FINITE ELEMENT ANALYSIS OF HEAT TRANSFER AND DEAN VORTICES OF RECTANGULAR CORRUGATED MICROCHANNEL

Abstract

In order to develop a rectangular corrugated microchannel (RCM) heat sink with high heat transfer and low pressure drop, a rectangular corrugated microchannel is designed and simulated, and then the effects of amplitude <i>A</i>, wavelength <i>λ</i>, and inlet flow velocity <i>u<sub>in</sub></i> on heat transfer performance, Dean vortices, and pressure drop are investigated. Furthermore, <i>A, λ</i>, and <i>u<sub>in</sub></i> are optimized according to the performance evaluation criterion (PEC). Moreover, the effect of microchannel number <i>N </i>on the microchannel heat sink is investigated at equal pump power. Finally, the optimal rectangular corrugated microchannel is compared with the rectangular straight microchannel (RSM) at equal pump power. The results show that the area and the number of Dean vortices, the average Nusselt number and the pressure drop increase gradually as <i>A</i> and <i>u<sub>in</sub></i> increase or as <i>λ</i> decreases. The comprehensive performance reaches the optimum at <i>A</i> = 0.3 mm, <i>λ</i> = 5 mm, and <i>u<sub>in</sub></i> = 1.4 m/s. Under equal pump power, as <i>N</i> increases, the total heat transfer area and the number of Dean vortices increase, so the thermal resistance and the temperature decrease and reach the optimum at <i>N</i> = 10. Compared to the regular streamline in the rectangular straight microchannel, the area and number of Dean vortices change with the curvature of the corrugated microchannel and reach the maximum at wave peak and valley. Compared to the rectangular straight microchannel, the optimal rectangular corrugated microchannel decreases the temperature by 31 K, decreases the thermal resistance by 57.03%, increases the average convective heat transfer coefficient by 219.49%, and increases the performance evaluation criterion by 131%, while it increases the pressure drop by 107.5%.