Thermalhydraulic assessment and design optimization of incorporating flow obstructors in a supercritical minichannel heat sink

Modulation of the thermalhydraulic characteristics of the miniaturized heat sink by geometric alteration is a less explored topic, particularly in conjunction with the supercritical fluids, which can experience both enhancement and deterioration in performance based on the conditions. The present study appraises the response of a square minichannel by incorporating rectangular obstructions, with the primary aim of identifying an optimized orientation and design. A performance evaluation criterion, defined as a combined change in both heat transfer coefficient and pressure drop because of geometric modification, is selected as the primary variable. Installation of the baffles substantially augments the turbulent mixing among the fluid layers, realizing a lower wall-to-fluid temperature differential and enhanced heat transfer coefficient. A relatively lower level of temperature is maintained within the baffled section, thereby delaying the appearance of heat transfer deterioration. Obstructions, however, considerably increases the pressure losses, necessitating careful selection of the dimensions. The use of three pairs of baffles has been identified to be the most feasible option. Desirable values of the height, thickness, and inclination angle for individual plates in this orientation have also been identified, along with a detailed thermalhydraulic assessment about the role of the operating variables with the optimum design.