Performance Analysis of Heat Sinks Designed for Additive Manufacturing

Significant levels of heat are generated in contemporary electronics, and next generation devices will continue to demand higher power despite decreasing size; therefore, highly effective cooling schemes are needed. Simultaneously, advances in metal additive manufacturing have enabled production of complex heat transfer devices previously impossible to traditionally manufacture. This paper introduces three novel prototypes, originally designed for a prior ASME Student Heat Sink Design Competition sponsored by the K-16 (Heat Transfer in Electronic Devices) technical committee, to demonstrate the abilities of selective laser melting processes in the fabrication of A357 aluminum, EOS aluminum, and copper heat sinks. The performance of each of these prototypes has been determined experimentally, and the effects of specific material and design choices are analyzed. Comparisons of experimental results show that the copper and EOS aluminum prototypes performed better than the A357 aluminum due to increased thermal conductivity; however, the gains in thermal performance from EOS aluminum to copper were much lower despite the large difference in thermal conductivity.

A Numerical and Experimental Study of a Novel Heat Sink Design for Natural Convection Cooling of LED Grow Lights

Light-emitting diode (LED) grow lights are increasingly used in large-scale indoor farming to provide controlled light intensity and spectrum to maximize photosynthesis at various growth stages of plants. As well as converting electricity into light, the LED chips generate heat, so the boards must be properly cooled to maintain the high efficiency and reliability of the LED chips. Currently, LED grow lights are cooled by forced convection air cooling, the fans of which are often the points of failure and also consumers of a significant amount of power. Natural convection cooling is promising as it does not require any moving parts, but one major design challenge is to improve its relatively low heat transfer rate. This paper presents a novel heat sink design for natural convection cooling of LED grow lights. The new design consists of a large rectangular fin array with openings in the base transverse to the fins to increase air flow, and hence the heat transfer. Numerical simulations and experimental testing of a prototype LED grow light with the new heat sink showed that openings achieved their intended purpose. It was found that the new heat sink can transfer the necessary heat flux within the safe operating temperature range of LED chips, which is adequate for cooling LED grow lights.