Aerodynamic Noise Prediction and Control Based on Impedance Boundary Condition

A numerical prediction method for aerodynamic noise based on Green's function and mixing theory is used to predict the aerodynamic noise, which generated by the interaction between unsteady flow and non compact impedance solid boundaries. The scattering effect of the non-compact impedance boundary on the acoustic waves is added into the Green's function, and the flow field is calculated by large eddy simulation, while the far-field noise is calculated by solving the Ffowcs Williams-Hawkings equation. The numerical simulation shows that the calculated results are in good agreement with the experimental results. By considering the influence of impedance boundary on sound propagation, it is possible to predict aerodynamic noise caused by flow more flexibly and accurately. Moreover, the noise can be effectively controlled by appropriate impedance arrangement.