壁面轴向导热对微细管内对流换热的影响

EFFECTS OF AXIAL HEAT CONDUCTION IN THE WALL ON CONVECTIVE HEAT TRANSFER IN MICROTUBES

本文通过数值解析的方法研究了考虑壁面轴向导热时微细管内的对流换热。结果表明,当管外为对流换热边界条件时,管内充分发展对流换热的Nu依然在3.66～4.36之间。但若忽略壁面轴向导热,采用一维热阻模型整理微细管内对流换热的实验数据将会导致错误的结论。

Effects of axial heat conduction in the wall on convective heat transfer in microtube have been studied analytically. It is shown that the Nusselt numbers inside microtube are still in the range of 3.66 and 4.36 with convective heat transfer boundary condition outside the tube. However, one-dimensional thermal resistance model which is usually used for the experimental data reduction will underestimate the Nusselt numbers, and leads to misunderstanding on convective heat transfer in microtube.