Reduction of the Aerodynamic Drag Due to Cooling Systems: An Analytical and Experimental Approach

The contribution of the underhood compartment to the total aerodynamic drag of the motor vehicles is analyzed by means of analytical models deduced from an integral balance of momentum. Two models of increasing complexity, and functions of the compartment geometry and the inlet/outlet static pressure coefficients, are proposed. The results deduced from each model are compared with experiments carried out in the windtunnel on a reduced scale model. This comparison makes it possible to discuss the capacity of each model to represent the physical phenomena, and enables the conception of improvements to the architecture of the underhood compartment.