and illustrated in the report through examples and case studies arising from ISOE experience. They are intended to

  7. Design and initial testing of a one-bladed 30-meter-diameter rotor on the NASA/DOE mod-O wind turbine

    Science.gov (United States)

    Corrigan, R. D.; Ensworth, C. B. F.

    1986-01-01

    The concept of a one-bladed horizontal-axis wind turbine has been of interest to wind turbine designers for many years. Many designs and economic analyses of one-bladed wind turbines have been undertaken by both United States and European wind energy groups. The analyses indicate significant economic advantages but at the same time, significant dynamic response concerns. In an effort to develop a broad data base on wind turbine design and operations, the NASA Wind Energy Project Office has tested a one-bladed rotor at the NASA/DOE Mod-O Wind Turbine Facility. This is the only known test on an intermediate-sized one-bladed rotor in the United States. The 15.2-meter-radius rotor consists of a tip-controlled blade and a counterweight assembly. A rigorous test series was conducted in the Fall of 1985 to collect data on rotor performance, drive train/generator dynamics, structural dynamics, and structural loads. This report includes background information on one-bladed rotor concepts, and Mod-O one-bladed rotor test configuration, supporting design analysis, the Mod-O one-blade rotor test plan, and preliminary test results.

  8. 14 CFR 27.661 - Rotor blade clearance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor blade clearance. 27.661 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure...

  9. 14 CFR 29.661 - Rotor blade clearance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor blade clearance. 29.661 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure...

  10. Multidisciplinary design optimization of film-cooled gas turbine blades

    Directory of Open Access Journals (Sweden)

    Talya Shashishekara S.

    1999-01-01

    Full Text Available Design optimization of a gas turbine blade geometry for effective film cooling toreduce the blade temperature has been done using a multiobjective optimization formulation. Three optimization formulations have been used. In the first, the average blade temperature is chosen as the objective function to be minimized. An upper bound constraint has been imposed on the maximum blade temperature. In the second, the maximum blade temperature is chosen as the objective function to be minimized with an upper bound constraint on the average blade temperature. In the third formulation, the blade average and maximum temperatures are chosen as objective functions. Shape optimization is performed using geometric parameters associated with film cooling and blade external shape. A quasi-three-dimensional Navier–Stokes solver for turbomachinery flows is used to solve for the flow field external to the blade with appropriate modifications to incorporate the effect of film cooling. The heat transfer analysis for temperature distribution within the blade is performed by solving the heat diffusion equation using the finite element method. The multiobjective Kreisselmeier–Steinhauser function approach has been used in conjunction with an approximate analysis technique for optimization. The results obtained using both formulations are compared with reference geometry. All three formulations yield significant reductions in blade temperature with the multiobjective formulation yielding largest reduction in blade temperature.

  11. Controller Design for Blade Load Reduction Using Synthetic Jets

    DEFF Research Database (Denmark)

    Soltani, Mohsen; Mirzaei, Mahmood

    2014-01-01

    strain gauges along the blade and the tower to estimate the contribution of each blade modal state to the vibration of the tower and the blades. The synthetic jet actuators are then controlled, such that the desired vibration modes are damped effectively. Designed estimator and controller are implemented...

  12. Digital radiographic technology; non-destructive testing of tubine blades

    OpenAIRE

    Penumadu, P.S.

    2014-01-01

    Inspection of turbine blades has always been a big challenge. Any irregularities in the blade have a huge impact on the gas turbine, so these blades have to be manufactured and inspected in the most sophisticated way possible. The evolution of digital radiographic technology took a leap forward to solve these problems in the industry environment which also enhances production quality and reduce rework.

  13. Improved design for large wind turbine blades of fibre composites (Phase 3) - Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, B.F. (Risoe DTU, Materials Research Div., Roskilde (Denmark)); Branner, K. (Risoe DTU, Wind Energy Div., Roskilde (Denmark)); Lund, E. (Aalborg Univ., Dept. of Mechanical Engineering, Aalborg (Denmark)); Wedel-Heinen, J. (Vestas Wind System, Randers (Denmark)); Garm, J.H. (LM Glasfiber, Kolding (Denmark))

    2009-06-15

    An overview is given of the activities of the project 'Improved design for large wind turbine blades (Phase 3)', partially supported by the Danish Energy Agency under the Ministry of Climate and Energy through the EFP-grant no. 33031-0078. The project was focussed at the development of new design methods for wind turbine blades, so that uncertainties associated with damage and defects can be reduced. The following topics with respect to failure modes were covered: Buckling-driven delamination of load-carrying laminates, cracking along interfaces in material joints, implementation of cohesive laws in finite element programmes and hierarchical finite element models. Methods and major research results of the project are summarised. Some future goals for future research activities are briefly discussed. (author)

  14. Investigation of a transsonic slot cooling system for high-temperature gas turbine blades; Untersuchung einer transsonischen Schlitzkuehlung fuer Hochtemperaturgasturbinenschaufeln

    Energy Technology Data Exchange (ETDEWEB)

    Moser, S.

    2003-07-01

    The author investigated a slot cooling system with transsonic blowout of cooling air for high-temperature gas turbine blades. The method has the advantage that the cooling film is closer to the blade surface and the boundary layer at the blade wall is not interrupted even at high blowout rates. This way, the cooling film will mix less with the hot gas flow, and the cooling effect will last longer. The method is based on the subsonic Coanda effect and the supersonic Prandtl-Meyer effect, both of which result in attachment of the cooling film to a curved surface. The investigations and the optimisation were carried out using the experimental system, measuring instruments and software of the Institute of Thermal Turbo-Engines and Machine Dynamics. [German] In dieser Arbeit wird eine Schlitzkuehlung mit transsonischer Kuehlluftausblasung fuer Hochtemperaturgasturbinenschaufeln untersucht. Der Vorteil dieser Kuehlmethode ist, dass der entstehende Kuehlfilm besser an die Schaufeloberflaeche anliegt und die Grenzschicht an der Schaufelwand auch bei hohen Ausblasraten nicht durchstossen wird. Dies bewirkt ein geringeres Vermischen des Kuehlfilms mit der heissen Gasstroemung und somit ein laengeres Anhalten des Kuehlungseffektes. Man bedient sich dabei zweier in der Stroemungslehre bekannter Effekte, naemlich dem subsonischen Coanda Effekt und dem im Ueberschall auftretenden Prandtl-Meyer Effekt. Beide bewirken das Anlegen der Kuehlfilme an eine gekruemmte Oberflaeche. Mit Hilfe der am Institut fuer thermische Turbomaschinen und Maschinendynamik zur Verfuegung stehenden Versuchsanlagen, Messgeraete und Software wurde die Untersuchung bzw. Optimierung der transsonischen Schlitzkuehlung durchgefuehrt. (orig.)

  15. Automatic optimisation of gamma dose rate sensor networks: The DETECT Optimisation Tool

    DEFF Research Database (Denmark)

    Helle, K.B.; Müller, T.O.; Astrup, Poul;

    2014-01-01

    chosen using regular grids or according to administrative constraints. Nowadays, however, the choice can be based on more realistic risk assessment, as it is possible to simulate potential radioactive plumes. To support sensor planning, we developed the DETECT Optimisation Tool (DOT) within the scope of...... monitoring network for early detection of radioactive plumes or for the creation of dose maps. The DOT is implemented as a stand-alone easy-to-use JAVA-based application with a graphical user interface and an R backend. Users can run evaluations and optimisations, and display, store and download the results....... The DOT runs on a server and can be accessed via common web browsers; it can also be installed locally. © 2014 Elsevier Ltd. All rights reserved...

  16. Optimisation d’une installation solaire

    OpenAIRE

    CHEKKAF, Omar; GUENINECHE, Nabil

    2014-01-01

    Notre travail consiste à optimiser le fonctionnement d'une installation simple qui comprend un capteur solaire (bouilleur), une turbine à vapeur et un condenseur. Nous avons effectué des calculs pour différents débits de masse, à l'entrée du capteur solaire et différentes températures à l'entrée de la turbine. Nous avons trouvé que l'augmentation du débit massique et de la différence de température entre l'entrée et la sortie, conduit à une augmentation de la quantité de chaleur produite par ...

