管壁导热对脉管内自然对流换热影响的研究

STUDY OF THE EFFECT OF TUBE WALL HEAT CONDUCTION ON THE NATURAL CONVECTION IN PULSE TUBE

本文计算了不同脉管倾角和管壁材料下脉管管壁导热对自然对流换热的影响。发现脉管壁面导热对换热的影响不仅体现在增加了壁面的纯导热部分,更主要的上强化了脉管内的自然对流;壁面和内部气体的温度差异沿脉符轴向的变化是管壁导热强化自然对流的主要原因。

The effect of the pulse tube wall heat conduction on the natural convection in the pulse tube was numerically investigated with the pulse tube of different materials being positioned at different orientations. It is found that the cylindrical envelope lateral wall heat conduction can significantly enhance the heat transfer from the hot end to the cold end, not only because the increase in pure heat conduction in the wall, but more importantly, also intensify the natural convection within the enclosure. This enhancement is resulted from the big temperature difference between the tube wall and the adjacent fluid near the hot and cold ends.