• 제목/요약/키워드: 로터 블레이드

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Wind Loads of 5 MW Horizontal-Axis Wind Turbine Rotor in Parked Condition (운전정지 조건에서 5 MW 수평축 풍력터빈 로터의 풍하중 해석)

  • Ryu, Ki-Wahn;Seo, Yun-Ho
    • Journal of the wind engineering institute of Korea
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    • v.22 no.4
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    • pp.163-169
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    • 2018
  • In this study, wind loads exerted on the offshore wind turbine rotor in parked condition were predicted with variations of wind speeds, yaw angles, azimuth angle, pitch angles, and power of the atmospheric boundary layer profile. The calculated wind loads using blade element theorem were compared with those of estimated aerodynamic loads for the simplified blade shape. Wind loads for an NREL's 5 MW scaled offshore wind turbine rotor were also compared with those of NREL's FAST results for more verification. All of the 6-component wind loads including forces and moments along the three axis were represented on a non-rotating coordinate system fixed at the apex of rotor hub. The calculated wind loads are applicable for the dynamic analysis of the wind turbine system, or obtaining the over-turning moment at the foundation of support structure for wind turbine system.

A Validation Study on Structural Load Analyses of TiltRotors in Wind Tunnel (풍동 시험용 틸트로터의 구조 하중 해석의 검증 연구)

  • Ui-Jin Hwang;Jae-Sang Park;Myeong-Kyu Lee
    • Journal of Aerospace System Engineering
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    • v.17 no.2
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    • pp.45-55
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    • 2023
  • This study conducted aeromechanics modeling and structural load analyses of Tilt Rotor Aeroacoustic Model (TRAM), a 25% scaled V-22 tiltrotor model used in wind tunnel tests. A rotorcraft comprehensive analysis code, CAMRAD II, was used. Analysis results of this study in low-speed forward flights were compared with DNW test and previous analysis results. Blade flap bending moments were in good agreement with measured data. Mean values and oscillatory loads for lead-lag bending and torsion moments were slightly different from measured data. However, when mean values were removed, results of structural loads for one rotor revolution were moderately compared with wind tunnel tests and previous analyses. Total forces and half peak-to-peak forces of the pitch link reasonably well matched with previous analysis results and measured data. Finally, harmonic magnitudes of blade structural loads were investigated.

Optimal Rotor Blade Design for Tidal In-stream Energy (조류발전용 로터 블레이드의 최적 형상 설계)

  • Yang, Chang-Jo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.17 no.1
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    • pp.75-82
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    • 2011
  • Marine current energy is one of the most interesting renewable and clean energy resources that have been less exploited. Especially, Korea has worldwide outstanding tidal current energy resources and it is highly required to develop tidal in-stream energy conversion system in coastal area. The objective of study is to investigate harnessing techniques of tidal current energy and to design the a 100 kW horizontal axis tidal turbine using blade element momentum theory with Prandtl's tip loss factor for optimal design procedures. In addition, Influence of Prandtl's tip loss factor at local blade positions as a function of tip speed ratio was studied, and the analysed results showed that power coefficient of designed rotor blade using NACA 63812 was 0.49 at rated tip speed ratio.

Development of Dynamic Balancing Techniques of a Rotor System Using Genetic Algorithm (유전자 알고리즘을 적용한 로터 시스템의 동적 밸런싱 기법 개발)

  • Kwon, Hyuck-Ju;Yu, Young-Hyun;Jung, Sung-Nam;Yun, Chul-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.12
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    • pp.1162-1169
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    • 2010
  • The dynamic balancing of a rotor system is needed to alleviate the imbalances originating from various sources encountered during blade manufacturing processes and environmental factors. This work aims at developing a comprehensive analysis system which consists of cumulative module of test D/B and selection of optimal control parameters. This system can be used for the dynamic balancing of helicopter rotors based on tracking results from the whirl tower test. For simplicity of the analysis, a linear relation is assumed between the balancing input parameters and the blade track responses leading to influence coefficients and thereby the rotor system identification is made. In addition, the balancing parameters of the individual blades are sought using the genetic algorithm and the effectiveness of the proposed method is demonstrated in comparison with the test results.