  17. Improving and optimising road pricing in Copenhagen

    DEFF Research Database (Denmark)

    Nielsen, Otto Anker; Larsen, Marie Karen

    2008-01-01

    though quite a number of proposed charging systems have been examined only a few pricing strategies have been investigated. This paper deals with the optimisation of different designs for a road pricing system in the Greater Copenhagen area with respect to temporal and spatial differentiation of the......The question whether to introduce toll rings or road pricing in Copenhagen has been discussed intensively during the last 10 years. The main results of previous analyses are that none of the systems would make a positive contribution at present, when considered from a socio-economic view. Even...... pricing levels. A detailed transport model was used to describe the demand effects. The model was based on data from a real test of road pricing on 500 car drivers. The paper compares the price systems with regard to traffic effects and generalised costs for users and society. It is shown how important it...

  18. VEHICLE DRIVING CYCLE OPTIMISATION ON THE HIGHWAY

    Directory of Open Access Journals (Sweden)

    Zinoviy STOTSKO

    2016-06-01

    Full Text Available This paper is devoted to the problem of reducing vehicle energy consumption. The authors consider the optimisation of highway driving cycle a way to use the kinetic energy of a car more effectively at various road conditions. The model of a vehicle driving control at the highway which consists of elementary cycles, such as accelerating, free rolling and deceleration under forces of external resistance, was designed. Braking, as an energy dissipation regime, was not included. The influence of the various longitudinal profiles of the road was taken into consideration and included in the model. Ways to use the results of monitoring road and traffic conditions are presented. The method of non-linear programming is used to design the optimal vehicle control function and phase trajectory. The results are presented by improved typical driving cycles that present energy saving as a subject of choice at a specified schedule.

  19. Optimisation study for radionuclides in effluents

    International Nuclear Information System (INIS)

    A summary of the Nuclear Energy Agency (NEA) Expert Group's report on the radiological significance and management of tritium, carbon-14, krypton-85 and iodine-129 arising from the nuclear fuel cycle is presented. The report sets out the current guidelines for radiological protection especially with respect to optimisation of the protection and limitation of the individual risk. Health effects, both fatal somatic and hereditary, are used as a suitable measurement of detriment to populations from radiation exposure. The methodology employed by the Expert Group is also detailed. The study makes no judgements as to the acceptability of the various management options that emerge from the analysis. Nevertheless, it is hoped that the study may provide a format to decision-makers for particular facilities. (U.K.)

  20. Optimising doses in paediatric CT scanning

    International Nuclear Information System (INIS)

    Computed tomography is still extensively used in paediatric imaging. This technique remains a benchmark for bone, lung, cardiovascular exploration and for emergency imaging. The multi-slice technique has revolutionized image quality by improving spatial resolution and bringing acquisition times down to a few seconds, thus almost totally eliminating the problem of movement artefacts common with children. This technique will not therefore be abandoned any time in the near future by paediatric radiologists. However, these multi-slice CT devices today allow rapid and repetitive exploration of large volumes, which can lead to significant individual exposure [1]. A number of surveys have shown that the exposure parameters used in paediatrics are too high when compared with adult protocols [2, 3] even though a lesser dose can provide equivalent image quality [4]. These paediatric CT optimisation measures are currently the subject of an extensive campaign in the literature [5-7]. (author)

  1. Optimisation of Miscanthus harvesting and storage strategies

    Energy Technology Data Exchange (ETDEWEB)

    Nixon, P.; Bullard, M.

    2003-07-01

    Miscanthus is a valuable biomass source of energy and this study was conducted with a view to maximising its potential through optimisation of harvesting, transport, drying and storage. The studies centred on two experimental plots established in southern England in 2001. Details of harvesting procedure, height of cut etc. are given. Drying under controlled and ambient conditions was monitored. The impact of rhizome damage and soil compaction on future crops was assessed. A superior mower conditioner-baler system was described, but the procedure for swath drying can probably be improved. The study was carried out over one season only. The main contractor was Energy Power Resources Ltd and the work was part of the DTI Renewable Energy Programme managed by Future Energy Solutions.

  2. Niobium Cavity Electropolishing Modelling and Optimisation

    CERN Document Server

    Ferreira, L M A; Forel, S; Shirra, J A

    2013-01-01

    It’s widely accepted that electropolishing (EP) is the most suitable surface finishing process to achieve high performance bulk Nb accelerating cavities. At CERN and in preparation for the processing of the 704 MHz high-beta Superconducting Proton Linac (SPL) cavities a new vertical electropolishing facility has been assembled and a study is on-going for the modelling of electropolishing on cavities with COMSOL® software. In a first phase, the electrochemical parameters were taken into account for a fixed process temperature and flow rate, and are presented in this poster as well as the results obtained on a real SPL single cell cavity. The procedure to acquire the data used as input for the simulation is presented. The modelling procedure adopted to optimise the cathode geometry, aimed at a uniform current density distribution in the cavity cell for the minimum working potential and total current is explained. Some preliminary results on fluid dynamics is also briefly described.

  3. Structural experiment of wind turbine blades; Fushayo blade no zairyo rikigakuteki jikken kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Seki, K.; Shimizu, Y.; Kuroyanagi, H. [Tokai University, Tokyo (Japan)

    1997-11-25

    Aluminum, GFRP and composite of aluminum coated with carbon as structural materials for wind turbine blades were bending-tested, to improve blade bending stiffness, understand stress conditions at each position, and clarify structural dynamic strength by the bending-failure test. It is possible to estimate stress conditions at each position from the test results of displacement and strain at each load. The test results with GFRP are well explained qualitatively by the boundary theory, known as a theory for composite materials. The test gives reasonable material strength data, useful for designing wind turbines of high functions and safety. The results of the blade bending-failure test are in good agreement with the calculated structural blade strength. It is also found that GFRP is a good material of high structural strength for wind turbines. 8 refs., 6 tabs.

  4. Effects of Blade to Blade Dissimilarities on Rotor Body Lead Lag Dynamics

    Science.gov (United States)

    McNulty, Michael J.

    1985-01-01

    Small blade-to-blade property differences are investigated to determine how they affect the behavior of a simple rotor-body system. An analytical approach is used which emphasizes the significance of these effects from the experimental point of view. It is found that the primary effect of blade-to-blade dissimilarities is the appearance of additional peaks in the frequency spectrum which are separated from the conventional response peaks by multiples of the rotor speed. These additional responses are potential experimental problems because when they occur near a mode of interest they act as contaminant frequencies which can make damping measurements difficult. Increased rotor-body coupling and a rotor shaft degree of freedom act to improve the situation by altering the frequency separation of the modes.

  5. Effects of blade-to-blade dissimilarities on rotor-body lead-lag dynamics

    Science.gov (United States)

    Mcnulty, M. J.

    1986-01-01

    Small blade-to-blade property differences are investigated to determine their effects on the behavior of a simple rotor-body system. An analytical approach is used which emphasizes the significance of these effects from the experimental point of view. It is found that the primary effect of blade-to-blade dissimilarities is the appearance of additional peaks in the frequency spectrum which are separated from the convention response modes by multiples of the rotor speed. These additional responses are potential experimental problems because when they occur near a mode of interest they act as contaminant frequencies which can make damping measurements difficult. The effects of increased rotor-body coupling and a rotor shaft degree of freedom act to improve the situation by altering the frequency separation of the modes.

  6. Effect of blade outlet angle on radial thrust of single-blade centrifugal pump

    Science.gov (United States)

    Nishi, Y.; Fukutomi, J.; Fujiwara, R.

