Aerodynamics of Vehicles Through Driving Tunnels - Experimental Study of Interference and Drag Reduction 2001-01-1044

Due to energy and material considerations, vehicle manufacturers move in the direction of producing smaller and lighter vehicles. With further reductions in the weight of vehicles, aerodynamic forces emerge as a major factor in energy and stability calculations. The situation becomes more important when moving through driving tunnels. Because of the limited space of a driving tunnel, vehicles are usually forced to interfere severely. 1/25-scale models for domestic bus and passenger car are employed. Three-dimensional pressure measurements are recorded for analyzing the aerodynamic behavior and calculating the drag coefficient. Measurements are supported by numerical calculations and flow visualization. Results show that vehicle interference has a favorable effect on reducing drag. However, stability considerations should be noticed.