矩形微通道内滑移区气体流动换热的数值模拟

Numerical simulation of gas flow and heat transfer in rectangular microchannel in slip flow regime

在等壁温边界条件下对矩形微细通道速度滑移区的对流换热进行了二维数值模拟. 在一阶速度滑移和温度跳跃的边界条件下,计算出了通道内的速度和温度以及压力分布. 比较了不同克努森数Kn对于滑移速度和跳跃温度的影响. 结果表明,由于气体的稀薄性,压力呈现更加线性化减小的趋势,随着Kn的增加,通道入口与出口处的滑移速度和跳跃温度呈现增加的趋势. 在通道入口附近,气流速度和温度变化剧烈,而在出口处截面平均流速和温度随Kn的增加而降低.

Two dimensional numerical simulation is presented for flow and heat transfer in rectangular microchannel with uniform wall temperature in slip regime. Numerical solutions are performed for the velocity and temperature under the first order slip boundary conditions. The influences of different Kn numbers on the slip velocity and jump temperature are investigated. The results show that the gas rarefaction makes the pressure distribution more linear. Both the slip velocity and jump temperature at the inlet and outlet of the microchannel increase with the increase of Kn numbers. The gas average velocity and mean temperature increase greatly at the channel entrance, and both the temperature and velocity at the channel exit decrease with the increase of Kn numbers.