    2012-11-01

    Single-blade centrifugal pumps are widely used as sewage pumps. However, a large radial thrust acts on a single blade during pump operation because of the geometrical axial asymmetry of the impeller. This radial thrust causes vibrations of the pump shaft, reducing the service life of bearings and shaft seal devices. Therefore, to ensure pump reliability, it is necessary to quantitatively understand the radial thrust and clarify the behavior and generation mechanism. This study investigated the radial thrust acting on two kinds of single-blade centrifugal impellers having different blade outlet angles by experiments and computational fluid dynamics (CFD) analysis. Furthermore, the radial thrust was modeled by a combination of three components, inertia, momentum, and pressure, by applying an unsteady conservation of momentum to this impeller. As a result, the effects of the blade outlet angle on both the radial thrust and the modeled components were clarified. The total head of the impeller with a blade outlet angle of 16 degrees increases more than the impeller with a blade outlet angle of 8 degrees at a large flow rate. In this case, since the static pressure of the circumference of the impeller increases uniformly, the time-averaged value of the radial thrust of both impellers does not change at every flow rate. On the other hand, since the impeller blade loading becomes large, the fluctuation component of the radial thrust of the impeller with the blade outlet angle of 16 degrees increases. If the blade outlet angle increases, the fluctuation component of the inertia component will increase, but the time-averaged value of the inertia component is located near the origin despite changes in the flow rate. The fluctuation component of the momentum component becomes large at all flow rates. Furthermore, although the time-averaged value of the pressure component is almost constant, the fluctuation component of the pressure component becomes large at a large flow rate

  7. Structural characterization of rotor blades through photogrammetry

    Science.gov (United States)

    Bernardini, Giovanni; Serafini, Jacopo; Enei, Claudio; Mattioni, Luca; Ficuciello, Corrado; Vezzari, Valerio

    2016-06-01

    This paper deals with the use of photogrammetry for the experimental identification of structural and inertial properties of helicopter rotor blades4. The identification procedure is based upon theoretical/numerical algorithms for the evaluation of mass and flexural stiffness distributions which are an extension of those proposed in the past by Larsen, whereas the torsional properties (stiffness and shear center position) are determined through the Euler–Bernoulli beam theory. The identification algorithms require the knowledge of the blade displacement field produced by known steady loads. These data are experimentally obtained through photogrammetric detection technique, which allows the identification of 3D coordinates of labeled points (markers) on the structure through the correlation of 2D digital photos. Indeed, the displacement field is simply evaluated by comparing the markers positions on the loaded configuration with those on the reference one. The proposed identification procedure, numerically and experimentally validated in the past by the authors, has been here applied to the structural characterization of two main rotor blades, designed for ultra-light helicopters. Strain gauges measurements have been used to assess the accuracy of the identified properties through natural frequencies comparison as well as to evaluate the blades damping characteristics.

  8. Fatigue Life of Wind Turbine Blades

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    2010-01-01

    The present paper analyses the possibility of reducing the expected damage accumulation during tower passage by modifying the wind turbine tower design from a traditional mono-tower to a tripod. Due to a narrow stagnation zone the stress reversals and hence the damage accumulation in the blades i...

  9. Modal analysis of wind turbine blades

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Hansen, M.H.; Baumgart, A.; Carlén, I.

    2002-01-01

    The modal analysis technique has been used to identify essential dynamic properties of wind turbine blades like natural frequencies, damping characteristics and mode shapes. Different experimental procedures have been considered, and the most appropriateof these has been selected. Although the co...

  10. DEM Simulations of Granular Secondary Flow in Cylindrical Vertical Bladed Mixer – Effect of Blade Rake.

    OpenAIRE

    Trávníčková, T. (Tereza); Havlica, J. (Jaromír); Kohout, M.

    2016-01-01

    Mixing of granular systems is one of the most used chemical engineering unit operations. However, detailed description of the dynamics of granular flows through experiments is difficult. Therefore, usage of mathematical modeling increases. In this paper we deal with DEM (Discreet Element Method) simulations of mixing glass beads in a cylindrical vertical bladed mixer. The aim of this work is to describe the influence of blade rake on the development of granular secondary flows for different s...

  11. Separated Pitch Control at Tip: Innovative Blade Design Explorations for Large MW Wind Turbine Blades

    Directory of Open Access Journals (Sweden)

    Ranjeet Agarwala

    2015-01-01

    Full Text Available This paper focuses on the deployment and evaluation of a separated pitch control at blade tip (SePCaT control strategy for large megawatt (MW wind turbine blade and explorations of innovative blade designs as a result of such deployment. SePCaT configurations varied from five to thirty percent of the blade length in 5 percentage increments (SePCaT5, SePCaT10, SePCaT15, SePCaT20, SePCaT25, and SePCaT30 are evaluated by comparing them to aerodynamical responses of the traditional blade. For low, moderate, high, and extreme wind speed variations treated as 10, 20, 30, and 40 percent of reference wind speeds, rotor power abatement in region 3 of the wind speed power curve is realized by feathering full length blade by 6, 9, 12, and 14 degrees, respectively. Feathering SePCaT30, SePCaT25, SePCaT20, and SePCaT15 by 14, 16, 26, and 30 degrees, respectively, achieves the same power abatement results when compared to traditional blade at low wind speeds. Feathering SePCaT30, SePCaT25, and SePCaT20 by 18, 26, and 30 degrees on the other hand has the same effect at high wind speeds. SePCaT30 feathered to 26 and 30 degrees has the same abatement effects when compared to traditional blade at high and extreme wind speeds.

  12. Certification of CFD heat transfer software for turbine blade analysis

    Science.gov (United States)

    Jordan, William A.

    2004-01-01

    Accurate modeling of heat transfer effects is a critical component of the Turbine Branch of the Turbomachinery and Propulsion Systems Division. Being able to adequately predict and model heat flux, coolant flows, and peak temperatures are necessary for the analysis of high pressure turbine blades. To that end, the primary goal of my internship this summer will be to certify the reliability of the CFD program GlennHT for the purpose of turbine blade heat transfer analysis. GlennHT is currently in use by the engineers in the Turbine Branch who use the FORTRAN 77 version of the code for analysis. The program, however, has been updated to a FORTRAN 90 version which is more robust than the older code. In order for the new code to be distributed for use, its reliability must first be certified. Over the course of my internship I will create and run test cases using the FORTRAN 90 version of GlennHT and compare the results to older cases which are known to be accurate, If the results of the new code match those of the sample cases then the newer version will be one step closer to certification for distribution. In order to complete these it will first be necessary to become familiar with operating a number of other programs. Among them are GridPro, which is used to create a grid mesh around a blade geometry, and FieldView, whose purpose is to graphically display the results from the GlennHT program. Once enough familiarity is established with these programs to render them useful, then the work of creating and running test scenarios will begin. The work is additionally complicated by a transition in computer hardware. Most of the working computers in the Turbine Branch are Silicon Graphics machines, which will soon be replaced by LINUX PC's. My project is one of the first to make use the new PC's. The change in system architecture however, has created several software related issues which have greatly increased the time and effort investments required by the project

  13. Intermetallic blades for fabric cutting. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Blue, C.A.; Sklad, S. [Oak Ridge National Lab., TN (United States); Shih, H.R. [Jackson State Univ., MS (United States); Off, J.W.A. [Textile/Clothing Technology Corp., Cary, NC (United States)

    1998-08-01

    This report describes the evaluation of nickel- and iron-aluminide blades for cutting fabric as opposed to conventional steel blades. The aluminides were selected as blade material because of their extremely high work-hardening rate and the possibility of forming aluminum oxide on the surface to further enhance the wear resistance. Unlike steel blades, they do not require heat treating to become strong. A testing facility using an Eastman cutter was designed and built at the Oak Ridge National Laboratory (ORNL) for testing of blades. Denim fabric supplied by Levi Strauss was used. For lack of sufficient fabric, heavy paper was also used. Extensive testing revealed that there were several issues in getting the true comparison between various blades. The most important issue was the consistent sharpening of the blade edge. With all of the effort and precautions, identical edges could not be put on the blades of all the different materials. The second issue was the limited availability of fabric to evaluate the end-of-life limit for the blade edges. Two nickel- and three iron-aluminide compositions were evaluated. Under test conditions, the iron-aluminide alloy (PM-60), based on FeAl, was found to outperform other aluminides and the steel blade. Based on the data presented in this report, the authors recommend that additional testing be carried out on both the steel and aluminide blades to determine the number of times each blade can be sharpened prior to its replacement. However, the recommended testing needs to be conducted on blades for which the identical cutting edges and sharpening are incorporated. They further recommend that if the iron-aluminide blade is truly superior, a cost analysis be performed to determine its commercial feasibility. The best aluminide blades should be tested by commercial textile companies.

