水平圆管内高普朗特数流体的凝固

本文从高普朗特数流体所具有的共同特性出发,用数值计算方法对在壁温一定的水平圆管内、伴随着非稳态自然对流换热的高普朗特数流体的凝固过程进行了解析。从而使管内发生的自然对流的流动样相随时间之推移的变化、液固两相非稳态温度分布与自然对流换热的关系、凝固界面的形状及其随时间的变化、自然对流对于凝固速度的影响等原来所不清楚的问题得以明确。

INWARD SOLIDIFICATION OF A HICH PRANDTLNUMBER FLUID IN A COOLED HORIZONTAL PIPE

Numerical solutions are given for inward solidification of a high Prandtl number fluid with temperature-dependent viscosity in an isothermally cooled horizcntal pipe. The high prandtl number fluid, which was housed in a pipe with a uniform surface temperature lower than the solidification temperature of the fluid, was initially in liquid phase. Transient flow patterns associated with free convections of the liquid and their effects on the development of the solid-liquid interface are presented in full. Variations of temperature distribution for both the liquid and the solid, and the interface position in the radial and axial directions are illustrated with time. The changes of bulk temperature of the liquid and the relevant Nusselt number with time are shown as a function of the Grashof number. The rate of development of the solidification interface is also given as a function of the Grash of number.