Effect of an Optimized Heatshield Design and an Aerodynamic Exhaust Tunnel Cover on Convective Heating of the Floor Pan

A thermal investigation based on measurements on 3 different front wheel driven vehicles has been carried out. Temperatures were recorded on road and test bench and showed the potential to improve the thermal protection in the area of the exhaust line tunnel.

This improvement can be achieved by design changes on the tunnel heatshield, which prevent convective heating of the body. Compared to the respective baseline conditions temperatures at the tunnel body were lowered by 15°C on average and in some regions by more than 40°C.

The investigation shows the potential of closing the tunnel area underneath the exhaust line for improving aerodynamic drag while keeping temperatures of the tunnel body and sensitive components at an acceptable level.