  14. Investigation of the impact of rain and particle erosion on rotor blade aerodynamics with an erosion test facility to enhancing the rotor blade performance and durability

    International Nuclear Information System (INIS)

    During their operational life span of around 20 years, the individual components of a wind turbine, especially the rotor blades, are exposed to extreme environmental influences. This is the result of the continuous exposure of wind turbines to the elements and of particularly high rotor blade tip speeds, which exceed a velocity of 90 m/s. These effects result in leading edge erosion. Rotor blades are therefore protected by special coating systems, e.g. varnishes and foils. The durability of those surface coatings varies depending on the location of the wind turbine and often proves to be insufficient. Additionally, there is no standardised test procedure for the evaluation of the durability and protective effect of the coating materials under the highly erosive conditions at the location of the wind turbines. In the course of this project, we will develop a testing procedure to evaluate the erosion of coating materials on actual leading edges of rotor blades, which will be applied in a test facility. The test rig will be capable of simulating a realistic application of rain and sand to gauge the effects of erosion. During the application, two test objects can be tested simultaneously. The geometry of the test objects will be adapted to represent that of real rotor blade tips. In order to generate comparable and transferable results, several challenges have to be met during the implementation, especially the realistic reproduction of environmental influences and the corrosion damage mechanism. In this regard, the duration of the test procedure is very important because a time lapse factor of 100-260 is intended. An operation of 20 years can thereby be simulated within 4 to 10 weeks

  15. Using Optimisation Techniques to Granulise Rough Set Partitions

    International Nuclear Information System (INIS)

    This paper presents an approach to optimise rough set partition sizes using various optimisation techniques. Three optimisation techniques are implemented to perform the granularisation process, namely, genetic algorithm (GA), hill climbing (HC) and simulated annealing (SA). These optimisation methods maximise the classification accuracy of the rough sets. The proposed rough set partition method is tested on a set of demographic properties of individuals obtained from the South African antenatal survey. The three techniques are compared in terms of their computational time, accuracy and number of rules produced when applied to the Human Immunodeficiency Virus (HIV) data set. The optimised methods results are compared to a well known non-optimised discretisation method, equal-width-bin partitioning (EWB). The accuracies achieved after optimising the partitions using GA, HC and SA are 66.89%, 65.84% and 65.48% respectively, compared to the accuracy of EWB of 59.86%. In addition to rough sets providing the plausabilities of the estimated HIV status, they also provide the linguistic rules describing how the demographic parameters drive the risk of HIV

  16. Wavy-Planform Helicopter Blades Make Less Noise

    Science.gov (United States)

    Brooks, Thomas F.

    2004-01-01

    Wavy-planform rotor blades for helicopters have been investigated for the first time in an effort to reduce noise. Two of the main sources of helicopter noise are blade/vortex interaction (BVI) and volume displacement. (The noise contributed by volume displacement is termed thickness noise.) The reduction in noise generated by a wavyplanform blade, relative to that generated by an otherwise equivalent straight-planform blade, affects both main sources: (1) the BVI noise is reduced through smoothing and defocusing of the aerodynamic loading on the blade and (2) the thickness noise is reduced by reducing gradients of thickness with respect to listeners on the ground.

  17. New Design of Blade Untwisting Device of Cyclone Unit

    Directory of Open Access Journals (Sweden)

    D. I. Misiulia

    2010-01-01

    Full Text Available The paper presents a new design of a blade untwisting device where blades are considered as a main element of the device. A profile of the blades corresponds to a circular arch. An inlet angle of  the blades is determined by stream aerodynamics in an exhaust pipe, and an exit angle is determined by rectilinear gas motion. Optimum geometrical parameters of the untwisting device have been determined and its application allows to reduce a pressure drop in the ЦН-15 cyclones by 28–30 % while screw-blade untwisting device recovers only 19–20 % of energy.

  18. Blade reliability collaborative : collection of defect, damage and repair data.

    Energy Technology Data Exchange (ETDEWEB)

    Ashwill, Thomas D.; Ogilvie, Alistair B.; Paquette, Joshua A.

    2013-04-01

    The Blade Reliability Collaborative (BRC) was started by the Wind Energy Technologies Department of Sandia National Laboratories and DOE in 2010 with the goal of gaining insight into planned and unplanned O&M issues associated with wind turbine blades. A significant part of BRC is the Blade Defect, Damage and Repair Survey task, which will gather data from blade manufacturers, service companies, operators and prior studies to determine details about the largest sources of blade unreliability. This report summarizes the initial findings from this work.

  19. Vibration-based SHM System: Application to Wind Turbine Blades

    DEFF Research Database (Denmark)

    Tcherniak, D.; Mølgaard, Lasse Lohilahti

    2015-01-01

    propagate along the blade and are measured by an array of accelerometers. Unsupervised learning is applied to the data: the vibration patterns corresponding to the undamaged blade are used to create a statistical model of the reference state. During the detection stage, the current vibration pattern is......This study presents an vibration-based system designed for structural health monitoring of wind turbine blades. Mechanical energy is introduced by means of an electromechanical actuator mounted inside the blade. The actuator's plunger periodically hits the blade structure; the induced vibrations...

  20. An alternative simple method in laryngoscope blade decontamination.

    Science.gov (United States)

    Orhan, Mehmet Emin; Saygun, Onur; Güzeldemir, M Erdal

    2002-06-01

    The cleaning and disinfection of laryngoscope blades is controversial. The aim of this study is to investigate the efficacy of two different chemical disinfectant agents and tap water where the laryngoscope blades were contaminated by different microorganisms and try to create a simple, effective and easy decontamination method. The results of our study demonstrate that the decontamination of the laryngoscope blades, which are cleansed with tap water, is not a reliable approach. In conclusion, mechanical cleaning of blades with water and the immersion in 2% glutaraldehyde or 10% polyvinyl pyrrolidine iodine for 10 minutes is an effective method for decontamination of laryngoscope blades. PMID:12138517

  1. Alternate blade cavitation on inducer; Inducer no kogoyoku cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, M. [Ebara Research Co. Ltd., Kanagawa (Japan); Huang, J.; Zhang, J.

    1996-08-25

    Concerning a flat-helical inducer with two blades, examinations on suction performance, cavitation development and internal flow conditions of the impeller were performed. As the suction pressure is reduced, the balanced cavity development on both blades is destroyed. Alternate blade cavitation, in which cavity development evolves on one blade while weakens on the other, can occur. When the alternate blade cavitation occurs, the theoretical and actual pump heads can decrease quickly. The following investigations were conducted to determine how this phenomenon develops. 6 refs., 8 figs.

  2. Thermal Imaging of Medical Saw Blades and Guides

    Energy Technology Data Exchange (ETDEWEB)

    Dinwiddie, Ralph Barton [ORNL; Steffner, Thomas E [ORNL

    2007-01-01

    Better Than New, LLC., has developed a surface treatment to reduce the friction and wear of orthopedic saw blades and guides. The medical saw blades were thermally imaged while sawing through fresh animal bone and an IR camera was used to measure the blade temperature as it exited the bone. The thermal performance of as-manufactured saw blades was compared to surface-treated blades, and a freshly used blade was used for temperature calibration purposes in order to account for any emissivity changes due to organic transfer layers. Thermal imaging indicates that the treated saw blades cut faster and cooler than untreated blades. In orthopedic surgery, saw guides are used to perfectly size the bone to accept a prosthesis. However, binding can occur between the blade and guide because of misalignment. This condition increases the saw blade temperature and may result in tissue damage. Both treated ad untreated saw guides were also studied. The treated saw guide operated at a significantly lower temperature than untreated guide. Saw blades and guides that operate at a cooler temperature are expected to reduce the amount of tissue damage (thermal necrosis) and may reduce the number of post-operative complications.

  3. Determination of Turbine Blade Life from Engine Field Data

    Science.gov (United States)

    Zaretsky, Erwin V.; Litt, Jonathan S.; Hendricks, Robert C.; Soditus, Sherry M.

    2013-01-01

    It is probable that no two engine companies determine the life of their engines or their components in the same way or apply the same experience and safety factors to their designs. Knowing the failure mode that is most likely to occur minimizes the amount of uncertainty and simplifies failure and life analysis. Available data regarding failure mode for aircraft engine blades, while favoring low-cycle, thermal-mechanical fatigue (TMF) as the controlling mode of failure, are not definitive. Sixteen high-pressure turbine (HPT) T-1 blade sets were removed from commercial aircraft engines that had been commercially flown by a single airline and inspected for damage. Each set contained 82 blades. The damage was cataloged into three categories related to their mode of failure: (1) TMF, (2) Oxidation/erosion (O/E), and (3) Other. From these field data, the turbine blade life was determined as well as the lives related to individual blade failure modes using Johnson-Weibull analysis. A simplified formula for calculating turbine blade life and reliability was formulated. The L10 blade life was calculated to be 2427 cycles (11 077 hr). The resulting blade life attributed to O/E equaled that attributed to TMF. The category that contributed most to blade failure was Other. If there were no blade failures attributed to O/E and TMF, the overall blade L(sub 10) life would increase approximately 11 to 17 percent.

