NUMERICAL ANALYSIS ON AERODYNAMIC SOUND SOURCES GENERATED BY LONGITUDINAL VORTEX

Abstract

To investigate the acoustic characteristics of aerodynamic noise produced by longitudinal vortex behind front-pillar of a vehicle, longitudinal vortex was reproduced by a delta wing whose attack angle of 15 degrees in the uniform flow velocity 30 m/s. Computational Fluid Dynamics (CFD) investigated the acoustic characteristics of longitudinal vortex in terms of rotational speed, vorticity and pressure fluctuations on the wing surface. As a result, it is considered that large acoustic pressure with high frequency may be generated at the tip and small one with low frequency at the rear, respectively.