Abstract: In view of the characteristics of high power light-emitting diode (LED), such as high heat fluxes and requirement of strict temperature control, a porous micro heat sink system is presented for thermal management of high power LED, which has high heat transport capability. The working principle and heat transfer characteristics of porous micro heat sink are analyzed. Numerical model for the micro heat sink is proposed to describe liquid flow and heat transfer based on the local thermal equilibrium of porous medium, and it is solved with SIMPLE algorithm. The numerical results show that the heated surface temperature of porous micro heat sink is low at high heat fluxes and the maximal temperature of heated surface is only 55.2 ℃ at the heat flux of 200 W/cm2. Increasing inlet fluid velocity can decrease the temperature in the micro heat sink and the heated surface temperature. The micro heat sink has good performance for the cooling of high power LED, and it can improve the reliability and life of LED. The numerical results obtained are useful for performance optimization and design of porous micro heat sink.

Key words: Heat dissipation, High heat flux, High power light-emitting diode(LED), Porous medium, Porous micro heat sink