  4. SBOAT: A Stochastic BPMN Analysis and Optimisation Tool

    DEFF Research Database (Denmark)

    Herbert, Luke Thomas; Hansen, Zaza Nadja Lee; Jacobsen, Peter

    2014-01-01

    exploration of the space of possible models. We present a simple example of a distributed stochastic system where we determine a reachability property and the value of associated rewards in states of interest for a generated range of models. This example is taken from a case company in the Danish baking...... parameterised reward annotations. SBOAT allows the optimisation of these processes by specifying optimisation goals by means of probabilistic control tree logic (PCTL). Optimisation is performed by means of an evolutionary algorithm where stochastic model checking, in the form of the PRISM model checker, is...

  5. Process optimisation - Increasing industrial efficiency; Prozessoptimierungen - Effizientere Industrie

    Energy Technology Data Exchange (ETDEWEB)

    Hegglin, R.

    2009-07-01

    This short article takes a look at how process optimisation can help industry save a large amount of energy. In an interview with Martin Pulfer from the Swiss Federal Office of Energy (SFOE), the following topics are discussed: Co-operation between Swiss federal and cantonal agencies, the ability of Swiss hi-tech industries to optimise their processes themselves, the technologies that can be used, where the greatest potential for making savings can be found, the federal programs available, financial aspects and the long-term goals involved in the optimisation of industrial processes.

  6. Profile control studies for JET optimised shear regime

    Energy Technology Data Exchange (ETDEWEB)

    Litaudon, X.; Becoulet, A.; Eriksson, L.G.; Fuchs, V.; Huysmans, G.; How, J.; Moreau, D.; Rochard, F.; Tresset, G.; Zwingmann, W. [Association Euratom-CEA, CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee, DRFC, 13 - Saint-Paul-lez-Durance (France); Bayetti, P.; Joffrin, E.; Maget, P.; Mayorat, M.L.; Mazon, D.; Sarazin, Y. [JET Abingdon, Oxfordshire (United Kingdom); Voitsekhovitch, I. [Universite de Provence, LPIIM, Aix-Marseille 1, 13 (France)

    2000-03-01

    This report summarises the profile control studies, i.e. preparation and analysis of JET Optimised Shear plasmas, carried out during the year 1999 within the framework of the Task-Agreement (RF/CEA/02) between JET and the Association Euratom-CEA/Cadarache. We report on our participation in the preparation of the JET Optimised Shear experiments together with their comprehensive analyses and the modelling. Emphasis is put on the various aspects of pressure profile control (core and edge pressure) together with detailed studies of current profile control by non-inductive means, in the prospects of achieving steady, high performance, Optimised Shear plasmas. (authors)

  7. Profile control studies for JET optimised shear regime

    International Nuclear Information System (INIS)

    This report summarises the profile control studies, i.e. preparation and analysis of JET Optimised Shear plasmas, carried out during the year 1999 within the framework of the Task-Agreement (RF/CEA/02) between JET and the Association Euratom-CEA/Cadarache. We report on our participation in the preparation of the JET Optimised Shear experiments together with their comprehensive analyses and the modelling. Emphasis is put on the various aspects of pressure profile control (core and edge pressure) together with detailed studies of current profile control by non-inductive means, in the prospects of achieving steady, high performance, Optimised Shear plasmas. (authors)

  8. Application of optimisation techniques in groundwater quantity and quality management

    Indian Academy of Sciences (India)

    Amlan Das; Bithin Datta

    2001-08-01

    This paper presents the state-of-the-art on application of optimisation techniques in groundwater quality and quantity management. In order to solve optimisation-based groundwater management models, researchers have used various mathematical programming techniques such as linear programming (LP), nonlinear programming (NLP), mixed-integer programming (MIP), optimal control theory-based mathematical programming, differential dynamic programming (DDP), stochastic programming (SP), combinatorial optimisation (CO), and multiple objective programming for multipurpose management. Studies reported in the literature on the application of these methods are reviewed in this paper.

  9. Application of optimization methods to helicopter rotor blade design

    Science.gov (United States)

    Chattopadhyay, A.; Walsh, J. L.

    1990-01-01

    A procedure for the minimum weight design of helicopter rotor blades with constraints on multiple coupled flap-lag natural frequencies, autorotational inertia, and centrifugal stress is presented. Optimum designs are obtained for blades with both rectangular and tapered planforms and are compared within a reference blade. The effects of higher-frequency constraints and stress constraints on the optimum blade designs are assessed. The results indicate that there is an increase in blade weight and a significant change in the design variable distributions with an increase in the number of frequency constraints. The inclusion of stress constraints has different effects on the wall thickness distributions of rectangular and tapered blades, but tends to increase the magnitude of the nonstructural segment weight distributions for both blade types.

  10. Structural Analysis and Design of the Composite Wind Turbine Blade

    Science.gov (United States)

    Wu, Wen-Hsiang; Young, Wen-Bin

    2012-06-01

    The wind turbine blade sustains various kinds of loadings during the operation and parking state. Due to the increasing size of the wind turbine blade, it is important to arrange the composite materials in a sufficient way to reach the optimal utilization of the material strength. Most of the composite blades are made of glass fibers composites while carbon fibers are also employed in recent years. Composite materials have the advantages of high specific strength and stress. This study develops a GUI interface to construct the blade model for the stress analysis using ANSYS. With the aid of visualization interface, the geometric model of the blade can be constructed by only a few data inputs. Based on the numerical stress analysis of the turbine blade, a simple iterative method was proposed to design the structure of the composite blade.

  11. Study on Aerodynamic Design Optimization of Turbomachinery Blades

    Institute of Scientific and Technical Information of China (English)

    Naixing CHEN; Hongwu ZHANG; Weiguang HUANG; Yanji XU

    2005-01-01

    This paper describes the study on aerodynamics design optimization of turbomachinery blading developed by the authors at the Institute of Engineering Thermophysics, Chinese Academy of Sciences, during the recent few years. The present paper describes the aspects mainly on how to use a rapid approach of profiling a 3D blading and of grid generation for computation, a fast and accurate viscous computation method and an appropriate optimization methodology_ including a blade parameterization algorithm to optimize turbomachinery blading aerodynamically. Any blade configuration can be expressed by three curves, they are the camber lines, the thickness distributions and the radial stacking line, and then the blade geometry can be easily parameterized by a number of parameters with three polynomials. A gradient-based parameterization analytical method and a response surface method were applied herein for blade optimization. It was found that the optimization process provides reliable design for turbomachinery with reasonable computing time.

  12. New Dynamic Spin Rig Capabilities Used to Determine Rotating Blade Dynamics

    Science.gov (United States)

    Provenza, Andrew J.

    2004-01-01

    interest and using the half-power method. The free decay of a composite blade vibrating at its first bending resonance while rotating at 3000 rp is shown. This new system is currently being used to support the Efficient Low-Noise Fan project at Glenn. The damping properties of prototype hollow composite blades specially designed to reduce fan noise are currently being determined.

