Importance and Determination of Lift Coefficient for Road Vehicles

Vehicle driving safety largely depends on frictional coupling between road and tire. lift force that effects vehicle in cruise adversely affects driving stability via reducing dynamic axle loads which is one of the main parameters of the holding between tire and road. in this study lift coefficient of bmw x5 e53 has been tried to be determine with a 1/24 scale model in a wind tunnel. according to obtained data after 100 km/h vehicle speed a rapid increase in lift force has been observed. when vehicle speed reached 200 km/h lift force has been determined as 280 n. using pressure distiribution on vehicle, the lift forces acting on vehicle axles has been considered.