Novel Approach towards Fuel Tank Heat Shield Design

Vehicle heat management has become a serious concern due to escalating under-hood and exhaust temperatures. Compact vehicle packaging caused by downsizing has further magnified this concern. In an automobile, fuel is stored in a metallic or plastic fuel tank. In addition to fuel storage, temperature inside fuel tank has to be maintained at a certain limit in order to control high fuel evaporation rate and prevent deterioration of parts. The fuel tank surface temperature is governed by heat rejection from the engine, exhaust system and heat radiated from the road. Generally, mechanical shielding has been found to be an efficient defense to the heat management problem. However ‘what to shield’, ‘where to place the shield’ and ‘how to shield’ are the major challenges. This paper describes a methodology followed to reduce temperature on fuel tank surface by varying material, geometry and layout of heat shields. Computational Fluid Dynamics (CFD) of different iterations were carried out and correlated with actual vehicle test to determine the most effective shielding arrangement between exhaust system and fuel tank.