考虑边界滑移的微通道热沉传热传质性能研究

考虑固液界面边界滑移条件,研究了具有矩形、椭圆形和三角形这3种不同截面形状的微通道热沉的传热传质性能。研究发现,随着滑移长度的增加,流体阻力逐渐减小,对流传热系数逐渐增大。具有相同滑移长度和截面形状的微通道热沉的流体阻力和对流传热系数均随水力直径的增加而减小。在微通道截面面积相同的条件下,三角形微通道热沉的对流传热性能最差;对于椭圆形和矩形微通道热沉,当水力直径小于某一临界值时,矩形传热效果更优,而大于这一临界值时,椭圆形传热效果更好。

Heat and Mass Transfer Performances of Fluid Flow in Microchannel Heat Sinks in Consideration of Boundary Slip

With considering the boundary slip at the solid-liquid interface, the heat and mass transfer performances of fluid flow in microchannel heat sinks with three different cross-sectional shapes, i.e., rectangular, elliptical and triangular were studied. The results show that the hydraulic resistance decreases but the convective heat transfer coefficient increases with the increasing of slip length. Under the constraints of fixed slip length and with the same cross-sectional shape, the hydraulic resistance and convective heat transfer coefficient of microchannel heat sinks with any cross-sectional shape decrease with the increase of hydraulic diameter of the microchannel. Regarding the microchannels with three different cross-sectional shapes, it is found that the triangular shaped microchannel has the worst heat transfer performance under the constraint of same cross-sectional area. For the elliptical and rectangular microchannels, the rectangular microchannel has better heat transfer performance when the hydraulic diameter of the microchannel is smaller than a critical value, but the elliptical microchannel has better convective heat transfer performance when the hydraulic diameter of the microchannel is larger than the critical value.