Thermal performance of microchannels with wavy walls for electronics cooling

Wavy walls are investigated in this paper as a passive scheme to improve the heat transfer performance of low-Reynolds-number laminar flows in microchannel heat sinks for electronics cooling applications. 3-D laminar fluid flow and heat transfer characteristics in microchannels with wavy walls are numerically studied for a 500-μm hydraulic diameter channel by varying the wavy feature amplitude at different Reynolds numbers (10, 20, 50, and 100). In addition, flow measurements are made using a micrometer-resolution particle image velocimetry technique for understanding the fundamentals of fluid flow in the wavy-walled microchannels for the considered Reynolds numbers. Based on the comparison with straight channels, it was found that wavy channels can provide improved heat transfer performance while keeping the pressure drop within acceptable limits. Accordingly, wavy channels are to found to provide an improvement of up to 26% in the overall performance (which includes the effect of wall waviness on heat transfer, pressure drop, and surface area) compared to microchannels with straight walls for the same pumping power and hence are attractive candidates for cooling of future electronics.