Performance of impingement-jet double-layer nested microchannel heat sinks with vertical central bifurcation–A numerical approach and experimental verification

The present research discusses a new design which makes use of vertical central bifurcation (CB) to improve the thermal performance of the impingement-jet double-layer nested microchannel heat sinks (IDN-MHS) which was produced via 3-Dimension printing methodologies. The CBs are introduced into the IDN-MHS to improve the heat transfer performance in comparison with the traditional inner-outer nested circuit IDN-MHS. Five 3-Dimension printing tests were produced for experimental verification, and it was shown that the results of simulation are in good agreements with results of experiment. The introduction of CBs shows effective thermal control of substrate temperature, and reduction of peak temperature on the substrate of IDN-MHS-CB. Yet, a distance of 0.76 mm between the vertical central bifurcation and the center plane shows the best overall performance. Both experimental studies and numerical simulations indicate that the heat transfer enhancement of IDN-MHS-CB_0.76 is significantly superior. Additionally, the average Nusselt number of IDN-MHS-CB_0.76 is higher than that of IDN-MHS. Although the proposed CB structure generates higher pressure drop penalty, the overall heat transfer characteristics factor of IDN-MHS-CB_0.76 still prevails other designs, which significantly outperforms that of IDN-MHS without bifurcation.