Aerodynamics of Road Vehicles: Results Obtained by Numerical Simulation

A first-order ‘panel’ method has been implemented to calculate the pressure distribution along the longitudinal midsection of some road vehicles. For computational simplicity, the local flow is tacitly assumed quasi-two-dimensional (two-dimensional with a small three-dimensional perturbation). Only the case of an axial symmetric flow, in the absence of lateral wind, was analysed. All external surface details, such as bumpers, cooling air duct entrance, windscreen wiper, etc., were removed, and the underside surface was made fairly smooth. Effects of the ground plane, through the ‘reflection principle’, and the body ‘wake’ have been considered. For a specific model of the passenger car, the lift force, per unit length, acting on the body, as well as its dimensionless coefficient, were calculated depending on the velocity of the vehicle.