Platooning and Base Flaps for Drag Reduction of Trucks

Experimental investigations on generic truck models were carried out on the combined drag reducing effects of platooning and base flaps. A towing tank facility was used with model scales of 1:15 and Reynolds numbers of up to 10 6 . Two vehicle and three vehicle configurations with variable intervehicle distances were analyzed without considering the influence of a ground proximity. The potential of two and three vehicle platoons for drag reduction is clearly demonstrated exemplary for flap angles of 15°. Under certain conditions base flaps increase these benefits. However, their effect depends on the intervehicle distance, the flap angle, and the vehicle position within the platoon. The platoon drag can be reduced by additional 25 % when base flaps are added which corresponds to an overall platoon drag reduction of about 40 %.