Search Results

Surface pressure fluctuations on the front side window of a car-like body are numerically predicted by means of time-dependent Navier-Stokes simulation. The numerical results indicate that there is a critical inclination angle for the front pillar where the wind noise changes drastically. The related characteristics of turbulent flow structure are studied and show the mechanism of wind noise generation.

A numerical analysis method is developed for predicting the pressure fluctuations on the front side window surface, aiming at the elucidation of the external aerodynamic flow structure about the front pillar of a road vehicle. The simulated results are assessed by comparison with the acoustic theory and reveal fairly well the dependence of the predicted surface pressure fluctuations upon the vehicle cruising speed with the sixth power law. The features of three dimensional vortical flow are clarified from the analysis of the simulated results, indicating the strong relationship between the vortical formation and the external pressure fluctuations on the front side window surface. The external pressure fluctuations seem to be strongly related to the vortex breakdown during its interaction with the front side window and the roof-side window junction.