Analysis of improved and original designs of a 16 inch long penultimate stage turbine blade

International Nuclear Information System (INIS)

Carnero, A.; Kubiak, J.A.; Mendez, R.

1994-01-01

A finite element analysis of 16 inch long penultimate stage (L-1) blade was carried out to evaluate the improved and the original designs. The original design of the blade involved the ''blade-tenon-shroud'' system to make blade groups (6 blades per group). The improved design applied the concept of Integral Shroud Blade (ISB). Thus all the blades made a 360 degree group. The paper presents an application of the finite element analysis method to compute the natural frequencies, steady-state and alternating stresses, deformation due to forces acting on the blades and modal shapes of the blade group. In the case of the improved design it was also necessary to carry out computation of the dynamic response of a 360 degree blade-disk arc. This was to include the effect of the flexible disk fastening where blade and disk interaction were important to identify certain resonant conditions. It was concluded from the finite element results, that the steady-state stresses in the improved blade were lower, and the tangential mode shapes were eliminated. This was a great advantage since in the original design the first tangential mode shape and the higher steady-state stresses in the tenon contributed to the frequent failure of the ''blade-tenon-shroud'' system

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.

Geometric accuracy of wax bade models manufactured in silicon moulds

Directory of Open Access Journals (Sweden)

G. Budzik

2010-01-01

Full Text Available The article presents the test results of the geometric accuracy of wax blade models manufactured in silicon moulds in the Rapid Tooling process, with the application of the Vacuum Casting technology. In batch production casting waxes are designed for the manufacture of models and components of model sets through injection into a metal die. The objective of the tests was to determine the possibility of using traditional wax for the production of casting models in the rapid prototyping process. Blade models made of five types of casting wax were measured. The definition of the geometric accuracy of wax blade models makes it possible to introduce individual modifications aimed at improving their shape in order to increase the dimensional accuracy of blade models manufactured in the rapid prototyping process.

Aero-Thermo-Structural Design Optimization of Internally Cooled Turbine Blades

Science.gov (United States)

Dulikravich, G. S.; Martin, T. J.; Dennis, B. H.; Lee, E.; Han, Z.-X.

1999-01-01

A set of robust and computationally affordable inverse shape design and automatic constrained optimization tools have been developed for the improved performance of internally cooled gas turbine blades. The design methods are applicable to the aerodynamics, heat transfer, and thermoelasticity aspects of the turbine blade. Maximum use of the existing proven disciplinary analysis codes is possible with this design approach. Preliminary computational results demonstrate possibilities to design blades with minimized total pressure loss and maximized aerodynamic loading. At the same time, these blades are capable of sustaining significantly higher inlet hot gas temperatures while requiring remarkably lower coolant mass flow rates. These results suggest that it is possible to design internally cooled turbine blades that will cost less to manufacture, will have longer life span, and will perform as good, if not better than, film cooled turbine blades.

Improvement of centrifugal pump performance through addition of splitter blades on impeller pump

Science.gov (United States)

Kurniawan, Krisna Eka; Santoso, Budi; Tjahjana, Dominicus Danardono Dwi Prija

2018-02-01

The workable way to improve pump performance is to redesign or modify the impellers of centrifugal pump. The purpose of impeller pump modification is to improve pump efficiency, reduce cross flow, reduce secondary incidence flows, and decrease backflow areas at impeller outlets. Number blades and splitter blades in the impeller are three. The outlet blade angle is 20°, and the rotating speed of impeller is 2400 rpm. The added splitter blades variations are 0.25, 0.375, and 0.5 of the original blade length. The splitter blade placements are on the outer side of the impeller. The addition of splitter blades on the outer side of the impeller with 0.5L increases the pump head until 22% and the pump has 38.66% hydraulic efficiency. The best efficiency point of water flow rate pump (Qbep) was 3.02 × 10-3 m3/s.

Applied modal analysis of wind turbine blades

Energy Technology Data Exchange (ETDEWEB)

Broen Pedersen, H.; Dahl Kristensen, O.J.

2003-02-01

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. Different equipment for mounting the accelerometers are investigated and the most suitable are chosen. Different excitation techniques are tried during experimental campaigns. After a discussion the pendulum hammer were chosen, and a new improved hammer was manufactured. Some measurement errors are investigated. The ability to repeat the measured results is investigated by repeated measurement on the same wind turbine blade. Furthermore the flexibility of the test set-up is investigated, by use of accelerometers mounted on the flexible adapter plate during the measurement campaign. One experimental campaign investigated the results obtained from a loaded and unloaded wind turbine blade. During this campaign the modal analysis are performed on a blade 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 Oeyes blade{sub E}V1 program. (au)

Bimetallic Blisks with Shrouded Turbine Blades for Gas Turbine Engines

Directory of Open Access Journals (Sweden)

L. A. Magerramova

2015-01-01

Full Text Available The paper discusses prospects of using blisks with shrouded blades. Increasing an engine life and efficiency as well as mass reduction can also be achieved by increasing blade numbers and decreasing disk diameter. But design engineers are faced with the problem of blade placement because of the disk size and root dimensions.The problem of increasing life and cyclic durability, vibration strength, and lightweight design of the turbine gas turbine wheels, can be solved by an elimination of blade - disk locks.The technology of manufacturing one-piece blisks by connecting the blades with the disc part using hot isostatic pressing was developed. This technology allows us to use blades with shrouds. It is necessary to increase efficiency and to improve high cycle fatigue performance of rotor blades.One of the pressing problems is to ensure the necessary position of shrouds in relation to each other in the manufacturing process as well as in the service. Numerical studies of the influence of the shroud mounting position on blade strength during operation allowed us to develop a methodology of choosing a shroud mounting position.Based on the two turbine wheels (LPT and HPT calculations advantages of blisk design with respect to the lock-based design were shown. Application of bimetallic blisks with shrouded blades resulted in a lifespan increase and weight reduction.In addition, other advantages of blisk design are as follows: possible reduction in the number of parts, elimination of leaks and fretting that take place in the blade - disk locks, exception of expensive broaching operations and disk alloy saving. The shortcoming is elimination of damping in root connection. In addition, there are no widely used repair methods.Despite these disadvantages the usage of bimetallic turbine blisks with shrouded blades is very promising.

About the problems and perspectives of making precision compressor blades

Directory of Open Access Journals (Sweden)

V. E. Galiev

2014-01-01

Full Text Available The problems of manufacturing blades with high precision profile geometry are considered in the article. The variant of the technology under development rules out the use of mechanical processing methods for blades airfoil. The article consists of an introduction and six small sections.The introduction sets out the requirements for modern aircraft engines, makes a list of problems arisen in the process of their manufacturing, and marks the relevance of the work.The first section analyzes the existing technology of precision blades. There is an illustration reflecting the stages of the process. Their advantages and disadvantages are marked.The second section provides an illustration, which shows the system-based blades used in the manufacturing process and a model of the work piece using the technology being developed. An analysis of each basing scheme is presented.In the third section we list the existing control methods of geometrical parameters of blades airfoil and present the measurement error data of devices. The special attention is paid to the impossibility to control the accuracy of geometrical parameters of precision blades.The fourth section presents the advantages of the electrochemical machining method with a consistent vibration of tool-electrode and with feeding the pulses of technology current over the traditional method. The article presents data accuracy and surface roughness of the blades airfoil reached owing to precision electrochemical machining. It illustrates machines that implement the given method of processing and components manufactured on them.The fifth section describes the steps of the developed process with justification for the use of the proposed operations.Based on the analysis, the author argues that the application of the proposed process to manufacture the precision compressor blades ensures producing the items that meet the requirements of the drawing.

Damage detection in wind turbine blades using acoustic techniques

Energy Technology Data Exchange (ETDEWEB)

Juengert, A., E-mail: anne.juengert@mpa.uni-stuttgart.de [Univ. of Stuttgart, Materialpruefungsanstalt Stuttgart, Stuttgart (Germany)

2013-05-15

Facing climate change, the use of renewable energy gains importance. The wind energy sector grows very fast. Bigger and more powerful wind turbines will be built in the coming decades and the safety and reliability of the turbines will become more important. Wind turbine blades have to be inspected at regular intervals, because they are highly stressed during operation and a blade breakdown can cause big economic damages. The turbine blades consist of fiber reinforced plastics (GFRP/CFRP) and sandwich areas containing wood or plastic foam. The blades are manufactured as two halves and glued together afterwards. Typical damages are delaminations within the GFRP or the sandwich and missing adhesive or deficient bond at the bonding surfaces. The regular inspections of wind turbine blades are performed manually by experts and are limited to visual appraisals and simple tapping tests. To improve the inspections of wind turbine blades non-destructive testing techniques using acoustic waves are being developed. To detect delaminations within the laminates of the turbine blade, a local resonance spectroscopy was used. To detect missing bond areas from the outside of the blade the impulse-echo-technique was applied. This paper is an updated reprint of an article published on ndt.net in 2008. (author)

Damage detection in wind turbine blades using acoustic techniques

International Nuclear Information System (INIS)

Juengert, A.

2013-01-01

Facing climate change, the use of renewable energy gains importance. The wind energy sector grows very fast. Bigger and more powerful wind turbines will be built in the coming decades and the safety and reliability of the turbines will become more important. Wind turbine blades have to be inspected at regular intervals, because they are highly stressed during operation and a blade breakdown can cause big economic damages. The turbine blades consist of fiber reinforced plastics (GFRP/CFRP) and sandwich areas containing wood or plastic foam. The blades are manufactured as two halves and glued together afterwards. Typical damages are delaminations within the GFRP or the sandwich and missing adhesive or deficient bond at the bonding surfaces. The regular inspections of wind turbine blades are performed manually by experts and are limited to visual appraisals and simple tapping tests. To improve the inspections of wind turbine blades non-destructive testing techniques using acoustic waves are being developed. To detect delaminations within the laminates of the turbine blade, a local resonance spectroscopy was used. To detect missing bond areas from the outside of the blade the impulse-echo-technique was applied. This paper is an updated reprint of an article published on ndt.net in 2008. (author)

The development of furrower model blade to paddlewheel aerator for improving aeration efficiency

Science.gov (United States)

Bahri, Samsul; Praeko Agus Setiawan, Radite; Hermawan, Wawan; Zairin Junior, Muhammad

2018-05-01

The successful of intensive aquaculture is strongly influenced by the ability of the farmers to overcome the deterioration of water quality. The problem is low dissolved oxygen through aeration process. The aerator device which widely used in pond farming is paddle wheel aerator because it is the best aerator in aeration mechanism and usable driven power. However, this aerator still has a low performance of aeration, so that the cost of aerator operational for aquaculture is still high. Up to now, the effort to improve the performance of aeration was made by two-dimensional blade design. Obviously, it does not provide the optimum result due to the power requirements for aeration is directly proportional to the increase of aeration rate. The aim of this research is to develop three-dimensional model furrowed blades. Design of Furrower model blades was 1.6 cm diameter hole, 45º of vertical angle blade position and 30º of the horizontal position. The optimum performance furrowed model blades operated on the submerged blade 9 cm with 567.54 Watt of electrical power consumption and 4.322 m3 of splash coverage volume. The standard efficiency aeration is 2.72 kg O2 kWh-1. The furrowed model blades can improve the aeration efficiency of paddlewheel aerator.

Pultrusion of a vertical axis wind turbine blade part-II: combining the manufacturing process simulation with a subsequent loading scenario

DEFF Research Database (Denmark)

Baran, Ismet; Hattel, Jesper Henri; Tutum, Cem Celal

2015-01-01

This paper in particular deals with the integrated modeling of a pultruded NACA0018 blade profile being a part of EU funded DeepWind project. The manufacturing aspects of the pultrusion process are associated with the preliminary subsequent service loading scenario. A 3D thermochemical analysis...

Bladed wheels damage detection through Non-Harmonic Fourier Analysis improved algorithm

Science.gov (United States)

Neri, P.

2017-05-01

Recent papers introduced the Non-Harmonic Fourier Analysis for bladed wheels damage detection. This technique showed its potential in estimating the frequency of sinusoidal signals even when the acquisition time is short with respect to the vibration period, provided that some hypothesis are fulfilled. Anyway, previously proposed algorithms showed severe limitations in cracks detection at their early stage. The present paper proposes an improved algorithm which allows to detect a blade vibration frequency shift due to a crack whose size is really small compared to the blade width. Such a technique could be implemented for condition-based maintenance, allowing to use non-contact methods for vibration measurements. A stator-fixed laser sensor could monitor all the blades as they pass in front of the spot, giving precious information about the wheel health. This configuration determines an acquisition time for each blade which become shorter as the machine rotational speed increases. In this situation, traditional Discrete Fourier Transform analysis results in poor frequency resolution, being not suitable for small frequency shift detection. Non-Harmonic Fourier Analysis instead showed high reliability in vibration frequency estimation even with data samples collected in a short time range. A description of the improved algorithm is provided in the paper, along with a comparison with the previous one. Finally, a validation of the method is presented, based on finite element simulations results.

Pultrusion of a vertical axis wind turbine blade part-II: combining the manufacturing process simulation with a subsequent loading scenario

NARCIS (Netherlands)

Baran, Ismet; Hattel, Jesper H.; Tutum, Cem C.; Akkerman, Remko

2015-01-01

This paper in particular deals with the integrated modeling of a pultruded NACA0018 blade profile being a part of EU funded DeepWind project. The manufacturing aspects of the pultrusion process are associated with the preliminary subsequent service loading scenario. A 3D thermo-chemical analysis of

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

Numerical Research on Effects of Splitter Blades to the Influence of Pump as Turbine

Directory of Open Access Journals (Sweden)

Yang Sun-Sheng

2012-01-01

Full Text Available Centrifugal pumps can be operated in reverse as small hydropower recovery turbines and are cheaper than bespoke turbines due to their ease of manufacture. Splitter blades technique is one of the techniques used in flow field optimization and performance enhancement of rotating machinery. To understand the effects of splitter blades to the steady and unsteady influence of PAT, numerical research was performed. 3D Navier-Stokes solver CFX was used in the performance prediction and analysis of PAT’s performance. Results show that splitter blades have a positive impact on PAT’s performance. With the increase of splitter blades, its required pressure head is dropped and its efficiency is increased. Unsteady pressure field analysis and comparison show that the unsteady pressure field within PAT is improved when splitter blades are added to impeller flow passage. To verify the accuracy of numerical prediction methods, an open PAT test rig was built at Jiangsu University. The PAT was manufactured and tested. Comparison between experimental and numerical results shows that the discrepancy between numerical and experimental results is acceptable. CFD can be used in the performance prediction and optimization of PAT.

Digital radiographic technology; non-destructive testing of tubine blades

NARCIS (Netherlands)

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

Improved blade element momentum theory for wind turbine aerodynamic computations

DEFF Research Database (Denmark)

Sun, Zhenye; Chen, Jin; Shen, Wen Zhong

2016-01-01

Blade element momentum (BEM) theory is widely used in aerodynamic performance predictions and design applications for wind turbines. However, the classic BEM method is not quite accurate which often tends to under-predict the aerodynamic forces near root and over-predict its performance near tip....... for the MEXICO rotor. Results show that the improved BEM theory gives a better prediction than the classic BEM method, especially in the blade tip region, when comparing to the MEXICO measurements. (C) 2016 Elsevier Ltd. All rights reserved....

Occupational exposures to styrene vapor in a manufacturing plant for fiber-reinforced composite wind turbine blades.

Science.gov (United States)

Hammond, Duane; Garcia, Alberto; Feng, H Amy

2011-07-01

A utility-scale wind turbine blade manufacturing plant requested assistance from the National Institute for Occupational Safety and Health (NIOSH) in controlling worker exposures to styrene at a plant that produced 37 and 42 m long fiber-reinforced wind turbine blades. The plant requested NIOSH assistance because previous air sampling conducted by the company indicated concerns about peak styrene concentrations when workers entered the confined space inside of the wind turbine blade. NIOSH researchers conducted two site visits and collected personal breathing zone and area air samples while workers performed the wind turbine blade manufacturing tasks of vacuum-assisted resin transfer molding (VARTM), gelcoating, glue wiping, and installing the safety platform. All samples were collected during the course of normal employee work activities and analyzed for styrene using NIOSH Method 1501. All sampling was task based since full-shift sampling from a prior Occupational Safety and Health Administration (OSHA) compliance inspection did not show any exposures to styrene above the OSHA permissible exposure limit. During the initial NIOSH site visit, 67 personal breathing zone and 18 area air samples were collected while workers performed tasks of VARTM, gelcoating, glue wipe, and installation of a safety platform. After the initial site visit, the company made changes to the glue wipe task that eliminated the need for workers to enter the confined space inside of the wind turbine blade. During the follow-up site visit, 12 personal breathing zone and 8 area air samples were collected from workers performing the modified glue wipe task. During the initial site visit, the geometric means of the personal breathing zone styrene air samples were 1.8 p.p.m. (n = 21) for workers performing the VARTM task, 68 p.p.m. (n = 5) for workers installing a safety platform, and 340 p.p.m. (n = 14) for workers performing the glue wipe task, where n is the number of workers sampled for a

Manufacturing technology of integrated textile-based sensor networks for in situ monitoring applications of composite wind turbine blades

Science.gov (United States)

Haentzsche, Eric; Mueller, Ralf; Huebner, Matthias; Ruder, Tristan; Unger, Reimar; Nocke, Andreas; Cherif, Chokri

2016-10-01

Based on in situ strain sensors consisting of piezo-resistive carbon filament yarns (CFYs), which have been successfully integrated into textile reinforcement structures during their textile-technological manufacturing process, a continuous load of fibre-reinforced plastic (FRP) components has been realised. These sensors are also suitable for structural health monitoring (SHM) applications. The two-dimensional sensor layout is made feasible by the usage of a modular warp yarn path manipulation unit. Using a functional model of a small wind turbine blade in thermoset composite design, the sensor function for basic SHM applications (e.g. static load monitoring) are demonstrated. Any mechanical loads along the pressure or suction side of the wind turbine blade can be measured and calculated via a correlative change in resistance of the CFYs within the textile reinforcement plies. Performing quasi-static load tests on both tensile specimen and full-scale wind turbine blade, elementary results have been obtained concerning electro-mechanical behaviour and spatial resolution of global and even local static stresses according to the CFY sensor integration length. This paper demonstrates the great potential of textile-based and textile-technological integrated sensors in reinforcement structures for future SHM applications of FRPs.

Fan Efficiency Improvement via Changing Guide Blade Shape Under Various Operating Conditions

Directory of Open Access Journals (Sweden)

G. I. Zamolodchikov

2017-01-01

Full Text Available The aim of this study is to examine the influence of sweep and tangential blade lean the guide vanes (GV on the pressure losses in the blade row, and development of an approach to creating the GV with a rationally-shaped blades to ensure increased efficiency in the partial operating conditions.A numerical simulation method was used for research. As an object to be studied, was used an axial fan comprising an impeller and a GV, which were profiled to have constant circulation of velocity in radius. Verification of numerical simulation was based on the experimental data of fan. It comprised a GV with a straight blade and a circular-arc blade, with an impeller remained stationary in both cases. Among the turbulence models under consideration, preference is given to k-ω, as under operating conditions close to design ones, its result falls within the confidence span of the experimental characteristics, and at much higher and lower discharge coefficients a discrepancy is 4% at most.  In addition to the characteristics, the fields of pressure losses in GV have been analyzed. Numerical modeling allowed us to have a well-reproduced structure of losses in the stationary blade row.Analysis of pressure loss fields has shown that in the original GV near the hub, on the blade back, under design conditions a flow breakdown takes off. In view of the research, was designed a new GV with a modified blade geometry. The GV blade axis near the hub was bent in the circumferential direction by 0.1 length of the blade. In the near-hub cross-sections the blade chord was increased by 10%.The results of numerical simulation have shown that, with the flow less than the designed one, a change of just the GV blade tip sections leads to reduced break-down zone near the hub by about 40% under both operating conditions without raising profile losses and to improved fan efficiency, which reduces fan drive power consumption under typical operating conditions in the propulsion

Aerodynamic Analysis of Morphing Blades

Science.gov (United States)

Harris, Caleb; Macphee, David; Carlisle, Madeline

2016-11-01

Interest in morphing blades has grown with applications for wind turbines and other aerodynamic blades. This passive control method has advantages over active control methods such as lower manufacturing and upkeep costs. This study has investigated the lift and drag forces on individual blades with experimental and computational analysis. The goal has been to show that these blades delay stall and provide larger lift-to-drag ratios at various angles of attack. Rigid and flexible airfoils were cast from polyurethane and silicone respectively, then lift and drag forces were collected from a load cell during 2-D testing in a wind tunnel. Experimental data was used to validate computational models in OpenFOAM. A finite volume fluid-structure-interaction solver was used to model the flexible blade in fluid flow. Preliminary results indicate delay in stall and larger lift-to-drag ratios by maintaining more optimal angles of attack when flexing. Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

Investigation Of Failure Mechanisms In A Wind Turbine Blade Root Sub-Structure

DEFF Research Database (Denmark)

Bender, Jens Jakob; Hallett, S.R.; Lindgaard, Esben

2017-01-01

and realistic results at the fraction of the cost of a full-scale test. Therefore, this work focuses on testing of sub-structures from the root end of wind turbine blades at the transition from the thick root laminate to the thinner main laminate. Some wind turbine blade manufacturers include pre-cured tapered...... beams in the root to reduce the time required to place the large quantity of material in the mould and to decrease manufacturing defects in these elements. However, this entails the risk of introducing other manufacturing defects during the Vacuum Assisted Resin Transfer Moulding process such as resin...... pockets and fibre wrinkles. Through this work it is sought to determine the effect that these manufacturing defects can have on the strength properties of the sub-structure. The sub-structures used in this work are cut out from actual wind turbine blades, meaning that the manufacturing defects...

Design and Evaluation of Glass/epoxy Composite Blade and Composite Tower Applied to Wind Turbine

Science.gov (United States)

Park, Hyunbum

2018-02-01

In the study, the analysis and manufacturing of small class wind turbine blade was performed. In the structural design, firstly the loading conditions are defined through the load case analysis. The proposed structural configuration of blade has a sandwich type composite structure with the E-glass/Epoxy face sheets and the Urethane foam core for lightness, structural stability, low manufacturing cost and easy manufacturing process. And also, this work proposes a design procedure and results of tower for the small scale wind turbine systems. Structural analysis of blade including load cases, stress, deformation, buckling, vibration and fatigue life was performed using the finite element method, the load spectrum analysis and the Miner rule. Moreover, investigation on structural safety of tower was verified through structural analysis by FEM. The manufacturing of blade and tower was performed based on structural design. In order to investigate the designed structure, the structural tests were conducted and its results were compared with the calculated results. It is confirmed that the final proposed blade and tower meet the design requirements.

Korean experience with steam turbine blade inspection

International Nuclear Information System (INIS)

Jung, Hyun Kyu; Park, D.Y.; Park, Hyung Jin; Chung, Min Hwa

1990-01-01

Several turbine blade accidents in Korea have emphasized the importance of their adequate periodic inspection. As a typical example, a broken blade was found in the Low Pressure (LP) turbine at the 950 MWe KORI unit 3 during the 1986 overhaul after one year commercial operation. Since then the Manufacturer and the Utility company (KEPCO) have been concerned about the need of blade root inspection. The ultrasonic testing was applied to detect cracks in the blade roots without removing the blades from rotor. Due to the complex geometry of the roots, the test results could not be evaluated easily. We feel that the currently applied UT technique seems to be less reliable and more effective method of inspection must be developed in the near future. This paper describes the following items: The causes and analysis of blade damage The inspection techniques and results The remedial action to be taken (Repair and Replacement) The future plan

Design and construction of a simple blade pitch measurement system for small wind turbines

Energy Technology Data Exchange (ETDEWEB)

Whale, Jonathan [Research Institute of Sustainable Energy, Murdoch University, Perth, WA 6150 (Australia)

2009-02-15

For small wind turbines to be reliable they must have in place good mechanisms to protect themselves against very high winds or sudden removal of load. One common protection method in small wind turbines is that of blade feathering. It is important that the blade feathering mechanism of a small wind turbine is tested before the turbine is installed in the field. This paper presents a simple system for monitoring the blade feathering of a turbine with an overall component cost that small wind turbine manufacturers can afford. The Blade Pitch Measurement System (BPMS) has been designed and constructed by the Research Institute of Sustainable Energy (RISE) and aids small wind turbine manufacturers in testing and optimising the settings of the blade feathering mechanisms on their machines. The results show that the BPMS was successful in recording the behaviour of the blade feathering mechanism in field trials with a 20 kW and a 30 kW wind turbine. The BPMS displays significant potential as an effective, inexpensive system for small wind turbine manufacturers to ensure the reliability of their pitch regulating over-speed protection mechanisms. (author)

The effect of product quality on the integrity of advanced surface engineering treatments applied to high speed steel circular saw blades

International Nuclear Information System (INIS)

Bradbury, S.R.; Sarwar, M.

1996-01-01

Advanced surface engineering technologies have been successfully applied to high speed steel drills and carbide single-point cutting tools, but, as yet, limited benefits have been realized when applying the same technologies to multi-point cutting tools of commercial quality. This paper discusses the factors that have limited the benefits of advanced surface engineering treatments when applied to high speed steel circular saw blades. Common manufacturing defects have been identified on the teeth of the blades. Tests which evaluate the blade performance throughout its useful life and examination by scanning electron microscopy (SEM) have shown that these defects adversely affect the performance and wear resistance of surface engineered blades. Further investigations suggest that significant improvements in coating integrity can be achieved through the careful preparation of the substrate surface and refinement of the cutting edge geometry prior to treatment. For this application, the need for refinement and enhancement of current manufacturing practices is demonstrated if the full benefits of advanced surface engineering are to be realized. (orig.)

Low Speed Technology for Small Turbine Development Reaction Injection Molded 7.5 Meter Wind Turbine Blade

Energy Technology Data Exchange (ETDEWEB)

David M. Wright; DOE Project Officer - Keith Bennett

2007-07-31

An optimized small turbine blade (7.5m radius) was designed and a partial section molded with the RIM (reaction-injection molded polymer) process for mass production. The intended market is for generic three-bladed wind turbines, 100 kilowatts or less, for grid-assist end users with rural and semi-rural sites, such as the farm/ranch market, having low to moderate IEC Class 3-4 wind regimes. This blade will have substantial performance improvements over, and be cheaper than, present-day 7.5m blades. This is made possible by the injection-molding process, which yields high repeatability, accurate geometry and weights, and low cost in production quantities. No wind turbine blade in the 7.5m or greater size has used this process. The blade design chosen uses a RIM skin bonded to a braided infused carbon fiber/epoxy spar. This approach is attractive to present users of wind turbine blades in the 5-10m sizes. These include rebladeing California wind farms, refurbishing used turbines for the Midwest farm market, and other manufacturers introducing new turbines in this size range.

Structural dynamic analysis of turbine blade

Science.gov (United States)

Antony, A. Daniel; Gopalsamy, M.; Viswanadh, Chaparala B. V.; Krishnaraj, R.

2017-10-01

In any gas turbine design cycle, blade design is a crucial element which needs maximum attention to meet the aerodynamic performance, structural safety margins, manufacturing feasibility, material availability etc. In present day gas turbine engines, most of the failures occur during engine development test and in-service, in rotor and stator blades due to fatigue and resonance failures. To address this issue, an extensive structural dynamic analysis is carried out to predict the natural frequencies and mode shapes using FE methods. Using the dynamics characteristics, the Campbell diagram is constructed to study the possibility of resonance at various operating speeds. In this work, the feasibility of using composite material in place of titanium alloy from the structural dynamics point of view. This is being attempted in a Low-pressure compressor where the temperatures are relatively low and fixed with the casings. The analysis will be carried out using FE method for different composite material with different lamina orientations chosen through the survey. This study will focus on the sensitivity of blade mode shapes to different laminae orientations, which will be used to alter the natural frequency and tailor the mode shapes. Campbell diagrams of existing titanium alloy are compared with the composite materials with different laminae at all critical operating conditions. The existing manufacturing methods and the proven techniques for blade profiles will also be discussed in this report.

The SNL100-03 Blade: Design Studies with Flatback Airfoils for the Sandia 100-meter Blade.

Energy Technology Data Exchange (ETDEWEB)

Griffith, Daniel; Richards, Phillip William

2014-09-01

A series of design studies were performed to inv estigate the effects of flatback airfoils on blade performance and weight for large blades using the Sandi a 100-meter blade designs as a starting point. As part of the study, the effects of varying the blade slenderness on blade structural performance was investigated. The advantages and disadvantages of blad e slenderness with respect to tip deflection, flap- wise & edge-wise fatigue resistance, panel buckling capacity, flutter speed, manufacturing labor content, blade total weight, and aerodynamic design load magn itude are quantified. Following these design studies, a final blade design (SNL100-03) was prod uced, which was based on a highly slender design using flatback airfoils. The SNL100-03 design with flatback airfoils has weight of 49 tons, which is about 16% decrease from its SNL100-02 predecessor that used conventional sharp trailing edge airfoils. Although not systematically optimized, the SNL100 -03 design study provides an assessment of and insight into the benefits of flatback airfoils for la rge blades as well as insights into the limits or negative consequences of high blade slenderness resulting from a highly slender SNL100-03 planform as was chosen in the final design definition. This docum ent also provides a description of the final SNL100-03 design definition and is intended to be a companion document to the distribution of the NuMAD blade model files for SNL100-03, which are made publicly available. A summary of the major findings of the Sandia 100-meter blade development program, from the initial SNL100-00 baseline blade through the fourth SNL100-03 blade study, is provided. This summary includes the major findings and outcomes of blade d esign studies, pathways to mitigate the identified large blade design drivers, and tool development that were produced over the course of this five-year research program. A summary of large blade tec hnology needs and research opportunities is also presented.

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)

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)

Recovery of waste from wind blade manufacturing; Reaproveitamento de residuos da fabricacao de pas eolicas

Energy Technology Data Exchange (ETDEWEB)

Toubia, Carim Miguel; Guerrero, Patricia Carla; Mancini, Sandro Donnini [Universidade Estadual Paulista - UNESP, Sorocaba, SP (Brazil)], e-mail: mancini@unesp.br

2011-07-01

Large wind turbines are equipped with blades manufactured in a complex process that employs composite ceramic / polymer and consequent generation and disposal of certain waste. Aiming to solve this problem, recycling processes must be applied to reduce the impact of disposal of such waste into the environment and the mechanical recycling, without melting the material, is one of the options for this purpose. The results from characterization tests showed that the waste materials have 40% and 70% fiberglass by weight and that the introduction of 10% waste to a virgin matrix reduces tensile strength by 25% although increases by 30% the modulus of elasticity. Overall, the study can demonstrate the existence of technically feasible solutions to the use of such waste. (author)

The impact of inertial forces on morphing wind turbine blade in vertical axis configuration

International Nuclear Information System (INIS)

Butbul, Jonathan; MacPhee, David; Beyene, Asfaw

2015-01-01

Highlights: • A novel flexible VAWT has been experimentally tested alongside numerically simulations. • Using FEA and CFD, direction of blade bending was predicted from inertial and aerodynamic forces. • High-speed camera footage has been used to validate the model. • The flexible VAWT was found to self-start in the majority of tests, while the rigid one did not. • It is suggested that flexible VAWTs can have improved performance in part-load applications. - Abstract: A novel flexible blade concept with the ability to morph and geometrically adapt to changing flow conditions has been proposed to improve part-load performance of horizontal-axis wind turbines. The extension of these benefits to a vertical axis wind turbine would make wind technology a more competitive player in the energy market. Both flexible and rigid wind turbine rotor blades for vertical axis application were modeled, designed, manufactured and tested. Their performances were tested in a low speed wind tunnel. The predicted magnitude and direction of blade morph was validated using a high speed camera as well as finite element analysis. The comparative results of straight rigid and straight morphing blades show that the coefficient of performance greatly depends on the tip speed ratio. Overall, the morphing blade has better performance at low RPMs, but the rigid blade performed better at high RPMs. It was observed that the flexible blade self-started in the majority of the experiments. At high RPM, the centrifugal force overwhelmed the lift force, bending the flexible blade out of phase in an undesired direction increasing drag and therefore reducing the coefficient of performance

Active Blade Pitch Control for Straight Bladed Darrieus Vertical Axis Wind Turbine of New Design

DEFF Research Database (Denmark)

Chougule, Prasad; Nielsen, Søren R.K.; Basu, Biswajit

2013-01-01

in a previous publication. Further, it is well know that the variation of the blade pitch angle during the rotation improves the power efficiency. A blade pitch variation is implemented by active blade pitch control, which operates as per wind speed and position of the blade with respect to the rotor. A double...

Analysis and improvement of gas turbine blade temperature measurement error

International Nuclear Information System (INIS)

Gao, Shan; Wang, Lixin; Feng, Chi; Daniel, Ketui

2015-01-01

Gas turbine blade components are easily damaged; they also operate in harsh high-temperature, high-pressure environments over extended durations. Therefore, ensuring that the blade temperature remains within the design limits is very important. In this study, measurement errors in turbine blade temperatures were analyzed, taking into account detector lens contamination, the reflection of environmental energy from the target surface, the effects of the combustion gas, and the emissivity of the blade surface. In this paper, each of the above sources of measurement error is discussed, and an iterative computing method for calculating blade temperature is proposed. (paper)

Analysis and improvement of gas turbine blade temperature measurement error

Science.gov (United States)

Gao, Shan; Wang, Lixin; Feng, Chi; Daniel, Ketui

2015-10-01

Gas turbine blade components are easily damaged; they also operate in harsh high-temperature, high-pressure environments over extended durations. Therefore, ensuring that the blade temperature remains within the design limits is very important. In this study, measurement errors in turbine blade temperatures were analyzed, taking into account detector lens contamination, the reflection of environmental energy from the target surface, the effects of the combustion gas, and the emissivity of the blade surface. In this paper, each of the above sources of measurement error is discussed, and an iterative computing method for calculating blade temperature is proposed.

A practical approach to fracture analysis at the trailing edge of wind turbine rotor blades

DEFF Research Database (Denmark)

Eder, Martin Alexander; Bitsche, Robert; Nielsen, Magda

2014-01-01

Wind turbine rotor blades are commonly manufactured from composite materials by a moulding process. Typically, the wind turbine blade is produced in two halves, which are eventually adhesively joined along their edges. Investigations of operating wind turbine blades show that debonding...

Composite blade damaging under impact

NARCIS (Netherlands)

Menouillard, T.; Réthoré, J.; Bung, H.; Suffis, A.

2006-01-01

Composites materials are now being used in primary aircraft structures, and other domains because of numerous advantages. A part of a continuous in-flight operating costs, gas turbine engine manufacturers are always looking for ways to decrease engine weight. This is the case of compressor blades

Design and evaluation of low-cost laminated wood composite blades for intermediate size wind turbines: Blade design, fabrication concept, and cost analysis

Science.gov (United States)

Lieblein, S.; Gaugeon, M.; Thomas, G.; Zueck, M.

1982-01-01

As part of a program to reduce wind turbine costs, an evaluation was conducted of a laminated wood composite blade for the Mod-OA 200 kW wind turbine. The effort included the design and fabrication concept for the blade, together with cost and load analyses. The blade structure is composed of laminated Douglas fir veneers for the primary spar and nose sections, and honeycomb cored plywood panels for the trailing edges sections. The attachment of the wood blade to the rotor hub was through load takeoff studs bonded into the blade root. Tests were conducted on specimens of the key structural components to verify the feasibility of the concept. It is concluded that the proposed wood composite blade design and fabrication concept is suitable for Mod-OA size turbines (125-ft diameter rotor) at a cost that is very competitive with other methods of manufacture.

Metallurgy of gas turbine blades with integral shroud and its influence on blades performance

International Nuclear Information System (INIS)

Mazur, Z.; Marino, C.; Kubiak, J.

1999-01-01

The influence of the microstructure of the gas turbine blades with integral shroud on the blades performance is presented. The analysis of the solidification process of the gas turbine blades during conventionally casting process (equiaxed grains) with all elements which has influence on the mode of its solidification and variation of the microstructure is carried out. Also, the evaluation of the failure of the gas turbine blade is present. A detailed analysis of the blade tip shroud microstructure (presence of the equiaxed and columnar grains) and its influence on the failure initiation and propagation is carried out. Finally, conclusions and some necessary improvements of the blades casting process to prevent blades failures are presented. (Author) 2 refs

Guidelines to Interpret Results of Mechanical Blade Test

International Nuclear Information System (INIS)

Arias Vega, F.; Sanz Martin, J. C.

1999-01-01

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)

Guidelines to Interpret Results of Mechanical Blade Test

Energy Technology Data Exchange (ETDEWEB)

Arias Vega, F.; Sanz Martin, J. C. [Ciemat, Madrid (Spain)

2000-07-01

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 blades as an allowable product, fit for use and working with a completely security during all the windturbine's lifetime. This work was carried out at the Wind Energy Division of the CIEMAT.DER and it is based on the author's 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)

Demonstration of an elastically coupled twist control concept for tilt rotor blade application

Science.gov (United States)

Lake, R. C.; Nixon, M. W.; Wilbur, M. L.; Singleton, J. D.; Mirick, P. H.

1994-01-01

The purpose of this Note is to present results from an analytic/experimental study that investigated the potential for passively changing blade twist through the use of extension-twist coupling. A set of composite model rotor blades was manufactured from existing blade molds for a low-twist metal helicopter rotor blade, with a view toward establishing a preliminary proof concept for extension-twist-coupled rotor blades. Data were obtained in hover for both a ballasted and unballasted blade configuration in sea-level atmospheric conditions. Test data were compared with results obtained from a geometrically nonlinear analysis of a detailed finite element model of the rotor blade developed in MSC/NASTRAN.

Accelerated fatigue testing of LM 19.1 blades

DEFF Research Database (Denmark)

Kristensen, Ole Jesper Dahl; Jørgensen, E.

2003-01-01

A series of 19.1 metre wind turbine blades manufactured by LM Glasfiber A/S of Lunderskov, Denmark were subjected to a series of flapwise fatigue tests. The object of these fatigue tests is to evaluate the impact of an increased load on the blade in afatigue test and to give information...... if it is possible to increase the load in fatigue test to shorten test time. The tests were carried out as a part of a project financed by the Danish Energy Agency. During the fatigue tests the blades have beensurveyed with thermal imaging equipment to determine how an increase in fatigue load affects the blade...... material. In addition to the thermal imaging surveillance the blades were instrumented with strain gauges. This report presents the temperature duringtest, calibration test results, moment range measurements, strain statistics, thermal imaging registrations and a determination of the size and cause...

A CFD analysis of blade row interactions within a high-speed axial compressor

Science.gov (United States)

Richman, Michael Scott

Aircraft engine design provides many technical and financial hurdles. In an effort to streamline the design process, save money, and improve reliability and performance, many manufacturers are relying on computational fluid dynamic simulations. An overarching goal of the design process for military aircraft engines is to reduce size and weight while maintaining (or improving) reliability. Designers often turn to the compression system to accomplish this goal. As pressure ratios increase and the number of compression stages decrease, many problems arise, for example stability and high cycle fatigue (HCF) become significant as individual stage loading is increased. CFD simulations have recently been employed to assist in the understanding of the aeroelastic problems. For accurate multistage blade row HCF prediction, it is imperative that advanced three-dimensional blade row unsteady aerodynamic interaction codes be validated with appropriate benchmark data. This research addresses this required validation process for TURBO, an advanced three-dimensional multi-blade row turbomachinery CFD code. The solution/prediction accuracy is characterized, identifying key flow field parameters driving the inlet guide vane (IGV) and stator response to the rotor generated forcing functions. The result is a quantified evaluation of the ability of TURBO to predict not only the fundamental flow field characteristics but the three dimensional blade loading.

Improving Project Manufacturing Coordination

Directory of Open Access Journals (Sweden)

Korpivaara Ville

2014-09-01

Full Text Available The objective of this research is to develop firms’ project manufacturing coordination. The development will be made by centralizing the manufacturing information flows in one system. To be able to centralize information, a deep user need assessment is required. After user needs have been identified, the existing system will be developed to match these needs. The theoretical background is achieved through exploring the literature of project manufacturing, development project success factors and different frameworks and tools for development project execution. The focus of this research is rather in customer need assessment than in system’s technical expertise. To ensure the deep understanding of customer needs this study is executed by action research method. As a result of this research the information system for project manufacturing coordination was developed to respond revealed needs of the stakeholders. The new system improves the quality of the manufacturing information, eliminates waste in manufacturing coordination processes and offers a better visibility to the project manufacturing. Hence it provides a solid base for the further development of project manufacturing.

Performance improvement of small-scale rotors by passive blade twist control

OpenAIRE

Lv, Peng; Prothin, Sebastien; Mohd Zawawi, Fazila; Bénard, Emmanuel; Morlier, Joseph; Moschetta, Jean-Marc

2015-01-01

A passive twist control is proposed as an adaptive way to maximize the overall efficiency of the small-scale rotor blade for multifunctional aircrafts. Incorporated into a database of airfoil characteristics, Blade Element Momentum Theory is implemented to obtain the blade optimum twist rates for hover and forward flight. In order to realize the required torsion of blade between hover and forward flight, glass/epoxy laminate blade is proposed based on Centrifugal Force Induced Twist concept. ...

Compression fatigue of Wind Turbine Blade composites materials and damage mechanisms

DEFF Research Database (Denmark)

Fraisse, Anthony; Brøndsted, Povl

According to the new IEC 61400-5-rev0 recommendation, which is under preparation it will be required to qualify wind turbine blade (WTB) composite materials in fatigue at R=0.1, R=-1, and R=10. As a minimum fatigue at R=-1 is required. This is a consequence of the ever-growing blades, where gravity...... driven edgewise bending introduces significant fully reversed cycling at the leading and trailing edges. Therefore, material manufacturer and WTB manufacturer demand test results of highest reliability and reproducibility. However, these equirements for compression-compression and tensioncompression...

Composites Manufacturing Education and Technology Facility Expedites Manufacturing Innovation

Energy Technology Data Exchange (ETDEWEB)

2017-01-01

The Composites Manufacturing Education and Technology facility (CoMET) at the National Wind Technology Center at the National Renewable Energy Laboratory (NREL) paves the way for innovative wind turbine components and accelerated manufacturing. Available for use by industry partners and university researchers, the 10,000-square-foot facility expands NREL's composite manufacturing research capabilities by enabling researchers to design, prototype, and test composite wind turbine blades and other components -- and then manufacture them onsite. Designed to work in conjunction with NREL's design, analysis, and structural testing capabilities, the CoMET facility expedites manufacturing innovation.

Analysis of alternative technologies stamping compressor blades of marine engines

Directory of Open Access Journals (Sweden)

Олександр Сергійович Аніщенко

2015-10-01

Full Text Available The author has made an analysis of several technologies stamping forgings compressor blades from titanium alloy ВT3-1. These technologies use different types of forming equipment: crank hot press, high-speed hammers, screw presses with hydraulic drive (SPHD, as well as isothermal forging hydraulic press. He pointed out the main advantages and disadvantages of the technology, noting that high-speed punching in the shipbuilding industry of Ukraine is not used for the manufacture of forgings blades. The article contains an economic analysis of the cost of forgings blades, which are made on four technologies: punching and calibration to crank hot press, stamping and calibration to press for isothermal forging, stamping and calibration on SPHD-press, stamping on SPHD-press and calibration to press for isothermal forging. The author has identified the effective use of these technologies. He showed that the use of SPHD-presses and hydraulic presses for isothermal forging reduces the cost of forging on the average 12% in comparison with the technology at the crank hot stamping press, increases the utilization of metal 1,3-1,5 times more, reduces power consumption 1,05-3,0 times less and complexity of manufacturing 1,8-4,2 times. However SPHD-press increases capital investment in the organization of stamping technology 2,6-5,3 times more and depreciation 2-4 times. Isothermal forging technology requires the cost of the stamps in 1,4-2,0 times higher than stamps for crank presses. The author argues that stamping forging blades technology improvement should be implemented saving basic materials first of all. Efficiency of isothermal stamping and calibration will be the higher, the more geometric dimensions of stamped forgings are

Reinforced wind turbine blades--an environmental life cycle evaluation.

