Optimization of wind resistance for heavy truck

To optimize the drag coefficient of heavy truck, the effect of rear spoilers and linking seals between cab and packing case was tested, in which the relative motion between truck and road and the pressed deformations of tires in real running under windless conditions were considered. The numerical simulation using commercial computational fluid dynamics software FLUENT and low-speed wind tunnel experiments were carried out to investigate the airflow characteristics around the US standard Class 8 truck and the drag coefficients of truck with different add-on devices. Analysis result indicates that by attaching the proper add-on devices, such as linking seals and rear spoilers, the rear vortices and front airflow sparation of packing case reduce, which results in the significant reduction of drag coefficient. At commercial speed of 90 km·h-1, drag coefficient decreases by 16.2% and its minimum value is 0.4854.