内嵌多孔材料矩形微通道复合热沉的构形优化

Constructal Optimization of Rectangle Microchannel Hybrid Heat Sink Embedded with Porous Medium

针对高热流密度电子器件的散热问题,建立了内嵌多孔材料矩形微通道复合热沉模型,对热沉单元端面纵横比和热沉整体长宽比进行了双自由度构形优化。结果表明:给定初始条件,对热沉单元端面纵横比进行单自由度优化,可使热沉火积当量热阻比初始值降低44.1%;随着入口Re数的增大,热沉火积当量热阻降低,热沉单元端面最优纵横比有所减小;多孔区域体积占比越大,热沉单元端面最优纵横比越小;较小的孔隙率有助于降低热沉的火积当量热阻;对热沉单元端面的纵横比和热沉整体的长宽比进行二次优化,火积当量热阻最小值比一次优化所得的最小值进一步降低了14.8%。

For the heat dissipation problem of electronic devices with high heat flux,a model of rectangle microchannel hybrid heat sink embedded with porous medium is developed.Aspect ratio of heat sink cell and length-width ratio of heat sink are opti⁃mized by numerical simulation method with double freedom degrees according to constructal theory.The results show that the initial conditions are given,entransy equivalent thermal resistance(EETR)is 44.1%lower than its initial value after the aspect ratio is op⁃timized.With the increase of Reynolds number,EETR drops and the optimal aspect ratio declines as well.A larger volume propor⁃tion of porous medium makes a smaller optimal aspect ratio.A smaller porosity is beneficial to reduce EETR of the optimal construct.The minimum EETR obtained from twice optimization with aspect ratio and length-width ratio further decreases by 14.8%than that obtained from single optimization.