Design and Feasibility Analysis of Microscale Bumped Channel with Supersonic Flow for Electronics Cooling

In this paper, microchannel heat sink cooling device utilizing supersonic gas flow with isentropic expansion has been designed and analyzed. The objective is to study the feasibility of the supersonic microchannel with bumped section design for electronics cooling. Numerical simulations on the designed microchannel flows and heat transfer analysis have been conducted (in conjunction with a supersonic air flow inside a heated fin array) and compared with experimental results in this paper. The performance of the designed microchannel is also compared with traditional Laval nozzles for the feasibility analysis. Under 350 and 330 K inlet temperature conditions, the calculated Nu number is found higher than pure through channel flows. The supersonic expanding flow is successfully generated with lower heat transfer temperatures and a simpler geometric shape. The design of 100-300 μm is found to have highest heat transfer for integrated microchannel width selection. For electronics cooling tests, the newly designed supersonic channel is found sufficient for a cooling capacity around 1.4 MW/m². In addition, the supersonic flow and heat transfer characteristics are also discussed into detail in this paper.