Synergistic mechanism in open microchannel and jet impingement hybrid cooling system

High-power, highly integrated electronic devices present significant challenges for thermal design. The conflict between bubble detachment paths and liquid replenishment paths leads to bubble aggregation and premature triggering of critical heat flux during the nucleation boiling stage, becoming a bottleneck for improving heat transfer capacity in flow boiling thermal design schemes. To study the mechanism of separated bubble detachment and liquid replenishment paths in an open microchannel under jet impingement, this paper investigates the influence of inertial force on bubble distribution by combining visual experimental results with simulation calculations. The results have found that as the top gap of the channel narrows, a large number of bubbles accumulate at the bottom of the channel, inhibiting nucleate boiling. This is because when the top gap shrinks, the increase in inertial force at the bottom of the channel (309.1%) is much higher than that at the top (50.9%). Under the action of inertial force, bubbles are more likely to detach and accumulate, which invalidates the mechanism where the channel flow and jet flow work together to separate bubble detachment path from liquid replenishment path, thereby making the critical heat flux more likely to be triggered. The research is of great significance for exploring the critical heat flux triggering mechanism in microchannels and improving the heat transfer capacity of microchannels.