Effects on Aerodynamic Characteristics by Flow Control on Underside of High-Speed Road Vehicle. Effect of Channel by Skirts.

Channels by skirts are considered in order to style the underside of vehicles in such a way as to facilitate the air flow in relation to stability problems. The ground effect of these channels attached to the middle or/and rear of the vehicle underside is investigated in a wind tunnel with a moving belt and a suction box. Flow visualization of the underside is carried out using the methods of oil and tufts. As a result, these channels can control the flow underneath the underside of the vehicle, which has an important effect on the aerodynamic lift. The diffuser-type channel is effective in reduction of the lift. But effect to the drag are small. From flow patterns, the flow inside the channel on the middle is referred to the flow in a sudden enlargement or a contraction, and that on the rear to that in a diffuser.