Aeroacoustic Simulation around Automobile Rear-view Mirror

Abstract

A method for performing aeroacoustic simulation, where the acoustic field is split from the flow field, is applied to the flow around an automobile rear-view mirror placed on a large solid plane. The flow can be obtained by performing large eddy simulation for the incompressible flow equations on colocated grids, while the acoustic equations are defined by the difference between the compressible and the incompressible flow equations, and solved by the finite volume method with the fourth order WENO scheme. The non-reflecting boundary conditions with a perfectly matched layer are applied to the outer boundary. Calculated results show clear sound emissions, where acoustic streamlines as propagation path are depicted based on acoustic intensity vectors. In this paper, two kinds of mirror shape, i.e., the eases with and without a strong vortex at the tip of a rear-view mirror are compared. Calculated results show some differences between them in the acoustic field. The sound pressure related with the pressure frequency of the generated vortex is increased in all directions, though the propagation path dose not show a large difference except near part of the body surface.