基于致动线/BPM模型结合的风力机气动噪声研究

Aeroacoustic Noise Analysis of Wind Turbines based on the Combination of Actuator Line Model and BPM Model

结合致动线模型和BPM半经验模型为声学扰动方程提供声源,计算NREL5MWRef风力机的声场传播。为提高效率采用声场与流场混合求解方法,对声场基于带有声源项的声学扰动方程进行微分计算,模拟点声源扩散并与声学理论对比,验证模型及方法的正确性。基于致动线模型进行风力机流场及声场的模拟计算,该模型建模与网格划分简单,并通过在声学扰动方程中添加基于BPM半经验模型的翼型自噪声源,来弥补致动线模型缺失翼型自噪声声源的不足。结果表明,结合致动线模型和BPM半经验模型,基于声学扰动方程计算风力机声场的方法正确、高效。

The sound source is obtained with the combination of actuator line model (ALM) and BPM semi-empirical model, and applied to the acoustic perturbation equation to calcaulate the aeroacoustic noise of the NREL5MWRef wind turbine. This approach is based on the hydrodynamic / acoustic splitting technique where the incompressible flow is first computed and the acoustic field is computed with the sound source resulted from the incompressible flow. The sound point source diffusion is simulated and the results are compared with those of experiments to verify the correctness of this method. The flow field and the sound field of the turbine are calculated based on ALM model with the added airfoil sound source of the BPM semi-empirical model. The results show that the approach combining the ALM model with the BPM semiempirical model based on the acoustic perturbation equation can calculate the acoustic field of the wind turbine correctly and effectively.