Thermal Effects of Shield Shape on Headlamps

Although a headlamp may meet optical specifications, it can still have thermal problems. In the present study, a high temperature beyond the melting point of the component materials was observed in the hot zone at the upper surface of the bezel and outer lens. Yet, the purpose of a numerical simulation of the thermal flow in a headlamp is not only to verify the thermal problem, but also to improve the headlamp design. Thus, a series of numerical simulations were performed while changing the geometrical shape of the headlamp. As a result, a change in the shape of the bulb shield was identified that was expected to decrease the temperature of the hot zone by 17°C The final design was then experimentally verified using thermocouples and an IR camera, which confirmed an actual drop of temperature of 23°C in the hot zone. Consequently, the maximum temperature on the bezel surface was reduced by increasing the distance between the bulb shield and the bulb.