摘要
以去离子水作为工质,在当量直径300-1570μm的微圆管(1cr18Ni9Ti)内进行层流流动与换热特性的实验研究。实验结果表明当壁面粗糙度超过1％时摩擦系数随着壁面相对粗糙度的增加而增加。在给定外壁面热流密度的条件下,当雷诺数小于100时,管壁轴向导热对换热特性的影响随着壁厚与内径比的增加而增大;当雷诺数大于100时,轴向导热的影响随着雷诺数的增加逐渐减弱,充分发展区的Nu数接近常规值4．36。
Experiment was conducted to reveal the flow and heat transfer characteristics with deionized water flowing through microtube （1Cr18Ni9Ti） in laminar state. The inner diameter of the test tube is from 300 to 1570 μm. The friction factor obtained from the experiments increases with the surface roughness increase when the relative roughness is greater 1%. For the given heat flux at the outside surface, if the Reynolds number is less than 100, the effect of heat conduction in the tube wall increases with the ratio of wall thickness to the inside diameter; if the Reynolds number is greater than 100, the heat conduction in the tube wall becomes weaker, and the Nusselt number in the fully-developed region approaches the conventional value 4.36.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2006年第5期829-831,共3页
Journal of Engineering Thermophysics
基金
973重点基础研究基金资助项目(No.G2000026303)
国家自然科学基金资助项目(No.50236010)
关键词
微圆管
层流
壁面粗糙度
摩擦系数
管壁轴向导热
microtube
laminar flow
surface roughness
friction factor
the axial heat conduction in tube wall
