Unsteady characteristics of flow over a realistic heavy vehicle

Abstract

Large-eddy simulation of turbulent flow around a 1:8 scale 15-ton heavy vehicle model is performed at Reynolds number of 9.1x10(5) to study unsteady characteristics of the surface forces. The drag coefficient and profiles of the mean streamwise velocity in the wake region are in good agreement with the experimental counterparts. Time histories of the drag, lift, and side forces are collected to analyze the frequency characteristics of forces applied on the vehicle surface. Velocity fluctuations near the vehicle surface are also obtained to study spectral features of the flow field. Results show that fluctuations of the streamwise velocity in the cab roof region are closely related to the drag frequency, whereas wake shedding heavily affects the frequency characteristics of the side force.