CFD-based Thrust Analysis of Unmanned Aerial Vehicle in Hover Mode: Effects of Single Rotor Blade Shape (무인비행체 블레이드 형상 변화에 따른 단일로터의 제자리 비행 추력성능 분석)

  • Yun, Jae Hyun;Choi, Ha-Young;Lee, Jongsoo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.5
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    • pp.513-520
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    • 2014
  • An unmanned aerial vehicle (UAV) should be designed to be as small and lightweight as possible to optimize the efficiency of changing the blade shape to enhance the aerodynamic performance, such as the thrust and power. In this study, a computational fluid dynamics (CFD) simulation of an unmanned multi-rotor aerial vehicle in hover mode was performed to explore the thrust performance in terms of the blade rotational speed and blade shape parameters (i.e., taper ratio and twist angle). The commercial ADINA-CFD program was used to generate the CFD data, and the results were compared with those obtained from blade element theory (BET). The results showed that changes in the blade shape clearly affect the aerodynamic thrust of a UAV rotor blade.

Sensing Technique of Mass Imbalance for Condition Monitoring of Wind Turbine Blade (풍력발전기 블레이드 상태 모니터링을 위한 질량 불균형 감지기법)

  • Lee, Jong Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.1
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    • pp.209-214
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    • 2011
  • A method to detect rotor mass imbalance, which is one of the typical faults of wind turbine, is presented for effective condition monitoring of wind turbine. Dynamic analysis for a three-bladed horizontal-axis wind turbine was carried out with adding mass to a blade for inflicting the rotor mass imbalance. It has been found that the added mass induce a resulting centrifugal force to nacelle and this leads to a transverse (relative to the rotor axis) oscillation of the nacelle. It has been also found that the amplitude of the oscillation is almost linearly increased as the added mass is increased.

Prediction of Vibration Characteristics of a Composite Rotor Blade via Deep Neural Networks (심층신경망을 이용한 복합재 로터 블레이드의 진동특성 예측)

  • Yoo, Seungho;Jeong, Inho;Kim, Hyejin;Cho, Haeseong;Kim, Taejoo;Kee, Youngjung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.5
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    • pp.317-323
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    • 2022
  • In this paper, a deep neural network(DNN) model for predicting the vibration characteristics of the composite rotor blade with c-spar cross section was developed. Herein, the present DNN model is defined by using the natural frequencies obtained through the in-house code based on the nonlinear co-rotational(CR) shell element. For the present DNN model, the accuracy of the model was evaluated via the data with a random distribution of thickness and a tendency to decrease in thickness along the blade span.

Rotor Hub Vibration Reduction Analysis Applying Individual Blade Control (개별 블레이드 조종을 통한 로터 허브 진동 저감 해석)

  • Kim, Taejoo;Wie, Seong-Yong;Kim, Minwoo;Lee, Dong-geon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.8
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    • pp.649-660
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    • 2021
  • Through analytical method based on S-76 model, the level of rotor hub vibration reduction was analyzed according to higher harmonic actuating by individual blade control. The higher harmonic actuating method for individual blades was divided into a method of generating an additional actuating force from the pitch-link in the rotating part and generating actuating force through the active trailing edge flap control of the blade. In the 100kts forward flight conditions, the hub load analysis was performed by changing the phase angle of 15 degree for the 2P/3P/4P/5P harmonic actuation for individual blades. Through the harmonic actuation results, the sensitivity of the rotor system according to the actuating conditions was analyzed, and the T-matrix representing the characteristics of the rotor system was derived based on this analysis result. And through this T-matrix, optimal higher harmonic actuating condition was derived to minimize hub vibration level for flight condition. In addition, the effect on the performance of the rotor system and the pitch-link load under minimum hub vibration condition, as well as the noise influence through the noise analysis were confirmed.

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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Dynamic Characteristics of Helicopter Bearingless Main Rotor (헬리콥터 무베어링 주로터의 동특성 시험)

  • Yun, Chul Yong;Song, Keun Woong;Kim, Deog-Kwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.5
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    • pp.439-446
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    • 2016
  • The characteristics of bearingless main rotor of helicopter are investigated through non-rotating tests and rotating tests. The stiffness and natural frequencies of rotor blades, flexbeam, and torque tube which are core components of baearingless rotor are measured to obtain input material properties for rotor analysis. The functional test on ground for assembly of one hub with damper, snubber, and no blade is carried out to check interfaces between components, kinematics of components, and pitch motion ranges under applied loads including centrifugal load. The 4-bladed bearingless rotor with 5.82m of rotor radius is tested on the whirl tower with rotation plane of 9.65m height. The thrust and power are measured to obtain hover performance and the frequencies and dampings of the rotor are obtained by excitation of cyclic pitch by hydraulic actuators.