速度滑移和温度阶跃对微尺度流动和换热的影响

1前言近年来，对微尺度换热器和微型槽道内介质的流动和换热的研究日益引起人们的重视[1]。但各研究者的结论却大相径庭[2-6],其流动与换热规律，迄今无统一认识。本文认为：随着流道尺寸的减小，边界效应的影响不可忽视。基于此，通过引入Knudsen数，以局部充分发展流动假设为前提，在N－S方程基础上，数值模拟了微槽道的流动与换热情况，并与国外的实验结果进行了对比分析[5-6].2压力分布方程的导出及与实验结果的比较首先从平行平板间的不可压缩流体流动分析入手，流动方向为X向。连续性方程可简化为：引入速度滑移边界条件：由式（1）…

EFFECTS OF SLIP-FLOW AND TEMPERATURE-JUMP ON MOMENTUM AND HEAT TRANSPORT IN MICRO-CHANNELS

Based on the assumption of locally fully developed flow and slip-fiow theory, we preseota method to simulate the heat transfer and momentum exchange of gas with a solid surfacein micro-channels, and the method was proved by comparing with Pfahler's exprimentalresults. Effect of the gas compressiblity and slip-flow on the skin friction was discussed indetail, the result demonstrates that Knudsen number should be considered in the analysisof flow in micro-domains. In the second part, the temperaturedump theory was studiedto explain the abnormal phenomina which is different from that of macro-scale channels.Some important conclusions of momentum and heat transports in microscale channels wereobtained.