• Title/Summary/Keyword: Blade-To-Blade

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Spanwise Aerodynamic Loads along the Wind Turbine Blade (풍력터빈 블레이드상의 공력하중분포 해석)

  • Lee, Kyo-Yeol;Ryu, Ki-Wahn
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.61.2-61.2
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    • 2011
  • The spanwise aerodynamic loads of the wind turbine blade are investigated numerically. The blade shape such as twist and chord length along the blade span is obtained from the procedure of aerodynamically optimal design. The rated tip speed ratio and the rated wind velocity are set to 7 and 12m/s respectively. The BEM method is applied to obtain both the aerodynamic performance of the wind turbine (Fig.1) and the spanwise aerodynamic loads along the blade span including Prandtl's tip loss factor. The maximum running power coefficient is occurred around 90% radial position from hub (Fig.2). The distributed aerodynamic loads along the blade span can be used for structure analysis.

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A Study on Failure Analysis of Turbine Blade using AFM and FEM (AFM과 유한요소법을 이용한 터빈 블레이드의 파손해석에 관한 연구)

  • 최우성;이동우;홍순혁;조석수;주원식
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.489-493
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    • 2000
  • Turbine blade has trouble of cracking at root region. Fracture surface of blade root is surveyed by SEM and AFM to clear relation between fracture mechanical parameter and surface parameter (striation width and surface roughness). Service stress is predicted by maximum height roughness $R_{max}$, on fractured surface and stress analysis on turbine blade. It is to thought that turbine blade is fractured by abnormal condition such as incorrect fittings between pin and pin hole but isn't fractured by normal service conditions such as steam pressure, centrifugal force and torsional force.

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A Parametric Investigation Into the Aeroelasticity of Composite Helicopter Rotor Blades in Forward Flight (전진비행시 복합재료 헬리콥터 회전익의 공탄성에 대한 파라미터 연구)

  • 정성남;김경남;김승조
    • Journal of KSNVE
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    • v.7 no.5
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    • pp.819-826
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    • 1997
  • The finite element analyses of a composite hingeless rotor blade in forward flight have been performed to investigate the influence of blade design parameters on the blade stability. The blade structure is represented by a single cell composite box-beam and its nonclassical effects such as transverse shear and torsion-related warping are considered. The nonlinear periodic differential equations of motion are obtained by moderate deflection beam theory and finite element method based on Hamilton principle. Aerodynamic forces are calculated using the quasi-steady strip theiry with compressibility and reverse flow effects. The coupling effects between the rotor blade and the fuselage are included in a free flight propulsive trim analysis. Damping values are calculated by using the Floquet transition matrix theory from the linearized equations perturbed at equilibrium position of the blade. The aeroelastic results were compared with an alternative analytic approch, and they showed good correlation with each other. Some parametric investigations for the helicopter design variables, such as pretwist and precone angles are carried out to know the aeroelastic behavior of the rotor.

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Research of New Type Small Wind Turbine System (새로운 방식의 소형 풍력발전기 시스템 고찰)

  • Kim, Yeong-Min;Hwang, Jong-Sun;Kim, Jong-Man;Kim, Byoung-Wook;Kim, Dong-Yong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05b
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    • pp.130-134
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    • 2005
  • The objectives of this study are to improve the aerodynamics performance on the down-wind blade system with folding type blade which consists of the folding type rotor blade, wind vane yawing stabilizer and a bevel gearbox. The aerodynamics performance for the new wind turbine system are compared with those of the conventional up-wind blade system. In addition to, a novel multi voltage inverter system is applied for reductions of harmonic.

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Optimal Design of Composite Rotor Blade Cross-Section using Discrete Design variable (이산설계변수를 고려한 복합재 로터블레이드 단면 최적설계)

  • Won, You-Jin;Lee, Soo-Yong
    • Journal of Aerospace System Engineering
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    • v.8 no.1
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    • pp.12-17
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    • 2014
  • In this paper, optimal design of composite rotor blade cross-section to consider manufacturability was performed. Skin thickness, torsion box thickness and skin lay-up angle were adopted as discrete design variables and The position and width of a torsion box were considered as continuous variables. An object function of optimal design is to minimize the mass of a rotor blade, and various constraints such as failure index, center mass, shear center, natural frequency and blade minimum mass per unit length were adopted. Finally, design variables such as the thickness and lay-up angles of a skin, and the thickness, position and width of a torsion box were determined by using an in-house program developed for the optimal design of rotor blade cross-section.

Study on the Analysis of Structural Dynamic Characteristics and Modal Test of Unmanned Helicopter Rotor Blades (무인헬리콥터 로터 블레이드의 구조적 진동특성 분석 및 시험에 관한 연구)

  • 정경렬;이종범;한성호;최길봉
    • Journal of KSNVE
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    • v.5 no.2
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    • pp.215-224
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    • 1995
  • In this paper, the three-dimensional finite element model is established to investigate the structural dynamic characteristics of rotor blade using a finite element analysis. Six natural frequencies and mode shapes are calculated by computer simulation. The first three flapping modal frequencies, the first two lead-lag modal frequencies, and the first feathering modal frequency are validated through comparison with the modal test results of the fixed rotor blade. The computer simulation results are found in good agreement with experimentally measured natural frequencies. The important results are obtained as follows: (1) Natural frequencies are changed due to the variation of rotational speed and fiber angle of rotor blade, (2) Weak coupling between flapping mode shape and lead-lag mode shape are detected, (3) Centrifugal force has more effect on flapping modal frequency than lead-lag modal frequency.

