Center Floor Undercover Air Guide Development to Improve Aerodynamic Drag for a Passenger Car

Cooling airflow is essential to the vehicle air conditioning system and engine cooling module. The cooling airflow in the engine room flows out through the front subframe, front wheelhouse, roll-rod, etc. and mixes with the upstream external flow in the underbody of the vehicle so that it affects the aerodynamic drag on the rear part of the vehicle. An air guide is developed to reduce the aerodynamic drag. It is attached on the center floor undercover and induces cooling airflow exited from the engine room to flow to the rear section of the underbody of a vehicle. It can reduce up to 2.3 % of the aerodynamic drag of baseline vehicle. Numerical flow simulations are performed at the velocity of 140 km/h vehicle driving condition.