风力机叶片动态失速时的非定常气动特性及严重的迟滞现象使得风力机功率实测值严重偏离其静态预测值。鉴于此,基于Theodorsen理论、基尔霍夫势流理论,在忽略低阶附加质量引起的下洗气流加速度项及状态变量转换后,提出一种包括翼型附着流和后缘动态分离流的新型动态失速模型。利用该模型分析NREL 5 MW海上风力机叶片6种翼型的非定常动态失速特性得出：通过翼型的气流在完全附着流与完全分离流之间不断转换,受附着流脱落尾诱导的动态下洗气流影响及边界层动态分离产生的压力滞后的双重作用,动态升力系数变化曲线和静态升力现象曲线偏差较大,6种翼型动态升力系数变化曲线均呈非常明显的迟滞环现象。DU40、DU35、DU30、DU25、DU21和NACA64这6种翼型动态升力系数增幅明显,分别达17.6%、60.9%、60.7%、55.1%、63.7%和40.8%。动态失速攻角极大地超过静态失速攻角,分别增大到36.53°、21.40°、20.20°、17.68°、16.97°和21.42°。6种翼型动态失速预测结果与公开实验数据结论一致,证实所提出的动态失速气动模型计算结果准确可信,具有较强通用性。
Abstract
The unsteady aerodynamic characteristics and serious time-lag of wind turbine blades during dynamic stall made the actual measured value of rotor power seriously deviate from its static prediction value. Therefore, ignoring the acceleration term of downwash flow caused by low-order added mass and undergoing state variable transformation, a novel dynamic stall prediction model including airfoil attachment flow and dynamic separation flow of trailing edge was proposed based on Theodorsen theory and Kirchhoff potential flow theory. The model was used to analyze the unsteady dynamic stall characteristics of six airfoils from NREL 5 MW offshore wind turbine blades. The conclusions were as follows. The airflow through the airfoil continuously varied between the fully attached flow and the fully separated flow. Due to the dual effects of the dynamic downwash flow induced by the shedding trailing edge vortex of the attached flow and the pressure lag caused by the dynamic separation of the boundary layer, the variation curve of the dynamic lift coefficient and the static lift phenomenon curve deviated greatly. The dynamic lift coefficient curves of six airfoils showed a very obvious time-lag phenomenon. The dynamic lift coefficients of DU40, DU35, DU30, DU25, DU21 and NACA64 airfoils increased significantly, reaching 17.6%, 60.9%, 60.7%, 55.1%, 63.7% and 40.8% respectively. The dynamic stall angle of attack greatly exceeded the static stall angle of attack, increasing to 36.53°, 21.40°, 20.20°, 17.68°, 16.97° and 21.42° respectively. The prediction values of six airfoils were consistent with the conclusions of public experimental data, which proved that the calculation results of the proposed model were accurate, reliable and universal.
关键词
Theodorsen理论 /
翼型 /
风力机叶片 /
升力系数 /
预测模型
Key words
Theodorsen theory /
airfoils /
wind turbine blades /
lift coefficient /
prediction models
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参考文献
[1] 贺德馨. 风工程与工业空气动力学[M]. 北京: 国防工业出版社, 2006: 144-145.
HE D Q.Wind engineering and industrial aerodynamics[M]. Beijing: National Defense Industry Press, 2006: 144-145.
[2] 胡丹梅. 水平轴风力机尾迹气动特性研究[D]. 上海: 上海交通大学, 2006.
HU D M.Study on aerodynamic characteristics of horizontal axis wind turbine wake[D]. Shanghai: Shanghai Jiao Tong University, 2006.
[3] 刘雄, 梁湿, 陈严, 等. 风力机翼型动态失速气动特性仿真[J]. 工程力学, 2015, 32(3): 203-211.
LIU X, LIANG S, CHEN Y, et al.Dynamic stall simulation of wind turbine airfoils[J]. Engineering mechanics, 2015, 32(3): 203-211.
[4] TARZANIN F J.Prediction of control loads due to blade stall[J]. Journal of the American Helicopter Society, 1972, 17(2): 33-46.
[5] SNEL H.Heuristic modelling of dynamic stall characteristics[C]//European Wind Energy Conference, Dublin Castle, Ireland, 1997: 429-433.
