Review of Aerodynamic Noise Prediction Using CFD 1999-01-1126

Recently, computational fluid dynamics (CFD) has made great progress. This paper reviews published papers on aerodynamic noise simulated by CFD and studies to what level CFD can predict aerodynamic noise for basic models and for applied models of automobiles. Based on noise generation mechanisms, aerodynamic noise is basically classified into two types, that is, noise induced by two-dimensional flow and by three-dimensional flow. As typical examples of noise generated by two-dimensional flow, wind throb at opened sliding roof, edge tone at the end of liftgate and aeolian tone generated by a cylindrical antenna are simulated by several computational schemes. As typical examples of three-dimensional flow, noise generated by A-pillar longitudinal vortex and noise from a side view mirror are computed by using a wing model and a actual vehicle, respectively.

Noise by two-dimensional flow can be almost estimated whereas noise by three-dimensional flow cannot be predicted at sufficient accuracy especially in high frequency range.

In order to predict noise with high accuracy it is necessary to improve computational techniques, based on noise data obtained by a carefully conducted wind-tunnel experiment which studies basic flow patterns with simple models.