不同尺度下相变材料熔化过程自然对流影响分析

为了解自然对流对固液相变传热的影响,采用有限容积法对重力条件下矩形腔内相变材料熔化过程进行了数值模拟。通过改变矩形腔的尺寸,分析了不同尺度对高温壁面平均Nu数(Nu数)及相变材料温度场、速度场的影响。结果表明:随着尺度增加,自然对流作用增强,Nu数逐步增大,液相区流动从稳定向周期振荡过渡,且流线越来越不规则。

Analysis of natural convection during melting of phase change materials under different scales

To study the influence of natural convection on solid-liquid phase change process, a numerical simulation of natural convection during melting of phase change materials in a rectangular cavity is carried out by using finite volume method. The effects on average Nu number of high temperature wall ( Nu number) and temperature/flow fields are analyzed for various scales of the cavity. The results show that the effects of natural convection are enhanced and the Nu number is increased with the increase of the scale, while the flow changes from a steady state to a periodical oscillatory state and the streamlines become more irregular as the scale of the cavity increases.