  13. Optimisation of a vertical spray boom for greenhouse spraying applications.

    Science.gov (United States)

    Nuyttens, D; Windey, S; Braekman, P; De Moor, A; Sonck, B

    2003-01-01

    The European Crop Protection Association (ECPA) and CLO-DVL joined forces in a project to stimulate a safe use of pesticides in Southern European countries. CLO-DVL optimised a method with mineral chelates to evaluate deposition tests. This quantitative method to evaluate spray deposits and to check spray distributions is used to assess two novel spraying techniques. Deposition tests with water-sensitive paper and mainly with the manganese and molybdenum chelates as tracer elements were performed with a manually pulled trolley and a motorised vehicle both equipped with vertical spray booms. Filter papers were attached to the tomato and pepper plants at several heights to obtain an indication of the spray distribution in the crop. Particular attention was paid to the effect on the spray distribution of the vertical nozzle distance (35 cm vs. 50 cm) and the spray distance to the crop. The tests proved that a nozzle spacing of 35 cm delivers a much better spray distribution than one of 50 cm. The optimal spray distance for flat fan nozzles with a spray angle of 80 degrees and a nozzle spacing of 35 cm is about 30 cm. PMID:15151329

  14. Optimisation of the ATLAS Track Reconstruction Software for Run-2

    Science.gov (United States)

    Salzburger, Andreas

    2015-12-01

    The reconstruction of particle trajectories in the tracking detectors of experiments at the Large Hadron Collider (LHC) is one of the most complex parts in analysing the data from beam-beam collisions. To maximise the integrated luminosity during Run-1 of the LHC data taking period, the number of simultaneous proton-proton interactions per beam crossing (pile- up) was steadily increased. The track reconstruction is the most time consuming reconstruction component and scales non-linearly in high luminosity environments. Flat budget projections (at best) for computing resources during the upcoming Run-2 of the LHC together with the demands of reconstructing higher pile-up collision data at rates more than double compared to Run-1 have put pressure on the track reconstruction software to meet the available computing resources. The ATLAS experiment has thus performed a two year long software campaign which led to a reduction of the reconstruction time for Run-2 conditions by a factor of four: a major part of the changes were improvements to the track reconstruction, which was reduced by more than a factor of five without any loss of output information for subsequent physics analysis. We present the methods used for analysing the software, the planning and deployment of updates and new methods implemented to optimise both algorithmic performance and event data.

  15. Optics Design and Lattice Optimisation for the HL-LHC

    CERN Document Server

    Holzer, B J; Fartoukh, S; Chancé, A; Dalena, B; Payet, J; Bogomyagkov, A; Appleby, R B; Kelly, S; Thomas, M B; Thompson, L; Korostelev, M; Hock, K M; Wolski, A; Milardi, C; Faus-Golfe, A; Resta Lopez, J

    2013-01-01

    The luminosity upgrade project of the LHC collider at CERN is based on a strong focusing scheme to reach lowest values of the β function at the collision points. Depending on the magnet technology (Nb3Sn or Nb-Ti) that will be available, a number of beam optics has been developed to define the specifications for the new superconducting magnets. In the context of the optics matching new issues have been addressed and new concepts have been used that play a major role in dealing with the extremely high beta functions. Quadrupole strength flexibility and chromatic corrections have been studied, the influence of the quadrupole fringe fields has been taken into account and the lattice in the matching section had been optimised including the needs of the crab cavities that will be installed. The transition between injection and low β optics has to guarantee smooth gradient changes over a wide range of β* values and the tolerances on misalignments and power converter ripple has been re-evaluated. Finally the succ...

  16. Facade optimisation - light, solar shading and insulation in consistence with technical equipment; Fassaden-Optimierung - Licht, Sonnen- und Waermeschutz mit der TGA im Einklang?

    Energy Technology Data Exchange (ETDEWEB)

    Hoerth, H. [AFC Air Flow Consulting, Zuerich (Switzerland)

    2006-07-01

    A critical issue in almost every construction project is the optimisation of the facade. Different wishes, ideas, standards, instructions etc. have to be fulfilled. Facade solar shading and thermal insulation have a direct influence on energy consumption and thermal comfort. However, is the particular shading device efficient? Will a better U-value really reduce the overall energy consumption? Double-facade constructions are often selected in refurbishing projects but also for new buildings. Questions often arise on total transmittance and sufficient cavity ventilation. Examples of optimisation methods and targets will be shown for such constructions. (orig.)

  17. Deflection estimation of a wind turbine blade using FBG sensors embedded in the blade bonding line

    International Nuclear Information System (INIS)

    Estimating the deflection of flexible composite wind turbine blades is very important to prevent the blades from hitting the tower. Several researchers have used fiber Bragg grating (FBG) sensors—a type of optical fiber sensor (OFS)—to monitor the structural behavior of the blades. They can be installed on the surface and/or embedded in the interior of composites. However, the typical installation positions of OFSs present several problems, including delamination of sensing probes and a higher risk of fiber breakage during installation. In this study, we proposed using the bonding line between the shear web and spar cap as a new installation position of embedded OFSs for estimating the deflection of the blades. Laboratory coupon tests were undertaken preliminarily to confirm the strain measuring capability of embedded FBG sensors in adhesive layers, and the obtained values were verified by comparison with results obtained by electrical strain gauges and finite element analysis. We performed static loading tests on a 100 kW composite wind turbine blade to evaluate its deflections using embedded FBG sensors positioned in the bonding line. The deflections were estimated by classical beam theory considering a rigid body rotation near the tip of the blade. The evaluated tip deflections closely matched those measured by a linear variable differential transformer. Therefore, we verified the capability of embedded FBG sensors for evaluating the deflections of wind turbine blades. In addition, we confirmed that the bonding line between the shear web and spar cap is a practical location to embed the FBG sensors. (paper)

  18. Optimization Design and Experimental Study of Low-Pressure Axial Fan with Forward-Skewed Blades

    OpenAIRE

    Li Yang; Ouyang Hua; Du Zhao-Hui

    2007-01-01

    This paper presents an experimental study of the optimization of blade skew in low pressure axial fan. Using back propagation (BP) neural network and genetic algorithm (GA), the optimization was performed for a radial blade. An optimized blade is obtained through blade forward skew. Measurement of the two blades was carried out in aerodynamic and aeroacoustic performance. Compared to the radial blade, the optimized blade demonstrated improvements in efficiency, total pres...

  19. Coolant Density and Control Blade History Effects in Extended BWR Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Ade, Brian J [ORNL; Marshall, William BJ J [ORNL; Bowman, Stephen M [ORNL; Gauld, Ian C [ORNL; Ilas, Germina [ORNL; Martinez-Gonzalez, Jesus S [ORNL

    2015-01-01

    Oak Ridge National Laboratory and the US Nuclear Regulatory Commission have initiated a multiyear project to investigate the application of burnup credit (BUC) for boiling water reactor (BWR) fuel in storage and transportation casks. This project includes two phases. The first phase investigates the applicability of peak reactivity methods currently used for spent fuel pools to spent fuel storage and transportation casks and the validation of reactivity (keff) calculations and predicted spent fuel compositions. The second phase focuses on extending BUC beyond peak reactivity. This paper documents work performed to date investigating some aspects of extended BUC. (The technical basis for application of peak reactivity methods to BWR fuel in storage and transportation systems is presented in a companion paper.) Two reactor operating parameters are being evaluated to establish an adequate basis for extended BWR BUC: (1) the effect of axial void profile and (2) the effect of control blade utilization during operation. A detailed analysis of core simulator data for one cycle of a modern operating BWR plant was performed to determine the range of void profiles and the variability of the profile experienced during irradiation. Although a single cycle does not provide complete data, the data obtained are sufficient to determine the primary effects and to identify conservative modeling approaches. These data were used in a study of the effect of axial void profile. The first stage of the study was determination of the necessary moderator density temporal fidelity in depletion modeling. After the required temporal fidelity was established, multiple void profiles were used to examine the effect on cask reactivity. The results of these studies are being used to develop recommendations for conservatively modeling the void profile effects for BWR depletion calculations. The second operational parameter studied was control blade history. Control blades are inserted in

  20. Analysis and optimisation of heterogeneous real-time embedded systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2006-01-01

    success of such new design methods depends on the availability of analysis and optimisation techniques. Analysis and optimisation techniques for heterogeneous real-time embedded systems are presented in the paper. The authors address in more detail a particular class of such systems called multi......-clusters, composed of several networks interconnected via gateways. They present a schedulability analysis for safety-critical applications distributed on multi-cluster systems and briefly highlight characteristic design optimisation problems: the partitioning and mapping of functionality, and the packing of...... application messages to frames. Optimisation heuristics for frame packing aimed at producing a schedulable system are presented. Extensive experiments and a real-life example show the efficiency of the frame-packing approach....

  1. Analysis and optimisation of heterogeneous real-time embedded systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2005-01-01

    success of such new design methods depends on the availability of analysis and optimisation techniques. Analysis and optimisation techniques for heterogeneous real-time embedded systems are presented in the paper. The authors address in more detail a particular class of such systems called multi......-clusters, composed of several networks interconnected via gateways. They present a schedulability analysis for safety-critical applications distributed on multi-cluster systems and briefly highlight characteristic design optimisation problems: the partitioning and mapping of functionality, and the packing of...... application messages to frames. Optimisation heuristics for frame packing aimed at producing a schedulable system are presented. Extensive experiments and a real-life example show the efficiency of the frame-packing approach....