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Heat/Mass Transfer Characteristics on Shroud with Turbine Blade Tip Clearances (터빈 블레이드 말단과 슈라우드 사이의 간극변화에 따른 슈라우드에서의 열/물질전달 특성)

  • Lee, Dong-Ho;Choe, Jong-Hyeon;Jo, Hyeong-Hui
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.3
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    • pp.414-421
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    • 2001
  • The present study is conducted to investigate the local heat/mass transfer characteristics on the shroud with blade tip clearances. The relative motion between blade and shroud has little influence on the overall heat transfer characteristics, except some local effects. Therefore, the relative motion between the blade and shroud is neglected in this study. A naphthalene sublimation method is employed to determine the detailed local heat/mass transfer coefficients on the surface of the shroud. The tip clearance is changed from 0.66% to 2.85% of the blade chord length. The flow enters the gap between the blade tip and shroud at the pressure side due to the pressure difference. Therefore, the heat/mass transfer characteristics on the shroud are changed significantly from those with endwall. At first, high heat/mass transfer occurs along the profile of blade at the pressure side due to the entrance effect and acceleration of the gap flow. Then, the heat/mass transfer coefficients on the shroud increase along the suction side of the blade because tip leakage vortices are generated and interact with the main flow. The results show that the heat/mass transfer characteristics are changed largely with the gap distance between the tip of turbine blade and the shroud.

Optimization of Stacking Line and Blade Profile for Design of Axial Flow Fan Blade (중첩선과 단면형상을 고려한 축류 송풍기 날개의 최적설계)

  • Samad, Abdus;Lee, Ki-Sang;Jung, Sang-Ho;Kim, Kwang-Yong
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.420-423
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    • 2008
  • This present work is to find optimum design of a NACA65 axial fan blade with weighted average surrogate model. The numerical analysis by Reynolds-average Navier-Stokes equations with shear stress turbulence(SST) is discretized by finite volume approximations and solved on hexahedral grids for flow analysis. The blade aerodynamic shape is modified by six design variables for the optimization. The blade profile as well as stacking line is modified to enhance blade total efficiency. Six design variables, airfoil maximum camber, maximum camber location, leading edge radius, trailing edge radius, lean angle at 50% span and lean angle at 100% span, are selected for blade profile to enhance the total efficiency. The PBA model which is basically weighted average of the basis surrogates is used to find the optimal design in the design space from the constructed response surface model for the objective function. By the optimization, the total efficiency is increased by 1.4%.

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Performance Analysis of a Steam Injected Gas Turbine Combined Heat and Power System Considering Turbine Blade Temperature Change (터빈 블레이드 온도 변화를 고려한 증기분사 가스터빈 열병합발전 시스템의 성능해석)

  • Kang, Soo Young;Kim, Jeong Ho;Kim, Tong Seop
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.6
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    • pp.18-24
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    • 2012
  • This study simulated the operation of a steam injected gas turbine combined heat and power (CHP) system. A full off-design analysis was carried out to examine the change in the turbine blade temperature caused by steam injection. The prediction of turbine blade temperature was performed for the operating modes suggested in the previous study where the limitation of compressor surge margin reduction was analyzed in the steam injected gas turbine. It was found that both the fully injected and partially injected operations suggested in the previous study would cause the blade temperature to exceed that of the pure CHP operation and the under-firing operation would provide too low blade temperature. An optimal operation was proposed where both the turbine inlet temperature and the injection amount were modulated to keep both the reference turbine blade temperature and the minimum compressor surge margin. The modulation was intended to maintain a stable compressor operation and turbine life. It was shown that the optimal operation would provide a larger power output than the under-firing operation and a higher efficiency than the original partially injected operation.

ANALYSIS OF A LAMINATED COMPOSITE WIND TURBINE BLADE CHARACTERISTICS THROUGH MATHEMATICAL APPROACH

  • CHOI, YOUNG-DO;GO, JAEGWI;KIM, SEOKCHAN
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.23 no.4
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    • pp.367-380
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    • 2019
  • A 1kW-class horizontal axis wind turbine (HAWT) rotor blade is taken into account to investigate elastic characteristics in 2-D. The elastic blade field is composed of symmetric cross-ply laminated composite material. Blade element momentum theory is applied to obtain the boundary conditions pressuring the blade, and the plane stress elasticity problem is formulated in terms of two displacement parameters with mixed boundary conditions. For the elastic characteristics a fair of differential equations are derived based on the elastic theory. The domain is divided by triangular and rectangular elements due to the complexity of the blade configuration, and a finite element method is developed for the governing equations to search approximate solutions. The results describe that the elastic behavior is deeply influenced by the layered angle of the middle laminate and the stability of the blade can be improved by controlling the layered angle of laminates, which can be evaluated by the mathematical approach.