LED JUNCTION AND HEATSINK NUMBER CALCULATION WITH COMPUTATIONAL FLUIDS DYNAMIC (CFD)


Sokmen K. F. , PULAT E., YAMANKARADENİZ N., COŞKUN S.

ISI BILIMI VE TEKNIGI DERGISI-JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY, vol.35, no.1, pp.69-75, 2015 (SCI-Expanded) identifier

Abstract

A LED (Light Emmitting Diode) is an optoelectronic component which includes active layer among N and P type semiconductor products like a sandwich and electrical taps. Since 1995 LED is used in automotive sector. On this application, 0.5-0.75-1-1.25 W powered a typical car head light LED's junction temperature (T-j) rates with HAD resolutions at 25, 50, 80 degrees C and heat transmission rates are calculated. The winglet numbers and types, optimum winglet gaps were found out with macro according to evidences. The geometric model of LED was designed by CATIA V5 R19 software. It is divided into its components with ICEM CFD and its temperature analysis is done via ANSYS CFX 14. Its airflow is assumed as in constant regime, laminar and solid. Thermo physical features of the weather's changes related to heat, buoyancy and radiation effects are taken into consideration. Heat transmission rate on circuit and temperature rates are calculated and compared with the literature rates. Appropriate fin design developed with the help of program developed and despite the increasing ambient temperature, junction temperatures taken appropriate values. Optimum fin interval was found to be an important parameter in the design of heat sinks. LED should be located where the ambient temperature is low in headlamp for LED life and performance to be expected level.