[6] TRAN C T, PETOT D.Semi-empirical model for the dynamic stall of airfoils in view of the application to the calculation of responses of a helicopter blade[J]. Vertica, 1981, 5(1): 35-53.
[7] HOLIERHOEK J G, VAAL J B, ZUIJLEN A H, et al.Comparing different dynamic stall models[J]. Wind energy, 2013, 16(1): 139-158.
[8] LESHMAN J G, BEDDOES T S.A generalized model for airfoil unsteady aerodynamic behavior and dynamic stall using the indicial method[C]//Proceeding of the 42nd Annual Forum of the American Helicopter Society, Washington D C, USA, 1986: 243-265.
[9] LEISHMAN J G, BEDDOES T S.A semi-empirical model for dynamic stall[J]. Journal of the American Helicopter Society, 1989, 34(3): 3-17.
[10] LEISHMAN J G.Validation of approximate indicial aerodynamic functions for two-dimensional subsonic flow[J]. Journal of aircraft, 1988, 25(10): 914-922.
[11] ØYES Y.Dynamic stall simulated as time lag of separation[R]. Roskilde: Department of Fluid Mechanics, Technical University of Denmark, 1991.
[12] JONES R T.Classical aerodynamic theory[M]. California: University Press of the Pacific, 2005.
[13] HANSEN M H, GAUNAA M, Madsen H A.A Beddoes-Leishman type dynamic stall model in state-space and indicial formulations[M]. Roskilde: Risø National Laboratory, 2004.
[14] ROCCHIO B, CHICCHIERO C, SALVETTI M V, et al.A simple model for deep dynamic stall conditions[J]. Wind energy, 2020, 23(4): 915-938.
[15] ELGAMMIL M, SANT T.A modified Beddoes Leishman model for unsteady aerodynamic blade load computation on wind turbine blades[J]. Journal of solar energy engineering, 2016, 138(5): 1-18.
[16] BOUTET J, DIMITRIADIS G, AMANDOLESE X.A modified Leishman-Beddoes model for airfoil sections undergoing dynamic stall at low Reynolds numbers[J]. Journal of fluids and structures, 2020, 93: 102852.
[17] LIU X, LIANG S, LI G, et al.An improved dynamic stall model and its effect on wind turbine fatigue load prediction[J]. Renewable energy, 2020, 156: 117-130.
[18] 朱呈勇, 李梦飞. 考虑三维旋转和动态失速的风力机气动力建模[J]. 中国电机工程学报, 2021, 41(8): 1-12.
ZHU C Y, LI M F.Aerodynamic modeling of wind turbines concerning rotational augmentation and dynamic stall[J]. Proceedings of the CSEE, 2021, 41(8): 1-12.
[19] 戴玉婷, 严慧. 基于非线性气动力的失速颤振计算与试验研究[J]. 工程力学, 2020, 37(8): 230-236.
DAI Y T, YAN H.Calculation and experimental study of stall flutter based on nonlinear aerodynamics[J]. Engineering mechanics, 2020, 37(8): 230-236.
[20] LEISHMAN J.Challenges in modeling the unsteady aerodynamics of wind turbines[C]//21st ASME Wind Energy Symposium and the 40th AIAA Aerospace Sciences Meeting, Reno, 2013, 1:28.
[21] THEODOSEN T.General theory of aerodynamic instability and the mechanism of flutter[R]. Langley: Langley Aeronautical Laboratory National Advisory Committee for Aeronautics, 1934.
[22] 雷航. 水平轴风电机组风轮系统动态载荷特性研究[D]. 北京: 华北电力大学, 2014.
LEI H.Dynamic load characteristics research for rotor system of horizontal axis wind turbine[D]. Beijing: North China Electric Power University, 2014.
[23] JONKMAN J, BUTTERFIELD S, MUSIAL W, et al.Definition of a 5-MW reference wind turbine for offshore system development[R]. USA National Renewable Energy Laboratory, 2009: 1-57.
[24] 胡丹梅, 李佳, 闫海津. 水平轴风力机翼型动态失速的数值模拟[J]. 中国电机工程学报, 2010, 30(20): 106-111.
HU D M, LI J, YAN H J.Numerical simulation of airfoil dynamic stall of horizontal axis wind turbine[J]. Proceedings of the CSEE, 2010, 30(20): 106-111.
基金
国家自然科学基金（51866012）; 内蒙古自然科学基金重大项目（2018ZD08）
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