Science.gov (United States)

Merugula, Laura; Khanna, Vikas; Bakshi, Bhavik R

2012-09-04

A fiberglass composite reinforced with carbon nanofibers (CNF) at the resin-fiber interface is being developed for potential use in wind turbine blades. An energy and midpoint impact assessment was performed to gauge impacts of scaling production to blades 40 m and longer. Higher loadings force trade-offs in energy return on investment and midpoint impacts relative to the base case while remaining superior to thermoelectric power generation in these indicators. Energy-intensive production of CNFs forces impacts disproportionate to mass contribution. The polymer nanocomposite increases a 2 MW plant's global warming potential nearly 100% per kWh electricity generated with 5% CNF by mass in the blades if no increase in electrical output is realized. The relative scale of impact must be compensated by systematic improvements whether by deployment in higher potential zones or by increased life span; the trade-offs are expected to be significantly lessened with CNF manufacturing maturity. Significant challenges are faced in evaluating emerging technologies including uncertainty in future scenarios and process scaling. Inventories available for raw materials and monte carlos analysis have been used to gain insight to impacts of this development.

Active Robust Control of Elastic Blade Element Containing Magnetorheological Fluid

Science.gov (United States)

Sivrioglu, Selim; Cakmak Bolat, Fevzi

2018-03-01

This research study proposes a new active control structure to suppress vibrations of a small-scale wind turbine blade filled with magnetorheological (MR) fluid and actuated by an electromagnet. The aluminum blade structure is manufactured using the airfoil with SH3055 code number which is designed for use on small wind turbines. An interaction model between MR fluid and the electromagnetic actuator is derived. A norm based multi-objective H2/H∞ controller is designed using the model of the elastic blade element. The H2/H∞ controller is experimentally realized under the impact and steady state aerodynamic load conditions. The results of experiments show that the MR fluid is effective for suppressing vibrations of the blade structure.

Wind turbine blade waste in 2050.

Science.gov (United States)

Liu, Pu; Barlow, Claire Y

2017-04-01

Wind energy has developed rapidly over the last two decades to become one of the most promising and economically viable sources of renewable energy. Although wind energy is claimed to provide clean renewable energy without any emissions during operation, but it is only one side of the coin. The blades, one of the most important components in the wind turbines, made with composite, are currently regarded as unrecyclable. With the first wave of early commercial wind turbine installations now approaching their end of life, the problem of blade disposal is just beginning to emerge as a significant factor for the future. This paper is aimed at discovering the magnitude of the wind turbine blade waste problem, looking not only at disposal but at all stages of a blade's lifecycle. The first stage of the research, the subject of this paper, is to accurately estimate present and future wind turbine blade waste inventory using the most recent and most accurate data available. The result will provide a solid reference point to help the industry and policy makers to understand the size of potential environmental problem and to help to manage it better. This study starts by estimating the annual blade material usage with wind energy installed capacity and average blade weight. The effect of other waste contributing factors in the full lifecycle of wind turbine blades is then included, using industrial data from the manufacturing, testing and in-service stages. The research indicates that there will be 43 million tonnes of blade waste worldwide by 2050 with China possessing 40% of the waste, Europe 25%, the United States 16% and the rest of the world 19%. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Design of Thermal Barrier Coatings Thickness for Gas Turbine Blade Based on Finite Element Analysis

Directory of Open Access Journals (Sweden)

Biao Li

2017-01-01

Full Text Available Thermal barrier coatings (TBCs are deposited on the turbine blade to reduce the temperature of underlying substrate, as well as providing protection against the oxidation and hot corrosion from high temperature gas. Optimal ceramic top-coat thickness distribution on the blade can improve the performance and efficiency of the coatings. Design of the coatings thickness is a multiobjective optimization problem due to the conflicts among objectives of high thermal insulation performance, long operation durability, and low fabrication cost. This work developed a procedure for designing the TBCs thickness distribution for the gas turbine blade. Three-dimensional finite element models were built and analyzed, and weighted-sum approach was employed to solve the multiobjective optimization problem herein. Suitable multiregion top-coat thickness distribution scheme was designed with the considerations of manufacturing accuracy, productivity, and fabrication cost.

Eddy current testing for blade edge micro cracks of aircraft engine

Science.gov (United States)

Zhang, Wei-min; Xu, Min-dong; Gao, Xuan-yi; Jin, Xin; Qin, Feng

2017-10-01

Based on the problems of low detection efficiency in the micro cracks detection of aircraft engine blades, a differential excitation eddy current testing system was designed and developed. The function and the working principle of the system were described, the problems which contained the manufacture method of simulated cracks, signal generating, signal processing and the signal display method were described. The detection test was carried out by taking a certain model aircraft engine blade with simulated cracks as a tested specimen. The test data was processed by digital low-pass filter in the computer and the crack signals of time domain display and Lissajous figure display were acquired. By comparing the test results, it is verified that Lissajous figure display shows better performance compared to time domain display when the crack angle is small. The test results show that the eddy current testing system designed in this paper is feasible to detect the micro cracks on the aeroengine blade and can effectively improve the detection efficiency of micro cracks in the practical detection work.

Definition of a 5MW/61.5m wind turbine blade reference model.

Energy Technology Data Exchange (ETDEWEB)

Resor, Brian Ray

2013-04-01

A basic structural concept of the blade design that is associated with the frequently utilized %E2%80%9CNREL offshore 5-MW baseline wind turbine%E2%80%9D is needed for studies involving blade structural design and blade structural design tools. The blade structural design documented in this report represents a concept that meets basic design criteria set forth by IEC standards for the onshore turbine. The design documented in this report is not a fully vetted blade design which is ready for manufacture. The intent of the structural concept described by this report is to provide a good starting point for more detailed and targeted investigations such as blade design optimization, blade design tool verification, blade materials and structures investigations, and blade design standards evaluation. This report documents the information used to create the current model as well as the analyses used to verify that the blade structural performance meets reasonable blade design criteria.

Super titanium blades for advanced steam turbines

International Nuclear Information System (INIS)

Coulon, P.A.

1990-01-01

In 1986, the Alsthom Steam Turbines Department launched the manufacture of large titanium alloy blades: airfoil length of 1360 mm and overall length of 1520 mm. These blades are designed for the last-stage low pressure blading of advanced steam turbines operating at full speed (3000 rpm) and rating between 300 and 800 MW. Using titanium alloys for steam turbine exhaust stages as substitutes for chrome steels, due to their high strength/density ratio and their almost complete resistance to corrosion, makes it possible to increase the length of blades significantly and correspondingly that steam passage section (by up to 50%) with a still conservative stresses level in the rotor. Alsthom relies on 8 years of experience in the field of titanium, since as early as 1979 large titanium blades (airfoil length of 1240 mm, overall length of 1430 mm) were erected for experimental purposes on the last stage of a 900 MW unit of the Dampierre-sur-Loire power plant and now totals 45,000 operating hours without problems. The paper summarizes the main properties (chemical, mechanical and structural) recorded on very large blades and is based in particular on numerous fatigue corrosion test results to justify the use of the Ti 6 Al 4 V alloy in a specific context of micrographic structure

Eco-Casting of Aeolian Blades and Solar Panels With Composites ...

African Journals Online (AJOL)

The technique used for manufacturing composite wind turbine blades and solar panels must be sure of environment-friendly. In order to achieve this objective, the closed mould manufacturing process that takes into account environment preservation and health protection besides assurance quality will be the subject of this ...

Hybrid anisotropic materials for wind power turbine blades

CERN Document Server

Golfman, Yosif

2012-01-01

Based on rapid technological developments in wind power, governments and energy corporations are aggressively investing in this natural resource. Illustrating some of the crucial new breakthroughs in structural design and application of wind energy generation machinery, Hybrid Anisotropic Materials for Wind Power Turbine Blades explores new automated, repeatable production techniques that expand the use of robotics and process controls. These practices are intended to ensure cheaper fabrication of less-defective anisotropic material composites used to manufacture power turbine blades. This boo

Mechanical characterization of composite repairs for fiberglass wind turbine blades

Science.gov (United States)

Chawla, Tanveer Singh

affects the propagation fracture toughness values of the repair. Repairs conducted on surfaces with partially ground top plies possess higher fracture toughness values than those conducted on surfaces with complete top plies ground off. The three top repair resin candidates were then evaluated against the base repair resin under fatigue loading. The specimen configuration and testing method were chosen so as to be able to test hand layup repairs under tension -- tension cyclic loading. It was observed that all three new repair resins perform better than the base repair resin. The selection of the optimum repair resin was based on results from mode I and fatigue testing. Global manufacturing regulations and standards were also of prime concern. The final new repair resin is being used by the company in all of its plants over the globe. The balance of this work involves study of the effect of mixed mode I -- mode II loading on the strength of repairs conducted on fiber reinforced composite parts using hand lay-up technique. The specimens for this part were similar to those manufactured for mode I testing but with different dimensions and layup. They were made and tested in accordance with ASTM D 6671 (Standard Test Method for Mixed Mode I -- Mode II Interlaminar Fracture Toughness of Unidirectional Fiber Reinforced Polymer Matrix Composites). Comparison was made between the fracture toughness of the above chosen optimum repair resin and the base repair resin. At least two levels of mode mixture GII/G (Mode II fracture toughness / Mode I and II fracture toughness) were examined. Also, two levels of grinding were considered (complete ply vs. partial ply ground off) in order to establish the influence of varying top-ply grinding depths on the strength of hand layup repairs conducted on fiberglass composite structures. The results of this work have the potential to improve the repair process for current fiberglass wind turbine blades.

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.

Intubation of prehospital patients with curved laryngoscope blade is more successful than with straight blade.

Science.gov (United States)

Alter, Scott M; Haim, Eithan D; Sullivan, Alex H; Clayton, Lisa M

2018-02-17

Direct laryngoscopy can be performed using curved or straight blades, and providers usually choose the blade they are most comfortable with. However, curved blades are anecdotally thought of as easier to use than straight blades. We seek to compare intubation success rates of paramedics using curved versus straight blades. Design: retrospective chart review. hospital-based suburban ALS service with 20,000 annual calls. prehospital patients with any direct laryngoscopy intubation attempt over almost 9years. First attempt and overall success rates were calculated for attempts with curved and straight blades. Differences between the groups were calculated. 2299 patients were intubated by direct laryngoscopy. 1865 had attempts with a curved blade, 367 had attempts with a straight blade, and 67 had attempts with both. Baseline characteristics were similar between groups. First attempt success was 86% with a curved blade and 73% with a straight blade: a difference of 13% (95% CI: 9-17). Overall success was 96% with a curved blade and 81% with a straight blade: a difference of 15% (95% CI: 12-18). There was an average of 1.11 intubation attempts per patient with a curved blade and 1.13 attempts per patient with a straight blade (2% difference, 95% CI: -3-7). Our study found a significant difference in intubation success rates between laryngoscope blade types. Curved blades had higher first attempt and overall success rates when compared to straight blades. Paramedics should consider selecting a curved blade as their tool of choice to potentially improve intubation success. Copyright © 2018 Elsevier Inc. All rights reserved.

Study of a wave power generator system using an air turbine having improved J-shaped blades; Kairyo J gatayoku kuki turbine wo mochiita haryoku hatsuden sochi no kenkyu

Energy Technology Data Exchange (ETDEWEB)

Honma, T; Omata, K; Kojima, N [Meiji University, Tokyo (Japan)

1997-11-25

An improved J-shaped blade, in which a J-shaped blade is combined with a small-size Savonius blade, has been developed, to further improve efficiency of an air turbine for wave power generator systems. A prototype model of stationary wave power generator has been developed using the improved blade, to confirm its power generation characteristics by tests in a water tank and small-scale ocean tests. The results are compared with the characteristics of the units with conventional blades. The air turbine unit with the improved blade shows an efficiency of 13 to 35%, which is higher by 10 to 20% than that of the turbine with a J-shaped blade and by 20 to 70% than that of the one with a Savonius blade, more noted at low speed of rotation. It is therefore considered that the turbine with the improved blade is suited for sea areas having a relatively low wave height. It is also considered that efficiency can be further enhanced, when one or more guide vanes are provided around the blade. 2 refs., 12 figs.

A methodology to guide the selection of composite materials in a wind turbine rotor blade design process

Science.gov (United States)

Bortolotti, P.; Adolphs, G.; Bottasso, C. L.

2016-09-01

This work is concerned with the development of an optimization methodology for the composite materials used in wind turbine blades. Goal of the approach is to guide designers in the selection of the different materials of the blade, while providing indications to composite manufacturers on optimal trade-offs between mechanical properties and material costs. The method works by using a parametric material model, and including its free parameters amongst the design variables of a multi-disciplinary wind turbine optimization procedure. The proposed method is tested on the structural redesign of a conceptual 10 MW wind turbine blade, its spar caps and shell skin laminates being subjected to optimization. The procedure identifies a blade optimum for a new spar cap laminate characterized by a higher longitudinal Young's modulus and higher cost than the initial one, which however in turn induce both cost and mass savings in the blade. In terms of shell skin, the adoption of a laminate with intermediate properties between a bi-axial one and a tri-axial one also leads to slight structural improvements.

Discussion paper on managing composite blade waste

DEFF Research Database (Denmark)

Skelton, Kristen

A sustainable process for dealing with wind turbines at the end of their service life is needed in order to maximize the environmental benefits of wind power from a life cycle approach. Most components of a wind turbine such as foundation, tower, components of the gear box and generator are alrea...... as practical examples and experiences from research and industry projects. Important sources have been obtained from researchers, the original equipment manufacturers (OEMs), operators and maintainers (O&Ms), waste handlers and those that use the recyclates from blade waste....... recyclable and treated accordingly. Nevertheless, wind turbine blades represent a challenge due to the materials used and their complex composition. The objective of this research note is to provide an overview of the different methods used for sectioning and recycling wind turbine blades as well...

Damage detection of engine bladed-disks using multivariate statistical analysis

Science.gov (United States)

Fang, X.; Tang, J.

2006-03-01

The timely detection of damage in aero-engine bladed-disks is an extremely important and challenging research topic. Bladed-disks have high modal density and, particularly, their vibration responses are subject to significant uncertainties due to manufacturing tolerance (blade-to-blade difference or mistuning), operating condition change and sensor noise. In this study, we present a new methodology for the on-line damage detection of engine bladed-disks using their vibratory responses during spin-up or spin-down operations which can be measured by blade-tip-timing sensing technique. We apply a principle component analysis (PCA)-based approach for data compression, feature extraction, and denoising. The non-model based damage detection is achieved by analyzing the change between response features of the healthy structure and of the damaged one. We facilitate such comparison by incorporating the Hotelling's statistic T2 analysis, which yields damage declaration with a given confidence level. The effectiveness of the method is demonstrated by case studies.

Passive damping of composite blades using embedded piezoelectric modules or shape memory alloy wires: a comparative study

International Nuclear Information System (INIS)

Bachmann, F; Delpero, T; Ermanni, P; De Oliveira, R; Sigg, A; Michaud, V; Schnyder, V; Jaehne, R; Bergamini, A

2012-01-01

Emission reduction from civil aviation has been intensively addressed in the scientific community in recent years. The combined use of novel aircraft engine architectures such as open rotor engines and lightweight materials offer the potential for fuel savings, which could contribute significantly in reaching gas emissions targets, but suffer from vibration and noise issues. We investigated the potential improvement of mechanical damping of open rotor composite fan blades by comparing two integrated passive damping systems: shape memory alloy wires and piezoelectric shunt circuits. Passive damping concepts were first validated on carbon fibre reinforced epoxy composite plates and then implemented in a 1:5 model of an open rotor blade manufactured by resin transfer moulding (RTM). A two-step process was proposed for the structural integration of the damping devices into a full composite fan blade. Forced vibration measurements of the plates and blade prototypes quantified the efficiency of both approaches, and their related weight penalty. (paper)

Passive damping of composite blades using embedded piezoelectric modules or shape memory alloy wires: a comparative study

Science.gov (United States)

Bachmann, F.; de Oliveira, R.; Sigg, A.; Schnyder, V.; Delpero, T.; Jaehne, R.; Bergamini, A.; Michaud, V.; Ermanni, P.

2012-07-01

Emission reduction from civil aviation has been intensively addressed in the scientific community in recent years. The combined use of novel aircraft engine architectures such as open rotor engines and lightweight materials offer the potential for fuel savings, which could contribute significantly in reaching gas emissions targets, but suffer from vibration and noise issues. We investigated the potential improvement of mechanical damping of open rotor composite fan blades by comparing two integrated passive damping systems: shape memory alloy wires and piezoelectric shunt circuits. Passive damping concepts were first validated on carbon fibre reinforced epoxy composite plates and then implemented in a 1:5 model of an open rotor blade manufactured by resin transfer moulding (RTM). A two-step process was proposed for the structural integration of the damping devices into a full composite fan blade. Forced vibration measurements of the plates and blade prototypes quantified the efficiency of both approaches, and their related weight penalty.

Study on measurement of leading and trailing edges of blades based on optical scanning system

Science.gov (United States)

Chao, Bi; Liu, Hongguang; Bao, Longxiang; Li, Di

2017-10-01

In the field of aeronautics, the geometry and dimensional accuracy of the blade edges has a large influence on the aerodynamic performance of aero engine. Therefore, a non-contact optical scanning system is established to realize the measurement of leading and trailing edges of blades in a rapid, precise and efficient manner in the paper. Based on the mechanical framework of a traditional CMM, the system is equipped with a specified sensing device as the scanning probe, which is made up by two new-style laser scanning sensors installed at a certain angle to each other by a holder. In the measuring procedure, the geometric dimensions of the measured blade edges on every contour plane are determined by the contour information on five transversals at the leading or trailing edges, which can be used to determine the machining allowance of the blades. In order to verify the effectiveness and practicality of the system set up, a precision forging blade after grinded is adopted as the measured object and its leading and trailing edges are measured by the system respectively. In the experiment, the thickness of blade edges on three contour planes is measured by the optical scanning system several times. As the experiment results show, the repeatability accuracy of the system can meet its design requirements and the inspecting demands of the blade edges. As a result, the optical scanning system could serve as a component of the intelligent manufacturing system of blades to improve the machining quality of the blade edges.

Prospects for the domestic production of large-sized cast blades and vanes for industrial gas turbines

Science.gov (United States)

Kazanskiy, D. A.; Grin, E. A.; Klimov, A. N.; Berestevich, A. I.

2017-10-01

Russian experience in the production of large-sized cast blades and vanes for industrial gas turbines is analyzed for the past decades. It is noted that the production of small- and medium-sized blades and vanes made of Russian alloys using technologies for aviation, marine, and gas-pumping turbines cannot be scaled for industrial gas turbines. It is shown that, in order to provide manufacturability under large-scale casting from domestic nickel alloys, it is necessary to solve complex problems in changing their chemical composition, to develop new casting technologies and to optimize the heat treatment modes. An experience of PAO NPO Saturn in manufacturing the blades and vanes made of ChS88U-VI and IN738-LC foundry nickel alloys for the turbines of the GTE-110 gas turbine unit is considered in detail. Potentialities for achieving adopted target parameters for the mechanical properties of working blades cast from ChS88UM-VI modified alloy are established. For the blades made of IN738-LC alloy manufactured using the existing foundry technology, a complete compliance with the requirements of normative and technical documentation has been established. Currently, in Russia, the basis of the fleet of gas turbine plants is composed by foreign turbines, and, for the implementation of the import substitution program, one can use the positive experience of PAO NPO Saturn in casting blades from IN738-LC alloy based on a reverse engineering technique. A preliminary complex of studies of the original manufacturer's blades should be carried out, involving, first of all, the determination of geometric size using modern measurement methods as well as the studies on the chemical compositions of the used materials (base metal and protective coatings). Further, verifying the constructed calculation models based on the obtained data, one could choose available domestic materials that would meet the operating conditions of the blades according to their heat resistance and corrosion

Updated Assessment of an Open Rotor Airplane Using an Advanced Blade Design

Science.gov (United States)

Hendricks, Eric S.; Berton, Jeffrey J.; Haller, William J.; Tong, Michael T.; Guynn, Mark D.

2013-01-01

Application of open rotor propulsion systems (historically referred to as "advanced turboprops" or "propfans") to subsonic transport aircraft received significant attention and research in the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Recent volatility in fuel prices and concern for aviation's environmental impact have renewed interest in open rotor propulsion, and revived research by NASA and a number of engine manufacturers. Over the last few years, NASA has revived and developed analysis capabilities to assess aircraft designs with open rotor propulsion systems. These efforts have been described in several previous papers along with initial results from applying these capabilities. The initial results indicated that open rotor engines have the potential to provide large reductions in fuel consumption and emissions. Initial noise analysis indicated that current noise regulations can be met with modern baseline blade designs. Improved blades incorporating low-noise features are expected to result in even lower noise levels. This paper describes improvements to the initial assessment, plus a follow-on study using a more advanced open rotor blade design to power the advanced singleaisle transport. The predicted performance and environmental results of these two advanced open rotor concepts are presented and compared.

Research Staff | Advanced Manufacturing Research | NREL

Science.gov (United States)

manages wind turbine rotor blade composite manufacturing projects at the National Wind Technology Center postdoctoral researcher working to develop and validate advanced composite manufacturing processes using novel materials for wind and marine and hydrokinetic (MHK) turbines. This includes hands-on composite

Blade-element/momentum theory

DEFF Research Database (Denmark)

Sørensen, Jens Nørkær

2016-01-01

Although there exists a large variety of methods for predicting performance and loadings of wind turbines, the only approach used today by wind turbine manufacturers is based on the blade-element/momentum (BEM) theory by Glauert (Aerodynamic theory. Springer, Berlin, pp. 169-360, 1935). A basic...... assumption in the BEM theory is that the flow takes place in independent stream tubes and that the loading is determined from two-dimensional sectional airfoil characteristics....

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)

The Forming of AISI 409 sheets for fan blade manufacturing

International Nuclear Information System (INIS)

Foroni, F. D.; Menezes, M. A.; Moreira Filho, L. A.

2007-01-01

The necessity of adapting the standardized fan models to conditions of higher temperature has emerged due to the growth of concern referring to the consequences of the gas expelling after the Mont Blanc tunnel accident in Italy and France, where even though, with 100 fans in operation, 41 people died. The objective of this work is to present an alternative to the market standard fans considering a new technology in constructing blades. This new technology introduces the use of the stainless steel AISI 409 due to its good to temperatures of gas exhaust from tunnels in fire situation. The innovation is centered in the process of a deep drawing of metallic sheets in order to keep the ideal aerodynamic superficies for the fan ideal performance. Through the impression of circles on the sheet plane it is shown, experimentally, that, during the pressing process, the more deformed regions on the sheet plane of the blade can not reach the deformation limits of the utilized sheet material

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.

Active Blade Vibration Control Being Developed and Tested

Science.gov (United States)

Johnson, Dexter

2003-01-01

Gas turbine engines are currently being designed to have increased performance, lower weight and manufacturing costs, and higher reliability. Consequently, turbomachinery components, such as turbine and compressor blades, have designs that are susceptible to new vibration problems and eventual in-service failure due to high-cycle fatigue. To address this problem, researchers at the NASA Glenn Research Center are developing and testing innovative active blade vibration control concepts. Preliminary results of using an active blade vibration control system, involving a rotor supported by an active magnetic bearing in Glenn's Dynamic Spin Rig, indicate promising results (see the photograph). Active blade vibration control was achieved using feedback of blade strain gauge signals within the magnetic bearing control loop. The vibration amplitude was reduced substantially (see the graphs). Also, vibration amplitude amplification was demonstrated; this could be used to enhance structural mode identification, if desired. These results were for a nonrotating two-bladed disk. Tests for rotating blades are planned. Current and future active blade vibration control research is planned to use a fully magnetically suspended rotor and smart materials. For the fully magnetically suspended rotor work, three magnetic bearings (two radial and one axial) will be used as actuators instead of one magnetic bearing. This will allow additional degrees of freedom to be used for control. For the smart materials work, control effectors located on and off the blade will be considered. Piezoelectric materials will be considered for on-the-blade actuation, and actuator placement on a stator vane, or other nearby structure, will be investigated for off-the-blade actuation. Initial work will focus on determining the feasibility of these methods by performing basic analysis and simple experiments involving feedback control.

EB-PVD process management for highly productive zirconia thermal barrier coating of turbine blades

International Nuclear Information System (INIS)

Reinhold, E.; Botzler, P.; Deus, C.

1999-01-01

Zirconia thermal barrier coatings are well used in the turbine manufacturing industry because they ensure extended lifetimes of turbine blades. Compared with other techniques, EB-PVD processes are best suited for the deposition on turbine blades with regard to the layer properties. Therefore EB-PVD coaters for turbine blades are becoming increasingly interesting. The coating costs per component are mainly dependent on a highly productive solution for the deposition task. Thus the EB-PVD process management has to be optimized in order to meet the productivity requirements of the manufacturers. This includes the requirement of high deposition rates, large deposition areas, long time stable production cycles as well as a matched duration of preheating, deposition and cooling down per charge. Modern EB-PVD solutions to be introduced allow deposition rates on blades up to 7 μm/min. The consequences for the technological process management and plant design concerning long time stable coating cycles with high productivity will be discussed. (orig.)

Structural investigation of composite wind turbine blade considering various load cases and fatigue life

International Nuclear Information System (INIS)

Kong, C.; Bang, J.; Sugiyama, Y.

2005-01-01

This study proposes a structural design for developing a medium scale composite wind turbine blade made of E-glass/epoxy for a 750 kW class horizontal axis wind turbine system. The design loads were determined from various load cases specified at the IEC61400-1 international specification and GL regulations for the wind energy conversion system. A specific composite structure configuration, which can effectively endure various loads such as aerodynamic loads and loads due to accumulation of ice, hygro-thermal and mechanical loads, was proposed. To evaluate the proposed composite wind turbine blade, structural analysis was performed by using the finite element method. Parametric studies were carried out to determine an acceptable blade structural design, and the most dominant design parameters were confirmed. In this study, the proposed blade structure was confirmed to be safe and stable under various load conditions, including the extreme load conditions. Moreover, the blade adapted a new blade root joint with insert bolts, and its safety was verified at design loads including fatigue loads. The fatigue life of a blade that has to endure for more than 20 years was estimated by using the well-known S-N linear damage theory, the service load spectrum, and the Spera's empirical equations. With the results obtained from all the structural design and analysis, prototype composite blades were manufactured. A specific construction process including the lay-up molding method was applied to manufacturing blades. Full-scale static structural test was performed with the simulated aerodynamic loads. From the experimental results, it was found that the designed blade had structural integrity. In addition, the measured results of deflections, strains, mass, and radial center of gravity agreed well with the analytical results. The prototype blade was successfully certified by an international certification institute, GL (Germanisher Lloyd) in Germany

Contactless Diagnostics of Turbine Blade Vibration and Damage

International Nuclear Information System (INIS)

Prochazka, Pavel; Vanek, Frantisek

2011-01-01

The study deals with the contactless diagnostic method used for the identification of steam turbine blade strain, vibration and damage. The tip-timing method based on the evaluation of time differences of blade passages in different rotor revolutions has been modified and improved to provide more precise and reliable results. A new approach to the analysis of the amplitude and time differences of impulse signals generated by a blade passage has been applied. Amplitudes and frequencies of vibrations and static position of blades ascertained by the diagnostic process are used to establish the state of blade damage. A contactless diagnostic system VDS-UT based on magneto-resistive sensors was developed in the Institute of Thermomechanics Academy of Sciences of the Czech Republic. The system provides on-line monitoring of vibration amplitudes and frequencies of all blades and notification of possible blade damage. Evaluation of the axial and circumferential components of the deflections by measuring the amplitude of blade impulse signals results in an overall improvement of the method. Using magneto-resistive sensors, blade elongation and untwisting can be determined as well.

Restoration of metal properties of circulation pump blades by the method of surface ultrasonic impact treatment

Science.gov (United States)

Povarov, V. P.; Urazov, O. V.; Bakirov, M. B.; Pakhomov, S. S.; Belunik, I. A.

2017-10-01

During the transition period to a market economy, the works producing equipment for the nuclear industry became lame duck companies. The market of heavy industry equipment reduced dramatically, and quality control requirements imposed to goods became lower. Deviations from regulations' requirements and technical specifications for equipment manufacture results in inevitable decrease of reliability during operation but also to failure during check tests. It is not always possible to replace promptly ill-conditioned equipment; in such cases, it is necessary to carry out compensatory measures for restoring working properties up to an acceptable level in order to ensure operational reliability due to the strength improvement of the components of machines and constructions during the whole service life or up to the scheduled date of equipment replacement. This paper is dedicated to development and practical implementation of restorative technology of strengthening ultrasonic treatment used for the metal of the blades of impellers of 16DPA10-28 circulation pumps of 10URS unit pump station located at Novovoronezh NPP-2. The dynamic surface treatment was implemented for compensating the technological defects of the metal of blades. It was revealed that the impact elastic-plastic deformation has a comprehensive compensation effect on the metal of blades in the initial state of delivery and creates the surface-strengthening layer with higher strength properties (strain hardening) of the depth up to 1.5 mm. The surface strain hardening increases the cyclic strength, re-distributes beneficially the residual technological and repair stresses, and heals small surface cracks improving the surface quality. The developed technology was used for treatment of 32 blades of impellers of 10PAC01AP001, 10PAC02AP001, 10PAC03AP001, 10PAC04AP001 circulation pumps. The implemented 100-h full-scale test of the pumps revealed the high efficiency of the developed technology and made it possible

A shape adaptive airfoil for a wind turbine blade

Science.gov (United States)

Daynes, Stephen; Weaver, Paul M.

2011-04-01

The loads on wind turbine components are primarily from the blades. It is important to control these blade loads in order to avoid damaging the wind turbine. Rotor control technology is currently limited to controlling the rotor speed and the pitch of the blades. As blades increase in length it becomes less desirable to pitch the entire blade as a single rigid body, but instead there is a requirement to control loads more precisely along the length of the blade. This can be achieved with aerodynamic control devices such as flaps. Morphing technologies are good candidates for wind turbine flaps because they have the potential to create structures that have the conflicting abilities of being load carrying, light-weight and shape adaptive. A morphing flap design with a highly anisotropic cellular structure is presented which is able to undergo large deflections and high strains without a large actuation penalty. An aeroelastic analysis couples the work done by aerodynamic loads on the flap, the flap strain energy and the required actuation work to change shape. The morphing flap is experimentally validated with a manufactured demonstrator and shown to have reduced actuation requirements compared to a conventional hinged flap.

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...... 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...... the description of the test setup, the test and an overview over the results from the test performed on the box girder. During the final test the box girder failed at 58 % of the expected ultimate load. Unfortunately, no definite conclusion could be made concerning the failure mechanism....

Numerical simulation on a straight-bladed vertical axis wind turbine with auxiliary blade

Science.gov (United States)

Li, Y.; Zheng, Y. F.; Feng, F.; He, Q. B.; Wang, N. X.

2016-08-01

To improve the starting performance of the straight-bladed vertical axis wind turbine (SB-VAWT) at low wind speed, and the output characteristics at high wind speed, a flexible, scalable auxiliary vane mechanism was designed and installed into the rotor of SB-VAWT in this study. This new vertical axis wind turbine is a kind of lift-to-drag combination wind turbine. The flexible blade expanded, and the driving force of the wind turbines comes mainly from drag at low rotational speed. On the other hand, the flexible blade is retracted at higher speed, and the driving force is primarily from a lift. To research the effects of the flexible, scalable auxiliary module on the performance of SB-VAWT and to find its best parameters, the computational fluid dynamics (CFD) numerical calculation was carried out. The calculation result shows that the flexible, scalable blades can automatic expand and retract with the rotational speed. The moment coefficient at low tip speed ratio increased substantially. Meanwhile, the moment coefficient has also been improved at high tip speed ratios in certain ranges.

Sub-scale Inverse Wind Turbine Blade Design Using Bound Circulation

Science.gov (United States)

Kelley, Christopher; Berg, Jonathan

2014-11-01

A goal of the National Rotor Testbed project at Sandia is to design a sub-scale wind turbine blade that has similitude to a modern, commercial size blade. However, a smaller diameter wind turbine operating at the same tip-speed-ratio exhibits a different range of operating Reynolds numbers across the blade span, thus changing the local lift and drag coefficients. Differences to load distribution also affect the wake dynamics and stability. An inverse wind turbine blade design tool has been implemented which uses a target, dimensionless circulation distribution from a full-scale blade to find the chord and twist along a sub-scale blade. In addition, airfoil polar data are interpolated from a few specified span stations leading to a smooth, manufacturable blade. The iterative process perturbs chord and twist, after running a blade element momentum theory code, to reduce the residual sum of the squares between the modeled sub-scale circulation and the target full-scale circulation. It is shown that the converged sub-scale design also leads to performance similarity in thrust and power coefficients. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy under Contract DE-AC04-94AL85000.

Hybrid fiber and nanopowder reinforced composites for wind turbine blades

Directory of Open Access Journals (Sweden)

Nikoloz M. Chikhradze

2015-01-01

Full Text Available The results of an investigation into the production of wind turbine blades manufactured using polymer composites reinforced by hybrid (carbon, basalt, glass fibers and strengthened by various nanopowders (oxides, carbides, borides are presented. The hybrid fiber-reinforced composites (HFRC were manufactured with prepreg technology by molding pre-saturated epoxy-strengthened matrix-reinforced fabric. Performance of the manufactured composites was estimated with values of the coefficient of operating condition (COC at a moderate and elevated temperature.

QUALITY IMPROVEMENT MODEL AT THE MANUFACTURING PROCESS PREPARATION LEVEL

Directory of Open Access Journals (Sweden)

Dusko Pavletic

2009-12-01

Full Text Available The paper expresses base for an operational quality improvement model at the manufacturing process preparation level. A numerous appropriate related quality assurance and improvement methods and tools are identified. Main manufacturing process principles are investigated in order to scrutinize one general model of manufacturing process and to define a manufacturing process preparation level. Development and introduction of the operational quality improvement model is based on a research conducted and results of methods and tools application possibilities in real manufacturing processes shipbuilding and automotive industry. Basic model structure is described and presented by appropriate general algorithm. Operational quality improvement model developed lays down main guidelines for practical and systematic application of quality improvements methods and tools.

Multi-life-stage monitoring system based on fibre bragg grating sensors for more reliable wind turbine rotor blades: Experimental and numerical analysis of deformation and failure in composite materials

DEFF Research Database (Denmark)

Pereira, Gilmar Ferreira

, design and optimisation of offshore wind turbines. The MareWint main scientific objective is to optimise the design of offshore wind turbines, maximise reliability, and minimise maintenance costs. Integrated within the innovative rotor blades work-package, this PhD project is focused on damage analysis...... are used to improve the design process, and the implemented sensor are used to control the manufacturing and operation stage of a wind turbine rotor blade. The FBG sensors measurement principle is analysed from a multi-life-stage (design, material testing, manufacturing, and operation) perspective......, and supported/validated by numerical models, software tools, signal post-processing, and experimental validation. The damage in the wind turbine rotor blade is analysed from a material perspective (fibre reinforced polymers) and used as a design property, meaning that damage is accepted in an operational wind...

Development of Improved Design and 3D Printing Manufacture of Cross-Flow Fan Rotor

Science.gov (United States)

2016-06-01

printer was used to print components of a carbon-fiber composite cross-flow fan rotor . These pieces were assembled and the thrust, power, and thrust...variables. A MarkForged Mark One 3D printer was used to print components of a carbon-fiber composite cross-flow fan rotor . These pieces were assembled... composite parts to be 3D printed. This technology showed promise in rapidly manufacturing complicated blade and rotor geometries. The objective of

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.

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...... 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....

Research on the nonintrusive measurement of the turbine blade vibration

Science.gov (United States)

Zhang, Shi hai; Li, Lu-ping; Rao, Hong-de

2008-11-01

It's one of the important ways to monitor the change of dynamic characteristic of turbine blades for ensuring safety operation of turbine unit. Traditional measurement systems for monitoring blade vibration generally use strain gauges attached to the surface of turbine blades, each strain gauge gives out an analogue signal related to blade deformation, it's maximal defect is only a few blades could be monitored which are attached by strain gauge. But the noncontact vibration measurement will be discussed would solve this problem. This paper deals with noncontact vibration measurement on the rotor blades of turbine through experiments. In this paper, the noncontact vibration measurement - Tip Timing Measurement will be presented, and will be improved. The statistics and DFT will be used in the improved measurement. The main advantage of the improved measurement is that only two sensors over the top of blades and one synchronous sensor of the rotor are used to get the exact vibration characteristics of the each blade in a row. In our experiment, we adopt NI Company's DAQ equipment: SCXI1001 and PCI 6221, three optical sensors, base on the graphics program soft LabVIEW to develop the turbine blade monitor system. At the different rotational speed of the rotor (1000r/m and 1200r/m) we do several experiments on the bench of the Turbine characteristic. Its results indicated that the vibration of turbine blade could be real-time monitored and accurately measured by the improved Tip Timing Measurement.

Analysing flow structures around a blade using spectral/hp method and HPIV

International Nuclear Information System (INIS)

Stoevesandt, Bernhard; Steigerwald, Christian; Shishkin, Andrei; Wagner, Claus; Peinke, Joachim

2007-01-01

A still difficult, yet pressing task for blade manufacturers and turbine producers is the correct prediction of the effects of turbulent winds on the blade. Reynolds Averaged Numerical Simulations (RANS) are a limited tool for calculating the effects. For large eddy simulations (LES) boundary layer calculation are still difficult therefore the spectral element method seems to be an approach to improve numerical calculations of flow separation. The flow field around an fx79-w151a airfoil has been calculated by the spectral element code NεκTαrusing a direct numerical simulation (DNS) solver. In a first step a laminar inflow on the airfoil at angle of attack of α = 12 0 and a Reynolds number of Re= 33000 was simulated using the 2D Version of the code. The flow pattern was compared to measurements using holographic particle induced velocimetry (HPIV) in a wind tunnel

Probability of Detection Study to Assess the Performance of Nondestructive Inspection Methods for Wind Turbine Blades.

Energy Technology Data Exchange (ETDEWEB)

Roach, Dennis P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rice, Thomas M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Paquette, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-07-01

Wind turbine blades pose a unique set of inspection challenges that span from very thick and attentive spar cap structures to porous bond lines, varying core material and a multitude of manufacturing defects of interest. The need for viable, accurate nondestructive inspection (NDI) technology becomes more important as the cost per blade, and lost revenue from downtime, grows. NDI methods must not only be able to contend with the challenges associated with inspecting extremely thick composite laminates and subsurface bond lines, but must also address new inspection requirements stemming from the growing understanding of blade structural aging phenomena. Under its Blade Reliability Collaborative program, Sandia Labs quantitatively assessed the performance of a wide range of NDI methods that are candidates for wind blade inspections. Custom wind turbine blade test specimens, containing engineered defects, were used to determine critical aspects of NDI performance including sensitivity, accuracy, repeatability, speed of inspection coverage, and ease of equipment deployment. The detection of fabrication defects helps enhance plant reliability and increase blade life while improved inspection of operating blades can result in efficient blade maintenance, facilitate repairs before critical damage levels are reached and minimize turbine downtime. The Sandia Wind Blade Flaw Detection Experiment was completed to evaluate different NDI methods that have demonstrated promise for interrogating wind blades for manufacturing flaws or in-service damage. These tests provided the Probability of Detection information needed to generate industry-wide performance curves that quantify: 1) how well current inspection techniques are able to reliably find flaws in wind turbine blades (industry baseline) and 2) the degree of improvements possible through integrating more advanced NDI techniques and procedures. _____________ S a n d i a N a t i o n a l L a b o r a t o r i e s i s a m u l t i

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.

Doctor Blade-Coated Polymer Solar Cells

KAUST Repository

Cho, Nam Chul

2016-10-25

In this work, we report polymer solar cells based on blade-coated P3HT:PC71BM and PBDTTT-EFT:PC71BM bulk heterojunction photoactive layers. Enhanced power conversion efficiency of 2.75 (conventional structure) and 3.03% (inverted structure) with improved reproducibility was obtained from blade-coated P3HT:PC71BM solar cells, compared to spin-coated ones. Furthermore, by demonstrating 3.10% efficiency flexible solar cells using blade-coated PBDTTT-EFT:PC71BM films on the plastic substrates, we suggest the potential applicability of blade coating technique to the high throughput roll-to-roll fabrication systems.

Microstructural Features in Corroded Celtic Iron Age Sword Blades

Science.gov (United States)

Ghiara, G.; Piccardo, P.; Campodonico, S.; Carnasciali, M. M.

2014-05-01

Archaeological artefacts made from iron and steel are often of critical importance for archaeometallurgical studies, which aim to understand the process of manufacturing, as the nearly complete alloy mineralization does not allow for any type of metallographic interpretation. In this study, three Iron Age sword blades dated from the second century BC (LaTène B2/D1) found in the archaeological site of Tintignac (Commune de Naves, Corrèze, France), were investigated. A multianalytical approach was employed to acquire a complete range of data from the partially or totally corroded objects. Analyses were carried out with the use of light optical microscopy, micro Raman spectroscopy, and scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy (EDXS). Remnants of metallographic features—ghost microstructure—in the corrosion layers of the blades were observed, allowing for a partial reconstruction of the manufacturing process.

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

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Per H.; Tesauro, A.; Bitsche, R. [Technical Univ. of Denmark. DTU Wind Energy, DTU Risoe Campus, Roskilde (Denmark)] [and others

2012-09-15

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 the description of the test setup, the test and an overview over the results from the test performed on the box girder. During the final test the box girder failed at 58 % of the expected ultimate load. Unfortunately, no definite conclusion could be made concerning the failure mechanism. (Author)

Reduced artefacts and improved assessment of hyperintense brain lesions with BLADE MR imaging in patients with neurofibromatosis type 1

Energy Technology Data Exchange (ETDEWEB)

Kalle, Thekla von; Fabig-Moritz, Claudia; Mueller-Abt, Peter; Zieger, Michael; Winkler, Peter [Department of Paediatric Radiology, Stuttgart (Germany); Blank, Bernd [Haematology and Immunology, Department of Paediatric Oncology, Stuttgart (Germany); Wohlfarth, Katrin [Siemens Healthcare Sector, Erlangen (Germany)

2009-11-15

Assessment of small brain lesions in children is often compromised by pulsation, flow or movement artefacts. MRI with a rotating blade-like k-space covering (BLADE, PROPELLER) can compensate for these artefacts. We compared T2-weighted FLAIR images that were acquired with different k-space trajectories (conventional Cartesian and BLADE) to evaluate the impact of BLADE technique on the delineation of small or low-contrast brain lesions. The subject group comprised 26 children with neurofibromatosis type 1 (NF 1), who had been routinely scanned at 1.5 T for optic pathway gliomas with both techniques and who had the typical hyperintense brain lesions seen in NF 1. Four experienced radiologists retrospectively compared unlabelled 4-mm axial images with respect to the presence of artefacts, visibility of lesions, quality of contour and contrast. Both techniques were comparable in depicting hyperintense lesions as small as 2 mm independent of contrast and edge definition. Pulsation and movement artefacts were significantly less common with BLADE k-space trajectory. In 7 of 26 patients (27%), lesions and artefacts were rated as indistinguishable in conventional FLAIR, but not in BLADE FLAIR images. BLADE imaging significantly improved the depiction of lesions in T2-W FLAIR images due to artefact reduction especially in the posterior fossa. (orig.)

Reduced artefacts and improved assessment of hyperintense brain lesions with BLADE MR imaging in patients with neurofibromatosis type 1

International Nuclear Information System (INIS)

Kalle, Thekla von; Fabig-Moritz, Claudia; Mueller-Abt, Peter; Zieger, Michael; Winkler, Peter; Blank, Bernd; Wohlfarth, Katrin

2009-01-01

Assessment of small brain lesions in children is often compromised by pulsation, flow or movement artefacts. MRI with a rotating blade-like k-space covering (BLADE, PROPELLER) can compensate for these artefacts. We compared T2-weighted FLAIR images that were acquired with different k-space trajectories (conventional Cartesian and BLADE) to evaluate the impact of BLADE technique on the delineation of small or low-contrast brain lesions. The subject group comprised 26 children with neurofibromatosis type 1 (NF 1), who had been routinely scanned at 1.5 T for optic pathway gliomas with both techniques and who had the typical hyperintense brain lesions seen in NF 1. Four experienced radiologists retrospectively compared unlabelled 4-mm axial images with respect to the presence of artefacts, visibility of lesions, quality of contour and contrast. Both techniques were comparable in depicting hyperintense lesions as small as 2 mm independent of contrast and edge definition. Pulsation and movement artefacts were significantly less common with BLADE k-space trajectory. In 7 of 26 patients (27%), lesions and artefacts were rated as indistinguishable in conventional FLAIR, but not in BLADE FLAIR images. BLADE imaging significantly improved the depiction of lesions in T2-W FLAIR images due to artefact reduction especially in the posterior fossa. (orig.)

