圆环形腔内凝固问题的热阻法近似解

对圆环表腔内的凝固问题进行研究，得到了热阻法近似解，以及在第三类边界条件下，该近似解的表达式，并用有关实验予以验证，用此公式计算了圆环形腔的性能，得出以下结论：圆环形腔蓄冷量大而蓄瓣最佳关径比为0.15-0.25；Bi数小于10时，增大Bi数才能起到强化凝固传热的作用，因此，用于冷却的表面传热系数应在Bi数小于10的范围内选取。

Approximate Solution of Heat Resistance Method for Solidification in Concentric Annulus

By study on the solidification in concentric annulus, anapproximate solution is obtained.The correlation of approximate solution of heat resistance method which describes the solidification process in concentric annulus with the third kind of the boundary conditions is developed and verified by experiments.The approximate solution is used to estimate the performance of concentric annulus.Following conclusions are obtained:①the optimum radius ratio of concentric annulus is 0.15 to 0.25 where its cold storage capacity is large while storage time is short,②only if Biot number is smaller than 10 can the increase of Biot number help to enhance solidification heat resistance.Therefore, it is the very region for selecting the cooling convection coefficients where Biot number is less than 10.All these results could guide the design of concentric annulus.