Fluid and Thermal Analysis for LED Headlamp with Parametric Studies

Thermal management of LED's junction temperature is one of the fundamental technologies for LED headlamp to ensure basic specifications in many aspects. Since almost all headlamps consist of a complex three-dimensional housing and lens, an evaluation of junction temperature depends on a theoretical prediction including numerical simulation in a development stage. In this study, we describe a simulation to predict LED's junction temperature using Fluid and Thermal Analysis for two LED headlamps. First model is a simplified headlamp with ten LED modules placed in a trapezoidal plastic box. The LED module includes a reflector, lens, heatsink and LED. Second model is a practical headlamp with twenty LEDs on a three-tiered bracket and optical systems using a housing and outer lens of a commercial vehicle. The calculated junction temperatures for both headlamps agree with estimated ones based upon measured temperatures underneath each LED. Next, parametric studies with conceptual models were carried out to evaluate the quantitative effect of geometrical parameters of components on junction temperature for each LED. According to the results of the parametric studies, we discussed about an optimal thickness of the bracket that has a major role as a passage of thermal energy from the LED to the heatsink.