Single-phase and two-phase hybrid cooling schemes for high-heat-flux thermal management of defense electronics

This study examines the cooling performance of two hybrid cooling schemes that capitalize upon the merits of both micro-channel flow and jet impingement to achieve the high cooling fluxes and uniform temperatures demanded by advanced defense electronics. The jets supply HFE 7100 liquid coolant gradually into each micro-channel. The cooling performances of two different jet configurations, a series of circular jets and a single slot jet, are examined both numerically and experimentally. The single-phase performances of both configurations are accurately predicted using 3D numerical simulation. Numerical results point to complex interactions between the jets and the micro-channel flow, and superior cooling performance is achieved by optimal selection of micro-channel height. The two-phase cooling performance of the circular jet configuration is found superior to that of the slot jet, especially in terms of high-flux heat dissipation. Unprecedented cooling fluxes as high as 1,127 W/cm² are achieved with the circular jets without incurring CHF.