Aeroacoustic noise prediction using hybrid RANS/LES method and FW-H equation

The computational aeroacoustic result of aerodynamic noise problems is highly dependent on the capturing accuracy of an unsteady flow in the numerical prediction of aerodynamic noise. As a benchmark for airframe noise computation, the noise prediction for tandem cylinders is performed in this paper. The flow around the cylinders is simulated using the limited numerical scale (LNS) method based on a nonlinear k-ε model. The aerodynamic results and flow features obtained from the simulation are analyzed and compared with the experimental results. The flow parameters on the sound source surface are also recorded as the preparation data and then are combined with the acoustic analogy based on the FW-H (Ffowcs Williams-Hawkings) equation to predict the aerodynamic noise at the far-field receiver points. Since the spans in the simulation are relatively short, the predicted results have to be corrected for the span length. The final acoustic results are in good agreement with the experimental data, which indicates that the present numerical method is valid for this kind of aerodynamic noise problems.