Flow and Stress Field Analysis of Different Fluids and Blades for Fermentation Process

Directory of Open Access Journals (Sweden)

Cheng-Chi Wang

2014-02-01

Full Text Available Fermentation techniques are applied for the biotechnology and are widely used for food manufacturing, materials processing, chemical reaction, and so forth. Different fluids and types of blades in the tank for fermentation cause distinct flow and stress field distributions on the surface between fluid and blade and various flow reactions in the tank appear. This paper is mainly focused on the analysis of flow field with different fluid viscosities and also studied the stress field acting on the blades with different scales and shapes of them under specific rotational speed. The results show that the viscosity of fluid influences the flow field and stress distributions on the blades. The maximum stress that acts on the blade is increased with the increasing of viscosity. On the other hand, the ratio of blade length to width influences stress distributions on the blade. At the same time, the inclined angle of blade is also the key parameter for the consideration of design and appropriate inclined angle of blade will decrease the maximum stress. The results provide effective means of gaining insights into the flow and stress distribution of fermentation process.

Development of tooling suitable for stall regulated blades

Energy Technology Data Exchange (ETDEWEB)

Hancock, M.

2001-07-01

The objectives of the project were to make significant improvements in the production of stall regulated blades in the areas of (a) the tip box, its housing, its mechanism and small GRP parts; (b) mould technology; (c) resins and glues and (d) root tooling. Although wood composite had been identified as a competitive technology for blades, compared with GRP blades, production volumes had been lower; reasons are given. The way in which the four areas identified for investigation were tackled are discussed. The study showed that the mould cycle time can be reduced to two days for a stall regulated blade and the blade quality can be improved by using the composite tip box and new resins. The time required for replication of moulds can be reduced by 40%.

Calibration procedures for improved accuracy of wind turbine blade load measurement

Energy Technology Data Exchange (ETDEWEB)

Dahlberg, J.Aa. [Aeronautical Research Inst. of Sweden, Bromma (Sweden); Johansson, Hjalmar [Teknikgruppen AB, Sollentuna (Sweden)

1996-12-01

External loads acting on wind turbine blades are mainly transferred via the hub to the rest of the structure. It is therefore a normal approach to measure the loads acting on the turbine by load measurements in the blade roots. The load measurement is often accomplished by measurements of strain on the surface of the blade or the hub. The strain signals are converted to loads by applying calibration factors to the measurements. This paper deals with difficulties associated with load measurements on two different wind turbines; one with strain gauges applied to a steel hub where a linear stress-load relationship is expected and the other with strain gauges applied to the GFRP blade close to the bearings where strong non-linearity`s and temperature effects are expected. This paper suggests calibration methods to overcome these problems. 2 refs, 11 figs

New Method for Dual-Axis Fatigue Testing of Large Wind Turbine Blades Using Resonance Excitation and Spectral Loading

Energy Technology Data Exchange (ETDEWEB)

White, D.

2004-04-01

The blades of a wind turbine are generally considered to be the most critical component of the wind turbine system. The fundamental purpose of performing fatigue tests on wind turbine blades is to demonstrate that a blade, when manufactured to a certain set of specifications, has the prescribed reliability and service life. The purpose of the research conducted for this project is the advancement of knowledge and capabilities in the area of wind turbine blade fatigue testing.

Conjugate calculation of a film-cooled blade for improvement of the leading edge cooling configuration

Directory of Open Access Journals (Sweden)

Norbert Moritz

2013-03-01

Full Text Available Great efforts are still put into the design process of advanced film-cooling configurations. In particular, the vanes and blades of turbine front stages have to be cooled extensively for a safe operation. The conjugate calculation technique is used for the three-dimensional thermal load prediction of a film-cooled test blade of a modern gas turbine. Thus, it becomes possible to take into account the interaction of internal flows, external flow, and heat transfer without the prescription of heat transfer coefficients. The focus of the investigation is laid on the leading edge part of the blade. The numerical model consists of all internal flow passages and cooling hole rows at the leading edge. Furthermore, the radial gap flow is also part of the model. The comparison with thermal pyrometer measurements shows that with respect to regions with high thermal load a qualitatively and quantitatively good agreement of the conjugate results and the measurements can be found. In particular, the region in the vicinity of the mid-span section is exposed to a higher thermal load, which requires further improvement of the cooling arrangement. Altogether the achieved results demonstrate that the conjugate calculation technique is applicable for reasonable prediction of three-dimensional thermal load of complex cooling configurations for blades.

Continuous improvement in manufacturing and inspection of fuel

International Nuclear Information System (INIS)

Domingon, A.; Ruiz, R.

2015-01-01

The manufacturing and inspection process of fuel assemblies in ENUSA is characterized by its robustness acquired over the last thirty years of experience in manufacturing. The reliability of these processes is based on a qualified processes and continuous improvement in the design and upgrading of equipment and optimization of software and manufacturing processes. Additionally, management and quality control systems have been improved in both software and measuring business objectives. this article emphasizes the improvements made over the past five years in management, production and inspection of fuel assemblies. (Author)

Experimental measurements of out-of-plane vibrations of a simple blisk design using Blade Tip Timing and Scanning LDV measurement methods

Science.gov (United States)

Di Maio, D.; Ewins, D. J.

2012-04-01

The study of dynamic properties of rotating structures, such as bladed discs, can be conveniently done using simple bladed discs where the blades do not have staggering angles. Simplified design, although not truly representative of real structures, can be easy and economic to manufacture and, still, very helpful for studying specific dynamic properties. An example of this can be called as mass mistune blisk study. Experimental measurements of vibrations of bladed discs under rotating conditions can be performed using Scanning Laser Doppler Vibrometer (SLDV) systems. However, in the aerospace industry, the vibrations of complex bladed discs must be measured under operating conditions which are more hostile than laboratory simulations. The Blade Tip Timing (BTT) measurement method is a measurement technique, which can be used to measure vibrations of bladed discs of an engine aircraft under operating conditions. However, the BTT technique is ineffective when used with a flat bladed disc whose blade vibrations cannot be measured. This can be detrimental when the use of controlled dynamic parameters, such as those obtained from a simple bladed disc design, can improve the confidence for the validation of post-processing software. This paper presents a work about experimental measurements of a simple bladed disc design whose vibrations were measured synchronously by Scanning LDV and BTT measurement systems. A rotating test rig and its mechanical modifications for the installation of the BTT probes are introduced. Implications of rotating a specimen inconsistently are presented so as solutions to obtained constant revolving speed. The experimental comparisons of forced response vibrations measured synchronously at one blade are presented and explained.

The SNL100-02 blade :

Energy Technology Data Exchange (ETDEWEB)

Griffith, Daniel

2013-11-01

A series of design studies are performed to investigate the effects of advanced core materials and a new core material strategy on blade weight and performance for large blades using the Sandia 100-meter blade designs as a starting point. The initial core material design studies were based on the SNL100-01 100- meter carbon spar design. Advanced core material with improved performance to weight was investigated with the goal to reduce core material content in the design and reduce blade weight. A secondary element of the core study was to evaluate the suitability of core materials from natural, regrowable sources such as balsa and recyclable foam materials. The new core strategy for the SNL100-02 design resulted in a design mass of 59 tons, which is a 20% reduction from the most recent SNL100-01 carbon spar design and over 48% reduction from the initial SNL100-00 all-glass baseline blade. This document provides a description of the final SNL100-02 design, includes a description of the major design modifications, and summarizes the pertinent blade design information. This document is also intended to be a companion document to the distribution of the NuMAD blade model files for SNL100-02 that are made publicly available.

Methodology for testing subcomponents; background and motivation for subcomponent testing of wind turbine rotor blades

DEFF Research Database (Denmark)

Antoniou, Alexandros; Branner, Kim; Lekou, D.J.

2016-01-01

This report aims to provide an overview of the design methodology followed by wind turbine blade structural designers, along with the testing procedure on full scale blades which are followed by testing laboratories for blade manufacturers as required by the relevant standards and certification...... bodies’ recommendations for design and manufacturing verification. The objective of the report is not to criticize the design methodology or testing procedure and the standards thereof followed in the wind energy community, but to identify those items offered by state of the art structural design tools...... investigations performed are based on the INNWIND.EU reference 10MW horizontal axis wind turbine [1]. The structural properties and material and layout definition used within IRPWIND are defined in the INNWIND.EU report [2]. The layout of the report includes a review of the structural analysis models used...

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)

A structural model for composite rotor blades and lifting surfaces

Science.gov (United States)

Rehfield, Lawrence W.; Atilgan, Ali R.

1987-01-01

Composite material systems are currently candidates for aerospace structures, primarily for the design flexibiity they offer i.e., it is possible to tailor the material and manufacturing approach to the application. Two notable examples are the wing of the Grumman/USAF/DARPA X-29 and rotor blades under development by the U.S.A. Aerostructures Directorate (AVSCOM), Langley Research Center. A working definition of elastic or structural tailoring is the use of structural concept, fiber orientation, ply stacking sequence, and a blend of materials to achieve specific performance goals. In the design process, choices of materials and dimensions are made which produce specific response characteristics which permit the selected goals to be achieved. Common choices for tailoring goals are preventing instabilities or vibration resonances or enhancing damage tolerance. An essential, enabling factor in the design of tailored composite structures is structural modeling that accurately, but simply, characterizes response. The objective of this paper is to improve the single-cell beam model for composite rotor blades or lifting surfaces and to demonstrate its usefullness in applications.

Three-dimensional flow analysis and improvement of slip factor model for forward-curved blades centrifugal fan

International Nuclear Information System (INIS)

Guo, En Min; Kim, Kwang Yong

2004-01-01

This work developed improved slip factor model and correction method to predict flow through impeller in forward-curved centrifugal fan. Both steady and unsteady three-dimensional CFD analyses were performed to validate the slip factor model and the correction method. The results show that the improved slip factor model presented in this paper could provide more accurate predictions for forward-curved centrifugal impeller than the other slip factor models since the present model takes into account the effect of blade curvature. The correction method is provided to predict mass-averaged absolute circumferential velocity at the exit of impeller by taking account of blockage effects induced by the large-scale backflow near the front plate and flow separation within blade passage. The comparison with CFD results also shows that the improved slip factor model coupled with the present correction method provides accurate predictions for mass-averaged absolute circumferential velocity at the exit of impeller near and above the flow rate of peak total pressure coefficient

Composite material bend-twist coupling for wind turbine blade applications

Science.gov (United States)

Walsh, Justin M.

Current efforts in wind turbine blade design seek to employ bend-twist coupling of composite materials for passive power control by twisting blades to feather. Past efforts in this area of study have proved to be problematic, especially in formulation of the bend-twist coupling coefficient alpha. Kevlar/epoxy, carbon/epoxy and glass/epoxy specimens were manufactured to study bend-twist coupling, from which numerical and analytical models could be verified. Finite element analysis was implemented to evaluate fiber orientation and material property effects on coupling magnitude. An analytical/empirical model was then derived to describe numerical results and serve as a replacement for the commonly used coupling coefficient alpha. Through the results from numerical and analytical models, a foundation for aeroelastic design of wind turbines blades utilizing biased composite materials is provided.

WindPACT Turbine Design Scaling Studies Technical Area 1-Composite Blades for 80- to 120-Meter Rotor

Energy Technology Data Exchange (ETDEWEB)

Griffin, D.A.

2001-04-30

The United States Department of Energy (DOE) through the National Renewable Energy Laboratory (NREL) implemented the Wind Partnership for Advanced Component Technologies (WindPACT) program. As part of the WindPACT program, Global Energy Concepts, LLC (GEC), was awarded contract number YAM-0-30203-01 to examine Technical Area 1-Blade Scaling, Technical Area 2-Turbine Rotor and Blade Logistics, and Technical Area 3-Self-Erecting Towers. This report documents the results of GEC's Technical Area 1-Blade Scaling. The primary objectives of the Blade-Scaling Study are to assess the scaling of current materials and manufacturing technologies for blades of 40 to 60 meters in length, and to develop scaling curves of estimated cost and mass for rotor blades in that size range.

Design, fabrication, and test of a steel spar wind turbine blade

Science.gov (United States)

Sullivan, T. L.; Sirocky, P. J., Jr.; Viterna, L. A.

1979-01-01

The design and fabrication of wind turbine blades based on 60 foot steel spars are discussed. Performance and blade load information is given and compared to analytical prediction. In addition, performance is compared to that of the original MOD-O aluminum blades. Costs for building the two blades are given, and a projection is made for the cost in mass production. Design improvements to reduce weight and improve fatigue life are suggested.

Design of a fibrous composite preform for wind turbine rotor blades

DEFF Research Database (Denmark)

Hansen, Jens Zangenberg; Brøndsted, Povl; Kofoed, M.

2014-01-01

The present work addresses the different factors and challenges one must cope with in the design process of a composite preform used for the load-carrying main laminate of a wind turbine rotor blade. The design process is split up into different key elements, each of which are presented...... and discussed separately. The key elements are all interconnected, which complicate the design process and involves an iterative procedure. The aim is to provide an overview of the process that governs the design of composite preforms for wind turbine blades. The survey can be used as an information source...... on composite preform manufacturing. Basic knowledge on wind turbine blade technology and composites is assumed. © 2013 Elsevier Ltd. All rights reserved....

Multiscale modelling of single crystal superalloys for gas turbine blades

NARCIS (Netherlands)

Tinga, T.

2009-01-01

Gas turbines are extensively used for power generation and for the propulsion of aircraft and vessels. Their most severely loaded parts, the turbine rotor blades, are manufactured from single crystal nickel-base superalloys. The superior high temperature behaviour of these materials is attributed to

Materials for Wind Turbine Blades: An Overview

DEFF Research Database (Denmark)

Mishnaevsky, Leon; Branner, Kim; Petersen, Helga Nørgaard

2017-01-01

A short overview of composite materials for wind turbine applications is presented here. Requirements toward the wind turbine materials, loads, as well as available materials are reviewed. Apart from the traditional composites for wind turbine blades (glass fibers/epoxy matrix composites), natural...... composites, hybrid and nanoengineered composites are discussed. Manufacturing technologies for wind turbine composites, as well their testing and modelling approaches are reviewed....

Materials for Wind Turbine Blades: An Overview.

Science.gov (United States)

Mishnaevsky, Leon; Branner, Kim; Petersen, Helga Nørgaard; Beauson, Justine; McGugan, Malcolm; Sørensen, Bent F

2017-11-09

A short overview of composite materials for wind turbine applications is presented here. Requirements toward the wind turbine materials, loads, as well as available materials are reviewed. Apart from the traditional composites for wind turbine blades (glass fibers/epoxy matrix composites), natural composites, hybrid and nanoengineered composites are discussed. Manufacturing technologies for wind turbine composites, as well their testing and modelling approaches are reviewed.

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....

Remote inspection of steam turbine blades

International Nuclear Information System (INIS)

Anon.

1987-01-01

During the past five years Reinhart and Associates, Inc. has been involved in remote examination of L-0 and L-1 steam turbine blade rows of in-place LP turbines using visual and eddy current techniques. These tests have concentrated on the trailing edge and blade-to-rotor attachment (Christmas tree) areas. These remote nondestructive examinations were performed through hand access ports of the inner shell. Since the remote scanning system was in a prototype configuration, the inspection was highly operator-dependent. Refinement of the scanning equipment would considerably improve the efficiency of the test; however, the feasibility of remote in-place inspection of turbine blades was established. To further improve this technology, and to provide for remote inspection of other areas of the blade and additional turbine designs, EPRI is funding a one-year project with Reinhart and Associates, Inc. This project will develop a new system that employs state-of-the-art multifrequency eddy current techniques, a miniature charged coupled device (CCD) television camera, and remote positioning equipment. Project results from the first six months are presented

Development of 1800 rpm, 43in. blade for large steam turbine

International Nuclear Information System (INIS)

Kuroda, Michio; Yamazaki, Yoshiaki; Namura, Kiyoshi; Taki, Takamitsu; Ninomiya, Satoshi.

1978-01-01

In the turbines for nuclear power generation, the inlet conditions of steam is low pressure and low temperature as compared with the turbines for thermal power generation, therefore generally the required steam flow rate is much more. It is the main problem to cope with this steam of large flow rate effectively with long final stage blades and to make a turbine compact. This newly developed blade aims at the turbines from 1100 to 1300 MW class for nuclear power generation and those of 1000 MW class for thermal power generation, and it is the first low revolution, long blade in Japan used for large capacity machines of 60 Hz. Hereinafter, the outline of various examinations carried out at the time of the tests on this blade and the features of this blade are described. There is large margin in the exhaust area with this blade, therefore the turbines with large power output and good performance can be produced. The loss of exhaust energy at turbine exit can be reduced, and thermal efficiency can be raised. Large capacity machines from 1100 to 1300 MW class can be manufactured with six-flow exhaust, tandem compound turbines. In order to confirm the reliability, the vibration characteristics of the blade were investigated in the test of this time, and also the overspeed test and endurance test were carried out. (Kako, I.)

Caution: Precision Error in Blade Alignment Results in Faulty Unsteady CFD Simulation

Science.gov (United States)

Lewis, Bryan; Cimbala, John; Wouden, Alex

2012-11-01

Turbomachinery components experience unsteady loads at several frequencies. The rotor frequency corresponds to the time for one rotor blade to rotate between two stator vanes, and is normally dominant for rotor torque oscillations. The guide vane frequency corresponds to the time for two rotor blades to pass by one guide vane. The machine frequency corresponds to the machine RPM. Oscillations at the machine frequency are always present due to minor blade misalignments and imperfections resulting from manufacturing defects. However, machine frequency oscillations should not be present in CFD simulations if the mesh is free of both blade misalignment and surface imperfections. The flow through a Francis hydroturbine was modeled with unsteady Reynolds-Averaged Navier-Stokes (URANS) CFD simulations and a dynamic rotating grid. Spectral analysis of the unsteady torque on the rotor blades revealed a large component at the machine frequency. Close examination showed that one blade was displaced by 0 .0001° due to round-off errors during mesh generation. A second mesh without blade misalignment was then created. Subsequently, large machine frequency oscillations were not observed for this mesh. These results highlight the effect of minor geometry imperfections on CFD solutions. This research was supported by a grant from the DoE and a National Defense Science and Engineering Graduate Fellowship.

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.

Reliability of wind turbine blades: An overview of materials testing

DEFF Research Database (Denmark)

Holmes, John W.; Sørensen, Bent F.; Brøndsted, Povl

2007-01-01

an understanding of how damage develops in composite structures, composite materials and adhesives. Designing reliable wind turbine blades also requires the further development of laboratory scale and full scale test methods to evaluate the structural response and durability of new materials under various loading......The structural reliability of wind turbine components can have a profound impact on both the profitability and reputation of a wind turbine manufacturer or supplier of wind turbine components. The issue of reliability is of critical concern when large wind farm co-operatives are considered......, and when wind turbines are located in remote regions where the cost of inspections and repairs can be very high. From a structural viewpoint, wind turbine blades are subjected to very complex loading histories with coupled deformation modes. The long-term reliability of wind turbine blades requires...

Application of heterogeneous blading systems is the way for improving efficiency of centrifugal energy pumps

Science.gov (United States)

Pochylý, F.; Haluza, M.; Fialová, S.; Dobšáková, L.; Volkov, A. V.; Parygin, A. G.; Naumov, A. V.; Vikhlyantsev, A. A.; Druzhinin, A. A.

2017-11-01

The results of independent research implemented by the teams of authors representing the Brno University of technology (Czech Republic) and Moscow Power Engineering Institute National Research University (Russia) are presented and compared. The possibilities for improving the energy efficiency of slow-speed centrifugal pumps (with a specific speed coefficient n s engineering—in thermal power stations, in heat electric-power stations, in nuclear power plants, and in boiler rooms—were investigated. These are supply pumps, condensate pumps, precharge pumps, etc. The pumps with such values of n s are widely used in some technological cycles of oil-and-gas and chemical industries too. The research was focused on achieving the shape of the pump efficiency characteristics providing a significant extension of its effective working zone and increasing its integrated efficiency. The results were obtained based on new approaches to the formation of a blading system of an impeller of a slow-speed centrifugal pump different from the traditional blading system. The analytical dependences illustrating the influence of individual geometry of a blading system on the efficiency were presented. The possibilities of purposeful changing of its structure were demonstrated. It was experimentally confirmed that use of the innovative blading system makes it possible to increase the pump efficiency by 1-4% (in the experiments for the pumps with n s = 33 and 55) and to extend its efficient working zone approximately by 15-20% (in the experiment for the pumps with n s = 33 and 66). The latter is especially important for the supply pumps of NPP power units. The experimental results for all investigated pumps are presented in comparison with the characteristics of the efficiency provided by the blading systems designed by traditional methods.

Improved Manufacturing Process for Pyronaridine Tetraphosphate

International Nuclear Information System (INIS)

Lee, Dong Won; Lee, Seung Kyu; Cho, Jun Ho; Yoon, Seung Soo

2014-01-01

Pyronaridine tetraphosphate (1) is a well-known antimalarial drug. However, it required a carefully optimized production process for the manufacture of pyronaridine tetraphosphate. Each step of its manufacturing process was reinvestigated. For the cyclization of 4-chloro-2-(6-methoxy-pyridin-3-yl-amino)-benzoic acid 6 to 7,10-dichloro-2-methoxybenzo[b]-1,5-naphthyridine 5, an improved process was developed to eliminated critical process impurity (BIA). By the redesign of the formation of triphosphate salt, the purity as API grade was increased. Thus, a robust manufacturing process with an acceptable process performance has been developed to produce high quality pyronaridine tetraphosphate

Flow and Stress Field Analysis of Different Fluids and Blades for Fermentation Process

OpenAIRE

Cheng-Chi Wang; Po-Jen Cheng; Kuo-Chi Liu; Ming-Yi Tsai

2014-01-01

Fermentation techniques are applied for the biotechnology and are widely used for food manufacturing, materials processing, chemical reaction, and so forth. Different fluids and types of blades in the tank for fermentation cause distinct flow and stress field distributions on the surface between fluid and blade and various flow reactions in the tank appear. This paper is mainly focused on the analysis of flow field with different fluid viscosities and also studied the stress field acting on t...

Moving blade for steam turbines with axial flow

International Nuclear Information System (INIS)

Raschke, K.; Wehle, G.

1976-01-01

The invention concerns the improvement of the production of moving blades for steam turbines with axial flow, especially of multi-blades produced by welding of the top plates. It is proposed to weld the top plates before the moving blades are fitted into the rotor. Welding is this made much easier and can be carried out under protective gas and with better results. (UWI) [de

Surface modeling method for aircraft engine blades by using speckle patterns based on the virtual stereo vision system

Science.gov (United States)

Yu, Zhijing; Ma, Kai; Wang, Zhijun; Wu, Jun; Wang, Tao; Zhuge, Jingchang

2018-03-01

A blade is one of the most important components of an aircraft engine. Due to its high manufacturing costs, it is indispensable to come up with methods for repairing damaged blades. In order to obtain a surface model of the blades, this paper proposes a modeling method by using speckle patterns based on the virtual stereo vision system. Firstly, blades are sprayed evenly creating random speckle patterns and point clouds from blade surfaces can be calculated by using speckle patterns based on the virtual stereo vision system. Secondly, boundary points are obtained in the way of varied step lengths according to curvature and are fitted to get a blade surface envelope with a cubic B-spline curve. Finally, the surface model of blades is established with the envelope curves and the point clouds. Experimental results show that the surface model of aircraft engine blades is fair and accurate.

Numerical Study on the Effect of Swept Blade on the Aerodynamic Performance of Wind Turbine at High Tip Speed Ratio

International Nuclear Information System (INIS)

Zuo, H M; Liu, C; Yang, H; Wang, F

2016-01-01

The current situation is that the development of high speed wind energy saturates gradually, therefore, it is highly necessary to develop low speed wind energy. This paper, based on a specific straight blade and by using Isight, a kind of multidiscipline optimization software, which integrates ICEM (Integrated Computer Engineering and Manufacturing) and CFD (Computational Fluid Dynamics) software, optimizes the blade stacking line (the centers of airfoil from blade root to tip) and acquires the optimization swept blade shape. It is found that power coefficient C p of swept blade is 3.2% higher than that of straight blade at the tip speed ratio of 9.82, that the thrust of swept blade receives is obviously less than that of straight blade. Inflow angle of attack and steam line on the suction of the swept and straight blade are also made a comparison. (paper)

Nonlinear aeroelastic modelling for wind turbine blades based on blade element momentum theory and geometrically exact beam theory

International Nuclear Information System (INIS)

Wang, Lin; Liu, Xiongwei; Renevier, Nathalie; Stables, Matthew; Hall, George M.

2014-01-01

Due to the increasing size and flexibility of large wind turbine blades, accurate and reliable aeroelastic modelling is playing an important role for the design of large wind turbines. Most existing aeroelastic models are linear models based on assumption of small blade deflections. This assumption is not valid anymore for very flexible blade design because such blades often experience large deflections. In this paper, a novel nonlinear aeroelastic model for large wind turbine blades has been developed by combining BEM (blade element momentum) theory and mixed-form formulation of GEBT (geometrically exact beam theory). The nonlinear aeroelastic model takes account of large blade deflections and thus greatly improves the accuracy of aeroelastic analysis of wind turbine blades. The nonlinear aeroelastic model is implemented in COMSOL Multiphysics and validated with a series of benchmark calculation tests. The results show that good agreement is achieved when compared with experimental data, and its capability of handling large deflections is demonstrated. Finally the nonlinear aeroelastic model is applied to aeroelastic modelling of the parked WindPACT 1.5 MW baseline wind turbine, and reduced flapwise deflection from the nonlinear aeroelastic model is observed compared to the linear aeroelastic code FAST (Fatigue, Aerodynamics, Structures, and Turbulence). - Highlights: • A novel nonlinear aeroelastic model for wind turbine blades is developed. • The model takes account of large blade deflections and geometric nonlinearities. • The model is reliable and efficient for aeroelastic modelling of wind turbine blades. • The accuracy of the model is verified by a series of benchmark calculation tests. • The model provides more realistic aeroelastic modelling than FAST (Fatigue, Aerodynamics, Structures, and Turbulence)

Improving Manufacturing Performance in South Africa : Report of the ...

International Development Research Centre (IDRC) Digital Library (Canada)

1995-01-01

Improving Manufacturing Performance in South Africa : Report of the Industrial Strategy Project. Couverture du livre Improving Manufacturing Performance in South Africa. Author(s):. Avril Joffe, David Kaplan, Raphael Kaplinsky et David Lewis. Publisher(s):. UCT Press, CRDI. January 1, 1995. ISBN: Épuisé. 264 pages.

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

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 extrusion...

Flow performance of highly loaded axial fan with bowed rotor blades

Science.gov (United States)

Chen, L.; Liu, X. J.; Yang, A. L.; Dai, R.

2013-12-01

In this paper, a partial bowed rotor blade was proposed for a newly designed high loaded axial fan. The blade was positively bowed 30 degrees from hub to 30 percent spanwise position. Flows of radial blade and bowed blade fans were numerically compared for various operation conditions. Results show that the fan's performance is improved. At the designed condition with flow coefficient of 0.52, the efficiency of the bowed blade fan is increased 1.44% and the static pressure rise is increased 11%. Comparing the flow structures, it can be found that the separated flow in the bowed fan is reduced and confined within 20 percent span, which is less than the 35 percent in the radial fan. It means that the bowed blade generates negative blade force and counteracts partial centrifugal force. It is alleviates the radial movements of boundary layers in fan's hub region. Flow losses due to 3D mixing are reduced in the rotor. Inlet flow to downstream stator is also improved.

Determination of the number of Vertical Axis Wind Turbine blades based on power spectrum

Directory of Open Access Journals (Sweden)

Fedak Waldemar

2017-01-01

Full Text Available Technology of wind exploitation has been applied widely all over the world and has already reached the level in which manufacturers want to maximize the yield with the minimum investment outlays. The main objective of this paper is the determination of the optimal number of blades in the Cup-Bladed Vertical Axis Wind Turbine. Optimizing the size of the Vertical Axis Wind Turbine allows the reduction of costs. The maximum power of the rotor is selected as the performance target. The optimum number of Vertical Axis Wind Turbine blades evaluation is based on analysis of a single blade simulation and its superposition for the whole rotor. The simulation of working blade was done in MatLab environment. Power spectrum graphs were prepared and compared throughout superposition of individual blades in the Vertical Axis Wind Turbine rotor. The major result of this research is the Vertical Axis Wind Turbine power characteristic. On the basis of the analysis of the power spectra, optimum number of the blades was specified for the analysed rotor. Power spectrum analysis of wind turbine enabled the specification of the optimal number of blades, and can be used regarding investment outlays and power output of the Vertical Axis Wind Turbine.

Determination of the number of Vertical Axis Wind Turbine blades based on power spectrum

Science.gov (United States)

Fedak, Waldemar; Anweiler, Stanisław; Gancarski, Wojciech; Ulbrich, Roman

2017-10-01

Technology of wind exploitation has been applied widely all over the world and has already reached the level in which manufacturers want to maximize the yield with the minimum investment outlays. The main objective of this paper is the determination of the optimal number of blades in the Cup-Bladed Vertical Axis Wind Turbine. Optimizing the size of the Vertical Axis Wind Turbine allows the reduction of costs. The maximum power of the rotor is selected as the performance target. The optimum number of Vertical Axis Wind Turbine blades evaluation is based on analysis of a single blade simulation and its superposition for the whole rotor. The simulation of working blade was done in MatLab environment. Power spectrum graphs were prepared and compared throughout superposition of individual blades in the Vertical Axis Wind Turbine rotor. The major result of this research is the Vertical Axis Wind Turbine power characteristic. On the basis of the analysis of the power spectra, optimum number of the blades was specified for the analysed rotor. Power spectrum analysis of wind turbine enabled the specification of the optimal number of blades, and can be used regarding investment outlays and power output of the Vertical Axis Wind Turbine.

The development and manufacture of wood composite wind turbine rotors

Science.gov (United States)

Zuteck, M. D.

1982-01-01

The physical properties, operational experience, and construction methods of the wood/epoxy composite MOD 0A wind turbine blades are considered. Blades of this type have accumulated over 10,000 hours of successful operation at the Kahuku, Hawaii and Block Island, Rhode Island test sites. That body of experience is summarized and related to the structural concepts and design drivers which motivated the original design and choice of interior layout. Actual manufacturing experience and associated low first unit costs for these blades, as well as projections for high production rates, are presented. Application of these construction techniques to a wide range of other blade sizes is also considered.

Effect of technological deviation on aerodynamic efficiency of reaction blades of steam and gas turbines at high Mach nos

International Nuclear Information System (INIS)

Husain, Z.

1991-01-01

During manufacture and assembly of steam and gas turbine blades there are always some technological deviation and is meant local increase or decrease in dimension at certain sections of the profile improper stagger angle of long blades during assembly etc. In this paper the effect of oversize in dimensions at certain important places along a reaction profile has been studied. The technological deviation has been made by sticking thin aluminium foils of 0.3 mm thickness and 15 mm width at inlet and exit tips of reactive profiles and its effect on aerodynamic efficiency at mach. nos ranging from 0.7 to 1.1. The object of performing these tests was to obtain comprehensive data based on which information suitable tolerances could be recommended during manufacture of these blades

IMHEX fuel cell repeat component manufacturing continuous improvement accomplishments

Energy Technology Data Exchange (ETDEWEB)

Jakaitis, L.A.; Petraglia, V.J.; Bryson, E.S. [M-C Power Corp., Burr Ridge, IL (United States)] [and others

1996-12-31

M-C Power is taking a power generation technology that has been proven in the laboratory and is making it a commercially competitive product. There are many areas in which this technology required scale up and refinement to reach the market entry goals for the IMHEX{reg_sign} molten carbonate fuel cell power plant. One of the primary areas that needed to be addressed was the manufacturing of the fuel cell stack. Up to this point, the fuel cell stack and associated components were virtually hand made for each system to be tested. M-C Power has now continuously manufactured the repeat components for three 250 kW stacks. M-C Power`s manufacturing strategy integrated both evolutionary and revolutionary improvements into its comprehensive commercialization effort. M-C Power`s objectives were to analyze and continuously improve stack component manufacturing and assembly techniques consistent with established specifications and commercial scale production requirements. Evolutionary improvements are those which naturally occur as the production rates are increased and experience is gained. Examples of evolutionary (learning curve) improvements included reducing scrap rates and decreasing raw material costs by buying in large quantities. Revolutionary improvements result in significant design and process changes to meet cost and performance requirements of the market entry system. Revolutionary changes often involve identifying new methods and developing designs to accommodate the new process. Based upon our accomplishments, M-C Power was able to reduce the cost of continuously manufactured fuel cell repeat components from the first to third 250 kW stack by 63%. This paper documents the continuous improvement accomplishments realized by M-C Power during IMHEX{reg_sign} fuel cell repeat component manufacturing.

Measurements of blade aerodynamics on a rotor in the field

Energy Technology Data Exchange (ETDEWEB)

Graham, J.M.R. [Imperical College, Dept. of Aeronautics, London (United Kingdom)

1997-12-31

This contribution describes the field test measurements undertaken on an instrumented rotor at the Rutherford Appleton Laboratory, Oxfordshire, UK, during the period 1994 - 97. The programme was directed at improving the prediction of the steady and unsteady rotor blade loading, particularly the loads arising from the stalling of the blade. The measured data consisted of blade surface pressure distributions sampled at 50Hz at 6 sections along the span of one blade of the 17m diameter, 3 bladed, fixed pitch, upwind H.A.W.T., together with measurements of the incident velocity. (au)

PV Cz silicon manufacturing technology improvements

Science.gov (United States)

Jester, T.

1995-09-01

This describes work done in the final phase of a 3-y, 3-phase contract to demonstrate cost reductions and improvements in manufacturing technology. The work focused on near-term projects in the SSI (Siemens Solar Industries) Czochralski (Cz) manufacturing facility in Camarillo, CA; the final phase was concentrated in areas of crystal growth, wafer technology, and environmental, safety, and health issues. During this period: (1) The crystal-growing operation improved with increased growth capacity; (2) Wafer processing with wire saws continued to progress; the wire saws yielded almost 50 percent more wafers per inch in production. The wire saws needs less etching, too; (3) Cell processing improvements focused on better handling and higher mechanical yield. The cell electrical distribution improved with a smaller standard deviation in the distribution; and (4) Module designs for lower material and labor costs continued, with focus on a new junction box, larger modules with larger cells, and less costly framing techniques. Two modules demonstrating these cost reductions were delivered during this phase.

A Failure Analysis Conducted on a Fractured AISI 5160 Steel Blade Which Separated from an Agricultural Rotary Cutter

Energy Technology Data Exchange (ETDEWEB)

Johnson, Alan A [Metals Research Inc., 101 West Chestnut St., Louisville, Kentucky, 40202 (United States); Storey, Randall J, E-mail: barbalan@bellsouth.net [Deptartment of Industrial Engineering, University of Louisville, Louisville, Kentucky, 40292 (United States)

2011-07-19

One of the six blades of an agricultural rotary cutter used for cutting down small trees and bushes broke into two pieces while the blades were rotating. One piece was hurled from the cutter and struck a young farmer, who had been operating the machine, causing a near fatal leg injury. In the ensuing litigation against the manufacturers and marketer of the machine each litigant retained a metallurgist and other experts. The metallurgists jointly directed laboratory work on the broken blade conducted at an independent laboratory according to a protocol which they developed and which was approved by the court. As a result of the laboratory work the present authors, working for the Plaintiffs, concluded that failure of the blade occurred because it contained quench cracks introduced when it was manufactured. The Defendants' metallurgists concluded that the blade had been misassembled onto the machine and, as a result, had failed by fatigue. Eventually, the case was set for a jury trial in a Circuit Court in rural Kentucky. The jury found for the Plaintiffs and awarded them $5.9 million in damages. Part of this judgement was later reversed by the Kentucky Court of Appeals and the case was then settled without a second trial under terms which were not revealed.

A Failure Analysis Conducted on a Fractured AISI 5160 Steel Blade Which Separated from an Agricultural Rotary Cutter

International Nuclear Information System (INIS)

Johnson, Alan A; Storey, Randall J

2011-01-01

One of the six blades of an agricultural rotary cutter used for cutting down small trees and bushes broke into two pieces while the blades were rotating. One piece was hurled from the cutter and struck a young farmer, who had been operating the machine, causing a near fatal leg injury. In the ensuing litigation against the manufacturers and marketer of the machine each litigant retained a metallurgist and other experts. The metallurgists jointly directed laboratory work on the broken blade conducted at an independent laboratory according to a protocol which they developed and which was approved by the court. As a result of the laboratory work the present authors, working for the Plaintiffs, concluded that failure of the blade occurred because it contained quench cracks introduced when it was manufactured. The Defendants' metallurgists concluded that the blade had been misassembled onto the machine and, as a result, had failed by fatigue. Eventually, the case was set for a jury trial in a Circuit Court in rural Kentucky. The jury found for the Plaintiffs and awarded them $5.9 million in damages. Part of this judgement was later reversed by the Kentucky Court of Appeals and the case was then settled without a second trial under terms which were not revealed.

Multidisciplinary Design Optimization for Glass-Fiber Epoxy-Matrix Composite 5 MW Horizontal-Axis Wind-Turbine Blades

Science.gov (United States)

Grujicic, M.; Arakere, G.; Pandurangan, B.; Sellappan, V.; Vallejo, A.; Ozen, M.

2010-11-01

A multi-disciplinary design-optimization procedure has been introduced and used for the development of cost-effective glass-fiber reinforced epoxy-matrix composite 5 MW horizontal-axis wind-turbine (HAWT) blades. The turbine-blade cost-effectiveness has been defined using the cost of energy (CoE), i.e., a ratio of the three-blade HAWT rotor development/fabrication cost and the associated annual energy production. To assess the annual energy production as a function of the blade design and operating conditions, an aerodynamics-based computational analysis had to be employed. As far as the turbine blade cost is concerned, it is assessed for a given aerodynamic design by separately computing the blade mass and the associated blade-mass/size-dependent production cost. For each aerodynamic design analyzed, a structural finite element-based and a post-processing life-cycle assessment analyses were employed in order to determine a minimal blade mass which ensures that the functional requirements pertaining to the quasi-static strength of the blade, fatigue-controlled blade durability and blade stiffness are satisfied. To determine the turbine-blade production cost (for the currently prevailing fabrication process, the wet lay-up) available data regarding the industry manufacturing experience were combined with the attendant blade mass, surface area, and the duration of the assumed production run. The work clearly revealed the challenges associated with simultaneously satisfying the strength, durability and stiffness requirements while maintaining a high level of wind-energy capture efficiency and a lower production cost.

Weight Assessment for Fuselage Shielding on Aircraft With Open-Rotor Engines and Composite Blade Loss

Science.gov (United States)

Carney, Kelly; Pereira, Michael; Kohlman, Lee; Goldberg, Robert; Envia, Edmane; Lawrence, Charles; Roberts, Gary; Emmerling, William

2013-01-01

The Federal Aviation Administration (FAA) has been engaged in discussions with airframe and engine manufacturers concerning regulations that would apply to new technology fuel efficient "openrotor" engines. Existing regulations for the engines and airframe did not envision features of these engines that include eliminating the fan blade containment systems and including two rows of counter-rotating blades. Damage to the airframe from a failed blade could potentially be catastrophic. Therefore the feasibility of using aircraft fuselage shielding was investigated. In order to establish the feasibility of this shielding, a study was conducted to provide an estimate for the fuselage shielding weight required to provide protection from an open-rotor blade loss. This estimate was generated using a two-step procedure. First, a trajectory analysis was performed to determine the blade orientation and velocity at the point of impact with the fuselage. The trajectory analysis also showed that a blade dispersion angle of 3deg bounded the probable dispersion pattern and so was used for the weight estimate. Next, a finite element impact analysis was performed to determine the required shielding thickness to prevent fuselage penetration. The impact analysis was conducted using an FAA-provided composite blade geometry. The fuselage geometry was based on a medium-sized passenger composite airframe. In the analysis, both the blade and fuselage were assumed to be constructed from a T700S/PR520 triaxially-braided composite architecture. Sufficient test data on T700S/PR520 is available to enable reliable analysis, and also demonstrate its good impact resistance properties. This system was also used in modeling the surrogate blade. The estimated additional weight required for fuselage shielding for a wing- mounted counterrotating open-rotor blade is 236 lb per aircraft. This estimate is based on the shielding material serving the dual use of shielding and fuselage structure. If the

Further dual purpose evolutionary optimization of small wind turbine blades

International Nuclear Information System (INIS)

Clifton-Smith, M J; Wood, D H

2007-01-01

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

Flow performance of highly loaded axial fan with bowed rotor blades

International Nuclear Information System (INIS)

Chen, L; Liu, X J; Yang, A L; Dai, R

2013-01-01

In this paper, a partial bowed rotor blade was proposed for a newly designed high loaded axial fan. The blade was positively bowed 30 degrees from hub to 30 percent spanwise position. Flows of radial blade and bowed blade fans were numerically compared for various operation conditions. Results show that the fan's performance is improved. At the designed condition with flow coefficient of 0.52, the efficiency of the bowed blade fan is increased 1.44% and the static pressure rise is increased 11%. Comparing the flow structures, it can be found that the separated flow in the bowed fan is reduced and confined within 20 percent span, which is less than the 35 percent in the radial fan. It means that the bowed blade generates negative blade force and counteracts partial centrifugal force. It is alleviates the radial movements of boundary layers in fan's hub region. Flow losses due to 3D mixing are reduced in the rotor. Inlet flow to downstream stator is also improved

Investigations on Vibration Characteristics of Sma Embedded Horizontal Axis Wind Turbine Blade

Science.gov (United States)

Jagadeesh, V.; Yuvaraja, M.; Chandhru, A.; Viswanathan, P.; Senthil kumar, M.

2018-02-01

Vibration induced in wind turbine blade is a solemn problem as it reduces the life of the blade and also it can create critical vibration onto the tower, which may cause serious damage to the tower. The aim of this paper is to investigate the vibration characteristics of the prototype horizontal axis wind turbine blade. Shape memory alloys (SMA), with its variable physical properties, provides an alternative actuating mechanism. Heating an SMA causes a change in the elastic modulus of the material and hence SMAs are used as a damping material. A prototype blade with S1223 profile has been manufactured and the natural frequency is found. The natural frequency is found by incorporating the single SMA wire of 0.5mm diameter over the surface of the blade for a length of 240 mm. Similarly, number of SMA wires over the blade is increased up to 3 and the natural frequency is found. Frequency responses showed that the embedment of SMA over the blade’s surface will increase the natural frequency and reduce the amplitude of vibration. This is because of super elastic nature of SMA. In this paper, when SMA wire of 0.5 mm diameter and of length of 720 mm is embedded on the blade, an increase in the natural frequency by 6.3% and reducing the amplitude by 64.8%. Results of the experimental modal and harmonic indicates the effectiveness of SMA as a passive vibration absorber and that it has potential as a modest and high-performance method for controlling vibration of the blade.

Are reactive thermoplastic polymers suitable for future wind turbine composite materials blades?

DEFF Research Database (Denmark)

Raghavalu Thirumalai, Durai Prabhakaran

2014-01-01

, it was found that only two potential reactive thermoplastic resin systems qualify for different processing requirements for blade manufacturing. Hence, the article focuses on the issues with the use of reactive polymers like APA-6 (Caprolactam) and CBT (Cyclic Butylene Terephtalate) resin systems for composite...

Improved Structure and Fabrication of Large, High-Power KHPS Rotors - Final Scientific/Technical Report

Energy Technology Data Exchange (ETDEWEB)

Corren, Dean [Verdant Power, Inc.; Colby, Jonathan [Verdant Power, Inc.; Adonizio, Mary Ann [Verdant Power, Inc.

