Temperature uniformity analysis and multi-objective optimization of the microchannel heat sink with cavities under longitudinal vortex flow

With the development of electronic devices toward a more centralized direction, there is an urgent need to introduce new technologies in the microchannel heat sink to address thermal deformation or failure caused by uneven temperature distribution. Therefore, microchannels with longitudinal vortex generators (LVGs) and different shapes of cavity structures combination are designed innovatively to address this issue. The laminar flow solver solves for single-phase, steady, and fully developed liquid flows through microchannels in the inlet Reynolds number range of 168-793. Study finds that the longitudinal vortex flow not only mixes the fluid in the mainstream region but also effectively weakens the retention effect in the cavities. Among all microchannels, the microchannel with LVGs and triangular cavities combination (MC-LTC) shows the best performance. Subsequently, multi-objective optimization of the MC-LTC is carried out using Non-dominated Sorting Genetic II Algorithm with the pumping power (Pp) and the temperature uniformity factor (E) as objective functions, and the relative heights (alpha, beta, gamma) of the three pairs of LVGs as the three design variables. The optimal solutions set for Pp and E range from 0.706 mW to 1.018 mW and 0.547 to 0.716, respectively. Among the five selected Pareto optimal solution parameters, MC-LTC (alpha = 0.6001, beta = 1.3528, gamma = 1.3707) and MC-LTC (alpha = 0.6001, beta = 1.0725, gamma = 1.3017) show the best temperature uniformity performance.