Thermo-Hydraulic Management System Employing Single-Phase Water Flow through Microchannels with Micro-Inserts Added Aiming for Performance Improvement

A microchannel heat exchanger effectively evacuates heat from a confined space. This paper attempts to gain insight into the combinatorial repercussions of simultaneously coupling two factors that affect a microchannel's performance, of which channel size and micro-insert complexity are the two main contributors. With water as the working fluid, an ANSYS-based numerical analysis was carried out for two distinct channel sizes, 1 and 2 mm, both with and without micro-inserts. The Reynolds numbers varied between 125 and 4992 and between 250 and 9985 for the 1 and 2 mm channels, respectively. For the 2 mm diameter channel, adding micro-inserts raised the overall pressure drop with increased Reynolds number. The inclusion of micro-inserts increased the pressure drop in the 1 mm channel at first, and thereafter the pressure drop decreased. Incorporating micro-inserts into the channel resulted in enhanced heat transfer. The trade-off between enhanced heat transfer performance and a larger pressure drop was calculated by evaluating the channel's overall performance using the thermal performance factor. Micro-inserts were found to be most useful for improving overall performance in the low-to-moderate Reynolds number range, and their effectiveness increased with decreasing channel size. Changing the channel diameter and structure of the design can improve heat transmission through microchannels.