2013-01-29

Verdant Power, Inc, working in partnership with the National Renewable Energy Laboratory (NREL), Sandia National Laboratories (SNL), and the University of Minnesota St. Anthony Falls Laboratory (SAFL), among other partners, used evolving Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) models and techniques to improve the structure and fabrication of large, high-power composite Kinetic Hydropower System (KHPS) rotor blades. The objectives of the project were to: design; analyze; develop for manufacture and fabricate; and thoroughly test, in the lab and at full scale in the water, the improved KHPS rotor blade.

Investigation on Suitability of Natural Fibre as Replacement Material for Table Tennis Blade

Science.gov (United States)

Arifin, A. M. T.; Fahrul Hassan, M.; Ismail, A. E.; Zulafif Rahim, M.; Rasidi Ibrahim, M.; Haq, R. H. Abdul; Rahman, M. N. A.; Yunos, M. Z.; Amin, M. H. M.

2017-08-01

This paper presents an investigation of suitability natural fibre as replacement material for table tennis blade, due to low cost, lightweight and apparently environmentally. Nowadays, natural fibre are one of the materials often used in replaced the main material on manufacturing sector, such as automotive, and construction. The objective of this study is to investigate and evaluate the suitability natural fiber materials to replace wood as a structure on table tennis blade. The mechanical properties of the different natural fibre material were examined, and correlated with characteristic of table tennis blade. The natural fibre selected for the study are kenaf (Hibiscus Cannabinus), jute, hemp, sisal (Agave Sisalana) and ramie. A further comparison was made with the corresponding properties of each type of natural fiber using Quality Function Deployment (QFD) and Theory of Inventive Problem Solving (TRIZ). TRIZ has been used to determine the most appropriate solution in producing table tennis blade. The results showed the most appropriate solution in producing table tennis blade using natural fibre is kenaf natural fibre. The selected on suitability natural fibre used as main structure on table tennis blade are based on the characteristics need for good performance of table tennis blade, such as energy absorption, lightweight, strength and hardness. Therefore, it shows an opportunity for replacing existing materials with a higher strength, lower cost alternative that is environmentally friendly.

Development of advanced blade pitching kinematics for cycloturbines and cyclorotors

Science.gov (United States)

Adams, Zachary Howard

Cycloturbines and cyclorotors are established concepts for extracting freesteam fluid energy and producing thrust which promise to exceed the performance of traditional horizontal axis turbines and rotors while maintaining unique operational advantages. However, their potential is not yet realized in widespread applications. A central barrier to their proliferation is the lack of fundamental understanding of the aerodynamic interaction between the turbine and the freestream flow. In particular, blade pitch must be precisely actuated throughout the revolution to achieve the proper blade angle of attack and maximize performance. So far, there is no adequate method for determining or implementing the optimal blade pitching kinematics for cyclorotors or cycloturbines. This dissertation bridges the pitching deficiency by introducing a novel low order model to predict improved pitch kinematics, experimentally demonstrating improved performance, and evaluating flow physics with a high order Navier-Stokes computational code. The foundation for developing advanced blade pitch motions is a low order model named Fluxline Theory. Fluid calculations are performed in a coordinate system fixed to streamlines whose spatial locations are not pre-described in order to capture the flow expansion/contraction and bending through the turbine. A transformation then determines the spatial location of streamlines through the rotor disk and finally blade element method integrations determine the power and forces produced. Validation against three sets of extant cycloturbine experimental data demonstrates improvement over other existing streamtube models. Fluxline Theory was extended by removing dependence on a blade element model to better understand how turbine-fluid interaction impacts thrust and power production. This pure momentum variation establishes a cycloturbine performance limit similar to the Betz Limit for horizontal axis wind turbines, as well as the fluid deceleration required

Multi-spectral temperature measurement method for gas turbine blade

Science.gov (United States)

Gao, Shan; Feng, Chi; Wang, Lixin; Li, Dong

2016-02-01

One of the basic methods to improve both the thermal efficiency and power output of a gas turbine is to increase the firing temperature. However, gas turbine blades are easily damaged in harsh high-temperature and high-pressure environments. Therefore, ensuring that the blade temperature remains within the design limits is very important. There are unsolved problems in blade temperature measurement, relating to the emissivity of the blade surface, influences of the combustion gases, and reflections of radiant energy from the surroundings. In this study, the emissivity of blade surfaces has been measured, with errors reduced by a fitting method, influences of the combustion gases have been calculated for different operational conditions, and a reflection model has been built. An iterative computing method is proposed for calculating blade temperatures, and the experimental results show that this method has high precision.

A smart segmented blade system for reducing weight of the wind turbine rotor

International Nuclear Information System (INIS)

Lu, Hongya; Zeng, Pan; Lei, Liping; Yang, Yabin; Xu, Yuejie; Qian, Lingyun

2014-01-01

Highlights: • A segmented blade system to light the wind turbine rotor is proposed. • The experiments in the wind tunnel and the numerical calculation are combined to validate the effectiveness of the design. • The moment of the blade below the hinged location are alleviated. • The mounting locations of the hinged rods significantly affect the moment distribution on the blade. • The gross weight of the blade can be reduced by 35.4%. - Abstract: The paper proposes a novel design concept for the wind turbine rotors. The design is composed of the segmented blades and a hinged-rods support structure (SBHR) as a means of reducing weight through alleviating the moment on the blade. A prototype of the design is manufactured. Focusing on the hinged-rods support structure (HRSS), a method combining the experiments and numerical calculation is developed to analyze its feasibility. The experiments in the wind tunnel platform were conducted to measure the loads at the root of the isolated blade and in the rods. A numerical model was developed to describe the designed wind turbine rotor using the measured loads in experiments. In the model, the mounting locations of the hinged rods significantly affected the moment distribution on the blade. Thus, two dimensionless indexes were determined to analyze its influences. The model perfectly explain the characteristics of the novel structure under different configurations. The results demonstrated that the moment of the blade below the hinged location were alleviated, which reduced the requirements for the material. A 43.1% reduction of the maximum moment can be achieved in the design. In addition, the gross reduced weight of the blade was estimated to be 35.4% based on the blade mass distribution along the span

A system approach for reducing the environmental impact of manufacturing and sustainability improvement of nano-scale manufacturing

Science.gov (United States)

Yuan, Yingchun

This dissertation develops an effective and economical system approach to reduce the environmental impact of manufacturing. The system approach is developed by using a process-based holistic method for upstream analysis and source reduction of the environmental impact of manufacturing. The system approach developed consists of three components of a manufacturing system: technology, energy and material, and is useful for sustainable manufacturing as it establishes a clear link between manufacturing system components and its overall sustainability performance, and provides a framework for environmental impact reductions. In this dissertation, the system approach developed is applied for environmental impact reduction of a semiconductor nano-scale manufacturing system, with three case scenarios analyzed in depth on manufacturing process improvement, clean energy supply, and toxic chemical material selection. The analysis on manufacturing process improvement is conducted on Atomic Layer Deposition of Al2O3 dielectric gate on semiconductor microelectronics devices. Sustainability performance and scale-up impact of the ALD technology in terms of environmental emissions, energy consumption, nano-waste generation and manufacturing productivity are systematically investigated and the ways to improve the sustainability of the ALD technology are successfully developed. The clean energy supply is studied using solar photovoltaic, wind, and fuel cells systems for electricity generation. Environmental savings from each clean energy supply over grid power are quantitatively analyzed, and costs for greenhouse gas reductions on each clean energy supply are comparatively studied. For toxic chemical material selection, an innovative schematic method is developed as a visual decision tool for characterizing and benchmarking the human health impact of toxic chemicals, with a case study conducted on six chemicals commonly used as solvents in semiconductor manufacturing. Reliability of

Performance of Savonius Blade Waterwheel with Variation of Blade Number

Science.gov (United States)

Sule, L.; Rompas, P. T. D.

2018-02-01

The utilization of water energy source is mainly used as a provider of electrical energy through hydroelectric power. The potential utilization of water flow energy is relatively small. The objective of this study is to know the best blade of Savonius waterwheel with various variables such as water discharge, blade number, and loading. The data used the efficiency of waterwheel, variation of blade number, variable water discharge, and loading in the shaft. The test results have shown that the performances of a top-water mill with the semicircular curve where the variation in the number of blades are 4, 6, and 8 at discharge and loading of 0.01587 m3/s and 1000 grams respectively were 9.945%, 13.929%, and 17.056% respectively. The blades number of 8 obtained the greatest performance. The more number of blades the greater the efficiency of the waterwheel Savonius.

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.

Methodology for wind turbine blade geometry optimization

Energy Technology Data Exchange (ETDEWEB)

Perfiliev, D.

2013-11-01

Nowadays, the upwind three bladed horizontal axis wind turbine is the leading player on the market. It has been found to be the best industrial compromise in the range of different turbine constructions. The current wind industry innovation is conducted in the development of individual turbine components. The blade constitutes 20-25% of the overall turbine budget. Its optimal operation in particular local economic and wind conditions is worth investigating. The blade geometry, namely the chord, twist and airfoil type distributions along the span, responds to the output measures of the blade performance. Therefore, the optimal wind blade geometry can improve the overall turbine performance. The objectives of the dissertation are focused on the development of a methodology and specific tool for the investigation of possible existing wind blade geometry adjustments. The novelty of the methodology presented in the thesis is the multiobjective perspective on wind blade geometry optimization, particularly taking simultaneously into account the local wind conditions and the issue of aerodynamic noise emissions. The presented optimization objective approach has not been investigated previously for the implementation in wind blade design. The possibilities to use different theories for the analysis and search procedures are investigated and sufficient arguments derived for the usage of proposed theories. The tool is used for the test optimization of a particular wind turbine blade. The sensitivity analysis shows the dependence of the outputs on the provided inputs, as well as its relative and absolute divergences and instabilities. The pros and cons of the proposed technique are seen from the practical implementation, which is documented in the results, analysis and conclusion sections. (orig.)

Multi-Objective Aerodynamic and Structural Optimization of Horizontal-Axis Wind Turbine Blades

Directory of Open Access Journals (Sweden)

Jie Zhu

2017-01-01

Full Text Available A procedure based on MATLAB combined with ANSYS is presented and utilized for the multi-objective aerodynamic and structural optimization of horizontal-axis wind turbine (HAWT blades. In order to minimize the cost of energy (COE and improve the overall performance of the blades, materials of carbon fiber reinforced plastic (CFRP combined with glass fiber reinforced plastic (GFRP are applied. The maximum annual energy production (AEP, the minimum blade mass and the minimum blade cost are taken as three objectives. Main aerodynamic and structural characteristics of the blades are employed as design variables. Various design requirements including strain, deflection, vibration and buckling limits are taken into account as constraints. To evaluate the aerodynamic performances and the structural behaviors, the blade element momentum (BEM theory and the finite element method (FEM are applied in the procedure. Moreover, the non-dominated sorting genetic algorithm (NSGA II, which constitutes the core of the procedure, is adapted for the multi-objective optimization of the blades. To prove the efficiency and reliability of the procedure, a commercial 1.5 MW HAWT blade is used as a case study, and a set of trade-off solutions is obtained. Compared with the original scheme, the optimization results show great improvements for the overall performance of the blade.

Performance and internal flow condition of mini centrifugal pump with splitter blades

International Nuclear Information System (INIS)

Shigemitsu, T; Fukutomi, J; Kaji, K; Wada, T

2012-01-01

Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-CFX) to investigate the internal flow condition in detail. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. The blade-to-blade low velocity regions are suppressed in the case with the splitter blades and the total pressure loss regions are decreased. The effects of the splitter blades on the performance and the internal flow condition are discussed in this paper.

3D numerical analysis and optimization of aerodynamic performance of turbine blade

International Nuclear Information System (INIS)

Wang Dingbiao; Xie Wen; Zhou Junjie

2010-01-01

To reduce the stator profile loss and improve the efficiency of the industrial steam turbine, a numerical analysis and optimization of the data for the steam turbine stator blade are conducted by the NUMECA,a CFD software. The result shows that, compared with the original blade, the 'after loading' blade is with the best static pressure coefficient distribution, and effectively postpones the transition point position, reduces the radial pressure gradient of suction surface, and cut down the secondary flow loss effectively. The total pressure losses of the 'after loading' blade is 1.03%, which is the least, and the single-stage efficiency is 94.462%, which is the maximum and increases 14.33%. Thus, the aerodynamic performance of stage is improved obviously, the profile loss decreases through using the 'after loading' blade. (authors)

Three-dimensional Improved Delayed Detached Eddy Simulation of a two-bladed vertical axis wind turbine

International Nuclear Information System (INIS)

Lei, Hang; Zhou, Dai; Bao, Yan; Li, Ye; Han, Zhaolong

2017-01-01

Highlights: • The Improved Delayed Detached Eddy Simulation and polyhedral mesh are utilized. • Power coefficient and wake velocity are compared between experiments and simulations. • Improved Delayed Detached Eddy Simulation shows more vortices under dynamic stall. • Different scales of flow separations are distinguished by these two models. - Abstract: The aerodynamic performance of a two-bladed vertical axis wind turbine is investigated using the turbulence model of the Improved Delayed Detached Eddy Simulation and the polyhedral mesh. The sliding mesh technique is used to simulate the rotation of the rotor. Meanwhile, the results obtained by the shear stress transport k-ω model are presented as contrast. Then, the simulated power coefficients at different tip speed ratios and the wake velocity are validated by comparison with the experimental data from available literature. It is shown that the power coefficients and wake velocity predicted by the Improved Delayed Detached Eddy Simulation are closer to the experimental data than those by the shear stress transport k-ω model. The pressure distributions predicted by the two turbulence models show different degrees of discrepancies in different scales of flow separation. By comparing the vorticity magnitude graphs, the Improved Delayed Detached Eddy Simulation is found to be able to capture more exquisite vortices after the flow separations. Limited by its inherent ability, the shear stress transport k-ω model predicts vortices that are less realistic than those of Improved Delayed Detached Eddy Simulation. Hence, it may cause some errors in predicting the pressure distributions, especially when the blades suffer dynamic stall. It is demonstrated that the Improved Delayed Detached Eddy Simulation is regarded as a reliable model to analyze the aerodynamic performance of vertical axis wine turbines.

Bladed disc crack diagnostics using blade passage signals

Science.gov (United States)

Hanachi, Houman; Liu, Jie; Banerjee, Avisekh; Koul, Ashok; Liang, Ming; Alavi, Elham

2012-12-01

One of the major potential faults in a turbo fan engine is the crack initiation and propagation in bladed discs under cyclic loads that could result in the breakdown of the engines if not detected at an early stage. Reliable fault detection techniques are therefore in demand to reduce maintenance cost and prevent catastrophic failures. Although a number of approaches have been reported in the literature, it remains very challenging to develop a reliable technique to accurately estimate the health condition of a rotating bladed disc. Correspondingly, this paper presents a novel technique for bladed disc crack detection through two sequential signal processing stages: (1) signal preprocessing that aims to eliminate the noises in the blade passage signals; (2) signal postprocessing that intends to identify the crack location. In the first stage, physics-based modeling and interpretation are established to help characterize the noises. The crack initiation can be determined based on the calculated health monitoring index derived from the sinusoidal effects. In the second stage, the crack is located through advanced detrended fluctuation analysis of the preprocessed data. The proposed technique is validated using a set of spin rig test data (i.e. tip clearance and time of arrival) that was acquired during a test conducted on a bladed military engine fan disc. The test results have demonstrated that the developed technique is an effective approach for identifying and locating the incipient crack that occurs at the root of a bladed disc.

Aerodynamic shape optimization of non-straight small wind turbine blades

International Nuclear Information System (INIS)

Shen, Xin; Yang, Hong; Chen, Jinge; Zhu, Xiaocheng; Du, Zhaohui

2016-01-01

Graphical abstract: Small wind turbine blades with 3D stacking lines (sweep and bend) have been considered and analyzed with an optimization code based on the lifting surface method. The results indicated that the power capture and the rotor thrust can be improved with these more complex geometries. The starting behavior of the small wind turbines can be improved by the optimization of the blade chord and twist angle distribution. - Highlights: • The small wind turbine blade was optimized with non-straight shape. • Lifting surface method with free wake was used for aerodyanmic performace evaluation. • The non-straight shape can be used to increase energy production and decrease the thrust. • The energy production should be sacrificed in order to increase the starting behavior. - Abstract: Small wind turbines usually operate in sub-optimal wind conditions in order to satisfy the demand where it is needed. The aerodynamic performance of small horizontal axis wind turbines highly depends on the geometry. In the present study, the geometry of wind turbine blades are optimized not only in terms of the distribution of the chord and twist angle but also with 3-dimensional stacking line. As the blade with 3-dimensional stacking line is given sweep in the plan of rotation and dihedral in the plan containing the blade and rotor axis, the common used blade element momentum method can no longer provide accurate aerodynamic performance solution. A lifting surface method with free wake model is used as the aerodynamic model in the present work. The annual energy production and the starting performance are selected as optimization objective. The starting performance is evaluated based on blade element method. The optimization of the geometry of the non-straight wind turbine blades is carried out by using a micro-genetic algorithm. Results show that the wind turbine blades with properly designed 3-dimensional stacking line can increase the annual energy production and have

Development of 52 inches last stage blade for steam turbines

International Nuclear Information System (INIS)

Suzuki, Atsuhide; Hisa, Shoichi; Nagao, Shinichiro; Ogata, Hisao

1986-01-01

The last stage blades of steam turbines are the important component controlling the power output and performance of plants. In order to realize a unit of large capacity and high efficiency, the proper exhaust area and the last stage blades having good performance are indispensable. Toshiba Corp. has completed the development of the 52 inch last stage blades for 1500 and 1800 rpm steam turbines. The 52 inch last stage blades are the longest in the world, which have the annular exhaust area nearly 1.5 times as much as that of 41 inch blades used for 1100 MW, 1500 rpm turbines in nuclear power stations. By adopting these 52 inch blades, the large capacity nuclear power plants up to 1800 MW can be economically constructed, the rate of heat consumption of 1350 MW plants is improved by 3 ∼ 4 % as compared with 41 inch blades, and in the plants up to 1100 MW, LP turbines can be reduced from three sets to two. The features of 52 inch blades, the flow pattern and blade form design, the structural strength analysis and the erosion withstanding property, and the verification by the rotation test of the actual blades, the performance test using a test turbine, the vibration analysis of the actually loaded blades and the analysis of wet steam behavior are reported. (Kako, I.)

Development of 52 inch last stage blade for steam turbine

International Nuclear Information System (INIS)

Kadoya, Yoshiki; Harada, Masakatsu; Watanabe, Eiichiro

1985-01-01

Mitsubishi Heavy Industries, Ltd. has developed the last stage blades with 1320 mm length for a 1800 rpm LP turbine, and the verification by rotating vibration test using actual blades was finished, thus the blades were completed. In a nuclear power plant with an A-PWR of 3800 MW thermal output, the 1350 MW steam turbine has one HP turbine and three LP turbines coupled in tandem, and the optimum last stage blades for the LP turbines became the 1320 mm blades. The completion of these blades largely contributes to the improvement of thermal efficiency and the increase of generator output in large nuclear power plants, and has the possibility to decrease three LP turbines to two in 900 MW plants, which reduces the construction cost. The velocity energy of steam coming out of last stage blades is abandoned as exhaust loss in a condenser, which is the largest loss in a turbine. The increase of exhaust area using long blades reduces this loss. The economy of the 1320 mm blades, the features of the 1320 mm blades, the aerodynamic design and its verification, the prevention of the erosion of the 1320 mm blades due to wet steam, the strength design, the anti-vibration design and its verification, and the CAD/CAM system are reported. (Kako, I.)

Turbomachine blade reinforcement

Science.gov (United States)

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.

Improved Methods for Production Manufacturing Processes in Environmentally Benign Manufacturing

Directory of Open Access Journals (Sweden)

Yan-Yan Wang

2011-09-01

Full Text Available How to design a production process with low carbon emissions and low environmental impact as well as high manufacturing performance is a key factor in the success of low-carbon production. It is important to address concerns about climate change for the large carbon emission source manufacturing industries because of their high energy consumption and environmental impact during the manufacturing stage of the production life cycle. In this paper, methodology for determining a production process is developed. This methodology integrates process determination from three different levels: new production processing, selected production processing and batch production processing. This approach is taken within a manufacturing enterprise based on prior research. The methodology is aimed at providing decision support for implementing Environmentally Benign Manufacturing (EBM and low-carbon production to improve the environmental performance of the manufacturing industry. At the first level, a decision-making model for new production processes based on the Genetic Simulated Annealing Algorithm (GSAA is presented. The decision-making model considers not only the traditional factors, such as time, quality and cost, but also energy and resource consumption and environmental impact, which are different from the traditional methods. At the second level, a methodology is developed based on an IPO (Input-Process-Output model that integrates assessments of resource consumption and environmental impact in terms of a materials balance principle for batch production processes. At the third level, based on the above two levels, a method for determining production processes that focus on low-carbon production is developed based on case-based reasoning, expert systems and feature technology for designing the process flow of a new component. Through the above three levels, a method for determining the production process to identify, quantify, assess, and optimize the

The Hybrid Lean System to Improve Manufacturing Environment

Directory of Open Access Journals (Sweden)

Ahmad Ahmad Nur Aizat

2017-01-01

Full Text Available Lean manufacturing is a systematic approch could increase manufacturing competitiveness by identifying and elminating waste through lean tools. However, these tools are often categorized into different groups, continues to be difficult for companies to select the most appropriate lean tool to be adopted, especially in respect of the SMEs whose knowledge of lean tools and associated principles are limited. This study is to propose solution on how to implement appropriate lean tools in food manufacturing industry located at Rengit, Johor. Qualitative method is used as a methodology to see the changes after the implementation of lean tools. Interview session also a part of method to collect data from respondents. The finding from this paper shows that implementation of an appropriate lean tool will help to eliminate waste in industry sector, maintain and control the inventory, improve quality of the product and improve overall operational process.

Anisotropic piezoelectric twist actuation of helicopter rotor blades: Aeroelastic analysis and design optimization

Science.gov (United States)

Wilkie, William Keats

1997-12-01

An aeroelastic model suitable for control law and preliminary structural design of composite helicopter rotor blades incorporating embedded anisotropic piezoelectric actuator laminae is developed. The aeroelasticity model consists of a linear, nonuniform beam representation of the blade structure, including linear piezoelectric actuation terms, coupled with a nonlinear, finite-state unsteady aerodynamics model. A Galerkin procedure and numerical integration in the time domain are used to obtain a soluti An aeroelastic model suitable for control law and preliminary structural design of composite helicopter rotor blades incorporating embedded anisotropic piezoelectric actuator laminae is developed. The aeroelasticity model consists of a linear, nonuniform beam representation of the blade structure, including linear piezoelectric actuation terms, coupled with a nonlinear, finite-state unsteady aerodynamics model. A Galerkin procedure and numerical integration in the time domain are used to obtain amited additional piezoelectric material mass, it is shown that blade twist actuation approaches which exploit in-plane piezoelectric free-stain anisotropies are capable of producing amplitudes of oscillatory blade twisting sufficient for rotor vibration reduction applications. The second study examines the effectiveness of using embedded piezoelectric actuator laminae to alleviate vibratory loads due to retreating blade stall. A 10 to 15 percent improvement in dynamic stall limited forward flight speed, and a 5 percent improvement in stall limited rotor thrust were numerically demonstrated for the active twist rotor blade relative to a conventional blade design. The active twist blades are also demonstrated to be more susceptible than the conventional blades to dynamic stall induced vibratory loads when not operating with twist actuation. This is the result of designing the active twist blades with low torsional stiffness in order to maximize piezoelectric twist authority

Mask manufacturing improvement through capability definition and bottleneck line management

Science.gov (United States)

Strott, Al

1994-02-01

In 1989, Intel's internal mask operation limited itself to research and development activities and re-inspection and pellicle application of externally manufactured masks. Recognizing the rising capital cost of mask manufacturing at the leading edge, Intel's Mask Operation management decided to offset some of these costs by manufacturing more masks internally. This was the beginning of the challenge they set to manufacture at least 50% of Intel's mask volume internally, at world class performance levels. The first step in responding to this challenge was the completion of a comprehensive operation capability analysis. A series of bottleneck improvements by focus teams resulted in an average cycle time improvement to less than five days on all product and less than two days on critical products.

Calculation of blade-data for the Hamilton standard structural analysis of the composite blade for the 18 meter diameter rotor and a comparison with FFA-calculation

Energy Technology Data Exchange (ETDEWEB)

Lundemo, C

1979-04-01

Section property data for the composite blade manufactured by Karlskronavarvet was calculated for the analysis performed by Hamilton Standard. The HS investigation was carried out for various operating conditions, including dynamic response loads, stresses, frequencies and dynamic stability. The Hamilton Standard results has been compared with the FFA (The Aeronautical Research Institute of Sweden) calculation. The results show that the stresses and moments calculated by HS never exceed the allowable levels for the hinged hub configuration. The natural frequencies seem to agree quite well with the measured frequencies. In the input data of the Hamilton Standard dynamic response analysis a too far aft position of the cordwise center of gravity of the outher third of the blade was used. Correct position will give lower stresses.

Aerodynamics and Optimal Design of Biplane Wind Turbine Blades

Science.gov (United States)

Chiu, Phillip

In order to improve energy capture and reduce the cost of wind energy, in the past few decades wind turbines have grown significantly larger. As their blades get longer, the design of the inboard region (near the blade root) becomes a trade-off between competing structural and aerodynamic requirements. State-of-the-art blades require thick airfoils near the root to efficiently support large loads inboard, but those thick airfoils have inherently poor aerodynamic performance. New designs are required to circumvent this design compromise. One such design is the "biplane blade", in which the thick airfoils in the inboard region are replaced with thinner airfoils in a biplane configuration. This design was shown previously to have significantly increased structural performance over conventional blades. In addition, the biplane airfoils can provide increased lift and aerodynamic efficiency compared to thick monoplane inboard airfoils, indicating a potential for increased power extraction. This work investigates the fundamental aerodynamic aspects, aerodynamic design and performance, and optimal structural design of the biplane blade. First, the two-dimensional aerodynamics of biplanes with relatively thick airfoils are investigated, showing unique phenomena which arise as a result of airfoil thickness. Next, the aerodynamic design of the full biplane blade is considered. Two biplane blades are designed for optimal aerodynamic loading, and their aerodynamic performance quantified. Considering blades with practical chord distributions and including the drag of the mid-blade joint, it is shown that biplane blades have comparable power output to conventional monoplane designs. The results of this analysis also show that the biplane blades can be designed with significantly less chord than conventional designs, a characteristic which enables larger blade designs. The aerodynamic loads on the biplane blades are shown to be increased in gust conditions and decreased under

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

Multipath Suppression with an Absorber for UWB Wind Turbine Blade Deflection Sensing Systems

DEFF Research Database (Denmark)

Zhang, Shuai; Franek, Ondrej; Eggers, Patrick Claus F.

2017-01-01

The deflection of a wind turbine blade can be monitored with an ultra-wideband (UWB) deflection sensing system which consists of one transmitting antenna at the blade tip and two receiving antennas at the blade root. The blade deflection is calculated by two estimated tip-root antenna distances...... verifications of the proposed method are carried out with different full-blade measurements. From all the results, it is found that the proposed technique can efficiently suppress multipath for the in-blade tip antenna, and improve the pulse wave front fidelity, so that the UWB sensing system can also...

Turbomachine blade assembly

Science.gov (United States)

Garcia Crespo, Andres Jose

2016-11-01

Embodiments of the present disclosure include a system comprising a turbomachine blade assembly having a blade portion, a shank portion, and a mounting portion, wherein the blade portion, the shank portion, and the mounting portion comprise a first plurality of plies extending from a tip of the airfoil to a base of the dovetail.

Detached-eddy simulation of flow around the NREL phase VI blade

DEFF Research Database (Denmark)

Johansen, Jeppe; Sørensen, Niels N.; Michelsen, J.A.

2002-01-01

the blade axis. Computed blade characteristics are compared with experimental data from the NREL/NASA Ames Phase VI unsteady experiment. The detached-eddy simulation model is a method for predicting turbulence in computational fluid dynamics computations, which combines a Reynolds-averaged Navier......-eddy simulation show considerably more three-dimensional flow structures compared to conventional two-equation Reynolds-averaged Navier–Stokes turbulence models, but no particular improvements are seen in the global blade characteristics. Copyright © 2002 John Wiley & Sons, Ltd.......The detached-eddy simulation model implemented in the computational fluid dynamics code EllipSys3D is used to calculate the flow around the non-rotating NREL Phase VI wind turbine blade. Results are presented for flow around a parked blade at fixed angle of attack and a blade pitching along...

Prevention of Dental Damage and Improvement of Difficult Intubation Using a Paraglossal Technique With a Straight Miller Blade

Directory of Open Access Journals (Sweden)

Yu-Feng Huang

2010-10-01

Full Text Available Patients with diseased teeth, or those who are difficult to intubate, have a higher risk of dental injury during laryngoscopy. We report 3 cases of smooth endotracheal intubation using a paraglossal technique with a straight Miller blade in patients with poor dentition. Three patients with poor dentition were scheduled to undergo surgery under general anesthesia. All patients presented with extremely loose upper central incisors and had lost the other right upper teeth, while micrognathia and prominent, loose upper incisors were noted in 1 case. We elected to use a straight Miller blade using a paraglossal approach. A nasopharyngeal airway was inserted after induction of general anesthesia to facilitate mask ventilation and prevent air leakage from the mask. The Miller blade was then inserted from the right corner of the mouth, avoiding contact with the vulnerable incisors, and advanced along the groove between the tongue and tonsil. The endotracheal tube was subsequently smoothly inserted after obtaining a grade 1 Cormack and Lehane view without dental trauma in all 3 cases. Direct laryngoscopy using the paraglossal straight blade technique avoids dental damage in patients with mobile upper incisors and no right maxillary molars. It is a practical alternative method that differs from the traditional Macintosh laryngoscope in patients with a high risk of dental injury during the procedure. This technique, which provides an improved view of the larynx, might also be helpful with patients in whom intubation is difficult.

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)

On the design and structural analysis of jet engine fan blade structures

Science.gov (United States)

Amoo, Leye M.

2013-07-01

Progress in the design and structural analysis of commercial jet engine fan blades is reviewed and presented. This article is motivated by the key role fan blades play in the performance of advanced gas turbine jet engines. The fundamentals of the associated physics are emphasized. Recent developments and advancements have led to an increase and improvement in fan blade structural durability, stability and reliability. This article is intended as a high level review of the fan blade environment and current state of structural design to aid further research in developing new and innovative fan blade technologies.

BWR control blade replacement strategies

Energy Technology Data Exchange (ETDEWEB)

Kennard, M W [Stoller Nuclear Fuel, NAC International, Pleasantville, NY (United States); Harbottle, J E [Stoller Nuclear Fuel, NAC International, Thornbury, Bristol (United Kingdom)

2000-02-01

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 B{sub 4}C 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)

BWR control blade replacement strategies

International Nuclear Information System (INIS)

Kennard, M.W.; Harbottle, J.E.

2000-01-01

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 B 4 C 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)

Variable Pitch Approach for Performance Improving of Straight-Bladed VAWT at Rated Tip Speed Ratio

Directory of Open Access Journals (Sweden)

Zhenzhou Zhao

2018-06-01

Full Text Available This paper presents a new variable pitch (VP approach to increase the peak power coefficient of the straight-bladed vertical-axis wind turbine (VAWT, by widening the azimuthal angle band of the blade with the highest aerodynamic torque, instead of increasing the highest torque. The new VP-approach provides a curve of pitch angle designed for the blade operating at the rated tip speed ratio (TSR corresponding to the peak power coefficient of the fixed pitch (FP-VAWT. The effects of the new approach are exploited by using the double multiple stream tubes (DMST model and Prandtl’s mathematics to evaluate the blade tip loss. The research describes the effects from six aspects, including the lift, drag, angle of attack (AoA, resultant velocity, torque, and power output, through a comparison between VP-VAWTs and FP-VAWTs working at four TSRs: 4, 4.5, 5, and 5.5. Compared with the FP-blade, the VP-blade has a wider azimuthal zone with the maximum AoA, lift, drag, and torque in the upwind half-cycle, and yields the two new larger maximum values in the downwind half-cycle. The power distribution in the swept area of the turbine changes from an arched shape of the FP-VAWT into the rectangular shape of the VP-VAWT. The new VP-approach markedly widens the highest-performance zone of the blade in a revolution, and ultimately achieves an 18.9% growth of the peak power coefficient of the VAWT at the optimum TSR. Besides achieving this growth, the new pitching method will enhance the performance at TSRs that are higher than current optimal values, and an increase of torque is also generated.

The effect of a heated skate blade on the ice surface

Energy Technology Data Exchange (ETDEWEB)

Hache, A. [Moncton Univ., NB (Canada). Dept. of Physics and Astronomy

2007-05-15

A new hockey skate using a heated blade, called the Therma Blade, cuts ice friction by half, thereby improving skating performance but has created questions about melting and damage of the ice surface. This paper discussed the effect of the heated skate blade on the ice surface. The paper discussed the thermal power produced by the Therma Blade skate, the ice melting capacity of the therma blade, and the ice temperature profile around the heated blade. It also examined the power dissipation by friction comparing the cold versus the heated blade. Units and definitions as well as conversion factors were also presented in appendix format. Constants and technical specifications were listed in an appendix. It was concluded that the maximum melting capacity of the therma blade is 0.7 grams of ice per skate per minute. This is the upper limit as set by the laws of physics, and this requires the skate to be completely static over ice at 0 degrees Celsius and all the power drawn by the battery to reach the ice friction force. 5 refs., 1 tab., 2 figs.

Preliminary Aerodynamic Investigation of Fan Rotor Blade Morphing

Science.gov (United States)

Tweedt, Daniel L.

2012-01-01

Various new technologies currently under development may enable controlled blade shape variability, or so-called blade morphing, to be practically employed in aircraft engine fans and compressors in the foreseeable future. The current study is a relatively brief, preliminary computational fluid dynamics investigation aimed at partially demonstrating and quantifying the aerodynamic potential of fan rotor blade morphing. The investigation is intended to provide information useful for near-term planning, as well as aerodynamic solution data sets that can be subsequently analyzed using advanced acoustic diagnostic tools, for the purpose of making fan noise comparisons. Two existing fan system models serve as baselines for the investigation: the Advanced Ducted Propulsor fan with a design tip speed of 806 ft/sec and a pressure ratio of 1.294, and the Source Diagnostic Test fan with a design tip speed of 1215 ft/sec and a pressure ratio of 1.470. Both are 22-in. sub-scale, low-noise research fan/nacelle models that have undergone extensive experimental testing in the 9- by 15-foot Low Speed Wind Tunnel at the NASA Glenn Research Center. The study, restricted to fan rotor blade morphing only, involves a fairly simple blade morphing technique. Specifically, spanwise-linear variations in rotor blade-section setting angle are applied to alter the blade shape; that is, the blade is linearly retwisted from hub to tip. Aerodynamic performance comparisons are made between morphed-blade and corresponding baseline configurations on the basis of equal fan system thrust, where rotor rotational speed for the morphed-blade fan is varied to change the thrust level for that configuration. The results of the investigation confirm that rotor blade morphing could be a useful technology, with the potential to enable significant improvements in fan aerodynamic performance. Even though the study is very limited in scope and confined to simple geometric perturbations of two existing fan

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

NARCIS (Netherlands)

Paternoster, Alexandre

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

The effectiveness of lean manufacturing audits in measuring operational performance improvements

Directory of Open Access Journals (Sweden)

Taggart, P.

2013-08-01

Full Text Available The hypothesis that lean manufacturing audits are an effective way to measure improvements in operational performance was tested using 64 manufacturing sites owned by a FTSE 100 company. Commonly-used lean characteristics were evaluated: policy deployment, standardised work, visual management and housekeeping, quick changeover techniques, total productive maintenance, continuous improvement (kaizen, error proofing, cultural awareness, material control, and levelling (heijunka. Operational performance was assessed employing commonly-used operational performance measures: on-time-delivery, inventory turns, and direct labour utilisation. The findings are that lean manufacturing audits are effective in measuring improvements in operational performance provided that the audit scope and the lean characteristics are aligned up front.

Elimination of motion and pulsation artifacts using BLADE sequences in shoulder MR imaging

International Nuclear Information System (INIS)

Lavdas, E.; Zaloni, E.; Vlychou, M.; Vassiou, K.; Fezoulidis, I.; Tsagkalis, A.; Dailiana, Z.

2015-01-01

To evaluate the ability of proton-density with fat-suppression BLADE (proprietary name for periodically rotated overlapping parallel lines with enhanced reconstruction in MR systems from Siemens Healthcare, PDFS BLADE) and turbo inversion recovery magnitude-BLADE (TIRM BLADE) sequences to reduce motion and pulsation artifacts in shoulder magnetic resonance examinations. Forty-one consecutive patients who had been routinely scanned for shoulder examination participated in the study. The following pairs of sequences with and without BLADE were compared: (a) Oblique coronal proton-density sequence with fat saturation of 25 patients and (b) oblique sagittal T2 TIRM-weighed sequence of 20 patients. Qualitative analysis was performed by two experienced radiologists. Image motion and pulsation artifacts were also evaluated. In oblique coronal PDFS BLADE sequences, motion artifacts have been significantly eliminated, even in five cases of non-diagnostic value with conventional imaging. Similarly, in oblique sagittal T2 TIRM BLADE sequences, image quality has been improved, even in six cases of non-diagnostic value with conventional imaging. Furthermore, flow artifacts have been improved in more than 80% of all the cases. The use of BLADE sequences is recommended in shoulder imaging, especially in uncooperative patients because it effectively eliminates motion and pulsation artifacts. (orig.)

Remote Monitoring of the Structural Health of Hydrokinetic Composite Turbine Blades

Energy Technology Data Exchange (ETDEWEB)

J.L. Rovey

2012-09-21

A health monitoring approach is investigated for hydrokinetic turbine blade applications. In-service monitoring is critical due to the difficult environment for blade inspection and the cost of inspection downtime. Composite blade designs have advantages that include long life in marine environments and great control over mechanical properties. Experimental strain characteristics are determined for static loads and free-vibration loads. These experiments are designed to simulate the dynamic characteristics of hydrokinetic turbine blades. Carbon/epoxy symmetric composite laminates are manufactured using an autoclave process. Four-layer composite beams, eight-layer composite beams, and two-dimensional eight-layer composite blades are instrumented for strain. Experimental results for strain measurements from electrical resistance gages are validated with theoretical characteristics obtained from in-house finite-element analysis for all sample cases. These preliminary tests on the composite samples show good correlation between experimental and finite-element strain results. A health monitoring system is proposed in which damage to a composite structure, e.g. delamination and fiber breakage, causes changes in the strain signature behavior. The system is based on embedded strain sensors and embedded motes in which strain information is demodulated for wireless transmission. In-service monitoring is critical due to the difficult environment for blade inspection and the cost of inspection downtime. Composite blade designs provide a medium for embedding sensors into the blades for in-situ health monitoring. The major challenge with in-situ health monitoring is transmission of sensor signals from the remote rotating reference frame of the blade to the system monitoring station. In the presented work, a novel system for relaying in-situ blade health measurements in hydrokinetic systems is described and demonstrated. An ultrasonic communication system is used to transmit

Damage tolerance and structural monitoring for wind turbine blades

DEFF Research Database (Denmark)

McGugan, Malcolm; Pereira, Gilmar Ferreira; Sørensen, Bent F.

2015-01-01

The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will b......The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation...

Using an energy management strategy to drive improved business results and improve manufacturing operations

Energy Technology Data Exchange (ETDEWEB)

Leroux, Marc

2010-09-15

Energy typically represents the single largest controllable cost in manufacturing, and is under constant scrutiny by all levels of management. In this paper we will examine the role and components of an energy management strategy, and focus on the benefits of looking at the strategy from a business perspective. We will then examine the role that an effective program, either existing or new, can play in a collaborative manufacturing environment, and how these improvements can reduce energy requirements while maintaining, or improving productivity.

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.

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)

Prioritization of manufacturing sectors in Serbia for energy management improvement – AHP method

International Nuclear Information System (INIS)

Jovanović, Bojana; Filipović, Jovan; Bakić, Vukman

2015-01-01

Highlights: • We used AHP method to prioritize manufacturing sectors in Serbia. • Priorities for energy management improvement according to five criteria. • Rank 1 – “Manufacture of food products”. • Rank 2 – “Manufacture of motor vehicles, trailers and semi-trailers”. • Rank 3 – “Manufacture of other non-metallic mineral products”. - Abstract: Manufacturing, which is destined to play the most significant role in the reindustrialization of Serbia is also one of the largest energy consumers and environmental polluters. In accordance with this, a large number of energy and environment management initiatives have been implemented over the years. In developed countries, these initiatives are at an advanced level, but not in Serbia. A group of manufacturers in Serbia has recognized the significance of the environmental initiatives implementation, but the interest in energy management improvement has remained low. Although these initiatives can be used to achieve cost reduction in industry, not all the manufacturing sectors equally value the importance of energy management improvement. Among all the manufacturing sectors, it is necessary to prioritize those with the potentials for energy management improvement, which can be done using different methods. In this paper, the AHP (Analytic Hierarchy Process) method was used to prioritize manufacturing sectors in Serbia in the area of energy management improvement. Using a created AHP questionnaires criteria weights were selected. These questionnaires were completed by the experts from the Serbian Chamber of Commerce and Industry, providing us with the opportunity to evaluate the Serbian manufacturing sectors based on the real life data. The results of the AHP method, which was used as the prioritization instrument, and their analysis are presented in the paper. As a part of a wider study, aimed at the improvement of the energy management in Serbia, the three manufacturing sectors with the highest

LP turbine retrofit modernization: Improvements in performance and operation

International Nuclear Information System (INIS)

Groenedaal, J.C.; Fowls, L.G.; Subbiah, R.; Maxwell, B.P.; Persson, B.

1996-01-01

Westinghouse Electric Corporation retrofitted six low pressure (LP) nuclear turbine rotors and associated blade path components at Ringhals 1, a 1960's vintage English Electric (GEC) unit located near Varobacka, Sweden, and operated by Vattenfall AB. This achieved significant performance improvements and provided improved mechanical features over the original equipment. This paper, discusses design, manufacture, installation, operation and project coordination. The retrofit processes employed for these units can be applied to any potential customers units

Numerical investigations on axial and radial blade rubs in turbo-machinery

Science.gov (United States)

Abdelrhman, Ahmed M.; Tang, Eric Sang Sung; Salman Leong, M.; Al-Qrimli, Haidar F.; Rajamohan, G.

2017-07-01

In the recent years, the clearance between the rotor blades and stator/casing had been getting smaller and smaller prior improving the aerodynamic efficiency of the turbomachines as demand in the engineering field. Due to the clearance reduction between the blade tip and the rotor casing and between rotor blades and stator blades, axial and radial blade rubbing could be occurred, especially at high speed resulting into complex nonlinear vibrations. The primary aim of this study is to address the blade axial rubbing phenomenon using numerical analysis of rotor system. A comparison between rubbing caused impacts of axial and radial blade rubbing and rubbing forces are also aims of this study. Tow rotor models (rotor-stator and rotor casing models) has been designed and sketched using SOILDSWORKS software. ANSYS software has been used for the simulation and the numerical analysis. The rubbing conditions were simulated at speed range of 1000rpm, 1500rpm and 2000rpm. Analysis results for axial blade rubbing showed the appearance of blade passing frequency and its multiple frequencies (lx, 2x 3x etc.) and these frequencies will more excited with increasing the rotational speed. Also, it has been observed that when the rotating speed increased, the rubbing force and the harmonics frequencies in x, y and z-direction become higher and severe. The comparison study showed that axial blade rub is more dangerous and would generate a higher vibration impacts and higher blade rubbing force than radial blade rub.