  2. Protection against natural radiation: Optimisation and decision exercises

    International Nuclear Information System (INIS)

    Six easy exercises are presented in which cost-benefit analysis is used to optimise protection against natural radiation or to decide whether protection is appropriate. The exercises are illustrative only and do not commit the Board. (author)

  3. Pre-Industry-Optimisation of the Laser Welding Process

    DEFF Research Database (Denmark)

    Gong, Hui

    This dissertation documents the investigations into on-line monitoring the CO2 laser welding process and optimising the process parameters for achieving high quality welds. The requirements for realisation of an on-line control system are, first of all, a clear understanding of the dynamic......, and monitoring signals are systematically studied and investigated. For gas parameter optimisation, there are 5 gas variables optimised when applying the Design of Experiment (DOE). One photo diode is set to monitor the welding process in order to characterise the consistence of the discrimination...... features of the welding process by applying FFT analysis of the signals. DOE is proven to be a useful tool for manual parameter optimisations in laser welding. The frequency of the photo diode signal could be related to weld quality measures, however, the application possibility of the signal in a control...

  4. Share-of-Surplus Product Line Optimisation with Price Levels

    Directory of Open Access Journals (Sweden)

    X. G. Luo

    2014-01-01

    Full Text Available Kraus and Yano (2003 established the share-of-surplus product line optimisation model and developed a heuristic procedure for this nonlinear mixed-integer optimisation model. In their model, price of a product is defined as a continuous decision variable. However, because product line optimisation is a planning process in the early stage of product development, pricing decisions usually are not very precise. In this research, a nonlinear integer programming share-of-surplus product line optimization model that allows the selection of candidate price levels for products is established. The model is further transformed into an equivalent linear mixed-integer optimisation model by applying linearisation techniques. Experimental results in different market scenarios show that the computation time of the transformed model is much less than that of the original model.

  5. An optimisation model of geothermal-energy conversion

    International Nuclear Information System (INIS)

    A mathematical model of the behaviour of a geothermal-energy source, based on the theoretical water well of different quality parameters has been presented. Heat energy magnification produced by the well by increasing the stream of pumping water is analysed. Optimisation analyses are conducted assuming different types of source: constant or dynamic parameters. The technical optimisation model maximises the net power of the source, which is the difference between the heat source power and the power of pumping. The optimisation model maximises the value of heat energy produced by the source minus the value of the electrical energy used for pumping. The technical and economic optimisation gives different results because the unit cost of heat energy is lower than that of electrical energy. (Author)

  6. Influence of Reynolds Number on Multi-Objective Aerodynamic Design of a Wind Turbine Blade

    Science.gov (United States)

    Ge, Mingwei; Fang, Le; Tian, De

    2015-01-01

    At present, the radius of wind turbine rotors ranges from several meters to one hundred meters, or even more, which extends Reynolds number of the airfoil profile from the order of 105 to 107. Taking the blade for 3MW wind turbines as an example, the influence of Reynolds number on the aerodynamic design of a wind turbine blade is studied. To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (CPopt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP). It is found that under the same configuration, the optimal design has a larger CPopt or AEP (CPopt//AEP) for the same ultimate load, or a smaller load for the same CPopt//AEP at higher Reynolds number. At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum Cpopt//AEP. If a wind turbine blade is designed by using an airfoil database with a mismatched Reynolds number from the actual one, both the load and Cpopt//AEP will be incorrectly estimated to some extent. In some cases, the assessment error attributed to Reynolds number is quite significant, which may bring unexpected risks to the earnings and safety of a wind power project. PMID:26528815

  7. Distributions of grain parameters on the surface of aircraft engine turbine blades

    Directory of Open Access Journals (Sweden)

    J. Chmiela

    2010-10-01

    Full Text Available In the quality assurance system for components cast using the lost wax method, the object of evaluation is the grain size on the surface of the casting. This paper describes a new method for evaluating the primary grain parameters on the surface of aircraft engine turbine blades. Effectiveness of the method has been tested on two macrostructures distinguished by a high degree of diversity in the grain size. The grounds for evaluating the grain parameters consist of geometric measurement of the turbine blade using a laser profilometer and of approximation of the measurement results using a polynomial of a proper degree. The so obtained analytical non-planar surface serves as a reference point for an assessment of the parameters of grains observed on the real blade surface of a variable curvature. The aspects subjected to evaluation included: the grain areas, shape and elongation coefficients of grains on a non-planar surface of the blade airfoil, using measurements taken on a perpendicular projection by means of a stereoscopic microscope and image analysis methods, and by making calculations using the Mathematica® package.

  8. Development of interactive design system, KAIT by computer-analysis for gas turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Tsuta, Toshio; Yamaji, Seiichi; Tanizawa, Tadashi; Isozaki, Toshiaki; Hamabe, Kenji; Hoshino, Akifumi; Sugimoto, Takao; Miyaji, Hiroshi; Take, Koji; Yoshigane, Masaru

    1987-08-20

    Upon development of various gas turbines, design of the turbine power generating portion provides the dominating influences over the turbine performance and durability. Heretofore, such design has been coped with by the accumulation of the technologies required during the design stage which had been programed individually, but due to the recent increase of development projects which contents have been upgraded, difficulties have arisen in coping with the performance design of blade profile, etc. which requires a time-consuming trial and error approach. Accordingly, Kawasaki Heavy Industries Co. has developed the Kawasaki Interactive Axial Gas Turbine Blade Design System (KAIT) which does the design and development of turbine blades, the most labor and time consuming work in designing a gas turbine, through the computer dialoguing on examination and analysis in each different specific field such as fluid dynamics, thermodynamics, structural mechanics, fatigue and high temperature strength etc.. This article explains the outline of this system. Thanks for this system, a blade with well balanced performance and durability can be designed in a short time. (13 figs, 12 refs)

  9. Influence of Reynolds Number on Multi-Objective Aerodynamic Design of a Wind Turbine Blade.

    Science.gov (United States)

    Ge, Mingwei; Fang, Le; Tian, De

    2015-01-01

    At present, the radius of wind turbine rotors ranges from several meters to one hundred meters, or even more, which extends Reynolds number of the airfoil profile from the order of 105 to 107. Taking the blade for 3MW wind turbines as an example, the influence of Reynolds number on the aerodynamic design of a wind turbine blade is studied. To make the study more general, two kinds of multi-objective optimization are involved: one is based on the maximum power coefficient (CPopt) and the ultimate load, and the other is based on the ultimate load and the annual energy production (AEP). It is found that under the same configuration, the optimal design has a larger CPopt or AEP (CPopt//AEP) for the same ultimate load, or a smaller load for the same CPopt//AEP at higher Reynolds number. At a certain tip-speed ratio or ultimate load, the blade operating at higher Reynolds number should have a larger chord length and twist angle for the maximum Cpopt//AEP. If a wind turbine blade is designed by using an airfoil database with a mismatched Reynolds number from the actual one, both the load and Cpopt//AEP will be incorrectly estimated to some extent. In some cases, the assessment error attributed to Reynolds number is quite significant, which may bring unexpected risks to the earnings and safety of a wind power project. PMID:26528815

  10. Multilevel optimisation of aerospace and lightweight structures incorporating postbuckling effects

    Science.gov (United States)

    Qu, Shuang

    The optimisation of aerospace structures is a very complex problem, due to the hundreds of design variables a multidisciplinary optimisation may contain, so that multilevel optimisation is required. This thesis presents the recent developments to the multilevel optimisation software VICONOPT MLO, which is a multilevel optimisation interface between the well established analysis and design software packages VICONOPT and MSC/NASTRAN. The software developed is called VICONOPT MLOP (Multilevel Optimisation with Postbuckling), and allows for postbuckling behaviour, using analysis based on the Wittrick-Williams algorithm. The objective of this research is to enable a more detailed insight into the multilevel optimisation and postbuckling behaviour of a complex structure. In VICONOPT MLOP optimisation problems, individual panels of the structural model are allowed to buckle before the design load is reached. These panels continue to carry load with differing levels of reduced stiffness. VICONOPT MLOP creates new MSC/NASTRAN data files based on this reduced stiffness data and iterates through analysis cycles to converge on an appropriate load re-distribution. Once load convergence has been obtained with an appropriate criterion, the converged load distribution is used as a starting point in the optimisation of the constituent panels, i.e. a new design cycle is started, in which the updated ply thicknesses for each panel are calculated by VICONOPT and returned to MSC/NASTRAN through VICONOPT MLOP. Further finite element analysis of the whole structure is then carried out to determine the new stress distributions in each panel. The whole process is repeated until a mass convergence criterion is met. A detailed overview of the functionality of VICONOPT MLOP is presented in the thesis. A case study is conducted into the multilevel optimisation of a composite aircraft wing, to demonstrate the capabilities of VICONOPT MLOP and identify areas for future studies. The results of

  11. Intelligent Support for a Computer Aided Design Optimisation Cycle

    OpenAIRE

    B. Dolšak; Novak, M.; J. Kaljun

    2006-01-01

    It is becoming more and more evident that  adding intelligence  to existing computer aids, such as computer aided design systems, can lead to significant improvements in the effective and reliable performance of various engineering tasks, including design optimisation. This paper presents three different intelligent modules to be applied within a computer aided design optimisation cycle to enable more intelligent and less experience-dependent design performance. 

