Thermal-dynamic performance enhancement analysis on central impinging jet double layer microchannel heat sinks with variable working flow conditions verified by SLM 3D printing technology for the powerful electronics cooling system

In order to further improve the thermal performance of parallel straight double-layer microchannel heat sinks, the central impinging jet double layer microchannel heat sinks are designed. Six kinds of working flow conditions are examined in the designed structure, the designs feature two inlets and three outlets. Simulations were conducted for all configurations and the corresponding experimental samples made by selective laser melting (SLM) 3D are conducted for verification of the numerical simulations. It is found that the test results for heat transfer performance and pressure drop penalty are in line with the numerical results. Through combining the advantages of impinging jets and double layer structures, the controlling of peak temperature and thermal uniformity on substrate is quite effective. In comparison with parallel straight double-layer microchannel heat sinks, the maximum temperature on substrate in the central impinging jet double layer microchannel heat sinks with optimal working condition decreases significantly. As Re = 580, the Nusselt number of the optimal working conditions reaches 38.18, which increases by 51.86 % compared with the referenced model. Taking the overall thermal performance factor ((Nu/Nu₀)/(Δp/Δp₀)^1/3) as the criterion to evaluate the comprehensive overall thermal performance, the optimal working condition has the value mentioned above up to 1.47 and the thermal resistance is at a very low level. It is worth mentioning that the pressure drop is not significantly increased under various working conditions.