Impact of Company Size on Manufacturing Improvement Practices: An empirical study

International Nuclear Information System (INIS)

Syan, C S; Ramoutar, K

2014-01-01

There is a constant search for ways to achieve a competitive advantage through new manufacturing techniques. Best performing manufacturing companies tend to use world-class manufacturing (WCM) practices. Although the last few years have witnessed phenomenal growth in the use of WCM techniques, their effectiveness is not well understood specifically in the context of less developed countries. This paper presents an empirical study to investigate the impact of company size on improving manufacturing performance in manufacturing organizations based in Trinidad and Tobago (T and T). Empirical data were collected via a questionnaire survey which was send to 218 manufacturing firms in T and T. Five different company sizes and seven different industry sectors were studied. The analysis of survey data was performed with the aid of Statistical Package for Social Sciences (SPSS) software. The study signified facilitating and impeding factors towards improving manufacturing performance. Their relative impact/importance is dependent on varying company size and industry sectors. Findings indicate that T and T manufacturers are still practicing traditional approaches, when compared with world class manufacturers. In the majority of organizations, these practices were not 100% implemented even though they started the implementation process more than 5 years ago. The findings provided some insights in formulating more optimal operational strategies, and later develop action plans towards more effective implementation of WCM in T and T manufacturers

Impact of Company Size on Manufacturing Improvement Practices: An empirical study

Science.gov (United States)

Syan, C. S.; Ramoutar, K.

2014-07-01

There is a constant search for ways to achieve a competitive advantage through new manufacturing techniques. Best performing manufacturing companies tend to use world-class manufacturing (WCM) practices. Although the last few years have witnessed phenomenal growth in the use of WCM techniques, their effectiveness is not well understood specifically in the context of less developed countries. This paper presents an empirical study to investigate the impact of company size on improving manufacturing performance in manufacturing organizations based in Trinidad and Tobago (T&T). Empirical data were collected via a questionnaire survey which was send to 218 manufacturing firms in T&T. Five different company sizes and seven different industry sectors were studied. The analysis of survey data was performed with the aid of Statistical Package for Social Sciences (SPSS) software. The study signified facilitating and impeding factors towards improving manufacturing performance. Their relative impact/importance is dependent on varying company size and industry sectors. Findings indicate that T&T manufacturers are still practicing traditional approaches, when compared with world class manufacturers. In the majority of organizations, these practices were not 100% implemented even though they started the implementation process more than 5 years ago. The findings provided some insights in formulating more optimal operational strategies, and later develop action plans towards more effective implementation of WCM in T&T manufacturers.

Effect of Geometric Uncertainties on the Aerodynamic Characteristic of Offshore Wind Turbine Blades

International Nuclear Information System (INIS)

Ernst, Benedikt; Schmitt, Henning; Seume, Jörg R

2014-01-01

Offshore wind turbines operate in a complex unsteady flow environment which causes unsteady aerodynamic loads. The unsteady flow environment is characterized by a high degree of uncertainty. In addition, geometry variations and material imperfections also cause uncertainties in the design process. Probabilistic design methods consider these uncertainties in order to reach acceptable reliability and safety levels for offshore wind turbines. Variations of the rotor blade geometry influence the aerodynamic loads which also affect the reliability of other wind turbine components. Therefore, the present paper is dealing with geometric uncertainties of the rotor blades. These can arise from manufacturing tolerances and operational wear of the blades. First, the effect of geometry variations of wind turbine airfoils on the lift and drag coefficients are investigated using a Latin hypercube sampling. Then, the resulting effects on the performance and the blade loads of an offshore wind turbine are analyzed. The variations of the airfoil geometry lead to a significant scatter of the lift and drag coefficients which also affects the damage-equivalent flapwise bending moments. In contrast to that, the effects on the power and the annual energy production are almost negligible with regard to the assumptions made

Pose estimation for mobile robots working on turbine blade

Energy Technology Data Exchange (ETDEWEB)

Ma, X.D.; Chen, Q.; Liu, J.J.; Sun, Z.G.; Zhang, W.Z. [Tsinghua Univ., Beijing (China). Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Dept. of Mechanical Engineering

2009-03-11

This paper discussed a features point detection and matching task technique for mobile robots used in wind turbine blade applications. The vision-based scheme used visual information from the robot's surrounding environment to match successive image frames. An improved pose estimation algorithm based on a scale invariant feature transform (SIFT) was developed to consider the characteristics of local images of turbine blades, pose estimation problems, and conditions. The method included a pre-subsampling technique for reducing computation and bidirectional matching for improving precision. A random sample consensus (RANSAC) method was used to estimate the robot's pose. Pose estimation conditions included a wide pose range; the distance between neighbouring blades; and mechanical, electromagnetic, and optical disturbances. An experimental platform was used to demonstrate the validity of the proposed algorithm. 20 refs., 6 figs.

Blade attachment assembly

Science.gov (United States)

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.

Bionic Design of Wind Turbine Blade Based on Long-Eared Owl's Airfoil.

Science.gov (United States)

Tian, Weijun; Yang, Zhen; Zhang, Qi; Wang, Jiyue; Li, Ming; Ma, Yi; Cong, Qian

2017-01-01

The main purpose of this paper is to demonstrate a bionic design for the airfoil of wind turbines inspired by the morphology of Long-eared Owl's wings. Glauert Model was adopted to design the standard blade and the bionic blade, respectively. Numerical analysis method was utilized to study the aerodynamic characteristics of the airfoils as well as the blades. Results show that the bionic airfoil inspired by the airfoil at the 50% aspect ratio of the Long-eared Owl's wing gives rise to a superior lift coefficient and stalling performance and thus can be beneficial to improving the performance of the wind turbine blade. Also, the efficiency of the bionic blade in wind turbine blades tests increases by 12% or above (up to 44%) compared to that of the standard blade. The reason lies in the bigger pressure difference between the upper and lower surface which can provide stronger lift.

Study on Design of High Efficiency and Light Weight Composite Propeller Blade for a Regional Turboprop Aircraft

Science.gov (United States)

Kong, Changduk; Lee, Kyungsun

2013-03-01

In this study, aerodynamic and structural design of the composite propeller blade for a regional turboprop aircraft is performed. The thin and wide chord propeller blade of high speed turboprop aircraft should have proper strength and stiffness to carry various kinds of loads such as high aerodynamic bending and twisting moments and centrifugal forces. Therefore the skin-spar-foam sandwich structure using high strength and stiffness carbon/epoxy composite materials is used to improve the lightness. A specific design procedure is proposed in this work as follows; firstly the aerodynamic configuration design, which is acceptable for the design requirements, is carried out using the in-house code developed by authors, secondly the structure design loads are determined through the aerodynamic load case analysis, thirdly the spar flange and the skin are preliminarily sized by consideration of major bending moments and shear forces using both the netting rule and the rule of mixture, and finally, the stress analysis is performed to confirm the structural safety and stability using finite element analysis commercial code, MSC. NASTRAN/PATRAN. Furthermore the additional analysis is performed to confirm the structural safety due to bird strike impact on the blade during flight operation using a commercial code, ANSYS. To realize the proposed propeller design, the prototype blades are manufactured by the following procedure; the carbon/epoxy composite fabric prepregs are laid up for skin and spar on a mold using the hand lay-up method and consolidated with a proper temperature and vacuum in the oven. To finalize the structural design, the full-scale static structural test is performed under the simulated aerodynamic loads using 3 point loading method. From the experimental results, it is found that the designed blade has a good structural integrity, and the measured results agree well with the analytical results as well.

Which way is the wind blowing for GRP? Materials and processes for manufacturing rotor blades

Energy Technology Data Exchange (ETDEWEB)

Bittmann, E. [Werkstoff and Struktur, Herreth (Germany)

2002-11-01

The material technology for the production of large-area rotor blades made of glass reinforced plastics (GRP) constitutes an important milestone in development. Customised resin systems, flexible, automated processing methods and high component quality document the progress made in the wind power industry. (orig.)

IMPROVED COMMUNICATION BETWEEN MANUFACTURING ROBOTS

Directory of Open Access Journals (Sweden)

R. Stopforth

2012-01-01

Full Text Available

ENGLISH ABSTRACT: Communication between manufacturing robots and autonomous vehicles in the industrial environment is important, sinceinstructions and information are crucial for communication between the control station and the robot station. Information is required between different manufacturing robots for optimal performance and dedication to industrial tasks within the environment. Failures in communication could cause robots to be a safety hazard or to perform tasks that are not required. This article shows how communication was improved with the use of the Robotics Communication Protocol (RCP and an extension of this protocol.

AFRIKAANSE OPSOMMING: Kommunikasie tussen vervaardigingsrobotte en outonome voertuie in ‘n industriële omgewing is belangrik, aangesien opdragte en inligting krities is vir kommunikasie tussen die beheerstasie en die robotstasie. Inligting word benodig tussen verskillende vervaardigingsrobotte vir optimale werkverrigting en toewyding aan take in die omgewing. Mislukte kommunikasie mag veroorsaak dat robotte ‘n veiligheidsrisiko word of veroorsaak dat onnodige take verrig word. Hierdie artikel toon hoe kommunikasie verbeter is deur die gebruik van die “robotika-kommunikasie-protokol” en ‘n uitbreiding van die protokol.

Materials of large wind turbine blades: Recent results in testing and modeling

DEFF Research Database (Denmark)

Mishnaevsky, Leon; Brøndsted, Povl; Nijssen, Rogier

2012-01-01

The reliability of rotor blades is the pre-condition for the development and wide use of large wind turbines. In order to accurately predict and improve the wind turbine blade behavior, three main aspects of the reliability and strength of rotor blades were considered: (i) development of methods...... of the effect of the microstructure of wind turbine blade composites on their strength and ways of microstructural optimization of the materials. By testing reference coupons, the effect of testing parameters (temperature and frequency) on the lifetime of blade composites was investigated, and the input data...... clustering, misalignments, interface properties and other factors on the strength and lifetime of the wind turbine blade materials were investigated in the micromechanical finite element simulations. The results described in this paper stem from the Rotor Structure and Materials task of the UPWIND project...

Effect of linear and non-linear blade modelling techniques on simulated fatigue and extreme loads using Bladed

Science.gov (United States)

Beardsell, Alec; Collier, William; Han, Tao

2016-09-01

There is a trend in the wind industry towards ever larger and more flexible turbine blades. Blade tip deflections in modern blades now commonly exceed 10% of blade length. Historically, the dynamic response of wind turbine blades has been analysed using linear models of blade deflection which include the assumption of small deflections. For modern flexible blades, this assumption is becoming less valid. In order to continue to simulate dynamic turbine performance accurately, routine use of non-linear models of blade deflection may be required. This can be achieved by representing the blade as a connected series of individual flexible linear bodies - referred to in this paper as the multi-part approach. In this paper, Bladed is used to compare load predictions using single-part and multi-part blade models for several turbines. The study examines the impact on fatigue and extreme loads and blade deflection through reduced sets of load calculations based on IEC 61400-1 ed. 3. Damage equivalent load changes of up to 16% and extreme load changes of up to 29% are observed at some turbine load locations. It is found that there is no general pattern in the loading differences observed between single-part and multi-part blade models. Rather, changes in fatigue and extreme loads with a multi-part blade model depend on the characteristics of the individual turbine and blade. Key underlying causes of damage equivalent load change are identified as differences in edgewise- torsional coupling between the multi-part and single-part models, and increased edgewise rotor mode damping in the multi-part model. Similarly, a causal link is identified between torsional blade dynamics and changes in ultimate load results.

Aerodynamic investigation of winglets on wind turbine blades using CFD

Energy Technology Data Exchange (ETDEWEB)

Johansen, Jeppe; Soerensen, Niels N.

2006-02-15

The present report describes the numerical investigation of the aerodynamics around a wind turbine blade with a winglet using Computational Fluid Dynamics, CFD. Five winglets were investigated with different twist distribution and camber. Four of them were pointing towards the pressure side (upstream) and one was pointing towards the suction side (downstream). Additionally, a rectangular modification of the original blade tip was designed with the same planform area as the blades with winglets. Results show that adding a winglet to the existing blade increase the force distribution on the outer approx 14 % of the blade leading to increased produced power of around 0.6% to 1.4% for wind speeds larger than 6 m/s. This has to be compared to the increase in thrust of around 1.0% to 1.6%. Pointing the winglet downstream increases the power production even further. The effect of sweep and cant angles is not accounted for in the present investigation and could improve the winglets even more. (au)

CFD computations of wind turbine blade loads during standstill operation KNOW-BLADE, Task 3.1 report

Energy Technology Data Exchange (ETDEWEB)

Soerensen, N.N.; Johansen, J.; Conway, S.

2004-06-01

Two rotors blades are computed during standstill conditions, using two different Navier-Stokes solvers EDGE and EllipSys3D. Both steady and transient linear {kappa} - {omega} RANS turbulence models are applied, along with steady non-linear RANS and transient DES simulations. The STORK 5.0 WPX blade is computed a three different tip pitch angles, 0, 26 and 50 degrees tip pitch angle, while the NREL Phase-VI blade is computed at 90 degrees tip pitch angle. Generally the CFD codes reproduce the measured trends quite well and the two involved CFD codes give very similar results. The discrepancies observed can be explained by the difference in the applied turbulence models and the fact that the results from one of the solvers are presented as instantaneous values instead of averaged values. The comparison of steady and transient RANS results show that the gain of using time true computations are very limited for this case, with respect to mean quantities. The same can be said for the RANS/DES comparison performed for the NREL rotor, even though the DES computation shows improved agreement at the tip and root sections. Finally, it is shown that the DES methodology provides a much more physical representation of the heavily stalled part of the flow over blades at high angles of attack. (au)

Blade Surface Pressure Distributions in a Rocket Engine Turbine: Experimental Work With On-Blade Pressure Transducers

Science.gov (United States)

Hudson, Susan T.; Zoladz, Thomas F.; Griffin, Lisa W.; Turner, James E. (Technical Monitor)

2000-01-01

Understanding the unsteady aspects of turbine rotor flowfields is critical to successful future turbine designs. A technology program was conducted at NASA's Marshall Space Flight Center to increase the understanding of unsteady environments for rocket engine turbines. The experimental program involved instrumenting turbine rotor blades with surface-mounted high frequency response pressure transducers. The turbine model was then tested to measure the unsteady pressures on the rotor blades. The data obtained from the experimental program is unique in three respects. First, much more unsteady data was obtained (several minutes per set point) than has been possible in the past. Also, two independent unsteady data acquisition systems and fundamental signal processing approaches were used. Finally, an extensive steady performance database existed for the turbine model. This allowed an evaluation of the effect of the on-blade instrumentation on the turbine's performance. This unique data set, the lessons learned for acquiring this type of data, and the improvements made to the data analysis and prediction tools will contribute to future turbine programs such as those for reusable launch vehicles.

On the inverse problem of blade design for centrifugal pumps and fans

Science.gov (United States)

Kruyt, N. P.; Westra, R. W.

2014-06-01

The inverse problem of blade design for centrifugal pumps and fans has been studied. The solution to this problem provides the geometry of rotor blades that realize specified performance characteristics, together with the corresponding flow field. Here a three-dimensional solution method is described in which the so-called meridional geometry is fixed and the distribution of the azimuthal angle at the three-dimensional blade surface is determined for blades of infinitesimal thickness. The developed formulation is based on potential-flow theory. Besides the blade impermeability condition at the pressure and suction side of the blades, an additional boundary condition at the blade surface is required in order to fix the unknown blade geometry. For this purpose the mean-swirl distribution is employed. The iterative numerical method is based on a three-dimensional finite element method approach in which the flow equations are solved on the domain determined by the latest estimate of the blade geometry, with the mean-swirl distribution boundary condition at the blade surface being enforced. The blade impermeability boundary condition is then used to find an improved estimate of the blade geometry. The robustness of the method is increased by specific techniques, such as spanwise-coupled solution of the discretized impermeability condition and the use of under-relaxation in adjusting the estimates of the blade geometry. Various examples are shown that demonstrate the effectiveness and robustness of the method in finding a solution for the blade geometry of different types of centrifugal pumps and fans. The influence of the employed mean-swirl distribution on the performance characteristics is also investigated.

On the inverse problem of blade design for centrifugal pumps and fans

International Nuclear Information System (INIS)

Kruyt, N P; Westra, R W

2014-01-01

The inverse problem of blade design for centrifugal pumps and fans has been studied. The solution to this problem provides the geometry of rotor blades that realize specified performance characteristics, together with the corresponding flow field. Here a three-dimensional solution method is described in which the so-called meridional geometry is fixed and the distribution of the azimuthal angle at the three-dimensional blade surface is determined for blades of infinitesimal thickness. The developed formulation is based on potential-flow theory. Besides the blade impermeability condition at the pressure and suction side of the blades, an additional boundary condition at the blade surface is required in order to fix the unknown blade geometry. For this purpose the mean-swirl distribution is employed. The iterative numerical method is based on a three-dimensional finite element method approach in which the flow equations are solved on the domain determined by the latest estimate of the blade geometry, with the mean-swirl distribution boundary condition at the blade surface being enforced. The blade impermeability boundary condition is then used to find an improved estimate of the blade geometry. The robustness of the method is increased by specific techniques, such as spanwise-coupled solution of the discretized impermeability condition and the use of under-relaxation in adjusting the estimates of the blade geometry. Various examples are shown that demonstrate the effectiveness and robustness of the method in finding a solution for the blade geometry of different types of centrifugal pumps and fans. The influence of the employed mean-swirl distribution on the performance characteristics is also investigated. (paper)

Multidisciplinary Optimization of Tilt Rotor Blades Using Comprehensive Composite Modeling Technique

Science.gov (United States)

Chattopadhyay, Aditi; McCarthy, Thomas R.; Rajadas, John N.

1997-01-01

An optimization procedure is developed for addressing the design of composite tilt rotor blades. A comprehensive technique, based on a higher-order laminate theory, is developed for the analysis of the thick composite load-carrying sections, modeled as box beams, in the blade. The theory, which is based on a refined displacement field, is a three-dimensional model which approximates the elasticity solution so that the beam cross-sectional properties are not reduced to one-dimensional beam parameters. Both inplane and out-of-plane warping are included automatically in the formulation. The model can accurately capture the transverse shear stresses through the thickness of each wall while satisfying stress free boundary conditions on the inner and outer surfaces of the beam. The aerodynamic loads on the blade are calculated using the classical blade element momentum theory. Analytical expressions for the lift and drag are obtained based on the blade planform with corrections for the high lift capability of rotor blades. The aerodynamic analysis is coupled with the structural model to formulate the complete coupled equations of motion for aeroelastic analyses. Finally, a multidisciplinary optimization procedure is developed to improve the aerodynamic, structural and aeroelastic performance of the tilt rotor aircraft. The objective functions include the figure of merit in hover and the high speed cruise propulsive efficiency. Structural, aerodynamic and aeroelastic stability criteria are imposed as constraints on the problem. The Kreisselmeier-Steinhauser function is used to formulate the multiobjective function problem. The search direction is determined by the Broyden-Fletcher-Goldfarb-Shanno algorithm. The optimum results are compared with the baseline values and show significant improvements in the overall performance of the tilt rotor blade.

Computational study of a High Pressure Turbine Nozzle/Blade Interaction

Science.gov (United States)

Kopriva, James; Laskowski, Gregory; Sheikhi, Reza

2015-11-01

A downstream high pressure turbine blade has been designed for this study to be coupled with the upstream uncooled nozzle of Arts and Rouvroit [1992]. The computational domain is first held to a pitch-line section that includes no centrifugal forces (linear sliding-mesh). The stage geometry is intended to study the fundamental nozzle/blade interaction in a computationally cost efficient manner. Blade/Nozzle count of 2:1 is designed to maintain computational periodic boundary conditions for the coupled problem. Next the geometry is extended to a fully 3D domain with endwalls to understand the impact of secondary flow structures. A set of systematic computational studies are presented to understand the impact of turbulence on the nozzle and down-stream blade boundary layer development, resulting heat transfer, and downstream wake mixing in the absence of cooling. Doing so will provide a much better understanding of stage mixing losses and wall heat transfer which, in turn, can allow for improved engine performance. Computational studies are performed using WALE (Wale Adapted Local Eddy), IDDES (Improved Delayed Detached Eddy Simulation), SST (Shear Stress Transport) models in Fluent.

Development of a Highly Stressed Bladed Rotor Made of a CFRP Using the Tailored Fiber Placement Technology

Science.gov (United States)

Uhlig, K.; Spickenheuer, A.; Bittrich, L.; Heinrich, G.

2013-05-01

Increasing the rotational frequency of bladed rotors used in turbomachinery leads to their increased efficiency and performance. Especially for turbomolecular pumps, this would allow either higher compression rates or smaller pump dimensions. The maximal rotational frequency is focused on the structural strength of the construction and the material used. Due to their high density, specific strength, and stiffness in the fiber direction, carbon-fiberreinforced plastics (CFRPs) seem to be ideal for such an application. The highly orthotropic material behavior of CFRPs demands new approaches in terms of their manufacturing and dimensioning. As a new approach, a rotor with 17 blades in a blade-integrated disk construction (BLISK) made of a CFRP, allowing a 35% higher burst speed than a bladed rotor made of a high-strength aluminum alloy, was developed. An appropriate fiber layout has to reflect the rotational symmetry, which demands either a radial or tangential fiber orientation. Therefore, the Tailored Fiber Placement (TFP) technology was used, which allows a high flexibility for the fiber layout. For consolidation, resin infiltration was performed using a modified vacuum-assisted process, and the final geometry was generated employing a milling machine. A radius-dependent layer setup of tangential and radial fibers was chosen to maximize the burst speed by using an adapted finite-element analysis. Additionally, a numerical modal analysis and a numerical failure analysis were performed. Finally, the theoretical results were verified on manufactured rotors by an experimental modal analysis and burst tests, where experimental data showed a good coincidence with numerical results.

Bionic Design of Wind Turbine Blade Based on Long-Eared Owl’s Airfoil

Directory of Open Access Journals (Sweden)

Weijun Tian

2017-01-01

Full Text Available The main purpose of this paper is to demonstrate a bionic design for the airfoil of wind turbines inspired by the morphology of Long-eared Owl’s wings. Glauert Model was adopted to design the standard blade and the bionic blade, respectively. Numerical analysis method was utilized to study the aerodynamic characteristics of the airfoils as well as the blades. Results show that the bionic airfoil inspired by the airfoil at the 50% aspect ratio of the Long-eared Owl’s wing gives rise to a superior lift coefficient and stalling performance and thus can be beneficial to improving the performance of the wind turbine blade. Also, the efficiency of the bionic blade in wind turbine blades tests increases by 12% or above (up to 44% compared to that of the standard blade. The reason lies in the bigger pressure difference between the upper and lower surface which can provide stronger lift.

Vibration reduction methods and techniques for rotorcraft utilizing on-blade active control, Phase I

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...

Redesign of steam turbine rotor blades and rotor packages – Environmental analysis within systematic eco-design approach

International Nuclear Information System (INIS)

Baran, Jolanta

2016-01-01

Highlights: • Systematic approach to eco-design of steam turbine rotor blades was applied. • Eco-innovative solutions are based on structural and technological change. • At the stage of detailed design the variants were analyzed using LCA. • Main achieved benefits: energy and material savings, lower environmental impact. • Benefits related to the possible scale of the solution practical application. - Abstract: Eco-design of steam turbine blades could be one of the possibilities of decreasing the environmental impact of energy systems based on turbines. The paper investigates the eco-design approach to elaboration of the rotor blades and packages. The purpose is to present the course of eco-design of the rotor blades and the rotor packages taking account of eco-design assumptions, solutions and the concept itself. The following eco-design variants of the rotor blades and the rotor packages are considered: elements of the rotor blades made separately (baseline variant of the rotor blades); elements of the rotor blades made of one piece of material; blades in packages made separately and welded (baseline variant of the rotor packages); packages milled as integral elements. At the stage of detailed design, the Life Cycle Assessment (LCA) is performed in relation to a functional unit – the rotor blades and packages ready for installation in a steam turbine, which is the stage of the turbine. The obtained results indicate that eco-innovative solutions for the turbine blades and packages could be achieved through structural and technological changes. Applying new solutions of the rotor blades may produce the following main benefits: 3.3% lower use of materials, 29.4% decrease in energy consumption at the manufacturing stage, 7.7% decrease in the environmental impact in the life cycle. In relation to the rotor packages, the following main benefits may be achieved: 20.5% lower use of materials, 25.0% decrease in energy consumption at the production stage, 16

Supplier selection or collaboration? Determining factors of performance improvement when outsourcing manufacturing

OpenAIRE

Dabhilkar, Mandar; Bengtsson, Lars; Haartman, Robin von; Åhlström, Pär

2009-01-01

An empirical study was designed to determine factors of performance improvement when outsourcing manufacturing. Findings from a survey of 136 manufacturing plants in Sweden show that most of them achieve their outsourcing motives, but not without trade-offs. Factors of performance improvements such as economies of scale or operations in low-cost countries can improve one performance dimension, such as product cost, yet negatively impact volume flexibility, speed or product innovation. The res...

Wind Turbine Blade Design System - Aerodynamic and Structural Analysis

Science.gov (United States)

Dey, Soumitr

2011-12-01

The ever increasing need for energy and the depletion of non-renewable energy resources has led to more advancement in the "Green Energy" field, including wind energy. An improvement in performance of a Wind Turbine will enhance its economic viability, which can be achieved by better aerodynamic designs. In the present study, a design system that has been under development for gas turbine turbomachinery has been modified for designing wind turbine blades. This is a very different approach for wind turbine blade design, but will allow it to benefit from the features inherent in the geometry flexibility and broad design space of the presented system. It starts with key overall design parameters and a low-fidelity model that is used to create the initial geometry parameters. The low-fidelity system includes the axisymmetric solver with loss models, T-Axi (Turbomachinery-AXIsymmetric), MISES blade-to-blade solver and 2D wing analysis code XFLR5. The geometry parameters are used to define sections along the span of the blade and connected to the CAD model of the wind turbine blade through CAPRI (Computational Analysis PRogramming Interface), a CAD neutral API that facilitates the use of parametric geometry definition with CAD. Either the sections or the CAD geometry is then available for CFD and Finite Element Analysis. The GE 1.5sle MW wind turbine and NERL NASA Phase VI wind turbine have been used as test cases. Details of the design system application are described, and the resulting wind turbine geometry and conditions are compared to the published results of the GE and NREL wind turbines. A 2D wing analysis code XFLR5, is used for to compare results from 2D analysis to blade-to-blade analysis and the 3D CFD analysis. This kind of comparison concludes that, from hub to 25% of the span blade to blade effects or the cascade effect has to be considered, from 25% to 75%, the blade acts as a 2d wing and from 75% to the tip 3D and tip effects have to be taken into account

Optimized chord and twist angle distributions of wind turbine blade considering Reynolds number effects

Energy Technology Data Exchange (ETDEWEB)

Wang, L.; Tang, X. [Univ. of Central Lancashire. Engineering and Physical Sciences, Preston (United Kingdom); Liu, X. [Univ. of Cumbria. Sustainable Engineering, Workington (United Kingdom)

2012-07-01

The aerodynamic performance of a wind turbine depends very much on its blade geometric design, typically based on the blade element momentum (BEM) theory, which divides the blade into several blade elements. In current blade design practices based on Schmitz rotor design theory, the blade geometric parameters including chord and twist angle distributions are determined based on airfoil aerodynamic data at a specific Reynolds number. However, rotating wind turbine blade elements operate at different Reynolds numbers due to variable wind speed and different blade span locations. Therefore, the blade design through Schmitz rotor theory at a specific Reynolds number does not necessarily provide the best power performance under operational conditions. This paper aims to provide an optimal blade design strategy for horizontal-axis wind turbines operating at different Reynolds numbers. A fixed-pitch variable-speed (FPVS) wind turbine with S809 airfoil is chosen as a case study and a Matlab program which considers Reynolds number effects is developed to determine the optimized chord and twist angle distributions of the blade. The performance of the optimized blade is compared with that of the preliminary blade which is designed based on Schmitz rotor design theory at a specific Reynolds number. The results demonstrate that the proposed blade design optimization strategy can improve the power performance of the wind turbine. This approach can be further developed for any practice of horizontal axis wind turbine blade design. (Author)

The SNL100-01 blade :

Energy Technology Data Exchange (ETDEWEB)

Griffith, Daniel

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.

New morphing blade section designs and structural solutions for smart blades

DEFF Research Database (Denmark)

Karakalas, Anargyros A.; Machairas, Theodore; Solomou, Alexandros

2015-01-01

Within INNWIND.EU new concepts are investigated having the ultimate goal to reduce the cost per kilowatt-hour of the produced energy. With increasing size of wind turbines, new approaches to load control are required to reduce the stresses in blades. Experimental and numerical studies in the fields...... of helicopter and wind turbine blade research have shown the potential of shape morphing in reducing blade loads. Morphing technologies, along with other control concepts, are investigated under Task 2.3 of WP “Lightweight Rotor”, against aerodynamic compliance and requirements of the complete wind turbine...... the efforts performed within Task 2.2 “Lightweight structural design” of INNWIND.Eu work-package WP2 “Lightweight Rotor” regarding the structural solutions necessary to accommodate the requirements of smart blades developed within work-package WP2 Task 2.3 “Active and passive loads control and alleviation...

Ceramic blade attachment system

Science.gov (United States)

Frey, G.A.; Jimenez, O.D.

1996-12-03

A turbine blade having a preestablished rate of thermal expansion is attached to a turbine flange having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine blade. The turbine flange includes a first upstanding flange and a second upstanding flange having a groove formed between them. The turbine flange further includes a recess. Each of the first and second upstanding flanges have a plurality of bores therein. A turbine blade has a first member and a second member positioned in one of the groove and the recess. Each of the first member and the second member have a plurality of bores therein. A pin is positioned in respective ones of the plurality of bores in the first and second upstanding members and the first and second members and attach the blade to the turbine flange. The pin has a preestablished rate of thermal expansion being substantially equal to the rate of thermal expansion of the blade. 4 figs.

Optimization of Savonius turbines using an obstacle shielding the returning blade

Energy Technology Data Exchange (ETDEWEB)

Mohamed, M.H.; Janiga, G.; Pap, E.; Thevenin, D. [Lab. of Fluid Dynamics and Technical Flows, University of Magdeburg ' ' Otto von Guericke' ' (Germany)

2010-11-15

Due to the worldwide energy crisis, research and development activities in the field of renewable energy have been considerably increased in many countries. In Germany, wind energy is becoming particularly important. Although considerable progress has already been achieved, the available technical design is not yet adequate to develop reliable wind energy converters for conditions corresponding to low wind speeds and urban areas. The Savonius turbine appears to be particularly promising for such conditions, but suffers from a poor efficiency. The present study considers a considerably improved design in order to increase the output power of a Savonius turbine with either two or three blades. In addition, the improved design leads to a better self-starting capability. To achieve these objectives, the position of an obstacle shielding the returning blade of the Savonius turbine and possibly leading to a better flow orientation toward the advancing blade is optimized. This automatic optimization is carried out by coupling an in-house optimization library (OPAL) with an industrial flow simulation code (ANSYS-Fluent). The optimization process takes into account the output power coefficient as target function, considers the position and the angle of the shield as optimization parameters, and relies on Evolutionary Algorithms. A considerable improvement of the performance of Savonius turbines can be obtained in this manner, in particular a relative increase of the power output coefficient by more than 27%. It is furthermore demonstrated that the optimized configuration involving a two-blade rotor is better than the three-blade design. (author)

Numerical investigation on aerodynamic performance of a novel vertical axis wind turbine with adaptive blades

International Nuclear Information System (INIS)

Wang, Ying; Sun, Xiaojing; Dong, Xiaohua; Zhu, Bing; Huang, Diangui; Zheng, Zhongquan

2016-01-01

Highlights: • A novel vertical axis wind turbine with deformed blades is designed. • The universal tendency of power characteristics for simulated turbine is found. • The whole flow field of different turbines from the aspect of vortex is analyzed. • The tracking analysis of vortex at different positions for a blade is conducted. • The aerodynamic performance of turbine with three deformed blades is analyzed. - Abstract: In this paper, a novel Darrieus vertical axis wind turbine was designed whose blade can be deformed automatically into a desired geometry and thus achieve a better aerodynamic performance. A series of numerical simulations were conducted by utilizing the United Computational Fluid Dynamics code. Firstly, analysis and comparison of the performance of undeformed and deformed blades for the rotors having different blades were conducted. Then, the power characteristics of each simulated turbine were summarized and a universal tendency was found. Secondly, investigation on the effect of blade number and solidity on the power performance of Darrieus vertical axis wind turbine with deformable and undeformable blades was carried out. The results indicated that compared to conventional turbines with same solidity, the maximum percentage increase in power coefficient that the low solidity turbine with three deformable blades can achieve is about 14.56%. When solidity is high and also turbine operates at low tip speed ratio of less than the optimum value, the maximum power coefficient increase for the turbines with two and four deformable blades are 7.51% and 8.07%, respectively. However, beyond the optimal tip speed ratio, the power improvement of the turbine using the deformable blades seems not significant and even slightly worse than the conventional turbines. The last section studied the transient behavior of vortex and turbulent flow structures around the deformable rotor blade to explore the physical mechanism of improving aerodynamic

Post Processing Methods used to Improve Surface Finish of Products which are Manufactured by Additive Manufacturing Technologies: A Review

Science.gov (United States)

Kumbhar, N. N.; Mulay, A. V.

2016-08-01

The Additive Manufacturing (AM) processes open the possibility to go directly from Computer-Aided Design (CAD) to a physical prototype. These prototypes are used as test models before it is finalized as well as sometimes as a final product. Additive Manufacturing has many advantages over the traditional process used to develop a product such as allowing early customer involvement in product development, complex shape generation and also save time as well as money. Additive manufacturing also possess some special challenges that are usually worth overcoming such as Poor Surface quality, Physical Properties and use of specific raw material for manufacturing. To improve the surface quality several attempts had been made by controlling various process parameters of Additive manufacturing and also applying different post processing techniques on components manufactured by Additive manufacturing. The main objective of this work is to document an extensive literature review in the general area of post processing techniques which are used in Additive manufacturing.

Properties variation according to heat treatment for gas turbine blade(bucket) material of GTD-111DS

International Nuclear Information System (INIS)

Kim, Moon Young; Park, Sang Yeal; Yang, Sung Ho

2006-01-01

The gas turbine components is used on high temperature conditions which under severely circumstance with start-up and stop several times. Therefore, it is used nickel-base superalloys like and GTD-111DS. Damaged buckets on the blade tip during operating are repaired per 24,000 hr to three times according to repair specification of manufacture. It is applied pre-heat, HIP(Hot Isostatic Pressing) and post-heat treatment to support welding repair on blade tip effectively. On this study, it is utilize of WRAP TM (Welding Repair Advanced Process) method to make tension test specimens for this study. And then, material strength and characteristic for GTD-111DS was analyzed

Axial compressor blade design for desensitization of aerodynamic performance and stability to tip clearance

Science.gov (United States)

Erler, Engin

Tip clearance flow is the flow through the clearance between the rotor blade tip and the shroud of a turbomachine, such as compressors and turbines. This flow is driven by the pressure difference across the blade (aerodynamic loading) in the tip region and is a major source of loss in performance and aerodynamic stability in axial compressors of modern aircraft engines. An increase in tip clearance, either temporary due to differential radial expansion between the blade and the shroud during transient operation or permanent due to engine wear or manufacturing tolerances on small blades, increases tip clearance flow and results in higher fuel consumption and higher risk of engine surge. A compressor design that can reduce the sensitivity of its performance and aerodynamic stability to tip clearance increase would have a major impact on short and long-term engine performance and operating envelope. While much research has been carried out on improving nominal compressor performance, little had been done on desensitization to tip clearance increase beyond isolated observations that certain blade designs such as forward chordwise sweep, seem to be less sensitive to tip clearance size increase. The current project aims to identify through a computational study the flow features and associated mechanisms that reduces sensitivity of axial compressor rotors to tip clearance size and propose blade design strategies that can exploit these results. The methodology starts with the design of a reference conventional axial compressor rotor followed by a parametric study with variations of this reference design through modification of the camber line and of the stacking line of blade profiles along the span. It is noted that a simple desensitization method would be to reduce the aerodynamic loading of the blade tip which would reduce the tip clearance flow and its proportional contribution to performance loss. However, with the larger part of the work on the flow done in this

LDV measurement of boundary layer on rotating blade surface in wind tunnel

Science.gov (United States)

Maeda, Takao; Kamada, Yasunari; Murata, Junsuke; Suzuki, Daiki; Kaga, Norimitsu; Kagisaki, Yosuke

2014-12-01

Wind turbines generate electricity due to extracting energy from the wind. The rotor aerodynamics strongly depends on the flow around blade. The surface flow on the rotating blade affects the sectional performance. The wind turbine surface flow has span-wise component due to span-wise change of airfoil section, chord length, twisted angle of blade and centrifugal force on the flow. These span-wise flow changes the boundary layer on the rotating blade and the sectional performance. Hence, the thorough understanding of blade surface flow is important to improve the rotor performance. For the purpose of clarification of the flow behaviour around the rotor blade, the velocity in the boundary layer on rotating blade surface of an experimental HAWT was measured in a wind tunnel. The velocity measurement on the blade surface was carried out by a laser Doppler velocimeter (LDV). As the results of the measurement, characteristics of surface flow are clarified. In optimum tip speed operation, the surface flow on leading edge and r/R=0.3 have large span-wise velocity which reaches 20% of sectional inflow velocity. The surface flow inboard have three dimensional flow patterns. On the other hand, the flow outboard is almost two dimensional in cross sectional plane.

Flapping inertia for selected rotor blades

Science.gov (United States)

Berry, John D.; May, Matthew J.

1991-01-01

Aerodynamics of helicopter rotor systems cannot be investigated without consideration for the dynamics of the rotor. One of the principal properties of the rotor which affects the rotor dynamics is the inertia of the rotor blade about its root attachment. Previous aerodynamic investigation have been performed on rotor blades with a variety of planforms to determine the performance differences due to blade planform. The blades tested for this investigation have been tested on the U.S. Army 2 meter rotor test system (2MRTS) in the NASA Langley 14 by 22 foot subsonic tunnel for hover performance. This investigation was intended to provide fundamental information on the flapping inertia of five rotor blades with differing planforms. The inertia of the bare cuff and the cuff with a blade extension were also measured for comparison with the inertia of the blades. Inertia was determined using a swing testing technique, using the period of oscillation to determine the effective flapping inertia. The effect of damping in the swing test was measured and described. A comparison of the flapping inertials for rectangular and tapered planform blades of approximately the same mass showed the tapered blades to have a lower inertia, as expected.

New blades shape up for dozers

Energy Technology Data Exchange (ETDEWEB)

Chironis, N.P.

1985-05-01

This article discusses the design of blades used on dozers for the reclamation work following surface mining. Two blades are described which have led to a 50% reduction in reclamation costs and a 20% reduction in fuel requirements over conventional equipment. These results are from work carried out at the Kayenta mine in Arizona, USA. Design considerations in the development of the blades are described. Descriptions of both the centre flow blades and the universal blades are given.

A randomized controlled study to evaluate and compare Truview blade with Macintosh blade for laryngoscopy and intubation under general anesthesia.

Science.gov (United States)

Timanaykar, Ramesh T; Anand, Lakesh K; Palta, Sanjeev

2011-04-01

The Truview EVO2™ laryngoscope is a recently introduced device with a unique blade that provides a magnified laryngeal view at 42° anterior reflected view. It facilitates visualization of the glottis without alignment of oral, pharyngeal, and tracheal axes. We compared the view obtained at laryngoscopy, intubating conditions and hemodynamic parameters of Truview with Macintosh blade. In prospective, randomized and controlled manner, 200 patients of ASA I and II of either sex (20-50 years), presenting for surgery requiring tracheal intubation, were assigned to undergo intubation using a Truview or Macintosh laryngoscope. Visualization of the vocal cord, ease of intubation, time taken for intubation, number of attempts, and hemodynamic parameters were evaluated. Truview provided better results for the laryngeal view using Cormack and Lehane grading, particularly in patients with higher airway Mallampati grading (P < 0.05). The time taken for intubation (33.06±5.6 vs. 23.11±57 seconds) was more with Truview than with Macintosh blade (P < 0.01). The Percentage of Glottic Opening (POGO) score was significantly higher (97.26±8) in Truview as that observed with Macintosh blade (83.70±21.5). Hemodynamic parameters increased after tracheal intubation from pre-intubation value (P < 0.05) in both the groups, but they were comparable amongst the groups. No postoperative adverse events were noted. Tracheal intubation using Truview blade provided consistently improved laryngeal view as compared to Macintosh blade without the need to align the oral, pharyngeal and tracheal axes, with equal attempts for successful intubation and similar changes in hemodynamics. However, the time taken for intubation was more with Truview.

A randomized controlled study to evaluate and compare Truview blade with Macintosh blade for laryngoscopy and intubation under general anesthesia

Directory of Open Access Journals (Sweden)

Ramesh T Timanaykar

2011-01-01

Full Text Available Background: The Truview EVO2 TM laryngoscope is a recently introduced device with a unique blade that provides a magnified laryngeal view at 42° anterior reflected view. It facilitates visualization of the glottis without alignment of oral, pharyngeal, and tracheal axes. We compared the view obtained at laryngoscopy, intubating conditions and hemodynamic parameters of Truview with Macintosh blade. Materials and Methods: In prospective, randomized and controlled manner, 200 patients of ASA I and II of either sex (20-50 years, presenting for surgery requiring tracheal intubation, were assigned to undergo intubation using a Truview or Macintosh laryngoscope. Visualization of the vocal cord, ease of intubation, time taken for intubation, number of attempts, and hemodynamic parameters were evaluated. Results: Truview provided better results for the laryngeal view using Cormack and Lehane grading, particularly in patients with higher airway Mallampati grading (P < 0.05. The time taken for intubation (33.06±5.6 vs. 23.11±57 seconds was more with Truview than with Macintosh blade (P < 0.01. The Percentage of Glottic Opening (POGO score was significantly higher (97.26±8 in Truview as that observed with Macintosh blade (83.70±21.5. Hemodynamic parameters increased after tracheal intubation from pre-intubation value (P < 0.05 in both the groups, but they were comparable amongst the groups. No postoperative adverse events were noted. Conclusion: Tracheal intubation using Truview blade provided consistently improved laryngeal view as compared to Macintosh blade without the need to align the oral, pharyngeal and tracheal axes, with equal attempts for successful intubation and similar changes in hemodynamics. However, the time taken for intubation was more with Truview.

Manufacturing Improvement Program for the Oil and Gas Industry Supply Chain and Marketing Cluster

Energy Technology Data Exchange (ETDEWEB)

Taylor, Robert [Oklahoma State Univ., Stillwater, OK (United States)

2016-09-28

This project supported upgrades for manufacturing companies in the oil and natural gas supply chain in Oklahoma. The goal is to provide assistance that will lead to the improved efficiency advancement of the manufacturing processes currently used by the existing manufacturing clients. The basis for the work is to improve the economic environment for the clients and the communities they serve.

Investigation of Structural Behavior due to Bend-Twist Couplings in Wind Turbine Blades

DEFF Research Database (Denmark)

Fedorov, Vladimir; Dimitrov, Nikolay Krasimirov; Berggreen, Christian

2010-01-01

for predicting the torsional response of the wind turbine blades with built-in bend-twist couplings. Additionally, a number of improved full-scale tests using an advanced bi-axial servo-hydraulic load control have been performed on a wind turbine blade section provided by Vestas Wind Systems A/S. In the present......One of the problematic issues concerning the design of future large composite wind turbine blades is the prediction of bend-twist couplings and torsion behaviour. The current work is a continuation of a previous work [1,2], and it examines different finite element modelling approaches...... of the blade cross section as the defining surface, off-setting the location of the shell elements according to the specified thickness. The experimental full-scale tests were carried out on an 8 m section of a 23 m wind turbine blade with specially implemented bend-twist coupling. The blade was tested under...

A blade deflection monitoring system

DEFF Research Database (Denmark)

2017-01-01

A wind turbine blade comprising a system for monitoring the deflection of a wind turbine blade is described. The system comprises a wireless range-measurement system, having at least one wireless communication device located towards the root end of the blade and at least one wireless communication...

Design Procedure of 4-Bladed Propeller

African Journals Online (AJOL)

PROF. O. E. OSUAGWU

2013-09-01

Sep 1, 2013 ... West African Journal of Industrial and Academic Research Vol.8 No.1 September 2013 ..... Number of blades. 5. Taylor's wake friction (w). The speed of ship (Vs), the number of propeller revolution (n), the blade number (Z) and the blade area ratio.... .... moment of inertia of a blade, the approximate.

