The Effects of Crosswind on the Aerodynamics of Vehicles Running in Close Proximity

Abstract

This paper deals with the aerodynamic interference between two vehicles which are running in close proximity and are subjected to crosswind. Measurements of the aerodynamic drag, side force and yawing moment were performed at different wind angles and longitudinal and lateral distances between two vehicles. In crosswind, extreme proximity between the vehicles ahead and behind provides several peaks of aerodynamic drag, side force and yawing moment acting on the vehicles. When one vehicle passes the other one in crosswind, the large variation in these forces and moment leads to the danger of driving. Numerical results by the CFD show a good agreement with experimental ones. They reveal that the aerodynamic drag is influenced by airflow behind the other vehicle, and that the side force and the yawing moment are also influenced by complicated airflow structure due to the aerodynamic interference between two vehicles.