  12. The planning and optimisation of DVB-H radio network

    OpenAIRE

    Penttinen, Jyrki T. J

    2011-01-01

    In the DVB-H (Digital Video Broadcasting - Handheld) radio network planning, there are details that lack final consensus in the scientific field. The aim of this doctoral dissertation is to investigate advanced DVB-H radio network planning and optimisation. This dissertation presents the results of measurement techniques, network coverage and quality estimation, technological and economical optimisation, as well as error correction and single frequency network performance. The outcome include...

  13. Multiobjective optimisation of bogie suspension to boost speed on curves

    Science.gov (United States)

    Milad Mousavi-Bideleh, Seyed; Berbyuk, Viktor

    2016-01-01

    To improve safety and maximum admissible speed on different operational scenarios, multiobjective optimisation of bogie suspension components of a one-car railway vehicle model is considered. The vehicle model has 50 degrees of freedom and is developed in multibody dynamics software SIMPACK. Track shift force, running stability, and risk of derailment are selected as safety objective functions. The improved maximum admissible speeds of the vehicle on curves are determined based on the track plane accelerations up to 1.5 m/s2. To attenuate the number of design parameters for optimisation and improve the computational efficiency, a global sensitivity analysis is accomplished using the multiplicative dimensional reduction method (M-DRM). A multistep optimisation routine based on genetic algorithm (GA) and MATLAB/SIMPACK co-simulation is executed at three levels. The bogie conventional secondary and primary suspension components are chosen as the design parameters in the first two steps, respectively. In the last step semi-active suspension is in focus. The input electrical current to magnetorheological yaw dampers is optimised to guarantee an appropriate safety level. Semi-active controllers are also applied and the respective effects on bogie dynamics are explored. The safety Pareto optimised results are compared with those associated with in-service values. The global sensitivity analysis and multistep approach significantly reduced the number of design parameters and improved the computational efficiency of the optimisation. Furthermore, using the optimised values of design parameters give the possibility to run the vehicle up to 13% faster on curves while a satisfactory safety level is guaranteed. The results obtained can be used in Pareto optimisation and active bogie suspension design problems.

  14. Custom optimisation of wedge angles in prostate radiotherapy

    International Nuclear Information System (INIS)

    A method for computing optimised wedge angles will be presented along with a performance evaluation over 12 patients with early prostate cancer. The method (an optimisation algorithm) was applied to standard 3 field treatment plans for each patient. The optimisation algorithm was based on simulated anealing using an efficient dose based cost function. The algorithm has been run in three PLAN MODES: (1) where the wedge angles were fixed by the human planner and only the beam-weights were optimised; (2) where both the wedge angles and beam-weights were optimised; and (3) where both the wedge angles and beam-weights were optimised and a non-uniform dose was prescribed to the PTV. In the latter PLAN MODE, a uniform 100% dose was prescribed to all of the PTV except for that region that overlaps with the rectum where a lower (e.g. 90%) dose was prescribed. The resulting optimised plans have been compared with those of the human planner who found beam-weights by conventional forward planning. Plans were compared on the basis of dose statistics, normal-tissue-complication-probability (NTCP) and tumour-control-probability (TCP). The results show that all 3 PLAN MODES produced plans with slightly higher TCP for the same rectal NTCP, than the human planner. The best results were observed for PLAN MODE 3, where a non-uniform PTV dose was prescribed. An average increase in TCP of 0.73% (± 0.20 95% confidence interval) is predicted. Probably the most significant benefit of the algorithm in the prostate setting is the time saved (about a factor of 10) in computing optimised beam-weights and wedge angles for this simple plan

  15. Optimising polarised neutron scattering measurements--XYZ and polarimetry analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cussen, L.D.; Goossens, D.J. E-mail: dgo@ansto.gov.au

    2002-09-21

    The analytic optimisation of neutron scattering measurements made using XYZ polarisation analysis and neutron polarimetry techniques is discussed. Expressions for the 'quality factor' and the optimum division of counting time for the XYZ technique are presented. For neutron polarimetry the optimisation is identified as analogous to that for measuring the flipping ratio and reference is made to the results already in the literature.

  16. Optimisation of composite materials using a multilevel decomposition approach

    OpenAIRE

    Chedid, Marwan Maurizio

    2009-01-01

    The design optimisation of thick composite components requires dealing with large number of design variables, highly non-linear equations and huge computational demand. A multi-level decomposition process has been developed to optimise these elements, investigating the potentialities of pre-existing approaches of the bioengineering field of hip and femoral implants. The strength of exploiting a multi-level decomposition process is related to the flexibility of choosing at each level spe...

  17. Real-time receding horizon optimisation of gas pipeline networks

    OpenAIRE

    Aalto, Hans

    2005-01-01

    Real-time optimisation of gas pipelines in transient conditions is considered to be a challenging problem. Many pipeline systems are, however, only mildly non-linear. It is shown, that even the shutdown event of a compressor station can be described using a linear model. A dynamic, receding horizon optimisation problem is defined, where the free response prediction of the pipeline is obtained from a pipeline simulator and the optimal values of the decision variables are obtained solving a Qua...

  18. Business process optimisation using an evolutionary multi-objective framework

    OpenAIRE

    Vergidis, K.

    2008-01-01

    In response to the increasingly volatile and competitive environment, organisations are examining how their core business processes may be redesigned in order to improve business performance and market responsiveness. However, there is a lack of holistic approaches towards business process redesign through optimisation. The aim of this research is to develop an evolutionary multi-objective optimisation framework for business processes capable of: (i) representing business process designs in a...

  19. Manufacturing of ceramic cutting blades by PIM

    Energy Technology Data Exchange (ETDEWEB)

    Rak, Z.S.; Snijders, G. [ECN Energy Efficiency, Petten (Netherlands)

    1997-09-01

    Ceramic cutting blades of differing size and thickness varying between 0.15-0.60 mm are manufactured by powder injection moulding (PIM) using a feedstock based on the yttria partially stabilised zirconia (TZ-3YS) powder and polyacetal-based system. The injection process ensures a high production efficiency, and is followed by a short catalytic debinding process (1 -3 h) at the temperatures of 105-115C. The sintered blades are machined to the final thickness, and if necessary, undergo an additional heat treatment in reducing conditions to improve the mechanical properties of the product. The influence of the manufacturing procedure on the quality of the final product is discussed. A comparison of the degree of densification, micro-structure and mechanical properties of ceramic knives manufactured by PIM, uniaxial pressing and tape casting is reviewed. 11 refs.

  20. Development of excitation and measurement for identification of rotating blade disks

    Czech Academy of Sciences Publication Activity Database

    Pešek, Luděk; Vaněk, František; Procházka, Pavel; Vaněk, Petr; Cibulka, Jan

    Vienna: Technische Universitat Wien, 2009 - (Springer, H.; Ecker, H.), s. 1-10 ISBN 978-3-200-01412-1. [Vibrations in Rotating Machines /8./. Vienna (AT), 23.02.2009-25.02.2009] R&D Projects: GA ČR GA101/09/1166 Institutional research plan: CEZ:AV0Z20760514 Keywords : vibrodiagnostic-measuring system * rotating bladed wheels vibration * travelling waves Subject RIV: BI - Acoustics