定热通量加热下微三角形槽道中滑移流动的换热特性

微三角形截面通道是现代工程实际应用中常涉及到的流动通道.针对微三角形槽道利用正交函数法求解了滑移流区内带温度跳跃边界条件的能量方程，对不可压缩气体在微三角形槽道内充分发展层流滑移流动的换热特性进行了理论分析，获得了轴向定热通量加热、周向均匀壁面温度条件下微三角形槽道内的温度分布和换热特性的分析解.计算结果表明：正交函数法适用于微三角形槽道内滑移流动换热特性的分析计算；在滑移流区，微三角形槽道内的平均Nusselt数随Knudsen数的增加而减小，其随高宽比变化的分布曲线随Knudsen数的增加而平行下移，Nusselt数比随Knudsen数的变化关系基本不受高宽比的影响.

ANALYSIS OF HEAT TRANSFER FOR GAS SLIP FLOW IN TRIANGULAR MICRO-CHANNELS WITH UNIFORM HEAT FLUX

In this paper a theoretical analysis of heat transfer characteristics is presented for the fully developed laminar flow of the incompressible gas in the triangular microchannels in slip flow regime.The energy equation with the temperature jump boundary conditions is solved by using a computation-oriented method of the orthonormal function analysis in the triangular microchannels heated with uniform heat flux along flowing direction and with isothermal walls. The theoretical calculations of dimensionless temperature profiles and the average Nusselt number in the microchannels are obtained. The results show that the orthonormal function method is applicable to study the heat transfer characteristics in the triangular microchannels.The average Nusselt number in triangular microchannels is lower for slip flow than that for no-slip flow, and decreases with increasing Knudsen number. The relation curve of average Nusselt number vs the aspect ratio of the triangular microchannels moves downward parallelly with increasing Knudsen number.