Heat transfer enhancement of LEDs with a combination of piezoelectric fans and a heat sink

This paper reports on the enhancement of the heat transfer in high power LEDs by a combination of piezoelectric fans and a heat sink. Experimental and numerical studies were conducted to evaluate the heat dissipation efficiency of the package of high power LEDs operating under multiple vibrating fans. Dual and quadruple vibrating fans were vertically positioned to a finned heat sink embedded in the LEDs package. Thermal resistance is observed to be sensitive to the separation distance between the two vibrating fans in array at their respective heat sink slots. Thermal resistance (R), the junction temperature (TJ), and the average heat transfer coefficient (h−) were estimated. A substantial reduction of the thermal resistance was observed at intermediate P/Apf = 7 separation distance at three different heating powers (Q). The computed results revealed that the dual fans enhanced the heat transfer performance by approximately 3.2 times, while the quadruple fans enhanced heat sink of the LEDs by 3.8 times compared to natural convection.