Thermal analysis and experimental verification on double-layer microchannel heat sinks with impact jet nested arrays

The present study investigate a novel combined features which make use of impingement jet nested arrays (IJNAs) to strength the thermal performance of double-layer microchannel heat sinks (DMCHS) based on 3D printing technologies. The IJNAs are firstly introduced into the DMCHS to enhance the thermal characteristics compared with the traditional straight and impact jet straight arrays DMCHS. Three 3D-printed test samples were manufactured for experiments, and it is found that the numerical simulations are in line with the experimental measurements. The thermal control of the substrate temperature by introducing IJNAs is very effective, and the reduction in peak temperature on substrate is more than 20 K lower than that of traditional DMCHS. The experimental study and numerical simulation both show that the heat transfer enhancement of the impingement jet and nested structure is very pronounced. Besides, the average Nusselt number of IJNA-DMCHS is 5.33% higher than that of IJSA-DMCHS. Even though the proposed structure of IJNA yields higher pressure drop penalty, the overall thermal performance factor that balances the influence of heat transfer augmentation and pressure drop penalty still favors the proposed IJNA-DMCHS with nested channels, and it outperforms considerably that of IJSA-DMCHS with straight channels.