Computational Aeroacoustics of a Generic Side View Mirror using Stress Blended Eddy Simulation

TL;DR

This study uses Stress Blended Eddy Simulation combined with FW-H equations to numerically analyze aerodynamic noise from a generic side-view mirror, showing good agreement with experimental data and effects of yawing on SPL reduction.

Contribution

It introduces a novel application of SBES coupled with FW-H for simulating mirror noise and explores yawing effects on sound reduction.

Findings

Simulation results match experimental data.

Yawing the mirror reduces SPL at receiver locations.

Flow attachment improves with yawing, decreasing noise.

Abstract

This paper presents a numerical investigation of aerodynamic noise generated by a generic side-view mirror mounted on a flat plate using the Stress Blended Eddy Simulation (SBES) coupled with the Ffowcs Williams and Hawkings (FW-H) equation. A grid evaluation study was performed using a standardised side-view mirror with a Reynolds Number (Re) of 5.2 x10^5 based on the diameter of the model. The predictions for hydrodynamic pressure fluctuations on the mirror, the window and the sound emitted at various microphone locations are in good agreement with previously published experimental data. In addition, our numerical results indicate that yawing the mirror closer to the side window results in the flow being attached to the rear of the mirror resulting in an overall reduction in Sound Pressure Level (SPL) at several receiver locations.