Aeroacoustic Tonal Noise Generation Analysis on a Simplified Side-View Mirror Using a High Order Discontinuous Galerkin Spectral Element Method

Avoiding narrowband components in the acoustic spectrum is one of the most critical objectives in the automotive aeroacoustic optimization process. The underlying physical mechanisms are not completely understood. In a preceding numerical and experimental investigation, we performed large eddy simulations of an early-development stage realistic side-view mirror, where tonal noise was captured and the principle mechanisms were identified. In this contribution, we present simulations on a simplified two-dimensional geometry that is based on these findings. It is shown that the basic flow topology relevant for tonal noise generation on the original side-view mirror as well as the tonal noise source is reproduced in the 2D case. Furthermore, we present comparisons with measurements and the necessity and influence of a splitter plate downstream of the 2D body to avoid large scale vortex shedding. The present results are the basis for ongoing, detailed numerical analyses of the fundamental source mechanism.