The automotive industry is making a transition to LEDs as the primary lighting source for many applications. The adoption of LEDs for forward lighting is met with hurdles like proper heat dissipation and high initial cost. In this project the problem of heat dissipation has been addressed and its effect on the headlight performance was also studied. A simple 7" round driving beam headlight was modelled with a heat sink for this project. In order to dissipate the heat effectively two methods were adopted: 1. Insertion of a heat pipe in heatsink and 2. Modification of LED pitch. So a total of four models - 1)headlight without heat pipe, 2)headlight with heat pipe, 3)headlight with modified LED pitch and without heat pipe and 4)headlight with modified LED pitch and heat pipe; were thermally analysed in a CFD thermal simulation software tool-6SigmaET. The critical temperatures obtained from the thermal simulation were used to determine the luminous flux of each LED. Then using the luminous flux values of the LEDs the illuminance test, required for type approval of headlight as per AIS 010(Part 1), was simulated in TracePro software for the four headlight models. The variation in the illuminance value due to the different junction temperatures of the LED was studied using the above simulation. Finally, the reliability of each model of LED headlight was calculated using the Arrhenius equation and military handbook for electronic equipmentMIL HDBK-217F.
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