BLADE acquisition method improves T2-weighted MR images of the female pelvis compared with a standard fast spin-echo sequence

International Nuclear Information System (INIS)

Fujimoto, Koji; Koyama, Takashi; Tamai, Ken; Morisawa, Nobuko; Okada, Tomohisa; Togashi, Kaori

2011-01-01

Purpose: To investigate feasibility of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER or BLADE) T2-weighted imaging (T2WI) of the female pelvis by comparing it with standard fast spin-echo T2WI (STD-T2WI). Materials and methods: Sagittal STD-T2WI and BLADE-T2WI of the female pelvis were performed with (36 patients) or without (15 patients) administration of butylscopolamine on a 1.5 T MR unit. Two radiologists independently rated depiction of the uterus, ovary, intestines, bladder, gynecological lesions, overall quality, and artifacts using a four-point scale. Results were compared between STD-T2WI vs. BLADE-T2WI either with (B+) or without (B−) administration of butylscopolamine, BLADE-T2WI (B−) vs. BLADE-T2WI (B+), and STD-T2WI (B+) vs. BLADE-T2WI (B−). Results: When butylscopolamine was administrated, depiction of the uterus, ovary, intestines, gynecological lesions, and overall image quality was rated higher and artifacts were rated fewer for BLADE-T2WI with significance compared with STD-T2WI. When the drug was not administrated, significant difference was observed in depiction of the lesion, overall quality, and artifacts. Depiction of the uterus, gynecological lesion, and overall quality was rated significantly higher and artifacts were fewer in BLADE-T2WI (B+) than in BLADE-T2WI (B−). Conclusion: BLADE method was feasible for female pelvic MRI, with best image quality in BLADE-T2WI (B+).

Corporate Philanthropy Toward Community Health Improvement in Manufacturing Communities.

Science.gov (United States)

McHugh, Megan; Farley, Diane; Maechling, Claude R; Dunlop, Dorothy D; French, Dustin D; Holl, Jane L

2018-06-01

Virtually all large employers engage in corporate philanthropy, but little is known about the extent to which it is directed toward improving community health. We conducted in-depth interviews with leaders of corporate philanthropy from 13 of the largest manufacturing companies in the US to understand how giving decisions were made, the extent to which funding was directed towards improving community health, and whether companies coordinate with local public health agencies. We found that corporate giving was sizable and directed towards communities in which the manufacturers have a large presence. Giving was aligned with the social determinants of health (i.e., aimed at improving economic stability, the neighborhood and physical environment, education, food security and nutrition, the community and social context, and the health care system). However, improving public health was not often cited as a goal of corporate giving, and coordination with public health agencies was limited. Our results suggest that there may be opportunities for public health agencies to help guide corporate philanthropy, particularly by sharing community-level data and offering their measurement and evaluation expertise.

大型风力机叶片的耦合优化方法%Coupling optimization method for MultiMW wind turbine blades

Institute of Scientific and Technical Information of China (English)

刘伟江; 潘柏松; 陈栋栋

2012-01-01

In order to reduce the cost of manufacturing the wind turbine blade,multidisciplinary design optimization method for MultiMW wind turbine blades with the design objective of minimum of blade efficiency cost was presented, based on the blade element momentum theory(BEM)and Euler-Bernoulli beam theory of composites material. Then,the coupling optimization method was applied in the design of a new wind turbine blade with a length of 50 meters. The results show that the balance between energy efficiency and the cost of manufacture can be easily found through the proposed methodology, and the blade efficiency cost is reduced by 8.84%.%为了降低兆瓦级风力机叶片的制造成本,通过耦合叶素动量理论与复合材料欧拉伯努利梁强度设计理论,综合考虑风能效率和成本,以叶片的风能效率成本最小化为优化目标,提出了大型风力发电机叶片的多学科优化设计方法.并基于该方法,对某50 m风力机叶片进行了优化设计.研究结果表明,该方法能够找到风能效率与成本的平衡设计点,叶片风能效率成本比传统设计方法设计的叶片减少了8.84％.

Design and Output Performance Model of Turbodrill Blade Used in a Slim Borehole

Directory of Open Access Journals (Sweden)

Yu Wang

2016-12-01

Full Text Available Small-diameter turbodrills have great potential for use in slim boreholes because of their lower cost and higher efficiency when used in geothermal energy and other underground resource applications. Multistage hydraulic components consisting of stators and rotors are key aspects of turbodrills. This study aimed to develop a suitable blade that can be used under high temperature in granite formations. First, prediction models for single- and multi-stage blades were established based on Bernoulli’s Equation. The design requirement of the blade for high-temperature geothermal drilling in granite was proposed. A Φ89 blade was developed based on the dimensionless parameter method and Bezier curve; the parameters of the blade, including its radial size, symotric parameters, and blade profiles, were input into ANASYS and CFX to establish a calculation model of the single-stage blade. The optimization of the blade structure of the small-diameter turbodrill enabled a multistage turbodrill model to be established and the turbodrill’s overall output performance to be predicted. The results demonstrate that the design can meet the turbodrill’s performance requirements and that the multistage model can effectively improve the accuracy of the prediction.

Study on an Undershot Cross-Flow Water Turbine with Straight Blades

Directory of Open Access Journals (Sweden)

Yasuyuki Nishi

2015-01-01

Full Text Available Small-scale hydroelectric power generation has recently attracted considerable attention. The authors previously proposed an undershot cross-flow water turbine with a very low head suitable for application to open channels. The water turbine was of a cross-flow type and could be used in open channels with the undershot method, remarkably simplifying its design by eliminating guide vanes and the casing. The water turbine was fitted with curved blades (such as the runners of a typical cross-flow water turbine installed in tube channels. However, there was ambiguity as to how the blades’ shape influenced the turbine’s performance and flow field. To resolve this issue, the present study applies straight blades to an undershot cross-flow water turbine and examines the performance and flow field via experiments and numerical analyses. Results reveal that the output power and the turbine efficiency of the Straight Blades runner were greater than those of the Curved Blades runner regardless of the rotational speed. Compared with the Curved Blades runner, the output power and the turbine efficiency of the Straight Blades runner were improved by about 31.7% and about 67.1%, respectively.

Analysis of impact resistance of composite fan blade. Fukugozai fan blade no taishogekisei no kaiseki

Energy Technology Data Exchange (ETDEWEB)

Miyachi, T; Okumura, H; Otake, K; Sofue, Y [Japan Society for Aeronautical and Space Sciences, Tokyo (Japan)

1992-01-05

Numerical analysis of impact response was carried out when a bird strike was simulated to study the applicability of fiber reinforced composite material to fan blades for turbo-fan engines. The validity of the numerical analysis was verified by comparing the analyzed results with impact tested results of a fan-blade model of Ti-alloy. The impact resistance was studied by applying this method to fan blades of composite materials such as carbon fiber, epoxy resin and carbon-silicate fiber reinforced Ti-alloy. The finite element method was used for the analysis by dividing the model into triangular flat elements. The relation between the impact load, the deformation of blade and the strain, the natural frequency characteristics, the elastic modulus and hetrogeneity of blade were considered to analyze the impact response. The impact load by the strike of 1.5 lbs bird is very severe to the fan blades for turbo-fan engines having the thrust of 5 ton class. 23 refs., 23 figs., 3 tabs.

Effect of number of blades on aerodynamic forces on a straight-bladed Vertical Axis Wind Turbine

International Nuclear Information System (INIS)

Li, Qing'an; Maeda, Takao; Kamada, Yasunari; Murata, Junsuke; Furukawa, Kazuma; Yamamoto, Masayuki

2015-01-01

Small wind turbine performance and safety standard for straight-bladed Vertical Axis Wind Turbine (VAWT) have not been developed in the world because of the lack of fundament experimental data. This paper focuses on the evaluation of aerodynamic forces depending on several numbers of blades in wind tunnel experiment. In the present study, the test airfoil of blade is symmetry airfoil of NACA 0021 and the number of blades is from two to five. Pressure acting on the surface of rotor blade is measured during rotation by multiport pressure devices and transmitted to a stationary system through wireless LAN. And then, the aerodynamic forces (tangential force, normal force et al.) are discussed as a function of azimuth angle, achieving a quantitative analysis of the effect of numbers of blades. Finally, the loads are compared with the experimental data of six-component balance. As a result, it is clarified that the power coefficient decreases with the increase of numbers of blades. Furthermore, the power which is absorbed from wind by wind turbine mainly depends on upstream region of azimuth angle of θ = 0°∼180°. In this way, these results are very important for developing the simple design equations and applications for straight-bladed VAWT. - Highlights: • Aerodynamic forces are measured by not only torque meter but also six-component balance. • The pressure distribution on the surface of rotor blade is directly measured by multiport pressure devices. • The power coefficient decreases with the increase of numbers of blades. • The fluctuation amplitudes from six-component balance show larger value than the results of pressure distribution.

Design, evaluation, and fabrication of low-cost composite blades for intermediate-size wind turbines

Science.gov (United States)

Weingart, O.

1981-01-01

Low cost approaches for production of 60 ft long glass fiber/resin composite rotor blades for the MOD-OA wind turbine were identified and evaluated. The most cost-effective configuration was selected for detailed design. Subelement and subscale specimens were fabricated for testing to confirm physical and mechanical properties of the composite blade materials, to develop and evaluate blade fabrication techniques and processes, and to confirm the structural adequacy of the root end joint. Full-scale blade tooling was constructed and a partial blade for tool and process tryout was built. Then two full scale blades were fabricated and delivered to NASA-LeRC for installation on a MOD-OA wind turbine at Clayton, New Mexico for operational testing. Each blade was 60 ft. long with 4.5 ft. chord at root end and 2575 lbs weight including metal hub adapter. The selected blade configuration was a three cell design constructed using a resin impregnated glass fiber tape winding process that allows rapid wrapping of primarily axially oriented fibers onto a tapered mandrel, with tapered wall thickness. The ring winder/transverse filament tape process combination was used for the first time on this program to produce entire rotor blade structures. This approach permitted the complete blade to be wound on stationary mandrels, an improvement which alleviated some of the tooling and process problems encountered on previous composite blade programs.

Blade pitch optimization methods for vertical-axis wind turbines

Science.gov (United States)

Kozak, Peter

Vertical-axis wind turbines (VAWTs) offer an inherently simpler design than horizontal-axis machines, while their lower blade speed mitigates safety and noise concerns, potentially allowing for installation closer to populated and ecologically sensitive areas. While VAWTs do offer significant operational advantages, development has been hampered by the difficulty of modeling the aerodynamics involved, further complicated by their rotating geometry. This thesis presents results from a simulation of a baseline VAWT computed using Star-CCM+, a commercial finite-volume (FVM) code. VAWT aerodynamics are shown to be dominated at low tip-speed ratios by dynamic stall phenomena and at high tip-speed ratios by wake-blade interactions. Several optimization techniques have been developed for the adjustment of blade pitch based on finite-volume simulations and streamtube models. The effectiveness of the optimization procedure is evaluated and the basic architecture for a feedback control system is proposed. Implementation of variable blade pitch is shown to increase a baseline turbine's power output between 40%-100%, depending on the optimization technique, improving the turbine's competitiveness when compared with a commercially-available horizontal-axis turbine.

Distribution of defects in wind turbine blades and reliability assessment of blades containing defects

DEFF Research Database (Denmark)

Stensgaard Toft, Henrik; Branner, Kim; Berring, Peter

2009-01-01

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 the material......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...... properties and the load but also on potential defects in the blades. As a numerical example the probability of failure is calculated for the main spar both with and without defects in terms of delaminations. The delaminations increase the probability of failure compared to a perfect blade, but by applying...

Active Vibration Reduction of Titanium Alloy Fan Blades (FAN1) Using Piezoelectric Materials

Science.gov (United States)

Choi, Benjamin; Kauffman, Jeffrey; Duffy, Kirsten; Provenza, Andrew; Morrison, Carlos

2010-01-01

The NASA Glenn Research Center is developing smart adaptive structures to improve fan blade damping at resonances using piezoelectric (PE) transducers. In this paper, a digital resonant control technique emulating passive shunt circuits is used to demonstrate vibration reduction of FAN1 Ti real fan blade at the several target modes. Single-mode control and multi-mode control using one piezoelectric material are demonstrated. Also a conceptual study of how to implement this digital control system into the rotating fan blade is discussed.

Anti-freeze coatings for the rotor blades of wind turbines; Anti-freeze Beschichtungen fuer Rotorblaetter von Windenergieanlagen

Energy Technology Data Exchange (ETDEWEB)

Siegmann, K.; Kaufmann, A.; Hirayama, M.

2006-07-01

This final report for the Swiss Federal Office of Energy (SFOE) takes a look at projects involving the development of suggestions for coatings for the rotor blades of wind turbines. The coatings are to reduce the formation of hoarfrost on the leading edges of the blades. Various coatings are described and the mechanisms involved in the formation of the frost and in keeping the blades as free as possible from frost are discussed. Global know-how on the subject is discussed, as is know-how available in Europe and Switzerland. Manufacturers, planning offices and installation operators are listed, as are research institutes who are dealing with this problem. In the summary, the authors stress the importance of choosing the coating most suitable for the actual climatic conditions at the wind turbine's location. A suggestion is made for further work in this area.

Study on the Pressure Pulsation inside Runner with Splitter Blades in Ultra-High Head Turbine

International Nuclear Information System (INIS)

Meng, L; Zhang, S P; Zhou, L J; Wang, Z W

2014-01-01

Runners with splitter blades were used widely for the high efficiency and stability. In this paper, the unsteady simulation of an ultra-high head turbine at the best efficiency point, 50% and 75% discharge points were established, to analyze the pressure pulsation in the vaneless space, rotating domain and the draft tube. First of all, runners with different length splitter blades and without splitter blades were compared to learn the efficiency and the pressure distribution on the blade surface. And then the amplitude of the pressure pulsation was analysed. The peak efficiency of the runner with splitter blades is remarkably higher than that of the corresponding impeller without splitter blades. And the efficiency of the turbine is the highest when the length ratio of the splitter blades is 0.75 times the main blades. The pressure pulsation characteristics were also influenced, because the amplitudes of the pulsation induced by the RSI phenomenon were changed as a result of more blades. At last, the best design plan of the length of the splitter blades (length ratio=0.825) was obtained, which improved the pressure pulsation characteristics without significant prejudice to the efficiency

Technological and economical assessment of alternative process chains for blisk manufacture

OpenAIRE

Klocke, Fritz; Schmitt, Robert; Zeis, Markus; Heidemanns, Lukas; Kerkhoff, Johannes; Heinen, Daniel; Klink, Andreas

2015-01-01

Due to the increase of blisk (blade integrated disk) demands instead of the conventional fir-tree design in current aero-engine concepts there is a high resource-driven need for a comprehensive evaluation of different process chain alternatives for blisk manufacture. Therefore, in this paper different manufacturing chains consisting of roughing, pre-finishing and finishing/polishing are compared to each other by the example of a HPC-blisk out of Inconel 718. Beside conventional milling and el...

Modelling of lightning streamer formation and propagation in wind turbine blades

DEFF Research Database (Denmark)

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

2013-01-01

of the air termination in enhancing the electric field and attracting the lightning discharge, thus shielding the blade surface and preventing electrical breakdown of the blade material. However, the number and location of the discrete receptors may be difficult to establish, since their performance....... The present paper presents a method to investigate the origin and propagation of streamers from different conductive elements of the blade when exposed to a high electric field. The calculations are performed using dynamic simulations with the finite element method, and the results have been correlated...... with high voltage tests in the laboratory. The algorithms developed are intended to be a new and improved tool for the design of the blade lightning protection system, in particular to assess the effectiveness of the air termination system and the effects of internal conductive materials. The simulation...

Post-purchase reassessment and improvement of neuroendoscope holder: importance of physician-manufacturer communication.

Science.gov (United States)

Ogawa, Yoshikazu; Nakata, Yusuke; Tominaga, Teiji

2014-01-01

Modern medical management requires constant quality improvement of the various instruments used for surgical procedures. Higher quality, less complicated handling, and reduced maintenance are all desirable qualities. However, any improvements in instrumentation require that surgeons must clearly understand the application of the device by adherence to the manufacturer's instructions. The weakness of this one-way information flow depends on the low interest among medical personnel for post-purchase reassessment. Service industries have research departments to investigate the post-purchase behavior of customers, and service recovery is considered essential to retain customers after service failure. All service providers can suffer service failures, and even the best providers may make errors in delivering service. Such an approach has been increasingly adopted in the risk management at medical institutions. We report our clinical trials of the post-purchase reassessment and product improvement of surgical instrumentation. Medical personnel reassessed the use of a newly developed endoscope holder based on the manufacturer's manual and made recommendations for possible improvements, which were examined by the manufacturer. Simple but important improvement was achieved for reducing the instability and uncertainty of instrument fixation. This bi-directional post-purchase communication between medical personnel and manufacturers can improve risk management in medical institutions.

Experimental determination of unsteady flow forces on turbine blades by hydraulic analogy; Determination experimentale, par analogie hydraulique, des efforts instationnaires sur les aubages d`une turbine

Energy Technology Data Exchange (ETDEWEB)

Verdonk, G. [GEC Alsthom Rateau, 93 - La Courneuve (France); Naudin, M. [Framatome Thermodyn, 71 - Le Creusot (France); Pluviose, M. [CNAM, 75 - Paris (France); Sankale, H. [CETIM, 44 - Nantes (France)

1998-06-01

The blades of turbomachinery undergo unsteady flow forces, created principally by the presence of a series of stator or diffuser blades prior to a series of rotor blades. The stage geometry is the main factor which defines the magnitude of these forces. The influence of both geometric and thermodynamic parameters is currently being analysed using a model representing the turbine blades and by applying the hydraulic analogy technique. The study is being conducted at CETIM in Nantes amongst a working group including manufacturers, research organisms, and technical center. Work is in progress and initial results have proved sufficiently encouraging for presentation at the forthcoming Symposium on multidisciplinary turbomachinery issues organised by the Societe Francaise des Mecaniciens. The study should eventually facilitate the optimisation of rotor blade dimensioning for total and partial injection turbine applications and furthermore to reduce the risk of blade failure. Following quantitative study, results obtained for a given geometry of total injection turbine are presented in this paper. (authors) 16 refs.

The Effects of International Operations on the Relationship Between Manufacturing Improvement Programs and Operational Performance

DEFF Research Database (Denmark)

Matyusz, Zsolt; Demeter, Krisztina; Boer, Harry

The link between manufacturing programs and operational performance, and the effects of company internal and external factors on that relationship, are well studied in the literature, both theoretically and empirically. However, previous studies rarely took into account how the scope of operations...... of the business unit affects the relationship between manufacturing programs and performances. We investigate the scope of operations from the manufacturing perspective (i.e. companies that manufacture in only one country have narrow scope of operations, while companies that manufacture in more than one country...... have broad scope of operations). We apply structural equation modelling (SEM) using PLS path modelling to investigate the effect of scope of operations on the relationship between manufacturing improvement programs and operational performance. Manufacturing improvement programs are programs like...

Blade design loads on the flow exciting force in centrifugal pump

International Nuclear Information System (INIS)

Xu, Y; Yang, A L; Langand, D P; Dai, R

2012-01-01

The three-dimensional viscous flow field of two centrifugal pumps, which have the same volute, design head, design flow rate and rotational speed but the blade design load, are analyzed based on large eddy simulation. The comparisons are implemented including the hydraulic efficiencies, flow field characteristics, pressure pulsations and unsteady forces applied on the impellers to investigate the effect of the design blade load on hydraulic performance and flow exciting force. The numerical results show that the efficiency of the pump, the impeller blade of which has larger design load, is improved by 1.1%∼2.9% compared to the centrifugal pump with lower blade design load. The pressure fluctuation of the pump with high design load is more remarkable. Its maximum amplitude of coefficient of static pressure is higher by 43% than the latter. At the same time the amplitude of unsteady radial force is increased by 11.6% in the time domain. The results also imply that the blade design load is an important factor on the excitation force in centrifugal pumps.

Integrated circuit cooled turbine blade

Science.gov (United States)

Lee, Ching-Pang; Jiang, Nan; Um, Jae Y.; Holloman, Harry; Koester, Steven

2017-08-29

A turbine rotor blade includes at least two integrated cooling circuits that are formed within the blade that include a leading edge circuit having a first cavity and a second cavity and a trailing edge circuit that includes at least a third cavity located aft of the second cavity. The trailing edge circuit flows aft with at least two substantially 180-degree turns at the tip end and the root end of the blade providing at least a penultimate cavity and a last cavity. The last cavity is located along a trailing edge of the blade. A tip axial cooling channel connects to the first cavity of the leading edge circuit and the penultimate cavity of the trailing edge circuit. At least one crossover hole connects the penultimate cavity to the last cavity substantially near the tip end of the blade.

Structural design optimization of a morphing trailing edge flap for wind turbine blades

DEFF Research Database (Denmark)

Barlas, Athanasios; Lin, Yu-Huan; Aagaard Madsen, Helge

A flap actuation system, the Controllable Rubber Trailing Edge Flap (CRTEF), for distributed load control on a wind turbine blade had been developed in the period from 2006 to 2013 at DTU (http://www.induflap.dk/). The purpose of the presented work is to optimize the structural design of the flex......A flap actuation system, the Controllable Rubber Trailing Edge Flap (CRTEF), for distributed load control on a wind turbine blade had been developed in the period from 2006 to 2013 at DTU (http://www.induflap.dk/). The purpose of the presented work is to optimize the structural design...... of the flexible part of the CRTEF based on a realistic blade section geometry in order to meet the required objectives and constraints. The objectives include the deflection requirements and the energy efficiency, while the constraints include the bending stiffness of the structure, the local shape deformations......, critical material strength, and manufacturing limitations. A model with arches forming concave on the flap surface and enclosing the voids to be pressurized results in the bending movement of the flap when pressure is applied on the voids to straighten the arches. The model is designed using SolidWorks...

Hydraulic performance of a low specific speed centrifugal pump with Spanwise-Slotted Blades

International Nuclear Information System (INIS)

Ye, D X; Li, H; Wang, Y

2013-01-01

The hydraulic efficiency of a low specific speed centrifugal pump is low because of the long and narrow meridian flow passage, and the severe disk friction. Spanwise slotted blade flow control technology has been applied to the low specific speed centrifugal pump. This paper concluded that spanwise slotted blades can improve the pump performance in both experiments and simulations. In order to study the influence to the impeller and volute by spanwise slotted blade, impeller efficiency and volute efficiency were defined. The minimum volute efficiency and the maximum pump efficiency appear at the same time in the design flow condition in the unsteady simulation. The mechanism of spanwise slotted blade flow control technology should be researched furthermore

Crack modeling of rotating blades with cracked hexahedral finite element method

Science.gov (United States)

Liu, Chao; Jiang, Dongxiang

2014-06-01

Dynamic analysis is the basis in investigating vibration features of cracked blades, where the features can be applied to monitor health state of blades, detect cracks in an early stage and prevent failures. This work presents a cracked hexahedral finite element method for dynamic analysis of cracked blades, with the purpose of addressing the contradiction between accuracy and efficiency in crack modeling of blades in rotor system. The cracked hexahedral element is first derived with strain energy release rate method, where correction of stress intensity factors of crack front and formulation of load distribution of crack surface are carried out to improve the modeling accuracy. To consider nonlinear characteristics of time-varying opening and closure effects caused by alternating loads, breathing function is proposed for the cracked hexahedral element. Second, finite element method with contact element is analyzed and used for comparison. Finally, validation of the cracked hexahedral element is carried out in terms of breathing effects of cracked blades and natural frequency in different crack depths. Good consistency is acquired between the results with developed cracked hexahedral element and contact element, while the computation time is significantly reduced in the previous one. Therefore, the developed cracked hexahedral element achieves good accuracy and high efficiency in crack modeling of rotating blades.

Noise aspects at aerodynamic blade optimisation projects

International Nuclear Information System (INIS)

Schepers, J.G.

1997-06-01

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

Combining Unsteady Blade Pressure Measurements and a Free-Wake Vortex Model to Investigate the Cycle-to-Cycle Variations in Wind Turbine Aerodynamic Blade Loads in Yaw

Directory of Open Access Journals (Sweden)

Moutaz Elgammi

2016-06-01

Full Text Available Prediction of the unsteady aerodynamic flow phenomenon on wind turbines is challenging and still subject to considerable uncertainty. Under yawed rotor conditions, the wind turbine blades are subjected to unsteady flow conditions as a result of the blade advancing and retreating effect and the development of a skewed vortical wake created downstream of the rotor plane. Blade surface pressure measurements conducted on the NREL Phase VI rotor in yawed conditions have shown that dynamic stall causes the wind turbine blades to experience significant cycle-to-cycle variations in aerodynamic loading. These effects were observed even though the rotor was subjected to a fixed speed and a uniform and steady wind flow. This phenomenon is not normally predicted by existing dynamic stall models integrated in wind turbine design codes. This paper couples blade pressure measurements from the NREL Phase VI rotor to a free-wake vortex model to derive the angle of attack time series at the different blade sections over multiple rotor rotations and three different yaw angles. Through the adopted approach it was possible to investigate how the rotor self-induced aerodynamic load fluctuations influence the unsteady variations in the blade angles of attack and induced velocities. The hysteresis loops for the normal and tangential load coefficients plotted against the angle of attack were plotted over multiple rotor revolutions. Although cycle-to-cycle variations in the angles of attack at the different blade radial locations and azimuth positions are found to be relatively small, the corresponding variations in the normal and tangential load coefficients may be significant. Following a statistical analysis, it was concluded that the load coefficients follow a normal distribution at the majority of blade azimuth angles and radial locations. The results of this study provide further insight on how existing engineering models for dynamic stall may be improved through

Ceramic blade with tip seal

Science.gov (United States)

Glezer, B.; Bhardwaj, N.K.; Jones, R.B.

1997-08-05

The present gas turbine engine includes a disc assembly defining a disc having a plurality of blades attached thereto. The disc has a preestablished rate of thermal expansion and the plurality of blades have a preestablished rate of thermal expansion being less than the preestablished rate of thermal expansion of the disc. A shroud assembly is attached to the gas turbine engine and is spaced from the plurality of blades a preestablished distance forming an interface there between. Positioned in the interface is a seal having a preestablished rate of thermal expansion being generally equal to the rate of thermal expansion of the plurality of blades. 4 figs.

Experimental investigation of damping for edgewise blade vibrations; Eksperimentel bestemmelse af daempning for kantsvingninger

Energy Technology Data Exchange (ETDEWEB)

Thomsen, K.; Thirstrup Petersen, J. [Forskningscenter Risoe (Denmark); Nim, E. [Bonus Energy A/S (Denmark); Oeye, S. [Danmarks Tekniske Univ. (Denmark); Pedersen, B. [LM Glasfiber A/S (Denmark)

2000-01-01

The main result of the investigation is a newly developed method to identify the effective damping for the edgewise blade mode shape for wind turbines. The method consists of an exciter mechanism which makes it possible to excite the edgewise blade mode shapes from the wind turbine nacelle and furthermore of an analysis method, which enables a straightforward determination of the damping. The analysis method is based on a local blade whirl description of the edgewise blade vibrations. The method is verified on a Bonus wind turbine and for this specific turbine the effective damping for edgewise blade vibrations has been determined. The results have been compared with aeroelastic simulations. The potential of the method is that the results can support the further development of aeroelastic models and fine tuning of parameters of importance of the edgewise blade vibration problem and thus improve the certainty in the predicted risk of vibrations. Furthermore, the method can be used for experimental investigation of the risk of edgewise blade vibrations for a specific turbine. (au)

Adaptor assembly for coupling turbine blades to rotor disks

Science.gov (United States)

Garcia-Crespo, Andres Jose; Delvaux, John McConnell

2014-09-23

An adaptor assembly for coupling a blade root of a turbine blade to a root slot of a rotor disk is described. The adaptor assembly includes a turbine blade having a blade root and an adaptor body having an adaptor root. The adaptor body defines a slot having an open end configured to receive the blade root of the turbine blade such that the adaptor root of the adaptor body and the blade root of the turbine blade are adjacent to one another when the blade root of the turbine blade is positioned within the slot. Both the adaptor root of the adaptor body and the blade root of the turbine blade are configured to be received within the root slot of the rotor disk.

Design, Fabrication, and Performance Test of a 100-W Helical-Blade Vertical-Axis Wind Turbine at Low Tip-Speed Ratio

Directory of Open Access Journals (Sweden)

Dowon Han

2018-06-01

Full Text Available A 100-W helical-blade vertical-axis wind turbine was designed, manufactured, and tested in a wind tunnel. A relatively low tip-speed ratio of 1.1 was targeted for usage in an urban environment at a rated wind speed of 9 m/s and a rotational speed of 170 rpm. The basic dimensions were determined through a momentum-based design method according to the IEC 61400-2 protocol. The power output was estimated by a mathematical model that takes into account the aerodynamic performance of the NACA0018 blade shape. The lift and drag of the blade with respect to the angle of attack during rotation were calculated using 2D computational fluid dynamics (CFD simulation to take into account stall region. The average power output calculated by the model was 108.34 W, which satisfies the target output of 100 W. The manufactured wind turbine was tested in a large closed-circuit wind tunnel, and the power outputs were measured for given wind speeds. At the design condition, the measured power output was 114.7 W, which is 5.9% higher than that of the mathematical model. This result validates the proposed design method and power estimation by the mathematical model.

A Non-Uniformly Under-Sampled Blade Tip-Timing Signal Reconstruction Method for Blade Vibration Monitoring

Directory of Open Access Journals (Sweden)

Zheng Hu

2015-01-01

Full Text Available High-speed blades are often prone to fatigue due to severe blade vibrations. In particular, synchronous vibrations can cause irreversible damages to the blade. Blade tip-timing methods (BTT have become a promising way to monitor blade vibrations. However, synchronous vibrations are unsuitably monitored by uniform BTT sampling. Therefore, non-equally mounted probes have been used, which will result in the non-uniformity of the sampling signal. Since under-sampling is an intrinsic drawback of BTT methods, how to analyze non-uniformly under-sampled BTT signals is a big challenge. In this paper, a novel reconstruction method for non-uniformly under-sampled BTT data is presented. The method is based on the periodically non-uniform sampling theorem. Firstly, a mathematical model of a non-uniform BTT sampling process is built. It can be treated as the sum of certain uniform sample streams. For each stream, an interpolating function is required to prevent aliasing in the reconstructed signal. Secondly, simultaneous equations of all interpolating functions in each sub-band are built and corresponding solutions are ultimately derived to remove unwanted replicas of the original signal caused by the sampling, which may overlay the original signal. In the end, numerical simulations and experiments are carried out to validate the feasibility of the proposed method. The results demonstrate the accuracy of the reconstructed signal depends on the sampling frequency, the blade vibration frequency, the blade vibration bandwidth, the probe static offset and the number of samples. In practice, both types of blade vibration signals can be particularly reconstructed by non-uniform BTT data acquired from only two probes.

Aeroelastic response and stability of tiltrotors with elastically-coupled composite rotor blades. Ph.D. Thesis

Science.gov (United States)

Nixon, Mark W.

1993-01-01

There is a potential for improving the performance and aeroelastic stability of tiltrotors through the use of elastically-coupled composite rotor blades. To study the characteristics of tiltrotors with these types of rotor blades it is necessary to formulate a new analysis which has the capabilities of modeling both a tiltrotor configuration and an anisotropic rotor blade. Background for these formulations is established in two preliminary investigations. In the first, the influence of several system design parameters on tiltrotor aeroelastic stability is examined for the high-speed axial flight mode using a newly-developed rigid-blade analysis with an elastic wing finite element model. The second preliminary investigation addresses the accuracy of using a one-dimensional beam analysis to predict frequencies of elastically-coupled highly-twisted rotor blades. Important aspects of the new aeroelastic formulations are the inclusion of a large steady pylon angle which controls tilt of the rotor system with respect to the airflow, the inclusion of elastic pitch-lag coupling terms related to rotor precone, the inclusion of hub-related degrees of freedom which enable modeling of a gimballed rotor system and engine drive-train dynamics, and additional elastic coupling terms which enable modeling of the anisotropic features for both the rotor blades and the tiltrotor wing. Accuracy of the new tiltrotor analysis is demonstrated by a comparison of the results produced for a baseline case with analytical and experimental results reported in the open literature. Two investigations of elastically tailored blades on a baseline tiltrotor are then conducted. One investigation shows that elastic bending-twist coupling of the rotor blade is a very effective means for increasing the flutter velocity of a tiltrotor, and the magnitude of coupling required does not have an adverse effect on performance or blade loads. The second investigation shows that passive blade twist control via

An innovative medium speed wind turbine rotor blade design for low wind regime (electrical power generation)

International Nuclear Information System (INIS)

Abas Abd Wahab; Chong Wen Tong

2001-01-01

This paper describes the preliminary study of a small-scale wind turbine rotor blade (a low wind speed region turbine). A new wind turbine rotor blade (AE2 blade) for stand alone system has been conceptualized, designed, constructed and tested. The system is a reduced size prototype (half-scaled) to develop an efficient (adapted to Malaysian wind conditions)and cost effective wind energy conversion system (WECS) with local design and production technique. The blades were constructed from aluminium sheet with metal blending technique. The layout and design of rotor blade, its innovative features and test results are presented. Results from indoor test showed that the advantages of AE2 blade in low speed, with the potential of further improvements. The best rotor efficiency, C P attained with simple AE2 blades rotor (number of blade = 3) was 37.3% (Betz efficiency = 63%) at tip speed ratio (TSR) = 3.6. From the fabrication works and indoor testing, the AE2 blade rotor has demonstrated its structural integrity (ease of assembly and transportation), simplicity, acceptable performance and low noise level. (Author)

Preliminary Investigation of Several Root Designs for Cermet Turbine Blades in Turbojet Engine III : Curved-root Design

Science.gov (United States)

Pinkel, Benjamin; Deutsch, George C; Morgan, William C

1955-01-01

Stresses om tje root fastenings of turbine blades were appreciably reduced by redesign of the root. The redesign consisted in curving the root to approximately conform to the camber of the airfoil and elimination of the blade platform. Full-scale jet-engine tests at rated speed using cermet blades of the design confirmed the improvement.

Bingham plastic fluid flow model in tape casting of ceramics using two doctor blades – analytical approach

DEFF Research Database (Denmark)

Jabbari, Masoud; Hattel, Jesper Henri

2014-01-01

One of the most common processes used in manufacturing of multilayer ceramic packages, multilayer capacitors and large scale integration circuits is tape casting. In this process, the wet tape thickness is one of the single most determining parameters affecting the final properties of the product......, and it is therefore of great interest to be able to control it. One way to control the tape thickness is to use a two doctor blade configuration in the tape casting machine. In this case, it becomes important to fix the height of the slurry in front of both doctor blades according to the desired tape thickness...... and casting speed (belt velocity). In the present work, the flow in both doctor blade regions of a slurry is described with a steady state momentum equation in combination with a Bingham plastic constitutive equation, and this is integrated to a closed form analytical solution for both reservoirs based...

Vibration analysis of gas turbine blade using FEM

International Nuclear Information System (INIS)

Iqbal, M.J.; Chohan, G.Y.; Khusnood, S.; Khan, M.A.

2003-01-01

In a typical turbo-machine, there is a stator row of blades, which guide the gases onto a rotor row of blades, to extract the mechanical power from the machine. A typical rotor blade was sees upstream disturbance from the stator row and as it rotates, receive a corresponding number of increasing and decreasing lift and moment forces alternating periodically, depending on the number of stator blades/nozzles/guide vanes. Thus all the blades in a turbo-machine receiver their major periodic excitation at a frequency equal to nozzle passing frequency. Since these forces are periodic, one has to consider several number of these harmonics in determining whether resonance takes place, when one of these harmonics coincides with any of the natural frequencies of the blades. Turbine blades have a variety of natural modes of vibration, predominantly as blade alone but also in combination with flexing of the disc rim. These mode occur at characteristic frequencies, which are determined by the distribution of mass and stiffness (in bending or torsion), resulting from the variable thickness over the blade area. Since the advent of steam turbines and their application in various sectors of industry, it is a common experience that a blade failure is a major cause of breakdown in these machines. Blade failures due to fatigue are predominantly vibration related. The dynamic loads on the blading can arise from many sources, the predominant being the source of the operation principles on which the machine is designed. This work deals with vibration analysis of a gas turbine blade using a finite element package ANSYS. Determined the natural frequencies and mode shapes for a turbine blade and a rectangular blade. Results have been validated experimentally using a rectangular blade. ANSYS results have also been compared against published results. (author)

Metallurgical failure analysis for a blade failed in a gas-turbine engine of a power plant

International Nuclear Information System (INIS)

Huda, Zainul

2009-01-01

The failed gas-turbine blades (first stage blades) (type Siemens V94.2 KWU) were acquired from TNB Research Sdn. Bhd: a subsidiary of Malaysian power-generation industry (TNB, Malaysia). The blades were sectioned for metallographic investigations. The microstructural characterization involved use of both optical as well as electron microscopes including application of EPMA technique. The Microstructures were compared for three spots selection i.e. leading edge of the blade (transverse and longitudinal), trailing edge of the blade (transverse and longitudinal), and centre (near the platform of the blade) (transverse and longitudinal). The material properties and behavior at high temperature were interpreted on the basis of the observed microstructures and the phases present in the alloy. The interpretations were related to the operating conditions of the turbine blade; and main cause of failure was found to be creep damage. Recommendations have been made for improved material performance.

Knowledge-based system for detailed blade design of turbines

Science.gov (United States)

Goel, Sanjay; Lamson, Scott

1994-03-01

A design optimization methodology that couples optimization techniques to CFD analysis for design of airfoils is presented. This technique optimizes 2D airfoil sections of a blade by minimizing the deviation of the actual Mach number distribution on the blade surface from a smooth fit of the distribution. The airfoil is not reverse engineered by specification of a precise distribution of the desired Mach number plot, only general desired characteristics of the distribution are specified for the design. Since the Mach number distribution is very complex, and cannot be conveniently represented by a single polynomial, it is partitioned into segments, each of which is characterized by a different order polynomial. The sum of the deviation of all the segments is minimized during optimization. To make intelligent changes to the airfoil geometry, it needs to be associated with features observed in the Mach number distribution. Associating the geometry parameters with independent features of the distribution is a fairly complex task. Also, for different optimization techniques to work efficiently the airfoil geometry needs to be parameterized into independent parameters, with enough degrees of freedom for adequate geometry manipulation. A high-pressure, low reaction steam turbine blade section was optimized using this methodology. The Mach number distribution was partitioned into pressure and suction surfaces and the suction surface distribution was further subdivided into leading edge, mid section and trailing edge sections. Two different airfoil representation schemes were used for defining the design variables of the optimization problem. The optimization was performed by using a combination of heuristic search and numerical optimization. The optimization results for the two schemes are discussed in the paper. The results are also compared to a manual design improvement study conducted independently by an experienced airfoil designer. The turbine blade optimization

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. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Genetic particle swarm parallel algorithm analysis of optimization arrangement on mistuned blades

Science.gov (United States)

Zhao, Tianyu; Yuan, Huiqun; Yang, Wenjun; Sun, Huagang

2017-12-01

This article introduces a method of mistuned parameter identification which consists of static frequency testing of blades, dichotomy and finite element analysis. A lumped parameter model of an engine bladed-disc system is then set up. A bladed arrangement optimization method, namely the genetic particle swarm optimization algorithm, is presented. It consists of a discrete particle swarm optimization and a genetic algorithm. From this, the local and global search ability is introduced. CUDA-based co-evolution particle swarm optimization, using a graphics processing unit, is presented and its performance is analysed. The results show that using optimization results can reduce the amplitude and localization of the forced vibration response of a bladed-disc system, while optimization based on the CUDA framework can improve the computing speed. This method could provide support for engineering applications in terms of effectiveness and efficiency.

Wind blade spar cap and method of making

Science.gov (United States)

Mohamed, Mansour H [Raleigh, NC

2008-05-27

A wind blade spar cap for strengthening a wind blade including an integral, unitary three-dimensional woven material having a first end and a second end, corresponding to a root end of the blade and a tip end of the blade, wherein the material tapers in width from the first to the second end while maintaining a constant thickness and decreasing weight therebetween, the cap being capable of being affixed to the blade for providing increased strength with controlled variation in weight from the root end to the tip end based upon the tapered width of the material thereof. The present inventions also include the method of making the wind blade spar cap and a wind blade including the wind blade spar cap.

Westinghouse fuel manufacturing systems: a step change in performance improvements

International Nuclear Information System (INIS)

Mutyala, Meena

2009-01-01

Today's competitive electrical generation industry demands that nuclear power plant operators minimize total operating costs, including fuel cycle cost while maintaining flawless fuel performance. The mission of Westinghouse Nuclear Fuel is to be the industry's most responsive supplier of flawless, value added fuel products and services, as judged by our customers. As nuclear is fast becoming the choice of many countries, existing manufacturing plants and facilities are once again running at full capacity. In this context Westinghouse Nuclear Fuel is committed to deliver a step change in performance improvement worldwide through its manufacturing operations by the introduction of a set of fundamentals collectively named the 'Westinghouse Fuel Manufacturing System' (WFMS), whose key principles are discussed in this paper. (author)

Composite ceramic blade for a gas turbine

Energy Technology Data Exchange (ETDEWEB)

Rossmann, A; Hoffmueller, W; Krueger, W

1980-06-26

The gas turbine blade consists of a supporting metal core which has at its lower end a modelled root and a profile blade made of ceramics enclosing it at some distance. The invention deals with a reliable connection between these two parts of the rotor blade: from the top end of the blade core a head protrudes supporting the thin-walled profile blade from below with a projection each pointing into the interior. The design of the projections and supporting surfaces is described and illustrated by drawings.

Structural and mechanism design of an active trailing-edge flap blade

DEFF Research Database (Denmark)

Lee, Jae Hwan; Natarajan, Balakumaran; Eun, Won Jong

2013-01-01

, as the blade is able to withstand increased centrifugal force. The cross-section of the active blade is designed first. A stress/strain recovery analysis is then conducted to verify its structural integrity. A one-dimensional beam analysis is also carried out to assist with the construction of the fan diagram...... of the rotor through modification of unsteady aerodynamic loads. Piezoelectric actuators installed inside the blade manipulate the motion of the trailing edge flap. The proposed blade rotates at higher speed and additional structures are included to support the actuators and the flap. This improves the design....... To select the actuator and design the flap actuation region, the flap hinge moment is estimated via a CFD analysis. To obtain the desired flap deflection of ±4°, three actuators are required. The design of the flap actuation region is validated using a test bed with a skin hinge. However, because the skin...

Local fatigue behavior in tapered areas of large offshore wind turbine blades

DEFF Research Database (Denmark)

Raeis Hosseiny, Seyed Aydin; Jakobsen, Johnny

2016-01-01

failure of an entire blade structure. The local strength degradation under an ultimate static loading, subsequent to several years of fatigue, is predicted for an offshore wind turbine blade. Fatigue failure indexes of different damage modes are calculated using a sub-modeling approach. Multi axial...... knock-down factors for ply-drop effects in wind turbine blades under multi-axial static and fatigue loadings can be obtained.......Thickness transitions in load carrying elements lead to improved geometries and efficient material utilization. However, these transitions may introduce localized areas with high stress concentrations and may act as crack initiators that could potentially cause delamination and further catastrophic...

Experimental Study of under-platform Damper Kinematics in Presence of Blade Dynamics

Science.gov (United States)

Botto, D.; Gastaldi, C.; Gola, M. M.; Umer, M.

2018-01-01

Among the different devices used in the aerospace industries under-platform dampers are widely used in turbo engines to mitigate the blade vibration. Nevertheless, the damper behaviour is not easy to simulate and engineers have been working in order to improve the accuracy with which theoretical contact models predict the damper behaviour. Majority of the experimental setups collect experimental data in terms of blade amplitude reduction which do not increase the knowledge about the damper dynamics and therefore the uncertainty on the damper behaviour remains a big issue. In this paper, a novel test rig has been purposely designed to accommodate a single blade and two under-platform dampers to deeply investigate the damper-blade interactions. In this test bench, a contact force measuring system was designed to extensively measure the damper contact forces. Damper kinematics is rebuilt by using the relative displacement measured between damper and blade. This paper describes the concept behind the new approach, shows the details of new test rig and discusses experimental results by comparing with previously measured results on an old experimental setup.

