The flow and aerodynamic noise calculation of a generic side mirror

摘要

The flow and aerodynamic noise of a generic side mirror in high-speed is evaluated using numerical simulation and experiment. The Reynolds number is Re=5.2×10⁵ basing on the mirror diameter. Transient flow field is analyzed by Large Eddy Simulation (LES), two different sub-grid scale (SGS) models named Smagorinsky-Lilly (SL) and Wall-Adapting Local Eddy-viscosity (WALE) are used to express the turbulent viscosity. Detailed velocity vectors and pressure fluctuation contours are compared by cut planes in the flow-field. Mean and transient pressure are also monitored at several points in the flow field and compared with corresponding experimental data. The sound propagation is predicted by the Ffowcs Williams-Hawkings (FW-H) acoustic analogy where wall pressure fluctuations and pressure temporal are treated as two source terms. The conclusion is that the SL model is a better candidate for this mirror simulation.