多孔侧肋双层微通道热沉构形优化

建立了多孔侧肋双层微通道复合热沉模型,选取最大热阻最小化为优化目标、热沉单元端面纵横比为优化变量,在热沉总体积和流体区域体积占比给定的条件下,对复合热沉进行了构形优化,并分析了冷却剂入口速度、多孔材料孔隙率、上下通道高度比、流体区域体积占比、肋厚比等参数对热沉最优构形的影响.结果表明:给定初始条件,优化热沉单元端面纵横比,可使最大热阻减小21.19％;在热沉单元端面纵横比较小时,减小孔隙率有利于降低最大热阻,而在热沉单元端面纵横比较大时,存在最优的孔隙率使得最大热阻最小;上下通道高度比和肋厚比的改变均未影响热沉最优构形.

Constructal Optimization of Double-layered Microchannel Heat Sink with Porous Side Fins

A model of double-layered microchannel heat sink with porous side fins is developed. Taking minimizing the maximum thermal resistance as the optimization objective and the aspect ratio of heat sink cell as the optimization variable, the constructal optimization was carried out for the heat sink with porous side fins under the constraints of given total volume of heat sink and volume proportion of fluid region. The effects of inlet velocity of coolant, porosity, the height ratio of upper channels to below channels, the volume proportion of fluid region and rib thickness ratio on the optimal constructs are analyzed, respectively. The results show that, with given the initial conditions, the maximum thermal resistance is 21.19% lower than its initial value after the aspect ratio is optimized. Decreasing the porosity is beneficial to reduce the maximum thermal resistance when the aspect ratio is smaller, while there is an optimal porosity to make the maximum thermal resistance minimize at a large aspect ratio. The changes of height ratio of upper channels to below channels and rib thickness ratio show few effects on the optimal construct.