Application of additive laser technologies in the gas turbine blades design process

Science.gov (United States)

Shevchenko, I. V.; Rogalev, A. N.; Osipov, S. K.; Bychkov, N. M.; Komarov, I. I.

2017-11-01

An emergence of modern innovative technologies requires delivering new and modernization existing design and production processes. It is especially relevant for designing the high-temperature turbines of gas turbine engines, development of which is characterized by a transition to higher parameters of working medium in order to improve their efficient performance. A design technique for gas turbine blades based on predictive verification of thermal and hydraulic models of their cooling systems by testing of a blade prototype fabricated using the selective laser melting technology was presented in this article. Technique was proven at the time of development of the first stage blade cooling system for the high-pressure turbine. An experimental procedure for verification of a thermal model of the blades with convective cooling systems based on the comparison of heat-flux density obtained from the numerical simulation data and results of tests in a liquid-metal thermostat was developed. The techniques makes it possible to obtain an experimentally tested blade version and to exclude its experimental adjustment after the start of mass production.

A laser-optical sensor system for blade vibration detection of high-speed compressors

Science.gov (United States)

Neumann, Mathias; Dreier, Florian; Günther, Philipp; Wilke, Ulrich; Fischer, Andreas; Büttner, Lars; Holzinger, Felix; Schiffer, Heinz-Peter; Czarske, Jürgen

2015-12-01

Improved efficiency as well as increased lifetime of turbines and compressors are important goals in turbomachinery development. A significant enhancement to accomplish these aims can be seen in online monitoring of the operating parameters of the machines. During the operation of compressors it is of high interest to predict critical events like flutter or stall which can be achieved by observing blade deformations and vibrations. We have developed a laser Doppler distance sensor (LDDS), which is capable of simultaneously measuring the radial blade expansions, the circumferential blade deflections as well as the circumferential velocities of the rotor blade tips. As a result, an increase of blade vibrations is measured before stall at characteristic frequencies. While the detected vibration frequencies and the vibration increase are in agreement with the measurement results of a commercial capacitive blade tip timing system, the measured values of the vibration amplitudes differ by a factor of three. This difference can be mainly attributed to the different measurement locations and to the different measurement approaches. Since the LDDS is applicable to metal as well as ceramic, carbon-fiber and glass-fiber reinforced composite blades, a universally applicable sensor system for stall prediction and status monitoring is presented.

The carbon fibre market and uses for composite wind blades

Energy Technology Data Exchange (ETDEWEB)

Lowe, J R [Tenax Fibers Gmbh and Co. KG, Wuppertal (Germany)

1996-09-01

Due to its excellent fatigue properties, low weight and high stiffness, carbon fibre reinforced plastic (CFRP) is the ideal material to use for the manufacture of wind blades. The present use of CFRP in the wind energy sector however is very low in comparison to glass fibre reinforced plastic (GFRP) materials. The main reason for this low use of CFRP is cost since at present times carbon fibre is valued ten times as much as glass fibre. This paper introduces carbon fibre as an alternative material to glass and examines the use of CFRP components in other high fatigue applications. (au)

A Framework Based on OEE and Wireless Technology for Improving Overall Manufacturing Operations

OpenAIRE

Garcia , Martha-Patricia; Santos , Javier; Arcelus , Mikel; Viles , Elisabeth

2011-01-01

Part 1: Production Process; International audience; Manufacturers have the challenge to increase productivity given complex manufacturing environments. A source that provides substantial levels of productivity is the overall equipment effectiveness (OEE) metric, which is an indicator to improve not only equipment utilization; but also the overall manufacturing operations, because of the valuable information that comes from the availability, performance and quality rates. Although information ...

Numerical analysis of the flow field in the pump chamber of a centrifugal pump with back blades

International Nuclear Information System (INIS)

Cao, L; Wang, Z W; Luo, Y Y; Liu, M

2013-01-01

Black blade is frequently used as a non-contact seal structure in centrifugal pumps transporting solid-liquid two-phase flow. However, it will disturb the flow in the pump and affect the pump performance. Numerical simulation for 3D turbulence in whole flow passage of a centrifugal pump with back blades was carried out based on RANS method, with SST k-ω turbulence model and SIMPLEC algorithm. Calculation for a similar pump without back blades was also carried out as a comparison. Boundary condition was improved due to the existence of back blade. The influence of back blades on the flow field was analysed qualitatively for three typical conditions. Meanwhile the leakage rate was calculated for several conditions and the effect of back blades was discussed. According to the results, compared with the condition without back blades, it could be seen that back blade apparently changed the flow state in the front chamber, improved near the front shroud and worsened near the pump cover. Velocity was increased and more fluid, which flowed into the front chamber from the pump cover side, flowed back to the spiral casing from the impeller shroud side. With the increase of discharge, the absolute value of leakage rate first went up and then dropped, as a consequence of the combination of two factors, discharge and differential pressure between the impeller outlet and inlet. The seal effect of back blades is most obvious under small discharge condition, and the leakage loss diminished as discharge increased

Numerical analysis of turbine blade tip treatments

Science.gov (United States)

Gopalaswamy, Nath S.; Whitaker, Kevin W.

1992-01-01

Three-dimensional solutions of the Navier-Stokes equations for a turbine blade with a turning angle of 180 degrees have been computed, including blade tip treatments involving cavities. The geometry approximates a preliminary design for the GGOT (Generic Gas Oxidizer Turbine). The data presented here will be compared with experimental data to be obtained from a linear cascade using original GGOT blades. Results have been computed for a blade with 1 percent clearance, based on chord, and three different cavity sizes. All tests were conducted at a Reynolds number of 4 x 10 exp 7. The grid contains 39,440 points with 10 spanwise planes in the tip clearance region of 5.008E-04 m. Streamline plots and velocity vectors together with velocity divergence plots reveal the general flow behavior in the clearance region. Blade tip temperature calculations suggest placement of a cavity close to the upstream side of the blade tip for reduction of overall blade tip temperature. The solutions do not account for the relative motion between the endwall and the turbine blade. The solutions obtained are generally consistent with previous work done in this area,

A New Manufacturing Service Selection and Composition Method Using Improved Flower Pollination Algorithm

Directory of Open Access Journals (Sweden)

Wenyu Zhang

2016-01-01

Full Text Available With an increasing number of manufacturing services, the means by which to select and compose these manufacturing services have become a challenging problem. It can be regarded as a multiobjective optimization problem that involves a variety of conflicting quality of service (QoS attributes. In this study, a multiobjective optimization model of manufacturing service composition is presented that is based on QoS and an environmental index. Next, the skyline operator is applied to reduce the solution space. And then a new method called improved Flower Pollination Algorithm (FPA is proposed for solving the problem of manufacturing service selection and composition. The improved FPA enhances the performance of basic FPA by combining the latter with crossover and mutation operators of the Differential Evolution (DE algorithm. Finally, a case study is conducted to compare the proposed method with other evolutionary algorithms, including the Genetic Algorithm, DE, basic FPA, and extended FPA. The experimental results reveal that the proposed method performs best at solving the problem of manufacturing service selection and composition.

Test Rig for Evaluating Active Turbine Blade Tip Clearance Control Concepts

Science.gov (United States)

Lattime, Scott B.; Steinetz, Bruce M.; Robbie, Malcolm G.

2003-01-01

Improved blade tip sealing in the high pressure compressor and high pressure turbine can provide dramatic improvements in specific fuel consumption, time-on-wing, compressor stall margin and engine efficiency as well as increased payload and mission range capabilities of both military and commercial gas turbine engines. The preliminary design of a mechanically actuated active clearance control (ACC) system for turbine blade tip clearance management is presented along with the design of a bench top test rig in which the system is to be evaluated. The ACC system utilizes mechanically actuated seal carrier segments and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. The purpose of this active clearance control system is to improve upon current case cooling methods. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, re-burst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). The active turbine blade tip clearance control system design presented herein will be evaluated to ensure that proper response and positional accuracy is achievable under simulated high-pressure turbine conditions. The test rig will simulate proper seal carrier pressure and temperature loading as well as the magnitudes and rates of blade tip clearance changes of an actual gas turbine engine. The results of these evaluations will be presented in future works.

Independent Blade Pitch Controller Design for a Three-Bladed Turbine Using Disturbance Accommodating Control

Energy Technology Data Exchange (ETDEWEB)

Wang, Na; Wright, Alan D.; Johnson, Kathryn E.

2016-08-01

Two independent pitch controllers (IPCs) based on the disturbance accommodating control (DAC) algorithm are designed for the three-bladed Controls Advanced Research Turbine to regulate rotor speed and to mitigate blade root flapwise bending loads in above-rated wind speed. One of the DAC-based IPCs is designed based on a transformed symmetrical-asymmetrical (TSA) turbine model, with wind disturbances being modeled as a collective horizontal component and an asymmetrical linear shear component. Another DAC-based IPC is designed based on a multiblade coordinate (MBC) transformed turbine model, with a horizontal component and a vertical shear component being modeled as step waveform disturbance. Both of the DAC-based IPCs are found via a regulation equation solved by Kronecker product. Actuator dynamics are considered in the design processes to compensate for actuator phase delay. The simulation study shows the effectiveness of the proposed DAC-based IPCs compared to a proportional-integral (PI) collective pitch controller (CPC). Improvement on rotor speed regulation and once-per-revolution and twice-per-revolution load reductions has been observed in the proposed IPC designs.

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.

A Take Stock of Turbine Blades Failure Phenomenon

Science.gov (United States)

Roy, Abhijit

2018-02-01

Turbine Blade design and engineering is one of the most complicated and important aspects of turbine technology. Experiments with blades can be simple or very complicated, depending upon parameters of analysis. Turbine blades are subjected to vigorous environments, such as high temperatures, high stresses, and a potentially high vibration environment. All these factors can lead to blade failures, which can destroy the turbine, and engine, so careful design is the prime consideration to resist those conditions. A high cycle of fatigue of compressor and turbine blades due to high dynamic stress caused by blade vibration and resonance within the operating range of machinery is common failure mode for turbine machine. Continuous study and investigation on failure of turbine blades are going on since last five decades. Some review papers published during these days aiming to present a review on recent studies and investigations done on failures of turbine blades. All the detailed literature related with the turbine blades has not been described but emphasized to provide all the methodologies of failures adopted by various researches to investigate turbine blade. This paper illustrate on various factors of failure.

Wind Turbine Blade with Angled Girders

DEFF Research Database (Denmark)

2011-01-01

The present invention relates to a reinforced blade for a wind turbine, particularly to a blade having a new arrangement of two or more girders in the blade, wherein each of the girders is connected to the upper part and the lower part of the shell and forms an angle with another girder thereby...

Composite Thickness Optimization of Offshore Wind Turbine Blade with Fixed outer Geometry

DEFF Research Database (Denmark)

Sjølund, Jonas Heidemann; Lund, Erik

2017-01-01

With the objective of mass minimization, a 73-m offshore wind turbine blade is optimized using a gradient based approach on a Finite Element (FE) model. Constant loads and a fixed outer geometry are assumed. Plies of the same material and same orientation are grouped together in plygroups. The th....... The thicknesses of the plygroups are chosen as design variables. Manufacturing constraints such as ply-drops are taken into account using linear constraints. Structural constraints include buckling, tip displacement and max. strain failure indices....

Advances in wind turbine blade design and materials

DEFF Research Database (Denmark)

Wind energy is gaining critical ground in the area of renewable energy, with wind energy being predicted to provide up to 8% of the world’s consumption of electricity by 2021. Advances in wind turbine blade design and materials reviews the design and functionality of wind turbine rotor blades...... as 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......, and characteristics of wind turbine blade airfoils. Part two discusses the fatigue behavior of composite wind turbine blades, including the micromechanical modelling and fatigue life prediction of wind turbine blade composite materials, and the effects of resin and reinforcement variations on the fatigue resistance...

Development of an anisotropic beam finite element for composite wind turbine blades in multibody system

DEFF Research Database (Denmark)

Kim, Taeseong; Hansen, Anders Melchior; Branner, Kim

2013-01-01

In this paper a new anisotropic beam finite element for composite wind turbine blades is developed and implemented into the aeroelastic nonlinear multibody code, HAWC2, intended to be used to investigate if use of anisotropic material layups in wind turbine blades can be tailored for improved...

Shape optimization of turbine blades with the integration of aerodynamics and heat transfer

Directory of Open Access Journals (Sweden)

Rajadas J. N.

1998-01-01

Full Text Available A multidisciplinary optimization procedure, with the integration of aerodynamic and heat transfer criteria, has been developed for the design of gas turbine blades. Two different optimization formulations have been used. In the first formulation, the maximum temperature in the blade section is chosen as the objective function to be minimized. An upper bound constraint is imposed on the blade average temperature and a lower bound constraint is imposed on the blade tangential force coefficient. In the second formulation, the blade average and maximum temperatures are chosen as objective functions. In both formulations, bounds are imposed on the velocity gradients at several points along the surface of the airfoil to eliminate leading edge velocity spikes which deteriorate aerodynamic performance. Shape optimization is performed using the blade external and coolant path geometric parameters as design variables. Aerodynamic analysis is performed using a panel code. Heat transfer analysis is performed using the finite element method. A gradient based procedure in conjunction with an approximate analysis technique is used for optimization. The results obtained using both optimization techniques are compared with a reference geometry. Both techniques yield significant improvements with the multiobjective formulation resulting in slightly superior design.

Slotted Blades Savonius Wind Turbine Analysis by CFD

Directory of Open Access Journals (Sweden)

Andrea Alaimo

2013-12-01

Full Text Available In this paper a new bucket configuration for a Savonius wind generator is proposed. Numerical analyses are performed to estimate the performances of the proposed configuration by means of the commercial code COMSOL Multiphysics® with respect to Savonius wind turbine with overlap only. Parametric analyses are performed, for a fixed overlap ratio, by varying the slot position; the results show that for slot positioned near the blade root, the Savonius rotor improves performances at low tip speed ratio, evidencing a better starting torque. This circumstance is confirmed by static analyses performed on the slotted blades in order to investigate the starting characteristic of the proposed Savonius wind generator configuration.

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

Incorporation of sweep in a transonic fan design using a 3D blade-row geometry package intended for aero-structural-manufacturing optimization

OpenAIRE

Abdelhamid, Hazen Fahmy

1997-01-01

Approved for public release; distribution is unlimited A new 3D blade row geometry package was developed and implemented. In the new representation the blade is described by six Bezier surfaces two of which represent the pressure and suction surfaces with sixteen points each. The leading and trailing edges are each represented by two Bezier surfaces. Only one extra parameter is required (in addition to the pressure and suction surfaces parameters) to define each of the leading and trailing...

Design and optimization for strength and integrity of tidal turbine rotor blades

International Nuclear Information System (INIS)

Liu, Pengfei; Veitch, Brian

2012-01-01

Tidal turbine rotor blade fractures and failures have resulted in substantial damage and hence cost of repair and recovery. The present work presents a rotor blade design and optimization method to address the blade structural strength design problem. The generic procedure is applicable to both turbine rotors and propellers. The optimization method seeks an optimum blade thickness distribution across the span with a prescribed constant safety factor for all the blade sections. This optimization procedure serves two purposes: while maintaining the required structural strength and integrity for an ultimate inflow speed, it aims to reduce the material to a minimum and to maintain power generation efficiency or improve the hydrodynamic efficiency. The value of the chosen minimum safety factor depends on the actual working conditions of the turbine in which the sectional peak loading and frequency are used: the harsher the environment, the larger the required safety factor. An engineering software tool with both hydrodynamic and structural capabilities was required to predict the instantaneous loading acting on all the blade sections, as well as the strength of a local blade section with a given blade geometry and chosen material. A time-domain, 3D unsteady panel method was then implemented based on a marine propeller software tool and used to perform the optimization. A 3-blade 20-m tidal turbine that was prototyped in parallel with the current work for the Bay of Fundy was used as an example for optimization. The optimum thickness distribution for a required safety factor at the ultimate possible inflow speed resulted in 37.6% saving in blade material. The blade thickness and distribution as a function of a maximum inflow speed of 6 m/s is also presented. The blade material used in the example was taken as nickel–aluminium–bronze (NAB) but the procedure was developed to be applicable to propeller or turbine blades of basically any material. -- Highlights: ► A

Adhesive Joints in Wind Turbine Blades

DEFF Research Database (Denmark)

Jørgensen, Jeppe Bjørn

to be determined in several different ways. The accuracy of different ways of measuring residual stresses in the adhesive was tested by applying five different methods on a single sandwich test specimen (laminate/adhesive/laminate) that was instrumented with strain gauges and fiber Bragg gratings. Quasi...... of the project is to develop new- and to improve the existing design rules for adhesive joints in wind turbine blades. The first scientific studies of adhesive joints were based on stress analysis, which requires that the bond-line is free of defects, but this is rarely the case for a wind turbine blade. Instead...... curing and test temperatures) on the formation of transverse cracks in the adhesive were tested experimentally. It was assumed that the transverse cracks evolved due to a combination of mechanical- and residual stresses in the adhesive. A new approach was developed that allows the residual stress...

Improving the strength of additively manufactured objects via modified interior structure

Science.gov (United States)

Al, Can Mert; Yaman, Ulas

2017-10-01

Additive manufacturing (AM), in other words 3D printing, is becoming more common because of its crucial advantages such as geometric complexity, functional interior structures, etc. over traditional manufacturing methods. Especially, Fused Filament Fabrication (FFF) 3D printing technology is frequently used because of the fact that desktop variants of these types of printers are highly appropriate for different fields and are improving rapidly. In spite of the fact that there are significant advantages of AM, the strength of the parts fabricated with AM is still a major problem especially when plastic materials, such as Acrylonitrile butadiene styrene (ABS), Polylactic acid (PLA), Nylon, etc., are utilized. In this study, an alternative method is proposed in which the strength of AM fabricated parts is improved employing direct slicing approach. Traditional Computer Aided Manufacturing (CAM) software of 3D printers takes only the geometry as an input in triangular mesh form (stereolithography, STL file) generated by Computer Aided Design software. This file format includes data only about the outer boundaries of the geometry. Interior of the artifacts are manufactured with homogeneous infill patterns, such as diagonal, honeycomb, linear, etc. according to the paths generated in CAM software. The developed method within this study provides a way to fabricate parts with heterogeneous infill patterns by utilizing the stress field data obtained from a Finite Element Analysis software, such as ABAQUS. According to the performed tensile tests, the strength of the test specimen is improved by about 45% compared to the conventional way of 3D printing.

The Study the Vibration Condition of the Blade of the Gas Turbine Engine with an All-metal Wire Rope Damper in the Area Mount of the Blade to the Disk

Science.gov (United States)

Melentjev, Vladimir S.; Gvozdev, Alexander S.

2018-01-01

Improving the reliability of modern turbine engines is actual task. This is achieved due to prevent a vibration damage of the operating blades. On the department of structure and design of aircraft engines have accumulated a lot of experimental data on the protection of the blades of the gas turbine engine from a vibration. In this paper we proposed a method for calculating the characteristics of wire rope dampers in the root attachment of blade of a gas turbine engine. The method is based on the use of the finite element method and transient analysis. Contact interaction (Lagrange-Euler method) between the compressor blade and the disc of the rotor has been taken into account. Contribution of contact interaction between details in damping of the system was measured. The proposed method provides a convenient way for the iterative selection of the required parameters the wire rope elastic-damping element. This element is able to provide the necessary protection from the vibration for the blade of a gas turbine engine.

Improved fixed point iterative method for blade element momentum computations

DEFF Research Database (Denmark)

Sun, Zhenye; Shen, Wen Zhong; Chen, Jin

2017-01-01

The blade element momentum (BEM) theory is widely used in aerodynamic performance calculations and optimization applications for wind turbines. The fixed point iterative method is the most commonly utilized technique to solve the BEM equations. However, this method sometimes does not converge...... are addressed through both theoretical analysis and numerical tests. A term from the BEM equations equals to zero at a critical inflow angle is the source of the convergence problems. When the initial inflow angle is set larger than the critical inflow angle and the relaxation methodology is adopted...

Mode extraction on wind turbine blades via phase-based video motion estimation

Science.gov (United States)

Sarrafi, Aral; Poozesh, Peyman; Niezrecki, Christopher; Mao, Zhu

2017-04-01

In recent years, image processing techniques are being applied more often for structural dynamics identification, characterization, and structural health monitoring. Although as a non-contact and full-field measurement method, image processing still has a long way to go to outperform other conventional sensing instruments (i.e. accelerometers, strain gauges, laser vibrometers, etc.,). However, the technologies associated with image processing are developing rapidly and gaining more attention in a variety of engineering applications including structural dynamics identification and modal analysis. Among numerous motion estimation and image-processing methods, phase-based video motion estimation is considered as one of the most efficient methods regarding computation consumption and noise robustness. In this paper, phase-based video motion estimation is adopted for structural dynamics characterization on a 2.3-meter long Skystream wind turbine blade, and the modal parameters (natural frequencies, operating deflection shapes) are extracted. Phase-based video processing adopted in this paper provides reliable full-field 2-D motion information, which is beneficial for manufacturing certification and model updating at the design stage. The phase-based video motion estimation approach is demonstrated through processing data on a full-scale commercial structure (i.e. a wind turbine blade) with complex geometry and properties, and the results obtained have a good correlation with the modal parameters extracted from accelerometer measurements, especially for the first four bending modes, which have significant importance in blade characterization.

The Impact of Soft Factors on Quality Improvement in Manufacturing Industry

Science.gov (United States)

Chan, Shiau Wei; Fauzi Ahmad, Md; Kong, Mei Wan

2017-08-01

Nowadays, soft factors have become the key factors of success in quality improvement of an organisation. Many organisations have neglected the importance of soft factors, this may influence the organisational performance. Hence, the purpose of this research is to examine the impact of soft factors on quality improvement in manufacturing industries. Six hypotheses were examined while considering six dimensions of soft factors including management commitment, customer focus, supplier relationship, employee involvement, training and education, and reward and recognition that have a positive impact on quality improvement. In this study, eighty one managers from the quality department were randomly selected in the manufacturing industry in Batu Pahat, Johor. The questionnaires were distributed to them. The researcher analysed the quantitatively collected data using descriptive analysis and correlation analysis. The findings of this study revealed that all soft factors are correlated to the quality improvement in an organisation with a high significant value but the regression analysis shows that the supplier relationship and employee involvement has more significant impact on quality improvement as compared to other soft factors which contributes of this study.

Online monitoring of dynamic tip clearance of turbine blades in high temperature environments

Science.gov (United States)

Han, Yu; Zhong, Chong; Zhu, Xiaoliang; Zhe, Jiang

2018-04-01

Minimized tip clearance reduces the gas leakage over turbine blade tips and improves the thrust and efficiency of turbomachinery. An accurate tip clearance sensor, measuring the dynamic clearances between blade tips and the turbine case, is a critical component for tip clearance control. This paper presents a robust inductive tip clearance sensor capable of monitoring dynamic tip clearances of turbine machines in high-temperature environments and at high rotational speeds. The sensor can also self-sense the temperature at a blade tip in situ such that temperature effect on tip clearance measurement can be estimated and compensated. To evaluate the sensor’s performance, the sensor was tested for measuring the tip clearances of turbine blades under various working temperatures ranging from 700 K to 1300 K and at turbine rotational speeds ranging from 3000 to 10 000 rpm. The blade tip clearance was varied from 50 to 2000 µm. The experiment results proved that the sensor can accurately measure the blade tip clearances with a temporal resolution of 10 µm. The capability of accurately measuring the tip clearances at high temperatures (~1300 K) and high turbine rotation speeds (~30 000 rpm), along with its compact size, makes it promising for online monitoring and active control of blade tip clearances of high-temperature turbomachinery.

Vibration and flutter of mistuned bladed-disk assemblies

Science.gov (United States)

Kaza, K. R. V.; Kielb, R. E.

1984-01-01

An analytical model for investigating vibration and flutter of mistuned bladed disk assemblies is presented. This model accounts for elastic, inertial and aerodynamic coupling between bending and torsional motions of each individual blade, elastic and inertial couplings between the blades and the disk, and aerodynamic coupling among the blades. The disk was modeled as a circular plate with constant thickness and each blade was represented by a twisted, slender, straight, nonuniform, elastic beam with a symmetric cross section. The elastic axis, inertia axis, and the tension axis were taken to be noncoincident and the structural warping of the section was explicitly considered. The blade aerodynamic loading in the subsonic and supersonic flow regimes was obtained from two-dimensional unsteady, cascade theories. All the possible standing wave modes of the disk and traveling wave modes of the blades were included. The equations of motion were derived by using the energy method in conjunction with the assumed mode shapes for the disk and the blades. Continuities of displacement and slope at the blade-disk junction were maintained. The equations were solved to investigate the effects of blade-disk coupling and blade frequency mistuning on vibration and flutter. Results showed that the flexibility of practical disks such as those used for current generation turbofans did not have a significant influence on either the tuned or mistuned flutter characteristics. However, the disk flexibility may have a strong influence on some of the system frequencies and on forced response.

Manufacture of conical springs with elastic medium technology improvement

Science.gov (United States)

Kurguzov, S. A.; Mikhailova, U. V.; Kalugina, O. B.

2018-01-01

This article considers the manufacturing technology improvement by using an elastic medium in the stamping tool forming space to improve the conical springs performance characteristics and reduce the costs of their production. Estimation technique of disk spring operational properties is developed by mathematical modeling of the compression process during the operation of a spring. A technique for optimizing the design parameters of a conical spring is developed, which ensures a minimum voltage value when operated in the edge of the spring opening.

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.

3-D Navier-Stokes Analysis of Blade Root Aerodynamics for a Tiltrotor Aircraft In Cruise

Science.gov (United States)

Romander, Ethan

2006-01-01

The blade root area of a tiltrotor aircraft's rotor is constrained by a great many factors, not the least of which is aerodynamic performance in cruise. For this study, Navier-Stokes CFD techniques are used to study the aerodynamic performance in cruise of a rotor design as a function of airfoil thickness along the blade and spinner shape. Reducing airfoil thickness along the entire blade will be shown to have the greatest effect followed by smaller but still significant improvements achieved by reducing the thickness of root airfoils only. Furthermore, altering the shape of the spinner will be illustrated as a tool to tune the aerodynamic performance very near the blade root.

Applying Value Stream Mapping Technique for Production Improvement in a Manufacturing Company: A Case Study

Science.gov (United States)

Jeyaraj, K. L.; Muralidharan, C.; Mahalingam, R.; Deshmukh, S. G.

2013-01-01

The purpose of this paper is to explain how value stream mapping (VSM) is helpful in lean implementation and to develop the road map to tackle improvement areas to bridge the gap between the existing state and the proposed state of a manufacturing firm. Through this case study, the existing stage of manufacturing is mapped with the help of VSM process symbols and the biggest improvement areas like excessive TAKT time, production, and lead time are identified. Some modifications in current state map are suggested and with these modifications future state map is prepared. Further TAKT time is calculated to set the pace of production processes. This paper compares the current state and future state of a manufacturing firm and witnessed 20 % reduction in TAKT time, 22.5 % reduction in processing time, 4.8 % reduction in lead time, 20 % improvement in production, 9 % improvement in machine utilization, 7 % improvement in man power utilization, objective improvement in workers skill level, and no change in the product and semi finished product inventory level. The findings are limited due to the focused nature of the case study. This case study shows that VSM is a powerful tool for lean implementation and allows the industry to understand and continuously improve towards lean manufacturing.

Improved mechanical properties of Ni-rich Ni3Al coatings produced by EB-PVD for repairing single crystal blades

Institute of Scientific and Technical Information of China (English)

Jing-Yong Sun; Yan-Ling Pei; Shu-Suo Li; Hu Zhang; Sheng-Kai Gong

2017-01-01

Active control of turbine blade tip clearance for aircraft engine continues to be a concern in engine operation,because turbine blades are subjected to wear and therefore cause an increasing tip clearance between the rotating blades and the shroud and also reduce the engine efficiency.In this work,a Ni-rich Ni3Al coating with γ'/γtwo-phase microstructure was deposited by electron beam physical vapor deposition (EB-PVD),which worked as repairing the worn blade tips of single crystal blades.Nb molten pool was used to increase the molten pool temperature and thus to enhance the deposition rate.The microstructures and mechanical properties can be modified by the deposition temperatures and the following heat treatments.All coatings consist of γ'and γ phases.At deposition temperature of 600 ℃,a dense microstructure can be achieved to produce a coating with grain size of ～ 1 μm and microhardness of ～HV 477.After being heated for 4 h at a temperature of 1,100 ℃,the coatings have a more uniform microstructure,and microhardness maintains at a high level of ～ HV 292.Effect of Hf and Zr on EB-PVD Ni3Al repair coating will be further investigated.

Computational investigation of flow control by means of tubercles on Darrieus wind turbine blades

Science.gov (United States)

Sevinç, K.; Özdamar, G.; Şentürk, U.; Özdamar, A.

2015-09-01

This work presents the current status of the computational study of the boundary layer control of a vertical axis wind turbine blade by modifying the blade geometry for use in wind energy conversion. The control method is a passive method which comprises the implementation of the tubercle geometry of a humpback whale flipper onto the leading edge of the blades. The baseline design is an H-type, three-bladed Darrieus turbine with a NACA 0015 cross-section. Finite-volume based software ANSYS Fluent was used in the simulations. Using the optimum control parameters for a NACA 634-021 profile given by Johari et al. (2006), turbine blades were modified. Three dimensional, unsteady, turbulent simulations for the blade were conducted to look for a possible improvement on the performance. The flow structure on the blades was investigated and flow phenomena such as separation and stall were examined to understand their impact on the overall performance. For a tip speed ratio of 2.12, good agreement was obtained in the validation of the baseline model with a relative error in time- averaged power coefficient of 1.05%. Modified turbine simulations with a less expensive but less accurate turbulence model yielded a decrease in power coefficient. Results are shown comparatively.

Deflection estimation of a wind turbine blade using FBG sensors embedded in the blade bonding line

International Nuclear Information System (INIS)

Kim, Sang-Woo; Kang, Woo-Ram; Jeong, Min-Soo; Lee, In; Kwon, Il-Bum

2013-01-01

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)

Process Modeling of Composite Materials for Wind-Turbine Rotor Blades: Experiments and Numerical Modeling

Directory of Open Access Journals (Sweden)

Birgit Wieland

2017-10-01

Full Text Available The production of rotor blades for wind turbines is still a predominantly manual process. Process simulation is an adequate way of improving blade quality without a significant increase in production costs. This paper introduces a module for tolerance simulation for rotor-blade production processes. The investigation focuses on the simulation of temperature distribution for one-sided, self-heated tooling and thick laminates. Experimental data from rotor-blade production and down-scaled laboratory tests are presented. Based on influencing factors that are identified, a physical model is created and implemented as a simulation. This provides an opportunity to simulate temperature and cure-degree distribution for two-dimensional cross sections. The aim of this simulation is to support production processes. Hence, it is modelled as an in situ simulation with direct input of temperature data and real-time capability. A monolithic part of the rotor blade, the main girder, is used as an example for presenting the results.

Process Modeling of Composite Materials for Wind-Turbine Rotor Blades: Experiments and Numerical Modeling.

Science.gov (United States)

Wieland, Birgit; Ropte, Sven

2017-10-05

The production of rotor blades for wind turbines is still a predominantly manual process. Process simulation is an adequate way of improving blade quality without a significant increase in production costs. This paper introduces a module for tolerance simulation for rotor-blade production processes. The investigation focuses on the simulation of temperature distribution for one-sided, self-heated tooling and thick laminates. Experimental data from rotor-blade production and down-scaled laboratory tests are presented. Based on influencing factors that are identified, a physical model is created and implemented as a simulation. This provides an opportunity to simulate temperature and cure-degree distribution for two-dimensional cross sections. The aim of this simulation is to support production processes. Hence, it is modelled as an in situ simulation with direct input of temperature data and real-time capability. A monolithic part of the rotor blade, the main girder, is used as an example for presenting the results.

Design Optimization of An Axial Flow Fan Blade Considering Airfoil Shape and Stacking Line

Energy Technology Data Exchange (ETDEWEB)

Lee, Ki Sang; Kim, Kwang Yong; Samad, Abdus [Inha Univ., Incheon (Korea, Republic of)

2007-07-01

This work presents a numerical optimization procedure for a low-speed axial flow fan blade with polynomial response surface approximation model. Reynolds-averaged Navier-Stokes equations with Shear Stress Turbulence (SST) model are discretized by finite volume approximations and solved on hexahedral grids for flow analyses. The airfoil shape as well as stacking line is modified to enhance blade total efficiency, i.e., the objective function. The design variables of blade lean, maximum thickness and location of maximum thickness are selected, and a design of experiments technique produces design points where flow analyses are performed to obtain values of the objective function. A gradient-based search algorithm is used to find the optimal design in the design space from the constructed response surface model for the objective function. As a main result, the efficiency is increased effectively by the present optimization procedure. And, it is also shown that the modification of blade lean is more effective to improve the efficiency rather than modifying blade profile.

Continuous improvement in manufacturing and inspection of fuel; Mejora continua en fabricacion e inspeccion de combustible

Energy Technology Data Exchange (ETDEWEB)

Domingon, A.; Ruiz, R.

2015-07-01

The manufacturing and inspection process of fuel assemblies in ENUSA is characterized by its robustness acquired over the last thirty years of experience in manufacturing. The reliability of these processes is based on a qualified processes and continuous improvement in the design and upgrading of equipment and optimization of software and manufacturing processes. Additionally, management and quality control systems have been improved in both software and measuring business objectives. this article emphasizes the improvements made over the past five years in management, production and inspection of fuel assemblies. (Author)

Pin and roller attachment system for ceramic blades

Science.gov (United States)

Shaffer, J.E.

1995-07-25

In a turbine, a plurality of blades are attached to a turbine wheel by way of a plurality of joints which form a rolling contact between the blades and the turbine wheel. Each joint includes a pin and a pair of rollers to provide rolling contact between the pin and an adjacent pair of blades. Because of this rolling contact, high stress scuffing between the blades and the turbine wheel reduced, thereby inhibiting catastrophic failure of the blade joints. 3 figs.

Independent Blade Pitch Controller Design for a Three-Bladed Turbine Using Disturbance Accommodating Control: Preprint

Energy Technology Data Exchange (ETDEWEB)

Wang, Na; Wright, Alan D.; Johnson, Kathryn E.

2016-07-29

Two independent pitch controllers (IPCs) based on the disturbance accommodating control (DAC) algorithm are designed for the three-bladed Controls Advanced Research Turbine to regulate rotor speed and to mitigate blade root flapwise bending loads in above-rated wind speed. One of the DAC-based IPCs is designed based on a transformed symmetrical-asymmetrical (TSA) turbine model, with wind disturbances being modeled as a collective horizontal component and an asymmetrical linear shear component. Another DAC-based IPC is designed based on a multiblade coordinate (MBC) transformed turbine model, with a horizontal component and a vertical shear component being modeled as step waveform disturbance. Both of the DAC-based IPCs are found via a regulation equation solved by Kronecker product. Actuator dynamics are considered in the design processes to compensate for actuator phase delay. The simulation study shows the effectiveness of the proposed DAC-based IPCs compared to a proportional-integral (PI) collective pitch controller (CPC). Improvement on rotor speed regulation and once-per-revolution and twice-per-revolution load reductions has been observed in the proposed IPC designs.

Computational assessment of the DeepWind aerodynamic performance with different blade and airfoil configurations

DEFF Research Database (Denmark)

Bedon, Gabriele; Schmidt Paulsen, Uwe; Aagaard Madsen, Helge

2017-01-01

An aerodynamic improvement of the DeepWind rotor is conducted adopting different rotor geometries and solutions with respect to the original configuration while keeping the comparison as fair as possible. The objective of this work is to find the most suitable configuration in order to maximize...... the power production and minimize the blade stress and the cost of energy. Different parameters are considered for the study. The DeepWind blade is characterized by a shape similar to the Troposkien geometry but asymmetric between the top and bottom parts. The blade shape is considered as a fixed parameter...

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.

Development and Testing of an Acoustoultrasonic Inspection Device for Condition Monitoring of Wind Turbine Blades

DEFF Research Database (Denmark)

McGugan, Malcolm

2011-01-01

In recent years the wind energy industry has grown rapidly (23% per annum) to the stage where a modern turbine blade exceeds the wing span of an Airbus A380, where offshore wind farms of 300MW are a reality, and where an 800MW total level of European power production 15 years ago has become...... for this dynamic new industry. There is a need to understand the effect(s) of more advanced designs and manufacturing approaches, the prevalence and significance of production defects in material and structure, and the optimization of maintenance/inspection effort through monitoring. Described in this paper......-layered structure must meet the requirements of greater size and quality demanded by the industry, whilst matching the harsher environments of offshore placement, and providing improvements in reliability and an upgraded life-cycle maintenance approach. Non-destructive inspection technology is an important topic...

Quality Improvement, Inventory Management, Lead Time Reduction and Production Scheduling in High-Mix Manufacturing Environments

Science.gov (United States)

2017-01-13

Quality Improvement , Inventory Management, Lead Time Reduction and Production Scheduling in High-mix Manufacturing Environments by Sean Daigle B.S...Mechanical Engineering Chairman, Department Committee on Graduate Theses 2 Quality Improvement , Inventory Management, Lead Time Reduction and... Production Scheduling in High-mix Manufacturing Environments by Sean Daigle Submitted to the Department of Mechanical Engineering on January 13, 2017, in

The Performance Test of Three Different Horizontal Axis Wind Turbine (HAWT Blade Shapes Using Experimental and Numerical Methods

Directory of Open Access Journals (Sweden)

Wen-Tong Chong

2013-06-01

Full Text Available Three different horizontal axis wind turbine (HAWT blade geometries with the same diameter of 0.72 m using the same NACA4418 airfoil profile have been investigated both experimentally and numerically. The first is an optimum (OPT blade shape, obtained using improved blade element momentum (BEM theory. A detailed description of the blade geometry is also given. The second is an untapered and optimum twist (UOT blade with the same twist distributions as the OPT blade. The third blade is untapered and untwisted (UUT. Wind tunnel experiments were used to measure the power coefficients of these blades, and the results indicate that both the OPT and UOT blades perform with the same maximum power coefficient, Cp = 0.428, but it is located at different tip speed ratio, λ = 4.92 for the OPT blade and λ = 4.32 for the UOT blade. The UUT blade has a maximum power coefficient of Cp = 0.210 at λ = 3.86. After the tests, numerical simulations were performed using a full three-dimensional computational fluid dynamics (CFD method using the k-ω SST turbulence model. It has been found that CFD predictions reproduce the most accurate model power coefficients. The good agreement between the measured and computed power coefficients of the three models strongly suggest that accurate predictions of HAWT blade performance at full-scale conditions are also possible using the CFD method.

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.

Manufacturing strategy issues in selected Indian manufacturing industry

Directory of Open Access Journals (Sweden)

Mahender Singh

2013-03-01

Full Text Available This paper presents some findings of Indian manufacturing sectors viz. automobile (especially two-wheeler, tractor and general manufacturing industry. Various manufacturing strategy issues such as competitive priorities, improvement activities, and performance measures, have been identified and assessed in Indian context. Sector wise comparison of competitive priorities, improvement activities i.e. advanced manufacturing technology (AMT, integrated information systems (IIS, and advanced management systems (AMS, and performance measure, is provided. Our results showed that most of the Indian companies are still emphasizing on quality. However, automobile sector has set to compete globally with high innovation rate, faster new product development, and continuous improvement. It is also observed that Indian companies are investing more in AMS as compared to IIS and AMT. Manufacturing competence index is also computed for each sector.

Nonlinear modeling of tuned liquid dampers (TLDs) in rotating wind turbine blades for damping edgewise vibrations

DEFF Research Database (Denmark)

Zhang, Zili; Nielsen, Søren R. K.; Basu, Biswajit

2015-01-01

Tuned liquid dampers (TLDs) utilize the sloshing motion of the fluid to suppress structural vibrations and become a natural candidate for damping vibrations in rotating wind turbine blades. The centrifugal acceleration at the tip of a wind turbine blade can reach a magnitude of 7–8g. This facilit......Tuned liquid dampers (TLDs) utilize the sloshing motion of the fluid to suppress structural vibrations and become a natural candidate for damping vibrations in rotating wind turbine blades. The centrifugal acceleration at the tip of a wind turbine blade can reach a magnitude of 7–8g...... free-surface elevation equally well, the one-mode model can still be utilized for the design of TLD. Parametric optimization of the TLD is carried out based on the one-mode model, and the optimized damper effectively improves the dynamic response of wind turbine blades....

Mach number scaling of helicopter rotor blade/vortex interaction noise

Science.gov (United States)

Leighton, Kenneth P.; Harris, Wesley L.

1985-01-01

A parametric study of model helicopter rotor blade slap due to blade vortex interaction (BVI) was conducted in a 5 by 7.5-foot anechoic wind tunnel using model helicopter rotors with two, three, and four blades. The results were compared with a previously developed Mach number scaling theory. Three- and four-bladed rotor configurations were found to show very good agreement with the Mach number to the sixth power law for all conditions tested. A reduction of conditions for which BVI blade slap is detected was observed for three-bladed rotors when compared to the two-bladed baseline. The advance ratio boundaries of the four-bladed rotor exhibited an angular dependence not present for the two-bladed configuration. The upper limits for the advance ratio boundaries of the four-bladed rotors increased with increasing rotational speed.

Modal characteristics and fatigue strength of compressor blades

International Nuclear Information System (INIS)

Kim, Kyung Kook; Lee, Young Shin

2014-01-01

High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

Modal characteristics and fatigue strength of compressor blades

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung Kook [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of); Lee, Young Shin [Chungnam National University, Daejeon (Korea, Republic of)

2014-04-15

High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

A review of manufacturing metrology for improved reliability of silicon photovoltaic modules

Science.gov (United States)

Davis, Kristopher O.; Walters, Joseph; Schneller, Eric; Seigneur, Hubert; Brooker, R. Paul; Scardera, Giuseppe; Rodgers, Marianne P.; Mohajeri, Nahid; Shiradkar, Narendra; Dhere, Neelkanth G.; Wohlgemuth, John; Rudack, Andrew C.; Schoenfeld, Winston V.

2014-10-01

In this work, the use of manufacturing metrology across the supply chain to improve crystalline silicon (c-Si) photovoltaic (PV) module reliability and durability is addressed. Additionally, an overview and summary of a recent extensive literature survey of relevant measurement techniques aimed at reducing or eliminating the probability of field failures is presented. An assessment of potential gaps is also given, wherein the PV community could benefit from new research and demonstration efforts. This review is divided into three primary areas representing different parts of the c-Si PV supply chain: (1) feedstock production, crystallization and wafering; (2) cell manufacturing; and (3) module manufacturing.

Improvements by employee motivation in the manufacture of nuclear fuel assemblies for LWRs

International Nuclear Information System (INIS)

Osseforth, E.; Engel, H.

2000-01-01

Nuclear fuel assemblies are manufactured on a very high technical level and automation. However there is still a need for more improvement. One of the most important ways is employees motivation, because improvements lives of the ideas, impulses, initiatives and commitments of its employees. It can be realized by the employee himself or a group. Three ways of improvement by employees are mainly implemented at ANF: (i) ANF's 3i - program, based on the standard implementation within Siemens, is the first and an important strategy to improve processes, products and costs. It is to involve all employees and make use of the full potential for improvement The individual employee or a group make a suggestion and receive a commendation depending on the benefits. (ii) Work groups with a high level of responsibility are the second part. The groups mainly organize their work, working time and improvements by themselves. They help each other in job training, are very flexible and able to do also most of the maintenance work. (iii) CIP - groups (Continuous Improvement Process), based on the philosophy of KAMEN is the third strategy. These groups come together to improve all processes in the manufacturing area, also the administration or logistical processes at ANF. CIP - groups are implemented as so called long-term groups, the members are from different levels and departments. By comparing the different ways in order to achieve manufacturing improvements, employees motivation is one of the most important and cheapest part and will increase in significance in future. (author)

Failure analysis of turbine blades

International Nuclear Information System (INIS)

Iorio, A.F.; Crespi, J.C.

