CFD-Analysis and Experimental Verification of an Automotive Fog Lamp

A thermal analysis of an automotive fog lamp is performed using the commercial computational fluid dynamics package CFX-4. The three-dimensional, steady-state analysis accounts for convection and radiation within the fluid domain and conduction and radiation within the solid domain. Radiation is modelled using a multi-band ray-tracing approach. The geometry is meshed in detail including bulb and filament. Results show a temperature distribution characterised by a hot spot on the lens. It is mainly caused by radiation which is specular reflected at the reflector and partly absorbed by the lens. The housing temperature field shows warmer areas on top and colder areas at the bottom induced by convective heat redistribution due to the air flow inside the fog lamp housing. The calculation is experimentally verified. The good agreement between measured and calculated temperatures approves the simulation method.