1989-01-01

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 SO 3 , 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) [es

Composite adaptive control of belt polishing force for aero-engine blade

Science.gov (United States)

Zhsao, Pengbing; Shi, Yaoyao

2013-09-01

The existing methods for blade polishing mainly focus on robot polishing and manual grinding. Due to the difficulty in high-precision control of the polishing force, the blade surface precision is very low in robot polishing, in particular, quality of the inlet and exhaust edges can not satisfy the processing requirements. Manual grinding has low efficiency, high labor intensity and unstable processing quality, moreover, the polished surface is vulnerable to burn, and the surface precision and integrity are difficult to ensure. In order to further improve the profile accuracy and surface quality, a pneumatic flexible polishing force-exerting mechanism is designed and a dual-mode switching composite adaptive control(DSCAC) strategy is proposed, which combines Bang-Bang control and model reference adaptive control based on fuzzy neural network(MRACFNN) together. By the mode decision-making mechanism, Bang-Bang control is used to track the control command signal quickly when the actual polishing force is far away from the target value, and MRACFNN is utilized in smaller error ranges to improve the system robustness and control precision. Based on the mathematical model of the force-exerting mechanism, simulation analysis is implemented on DSCAC. Simulation results show that the output polishing force can better track the given signal. Finally, the blade polishing experiments are carried out on the designed polishing equipment. Experimental results show that DSCAC can effectively mitigate the influence of gas compressibility, valve dead-time effect, valve nonlinear flow, cylinder friction, measurement noise and other interference on the control precision of polishing force, which has high control precision, strong robustness, strong anti-interference ability and other advantages compared with MRACFNN. The proposed research achieves high-precision control of the polishing force, effectively improves the blade machining precision and surface consistency, and

Multidisciplinary Aerodynamic Design of a Rotor Blade for an Optimum Rotor Speed Helicopter

Directory of Open Access Journals (Sweden)

Jiayi Xie

2017-06-01

Full Text Available The aerodynamic design of rotor blades is challenging, and is crucial for the development of helicopter technology. Previous aerodynamic optimizations that focused only on limited design points find it difficult to balance flight performance across the entire flight envelope. This study develops a global optimum envelope (GOE method for determining blade parameters—blade twist, taper ratio, tip sweep—for optimum rotor speed helicopters (ORS-helicopters, balancing performance improvements in hover and various freestream velocities. The GOE method implements aerodynamic blade design by a bi-level optimization, composed of a global optimization step and a secondary optimization step. Power loss as a measure of rotor performance is chosen as the objective function, referred to as direct power loss (DPL in this study. A rotorcraft comprehensive code for trim simulation with a prescribed wake method is developed. With the application of the GOE method, a DPL reduction of as high as 16.7% can be achieved in hover, and 24% at high freestream velocity.

Experimental Evaluation of Cermet Turbine Stator Blades for Use at Elevated Gas Temperatures

Science.gov (United States)

Chiarito, Patrick T.; Johnston, James R.

1959-01-01

The suitability of cermets for turbine stator blades of a modified turbojet engine was determined at an average turbine-inlet-gas temperature of 2000 F. Such an increase in temperature would yield a premium in thrust from a service engine. Because the cermet blades require no cooling, all the available compressor bleed air could be used to cool a turbine made from conventional ductile alloys. Cermet blades were first run in 100-hour endurance tests at normal gas temperatures in order to evaluate two methods for mounting them. The elevated gas-temperature test was then run using the method of support considered best for high-temperature operation. After 52 hours at 2000 F, one of the group of four cermet blades fractured probably because of end loads resulting from thermal distortion of the spacer band of the nozzle diaphragm. Improved design of a service engine would preclude this cause of premature failure.

Calculation of the Stiffness in the Roll Tensioning of the Circular Saw Blade

Directory of Open Access Journals (Sweden)

Linh Vo Tung

2016-01-01

Full Text Available The circular blade has been widely used in some projects such as cutting stone, wood and other projects. Owing to its particularity and wide use, it has an important position in cutting industry. Roll tensioning is considered as an effective method which can be used to improve the stiffness and performance of the circular saw blade. The effect of rolling position and width in the roll tensioning is obvious. In this paper the calculation of the maximum stiffness at different rolling position and width in the rolling were carried out through the finite -element. The results show that three ideal points are found. And when rolling position is Ø950mm and rolling width is 20mm, the maximum stiffness of the circular saw blade whose minimum deformation is 0.028mm is found. The roll tensioning can increase the stiffness of the saw blade. It will provide a theoretical basis and guidance for the actual production.

Integrity assessment of stationary blade ring for nuclear power plant

International Nuclear Information System (INIS)

Park, Jung Yong; Chung, Yong Keun; Park, Jong Jin; Kang, Yong Ho

2004-01-01

The inner side between HP stationary blades in no.1 turbine of nuclear power plant A is damaged by the FAC(Flow Assisted Corrosion) which is exposed to moisture. For many years the inner side is repaired by welding the damaged part, however, the FAC continues to deteriorate the original material of the welded blade ring. In this study, we have two stages to verify the integrity of stationary blade ring in nuclear power plant A. In the stage I, replication of blade ring is performed to survey the microstructure of blade ring. In the stage II, the stress analysis of blade ring is performed to verify the structural safety of blade ring. Throughout the two stages analysis of blade ring, the stationary blade ring had remained undamaged

Multidisciplinary design optimization of film-cooled gas turbine blades

OpenAIRE

Shashishekara S. Talya; J. N. Rajadas; A. Chattopadhyay

1999-01-01

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 ...

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.

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...... is investigated by repeated measurement on the same wind turbine blade. Furthermore the flexibility of the test set-up is investigated, by use ofaccelerometers mounted on the flexible adapter plate during the measurement campaign. One experimental campaign investigated the results obtained from a loaded...... and 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...

Repairing methods of steam turbine blades using welding procedures

International Nuclear Information System (INIS)

Mazur, Z.; Cristalinas, V.; Kubiak, J.

1995-01-01

The steam turbine blades are subjected to the natural permanent wear or damage, which may be of mechanical or metallurgical origin. The typical damage occurring during the lifetime of turbine blading may be erosion, corrosion, foreign objects damage, rubbing and cracking caused by high cycle fatigue and creep crack growth. The nozzle and diaphragm vanes (stationary blades) of the steam turbine are elements whose damage is commonly occurring and they require special repair processes. The damage of the blade trailing edge of nozzle and diaphragm vanes, due to the former causes, may be refurbished by welding deposits or stainless steel inserts welded to the blades. Both repair methods of the stationary steam turbine blades are presented. The results of the blades refurbishment are an increase of the turbine availability, reliability and efficiency, and a decrease of the risk that failure will occur. Also, the repair cost versus the spare blades cost represent significant reduction of expenditure. 7 refs

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.

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.

Improvement of the Zircaloy fuel can manufacturing process

International Nuclear Information System (INIS)

1986-01-01

The following work has been performed in order to ensure more reliable supply of start material for the manufacture of Zy-2 and Zy-4 fuel cans, and to improve the processing techniques and product quality: 1) Two complete production campaigns with the ingot suppliers Western Zirconium and Ugine Aciers. 2) Development of new ingot dimensions (rolling tests). 3) Development of a mechanized washing and cleansing procedure. 4) Development of a new abrasive treatment technique (wet sand blasting). (orig./HP) [de

Full-Scale Fatigue Testing of a Wind Turbine Blade in Flapwise Direction and Examining the Effect of Crack Propagation on the Blade Performance

Directory of Open Access Journals (Sweden)

Othman Al-Khudairi

2017-10-01

Full Text Available In this paper, the sensitivity of the structural integrity of wind turbine blades to debonding of the shear web from the spar cap was investigated. In this regard, modal analysis, static and fatigue testing were performed on a 45.7 m blade for three states of the blade: (i as received blade (ii when a crack of 200 mm was introduced between the web and the spar cap and (iii when the crack was extended to 1000 mm. Calibration pull-tests for all three states of the blade were performed to obtain the strain-bending moment relationship of the blade according to the estimated target bending moment (BM which the blade is expected to experience in its service life. The resultant data was used to apply appropriate load in the fatigue tests. The blade natural frequencies in flapwise and edgewise directions over a range of frequency domain were found by modal testing for all three states of the blade. The blade first natural frequency for each state was used for the flapwise fatigue tests. These were performed in accordance with technical specification IEC TS 61400-23. The fatigue results showed that, for a 200 mm crack between the web and spar cap at 9 m from the blade root, the crack did not propagate at 50% of the target BM up to 62,110 cycles. However, when the load was increased to 70% of target BM, some damages were detected on the pressure side of the blade. When the 200 mm crack was extended to 1000 mm, the crack began to propagate when the applied load exceeded 100% of target BM and the blade experienced delaminations, adhesive joint failure, compression failure and sandwich core failure.

Full-Scale Fatigue Testing of a Wind Turbine Blade in Flapwise Direction and Examining the Effect of Crack Propagation on the Blade Performance.

Science.gov (United States)

Al-Khudairi, Othman; Hadavinia, Homayoun; Little, Christian; Gillmore, Gavin; Greaves, Peter; Dyer, Kirsten

2017-10-03

In this paper, the sensitivity of the structural integrity of wind turbine blades to debonding of the shear web from the spar cap was investigated. In this regard, modal analysis, static and fatigue testing were performed on a 45.7 m blade for three states of the blade: (i) as received blade (ii) when a crack of 200 mm was introduced between the web and the spar cap and (iii) when the crack was extended to 1000 mm. Calibration pull-tests for all three states of the blade were performed to obtain the strain-bending moment relationship of the blade according to the estimated target bending moment (BM) which the blade is expected to experience in its service life. The resultant data was used to apply appropriate load in the fatigue tests. The blade natural frequencies in flapwise and edgewise directions over a range of frequency domain were found by modal testing for all three states of the blade. The blade first natural frequency for each state was used for the flapwise fatigue tests. These were performed in accordance with technical specification IEC TS 61400-23. The fatigue results showed that, for a 200 mm crack between the web and spar cap at 9 m from the blade root, the crack did not propagate at 50% of the target BM up to 62,110 cycles. However, when the load was increased to 70% of target BM, some damages were detected on the pressure side of the blade. When the 200 mm crack was extended to 1000 mm, the crack began to propagate when the applied load exceeded 100% of target BM and the blade experienced delaminations, adhesive joint failure, compression failure and sandwich core failure.

Structural and mechanism design of an active trailing-edge flap blade

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Hwan [Samsung Techwin R and D Center, Seongnam (Korea, Republic of); Natarajan, Balakumaran; Eun, Won Jong; Shin, Sang Joon [Seoul National University, Seoul (Korea, Republic of); R, Viswamurthy S. [National Aerospace Laboratories, Bangalore (India); Park, Jae Sang [Agency for Defense Development, Daejeon (Korea, Republic of); Kim, Tae Song [Technical University of Denmark, Risoe Campus, Roskilde (Denmark)

2013-09-15

A conventional rotor control system restricted at 1/rev frequency component is unable to vary the hub vibratory loads and the aero acoustic noise, which exist in high frequency components. Various active rotor control methodologies have been examined in the literature to alleviate the problem of excessive hub vibratory loads and noise. The active control device manipulates the blade pitch angle with arbitrary higher harmonic frequencies individually. In this paper, an active trailing-edge flap blade, which is one of the active control methods, is developed to reduce vibratory loads and noise of the rotor through modification of unsteady aerodynamic loads. Piezoelectric actuators installed inside the blade manipulate the motion of the trailing edge flap. The proposed blade rotates at higher speed and additional structures are included to support the actuators and the flap. This improves the design, as the blade is able to withstand increased centrifugal force. The cross-section of the active blade is designed first. A stress/strain recovery analysis is then conducted to verify its structural integrity. A one-dimensional beam analysis is also carried out to assist with the construction of the fan diagram. To select the actuator and design the flap actuation region, the flap hinge moment is estimated via a CFD analysis. To obtain the desired flap deflection of ±4 .deg. , three actuators are required. The design of the flap actuation region is validated using a test bed with a skin hinge. However, because the skin hinge induces additional flap hinge moment, it does not provide sufficient deflection angle. Therefore, the flap hinge is replaced by a pin-type hinge, and the results are evaluated.

Spacer grid with mixing blades for nuclear fuel assembly

International Nuclear Information System (INIS)

Noailly, J.

1986-01-01

The spacer grid for nuclear fuel assembly has two sets of intersecting metal plates provided with blades and defining cells. The plates are fitted only with half-blades associated with a single grid opening. The half-blades of adjacent cells are arranged at 90deg C to each other and each plate has at most one half-blade at each corner of a cell. The invention concerns fuel assemblies of pressurized water reactors. The blades arranged on a single side of the plate provide a good hydraulic uniformity. The invention provides a uniform distribution of blades (and thus of absorbing material in each hydraulic cell) [fr

Simple method for thick blade calculation. Part 2. Application to a thin blade; Kanbenna ichiatsuyoku keisanho (zokuho). Usui tsubasa eno tekiyo

Energy Technology Data Exchange (ETDEWEB)

Maita, S; Ando, J; Nakatake, K [Kyushu University, Fukuoka (Japan). Faculty of Engineering

1996-04-10

A source and QCM (SQCM) method has been developed, by which the blade performance can be calculated in a short time with satisfying the Kutta`s condition without repeating calculations even for the three-dimensional blade. Performances were calculated for the two-dimensional and three-dimensional blades. The SQCM has provided appropriate results. However, it was found that there are some problems for thin blades. In this study, the SQCM has been applied to a thin blade. The conventional eddy model equation of SQCM is not a continuous distribution in the strict sense. In this study, this problem has been modified. When point eddies with constant strength are in line continuously within the interval, the induced velocity at an arbitrary position can be expressed by the integral equation using a position of marginal point of the interval. This equation can be analyzed by the integral of influence coefficient. The position of marginal point of the interval is a position of control point determined by the QCM theory. As a result of the modification, it was found that the SQCM in response to a thin blade has provided precise calculation results stably even for an ultra thin blade with the blade thickness ratio of 0.001. 1 ref., 8 figs.

Piezoelectric actuation of helicopter rotor blades

Science.gov (United States)

Lieven, Nicholas A. J.

2001-07-01

The work presented in this paper is concerned with the application of embedded piezo-electric actuators in model helicopter rotor blades. The paper outlines techniques to define the optimal location of actuators to excite particular modes of vibration whilst the blade is rotating. Using composite blades the distribution of strain energy is defined using a Finite Element model with imposed rotor-dynamic and aerodynamics loads. The loads are specified through strip theory to determine the position of maximum bending moment and thus the optimal location of the embedded actuators. The effectiveness of the technique is demonstrated on a 1/4 scale fixed cyclic pitch rotor head. Measurement of the blade displacement is achieved by using strain gauges. In addition a redundant piezo-electric actuator is used to measure the blades' response characteristics. The addition of piezo-electric devices in this application has been shown to exhibit adverse aeroelastic effects, such as counter mass balancing and increased drag. Methods to minimise these effects are suggested. The outcome of the paper is a method for defining the location and orientation of piezo-electric devices in rotor-dynamic applications.

Individual blade pitch for yaw control

International Nuclear Information System (INIS)

Navalkar, S T; Van Wingerden, J W; Van Kuik, G A M

2014-01-01

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

Liquid Impact Erosion Mechanism and Theoretical Stress Analysis in TiN-Coated Turbine Blade

International Nuclear Information System (INIS)

Lee, M. K.; Kim, W. W.; Kim, S. J.; Rhee, C. K.; Kim, Y. S.

2000-01-01

Coating of TiN film was done by reactive magnetron sputter ion plating to improve the liquid impact erosion resistance of steam turbine blade materials, 12Cr steel and Stellite 6B, for nuclear power plant application. TiN coated blade materials were initially deformed with depressions due to plastic deformation of the ductile substrate. The increase in the curvature in the depressions induced stress concentration with increasing number of impacts, followed by circumferential fracture of the TiN coating due to the circular propagation of cracks. The liquid impact erosion resistance of the blade materials was greatly improved by TiN coating done with the optimum ion plating condition. Damage decreased with increasing TiN coating thickness. According to the theoretical analysis of stresses generated by liquid impact, TiN coating alleviated the impact stress of 12Cr steel and Stellite 6B due to stress attenuation and stress wave reactions such as reflection and transmission at the coating substrate interface

Active Piezoelectric Vibration Control of Subscale Composite Fan Blades

Science.gov (United States)

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

2012-01-01

As part of the Fundamental Aeronautics program, researchers at NASA Glenn Research Center (GRC) are investigating new technologies supporting the development of lighter, quieter, and more efficient fans for turbomachinery applications. High performance fan blades designed to achieve such goals will be subjected to higher levels of aerodynamic excitations which could lead to more serious and complex vibration problems. Piezoelectric materials have been proposed as a means of decreasing engine blade vibration either through a passive damping scheme, or as part of an active vibration control system. For polymer matrix fiber composite blades, the piezoelectric elements could be embedded within the blade material, protecting the brittle piezoceramic material from the airflow and from debris. To investigate this idea, spin testing was performed on two General Electric Aviation (GE) subscale composite fan blades in the NASA GRC Dynamic Spin Rig Facility. The first bending mode (1B) was targeted for vibration control. Because these subscale blades are very thin, the piezoelectric material was surface-mounted on the blades. Three thin piezoelectric patches were applied to each blade two actuator patches and one small sensor patch. These flexible macro-fiber-composite patches were placed in a location of high resonant strain for the 1B mode. The blades were tested up to 5000 rpm, with patches used as sensors, as excitation for the blade, and as part of open- and closed-loop vibration control. Results show that with a single actuator patch, active vibration control causes the damping ratio to increase from a baseline of 0.3% critical damping to about 1.0% damping at 0 RPM. As the rotor speed approaches 5000 RPM, the actively controlled blade damping ratio decreases to about 0.5% damping. This occurs primarily because of centrifugal blade stiffening, and can be observed by the decrease in the generalized electromechanical coupling with rotor speed.

Structural Optimization Design of Horizontal-Axis Wind Turbine Blades Using a Particle Swarm Optimization Algorithm and Finite Element Method

Directory of Open Access Journals (Sweden)

Pan Pan

2012-11-01

Full Text Available This paper presents an optimization method for the structural design of horizontal-axis wind turbine (HAWT blades based on the particle swarm optimization algorithm (PSO combined with the finite element method (FEM. The main goal is to create an optimization tool and to demonstrate the potential improvements that could be brought to the structural design of HAWT blades. A multi-criteria constrained optimization design model pursued with respect to minimum mass of the blade is developed. The number and the location of layers in the spar cap and the positions of the shear webs are employed as the design variables, while the strain limit, blade/tower clearance limit and vibration limit are taken into account as the constraint conditions. The optimization of the design of a commercial 1.5 MW HAWT blade is carried out by combining the above method and design model under ultimate (extreme flap-wise load conditions. The optimization results are described and compared with the original design. It shows that the method used in this study is efficient and produces improved designs.

Effect of Blade Pitch Angle on the Aerodynamic Characteristics of a Straight-bladed Vertical Axis Wind Turbine Based on Experiments and Simulations

Directory of Open Access Journals (Sweden)

Yanzhao Yang

2018-06-01

Full Text Available The blade pitch angle has a significant influence on the aerodynamic characteristics of horizontal axis wind turbines. However, few research results have revealed its impact on the straight-bladed vertical axis wind turbine (Sb-VAWT. In this paper, wind tunnel experiments and CFD simulations were performed at the Sb-VAWT to investigate the effect of different blade pitch angles on the pressure distribution on the blade surface, the torque coefficient, and the power coefficient. In this study, the airfoil type was NACA0021 with two blades. The Sb-VAWT had a rotor radius of 1.0 m with a spanwise length of 1.2 m. The simulations were based on the k-ω Shear Stress Transport (SST turbulence model and the wind tunnel experiments were carried out using a high-speed multiport pressure device. As a result, it was found that the maximum pressure difference on the blade surface was obtained at the blade pitch angle of β = 6° in the upstream region. However, the maximum pressure coefficient was shown at the blade pitch angle of β = 8° in the downstream region. The torque coefficient acting on a single blade reached its maximum value at the blade pitch angle of β = 6°. As the tip speed ratio increased, the power coefficient became higher and reached the optimum level. Subsequently, further increase of the tip speed ratio only led to a quick reversion of the power coefficient. In addition, the results from CFD simulations had also a good agreement with the results from the wind tunnel experiments. As a result, the blade pitch angle did not have a significant influence on the aerodynamic characteristics of the Sb-VAWT.

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.

A Comparison of Afghanistan, Yuma, Az, and Manufactured Sands Melted on EB-PVD Thermal Barrier Coatings

Science.gov (United States)

2014-09-18

mentoring me through the field of geology . His vast knowledge in this field and close “First Cousins” motivate me to broaden my knowledge within the...Blade sand sample BC – Bond Coat Button A – TBC Button made by Manufacturer A Button B – TBC Button made by Manufacturer B Ca – Calcium CMAS... Calcium , Magnesium, Aluminum, Silicate CTIO – Coating Technology Integration Office Cr – Chromium CTE – Coefficient of Thermal Expansion DoD

Selection of a high performance alloy for gas turbine blade using finite element methods

International Nuclear Information System (INIS)

Khawaja, H.A.; Khan, A.M.; Ali, S.T.

2007-01-01

With the extensive increase in the utilization of energy resources in the modern era, the need of energy extraction from various resources has pronounced in recent years. Thus comprehensive efforts have been made around the globe in the technological development of turbo machines where means of energy extraction is energized fluids. This development led the eviation industry to power boost due to better performing engines. Meanwhile, the structural conformability requirements relative to the functional requirements have also increased with the advent of newer, better performing materials. Thus there is a need to study the material behavior and its usage with the idea of selecting the best possible material for its application. In this work a gas turbine blade of a small turbofan engine, where geometry and aerodynamic data was available, was analyzed for its structural behavior in the proposed mission envelope, where the engine turbine is subjected to high thermal, inertial and aerodynamic loads. FE linear stress analysis was carried out on the turbine blade. The results revealed the upper limit of UTS for the blade. Based on the limiting factor, high performance alloys were selected from the literature. The two most recommended alloy categories for gas turbine blades are NIMONIC and INCONEL from where total of 21 types of INCONEL alloys and 12 of NIMONIC alloys, available on on commercial bases, were analyzed individually to meet the INCONEL alloys for further analysis. On the basis of stress-strain behavior of finalized alloys, the FE restriction of UFOS of 1.33 and yield strength. Final selection is made keeping in view other factors like manufacturability and workability in due consideration. (author)

Methodology for Structural Integrity Analysis of Gas Turbine Blades

Directory of Open Access Journals (Sweden)

Tiago de Oliveira Vale

2012-03-01

Full Text Available One of the major sources of stress arising in turbomachinery blades are the centrifugal loads acting at any section of the airfoil. Accounting for this phenomenon stress evaluation of the blade attachment region in the disc has to be performed in order to avoid blade failure. Turbomachinery blades are generally twisted, and the cross section area varies from the root of the blade to the tip. The blade root shape at the attachment region is of great concern. Stress concentrations are predictable at this contact region. In this paper, a finite element model has been created for the purpose of assessing stress at the joint region connecting the blade to the disc slot. Particular attention was paid to the geometric modeling of the "fir-tree" fixing, which is now used in the majority of gas turbine engines. This study has been performed using the commercial software ANSYS 13.0. The disc and blade assembly are forced to move with a certain rotational velocity. Contact connections are predicted on the common faces of the blade and on the disc at the root. Solutions can be obtained to allow the evaluation of stresses. Results can be compared with the mechanical properties of the adopted material.

Modeling of uncertainties for wind turbine blade design

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Toft, Henrik Stensgaard

2014-01-01

Wind turbine blades are designed by a combination of tests and numerical calculations using finite element models of the blade. The blades are typically composite structures with laminates of glass-fiber and/or carbon-fibers glued together by a matrix material. This paper presents a framework...

Blade size and weight effects in shovel design.

Science.gov (United States)

Freivalds, A; Kim, Y J

1990-03-01

The shovel is a basic tool that has undergone only nominal systematic design changes. Although previous studies found shovel-weight and blade-size effects of shovelling, the exact trade-off between the two has not been quantified. Energy expenditure, heart rate, ratings of perceived exertion and shovelling performance were measured on five subjects using five shovels with varying blade sizes and weights to move sand. Energy expenditure, normalised to subject weight and load handled, varied quadratically with the blade-size/shovel-weight (B/W) ratio. Minimum energy cost was at B/W = 0.0676 m2/kg, which for an average subject and average load would require an acceptable 5.16 kcal/min of energy expenditure. Subjects, through the ratings of perceived exertion, also strongly preferred the lighter shovels without regard to blade size. Too large a blade or too heavy a shovel increased energy expenditure beyond acceptable levels, while too small a blade reduced efficiency of the shovelling.

Flow characteristics in nuclear steam turbine blade passage

International Nuclear Information System (INIS)

Ahn, H.J.; Yoon, W.H.; Kwon, S.B.

1995-01-01

The rapid expansion of condensable gas such as moist air or steam gives rise to nonequilibrium condensation. As a result of irreversibility of condensation process in the nuclear steam turbine blade passage, the entropy of the flow increases, and the efficiency of the turbine decreases. In the present study, in order to investigate the flow characteristics of moist air in two-dimensional turbine blade passage which is made from the configuration of the last stage tip section of the actual nuclear steam turbine moving blade, the static pressures along both pressure and suction sides of blade are measured by static pressure taps and the distribution of Mach number on both sides of the blade are obtained by using the measured static pressure. Also, the flow field is visualized by a Schlieren system. From the experimental results, the effects of the stagnation temperature and specific humidity on the flow properties in the two dimensional steam turbine blade passage are clearly identified

49 CFR 236.707 - Blade, semaphore.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Blade, semaphore. 236.707 Section 236.707 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Blade, semaphore. The extended part of a semaphore arm which shows the position of the arm. ...

A New Hoe Blade for Inter-Row Weeding

DEFF Research Database (Denmark)

Green, O.; Znova, L.; Melander, Bo

2016-01-01

and weeds are relatively small. The term ‘Ducksfoot’ covers a range of hoe blade configurations where all have some resemblance with the shape of a ducks foot. However, the ‘Ducksfoot’ blade is not an optimal solution for weed control in narrow inter-row spaces. Several disadvantages have been encountered...... and the draft forces needed to pull it were approx. half those measured for a ‘Ducksfoot’ blade. The weeding features of the new L-blade will be further studied under field conditions....

Rocket Engine Turbine Blade Surface Pressure Distributions Experiment and Computations

Science.gov (United States)

Hudson, Susan T.; Zoladz, Thomas F.; Dorney, Daniel J.; Turner, James (Technical Monitor)

2002-01-01

Understanding the unsteady aspects of turbine rotor flow fields is critical to successful future turbine designs. A technology program was conducted at NASA's Marshall Space Flight Center to increase the understanding of unsteady environments for rocket engine turbines. The experimental program involved instrumenting turbine rotor blades with miniature surface mounted high frequency response pressure transducers. The turbine model was then tested to measure the unsteady pressures on the rotor blades. The data obtained from the experimental program is unique in two respects. First, much more unsteady data was obtained (several minutes per set point) than has been possible in the past. Also, an extensive steady performance database existed for the turbine model. This allowed an evaluation of the effect of the on-blade instrumentation on the turbine's performance. A three-dimensional unsteady Navier-Stokes analysis was also used to blindly predict the unsteady flow field in the turbine at the design operating conditions and at +15 degrees relative incidence to the first-stage rotor. The predicted time-averaged and unsteady pressure distributions show good agreement with the experimental data. This unique data set, the lessons learned for acquiring this type of data, and the improvements made to the data analysis and prediction tools are contributing significantly to current Space Launch Initiative turbine airflow test and blade surface pressure prediction efforts.

Non-invasive dynamic measurement of helicopter blades

Science.gov (United States)

Serafini, J.; Bernardini, G.; Mattioni, L.; Vezzari, V.; Ficuciello, C.

2017-08-01

This paper presents the development and the application on helicopter blades of a measurement system based on FBG strain gauges. Here, the main goal is the structural characterization of the main rotor blades, with the aim of showing the potentialities of such a system in blades quality check applications, as well as in the development of structural health monitoring and rotor state feedback devices. The device has been used in both non-rotating and rotating tests, and does not require the presence of slip rings or optical joint since it is completely allocated in the rotating system. It has been successfully applied to characterize the frequency response of blades lead-lag, flap and torsion deformations, up to 250 Hz.

Laser-based gluing of diamond-tipped saw blades

Science.gov (United States)

Hennigs, Christian; Lahdo, Rabi; Springer, André; Kaierle, Stefan; Hustedt, Michael; Brand, Helmut; Wloka, Richard; Zobel, Frank; Dültgen, Peter

2016-03-01

To process natural stone such as marble or granite, saw blades equipped with wear-resistant diamond grinding segments are used, typically joined to the blade by brazing. In case of damage or wear, they must be exchanged. Due to the large energy input during thermal loosening and subsequent brazing, the repair causes extended heat-affected zones with serious microstructure changes, resulting in shape distortions and disadvantageous stress distributions. Consequently, axial run-out deviations and cutting losses increase. In this work, a new near-infrared laser-based process chain is presented to overcome the deficits of conventional brazing-based repair of diamond-tipped steel saw blades. Thus, additional tensioning and straightening steps can be avoided. The process chain starts with thermal debonding of the worn grinding segments, using a continuous-wave laser to heat the segments gently and to exceed the adhesive's decomposition temperature. Afterwards, short-pulsed laser radiation removes remaining adhesive from the blade in order to achieve clean joining surfaces. The third step is roughening and activation of the joining surfaces, again using short-pulsed laser radiation. Finally, the grinding segments are glued onto the blade with a defined adhesive layer, using continuous-wave laser radiation. Here, the adhesive is heated to its curing temperature by irradiating the respective grinding segment, ensuring minimal thermal influence on the blade. For demonstration, a prototype unit was constructed to perform the different steps of the process chain on-site at the saw-blade user's facilities. This unit was used to re-equip a saw blade with a complete set of grinding segments. This saw blade was used successfully to cut different materials, amongst others granite.

Numerical and Theoretical Investigations Concerning the Continuous-Surface-Curvature Effect in Compressor Blades

Directory of Open Access Journals (Sweden)

Yin Song

2014-12-01

Full Text Available Though the importance of curvature continuity on compressor blade performances has been realized, there are two major questions that need to be solved, i.e., the respective effects of curvature continuity at the leading-edge blend point and the main surface, and the contradiction between the traditional theory and experimental observations in the effect of those novel leading-edge shapes with smaller curvature discontinuity and sharper nose. In this paper, an optimization method to design continuous-curvature blade profiles which deviate little from datum blades is proposed, and numerical and theoretical analysis is carried out to investigate the continuous-curvature effect on blade performances. The results show that the curvature continuity at the leading-edge blend point helps to eliminate the separation bubble, thus improving the blade performance. The main-surface curvature continuity is also beneficial, although its effects are much smaller than those of the blend-point curvature continuity. Furthermore, it is observed that there exist two factors controlling the leading-edge spike, i.e., the curvature discontinuity at the blend point which dominates at small incidences, and the nose curvature which dominates at large incidences. To the authors’ knowledge, such mechanisms have not been reported before, and they can help to solve the sharp-leading-edge paradox.

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)

Blade runner. Blade server and virtualization technology can help hospitals save money--but they are far from silver bullets.

Science.gov (United States)

Lawrence, Daphne

2009-03-01

Blade servers and virtualization can reduce infrastructure, maintenance, heating, electric, cooling and equipment costs. Blade server technology is evolving and some elements may become obsolete. There is very little interoperability between blades. Hospitals can virtualize 40 to 60 percent of their servers, and old servers can be reused for testing. Not all applications lend themselves to virtualization--especially those with high memory requirements. CIOs should engage their vendors in virtualization discussions.

Experimental Investigation of Inter-Blade Vortices in a Model Francis Turbine

Science.gov (United States)

LIU, Demin; LIU, Xiaobing; ZHAO, Yongzhi

2017-07-01

The inter-blade vortex in a Francis turbine becomes one of the main hydraulic factors that are likely to cause blade erosion at deep part load operating conditions. However, the causes and the mechanism of inter-blade vortex are still under investigation according to present researches. Thus the causes of inter-blade vortex and the effect of different hydraulic parameters on the inter-blade vortex are investigated experimentally. The whole life cycle of the inter-blade vortex is observed by a high speed camera. The test results illustrate the whole life cycle of the inter-blade vortex from generation to separation and even to fading. It is observed that the inter-blade vortex becomes stronger with the decreasing of flow and head, which leads to pressure fluctuation. Meanwhile, the pressure fluctuations in the vane-less area and the draft tube section become stronger when inter-blade vortices exist in the blade channel. The turbine will be damaged if operating in the inter-blade vortex zone, so its operating range must be far away from that zone. This paper reveals the main cause of the inter-blade vortex which is the larger incidence angle between the inflow angle and the blade angle on the leading edge of the runner at deep part load operating conditions.

A DMAIC approach for process capability improvement an engine crankshaft manufacturing process

Science.gov (United States)

Sharma, G. V. S. S.; Rao, P. Srinivasa

2014-05-01

The define-measure-analyze-improve-control (DMAIC) approach is a five-strata approach, namely DMAIC. This approach is the scientific approach for reducing the deviations and improving the capability levels of the manufacturing processes. The present work elaborates on DMAIC approach applied in reducing the process variations of the stub-end-hole boring operation of the manufacture of crankshaft. This statistical process control study starts with selection of the critical-to-quality (CTQ) characteristic in the define stratum. The next stratum constitutes the collection of dimensional measurement data of the CTQ characteristic identified. This is followed by the analysis and improvement strata where the various quality control tools like Ishikawa diagram, physical mechanism analysis, failure modes effects analysis and analysis of variance are applied. Finally, the process monitoring charts are deployed at the workplace for regular monitoring and control of the concerned CTQ characteristic. By adopting DMAIC approach, standard deviation is reduced from 0.003 to 0.002. The process potential capability index ( C P) values improved from 1.29 to 2.02 and the process performance capability index ( C PK) values improved from 0.32 to 1.45, respectively.

Accelerated rain erosion of wind turbine blade coatings

DEFF Research Database (Denmark)

Zhang, Shizhong

. There are four chapters in the thesis. In chapter 1, a literature survey provides background information to the field. Topics discussed are the global wind energy development, possible wind turbine constructions, blade structures and materials, blade coatings, and liquid erosion mechanisms. In chapter 2......During operation, the fast-moving blades of wind turbines are exposed to continuous impacts with rain droplets, hail, insects, or solid particles. This can lead to erosion of the blades, whereby the electrical efficiency is compromised and expensive repairs may be required. One possible solution...

Design Of Rotor Blade For Vertical Axis Wind Turbine Using Double Aerofoil

DEFF Research Database (Denmark)

Chougule, Prasad; Ratkovich, Nicolas Rios; Kirkegaard, Poul Henning

Nowadays, small vertical axis wind turbines are receiving more attention compared to horizontal wind turbines due to their suitability in urban use because they generate less noise, have bird free turbines and lower cost. There is few vertical axis wind turbines design with good power curve....... However, the efficiency of power extraction has not been improved. Therefore, an attempt has been made to utilize high lift technology in practice for vertical axis wind turbines in order to improve power efficiency. High lift is obtained by double aerofoil elements mainly used in aeroplane wing design....... In this current work two aerofoils are used to design a rotor blade for a vertical axis wind turbine to improve the power efficiency on the rotor. Double aerofoil blade design consists of a main aerofoil and a slat aerofoil. The parameters related to position and orientation of the slat aerofoil with respect...

An aerodynamic study on flexed blades for VAWT applications

Science.gov (United States)

Micallef, Daniel; Farrugia, Russell; Sant, Tonio; Mollicone, Pierluigi

2014-12-01

There is renewed interest in aerodynamics research of VAWT rotors. Lift type, Darrieus designs sometimes use flexed blades to have an 'egg-beater shape' with an optimum Troposkien geometry to minimize the structural stress on the blades. While straight bladed VAWTs have been investigated in depth through both measurements and numerical modelling, the aerodynamics of flexed blades has not been researched with the same level of detail. Two major effects may have a substantial impact on blade performance. First, flexing at the equator causes relatively strong trailing vorticity to be released. Secondly, the blade performance at each station along the blade is influenced by self-induced velocities due to bound vorticity. The latter is not present in a straight bladed configuration. The aim of this research is to investigate these effects in relation to an innovative 4kW wind turbine concept being developed in collaboration with industry known as a self-adjusting VAWT (or SATVAWT). The approach used in this study is based on experimental and numerical work. A lifting line free-wake vortex model was developed. Wind tunnel power and hot-wire velocity measurements were performed on a scaled down, 60cm high, three bladed model in a closed wind tunnel. Results show a substantial axial wake induction at the equator resulting in a lower power generation at this position. This induction increases with increasing degree of flexure. The self-induced velocities caused by blade bound vorticity at a particular station was found to be relatively small.

An aerodynamic study on flexed blades for VAWT applications

International Nuclear Information System (INIS)

Micallef, Daniel; Farrugia, Russell; Sant, Tonio; Mollicone, Pierluigi

2014-01-01

There is renewed interest in aerodynamics research of VAWT rotors. Lift type, Darrieus designs sometimes use flexed blades to have an 'egg-beater shape' with an optimum Troposkien geometry to minimize the structural stress on the blades. While straight bladed VAWTs have been investigated in depth through both measurements and numerical modelling, the aerodynamics of flexed blades has not been researched with the same level of detail. Two major effects may have a substantial impact on blade performance. First, flexing at the equator causes relatively strong trailing vorticity to be released. Secondly, the blade performance at each station along the blade is influenced by self-induced velocities due to bound vorticity. The latter is not present in a straight bladed configuration. The aim of this research is to investigate these effects in relation to an innovative 4kW wind turbine concept being developed in collaboration with industry known as a self-adjusting VAWT (or SATVAWT). The approach used in this study is based on experimental and numerical work. A lifting line free-wake vortex model was developed. Wind tunnel power and hot-wire velocity measurements were performed on a scaled down, 60cm high, three bladed model in a closed wind tunnel. Results show a substantial axial wake induction at the equator resulting in a lower power generation at this position. This induction increases with increasing degree of flexure. The self-induced velocities caused by blade bound vorticity at a particular station was found to be relatively small

Structural optimization procedure of a composite wind turbine blade for reducing both material cost and blade weight

Science.gov (United States)

Hu, Weifei; Park, Dohyun; Choi, DongHoon

2013-12-01

A composite blade structure for a 2 MW horizontal axis wind turbine is optimally designed. Design requirements are simultaneously minimizing material cost and blade weight while satisfying the constraints on stress ratio, tip deflection, fatigue life and laminate layup requirements. The stress ratio and tip deflection under extreme gust loads and the fatigue life under a stochastic normal wind load are evaluated. A blade element wind load model is proposed to explain the wind pressure difference due to blade height change during rotor rotation. For fatigue life evaluation, the stress result of an implicit nonlinear dynamic analysis under a time-varying fluctuating wind is converted to the histograms of mean and amplitude of maximum stress ratio using the rainflow counting algorithm Miner's rule is employed to predict the fatigue life. After integrating and automating the whole analysis procedure an evolutionary algorithm is used to solve the discrete optimization problem.

Helicopter blades running elevation measurement using omnidirectional vision

Directory of Open Access Journals (Sweden)

Chengtao CAI

2017-12-01

Full Text Available Omnidirectional dynamic space parameters of high-speed rotating helicopter blades are precise 3D vector description of the blades. In particular, the elevation difference is directly related to the aerodynamic performance and maneuverability of the helicopter. The state of the art detection techniques based on optics and common vision have several drawbacks, such as high demands on devices but poor extensibility, limited measurement range and fixed measurement position. In this paper, a novel approach of helicopter blades running elevation measurement is proposed based on omnidirectional vision. With the advantages of panoramic visual imaging integration, 360° field of view and rotation in-variance, high-resolution images of all rotating blades positions are obtained at one time. By studying the non-linear calibration and calculation model of omnidirectional vision system, aiming at solving the problem of inaccurate visual space mapping model, the omnidirectional and full-scale measurement of the elevation difference are finalized. Experiments are carried out on our multifunctional simulation blades test system and the practical blades test tower, respectively. The experimental results demonstrate the effectiveness of the proposed method and show that the proposed method can considerably reduce the complexity of measurement. Keywords: Full-scale measurement, Helicopter blades elevation, Non-linear calibration, Omnidirectional vision, Unified sphere model

KNOW-BLADE task-3.2 report: Tip shape study

DEFF Research Database (Denmark)

Sørensen, Niels N.; Johansen, Jeppe; Conway, S.

2005-01-01

For modern rotor blades with their very large aspect ratio, the blade tip is a very limited part of the overall rotor, and as such of limited importance for the overall aerodynamics of the rotor. Even though they may not be very important for the overallpower production, the tip noise can be very...... important for the acoustics of the rotor [15], and the blade tips can as well be important for the aerodynamic damping properties of the rotor blades [13]. Unfortunately, not many options exists for predictingthe aerodynamic behavior of blade tips using computational methods. Experimentally it is di...

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.

Fundamental investigation on the impact strength of hollow fan blades

Energy Technology Data Exchange (ETDEWEB)

Ikeda, T; Miyachi, T; Sofue, Y

1985-01-01

Models of hollow fan blades were made and tested to prove that their strength is sufficient for use in real engines. The hollow blades were fabricated by diffusion bonding of two titanium alloy (6Al-4V-Ti) plates, one of which had three spanwise stiffners and the other being flat plate. The model as a nontwisted tapered blade. Impact tests were carried out on the hollow fan blade models in which the ingestion of a 1.5 pounds bird was simulated. Solid blades with the same external form were also tested by similar methods for comparison. The results of these tests show that properly designed hollow blades have sufficient stiffness and strength for use as fan blades in the turbo-fan engine.

Improved Large Aperture Collector Manufacturing

Energy Technology Data Exchange (ETDEWEB)

O' Rourke, Deven [Abengoa Solar LLC, Lakewood, CO (United States); Farr, Adrian [Abengoa Solar LLC, Lakewood, CO (United States)

2015-12-01

The parabolic trough is the most established CSP technology and carries a long history of design experimentation dating back to the 1970’s. This has led to relatively standardized collector architectures, a maturing global supply chain, and a fairly uniform cost reduction strategy. Abengoa has deployed more than 1,500MWe of CSP troughs across several countries and has built and tested full-scale prototypes of many R&D concepts. The latest trough R&D efforts involved efforts to internalize non-CSP industry experience including a preliminary DFMA principles review done with Boothroyd Dewhurst, a construction literature review by the Arizona State University School of Construction Management, and two more focused manufacturing engineering subcontracts done by Ricardo Inc. and the nonprofit Edison Welding Institute. The first two studies highlighted strong opportunities in lowering part count, standardizing components and fasteners, developing modular designs to support prefabrication and automation, and devising simple, error-proof manual assembly methods. These principles have delivered major new cost savings in otherwise “mature” products in analogous industries like automotive, truck trailer manufacture, metal building fabrication, and shipbuilding. For this reason, they were core in the design development of the SpaceTube® collector, and arguably key to its early successes. The latter two studies were applied specifically to the first-generation SpaceTube® design and were important in setting the direction of the present SolarMat project. These studies developed a methodology to analyze the costs of manufacture and assembly, and identify new tooling concepts for more efficient manufacture. Among the main opportunities identified in these studies were the automated mirror arm manufacturing concept and the need for a less infrastructure-intensive assembly line, both of which now form central pillars of the SolarMat project strategy. These new designs will be

Family of airfoil shapes for rotating blades. [for increased power efficiency and blade stability

Science.gov (United States)

Noonan, K. W. (Inventor)

1983-01-01

An airfoil which has particular application to the blade or blades of rotor aircraft such as helicopters and aircraft propellers is described. The airfoil thickness distribution and camber are shaped to maintain a near zero pitching moment coefficient over a wide range of lift coefficients and provide a zero pitching moment coefficient at section Mach numbers near 0.80 and to increase the drag divergence Mach number resulting in superior aircraft performance.

Blade Bearing Friction Estimation of Operating Wind Turbines