Heat transfer characteristics of gaseous flows in micro-channel with constant heat flux

Abstract

Two-dimensional compressible momentum and energy equations are solved to obtain the heat transfer characteristics of gaseous flows in parallel-plate micro-channels with CHF (constant heat flux) for no-slip regime. The numerical methodology is based on the Arbitrary-Lagrangian–Eulerian (ALE) method. The computations are performed for channels with constant heat flux which ranges from 10 2 to 10 4 W m −2 . The channel height ranges from 10 to 100 μm and the aspect ratio of the channel length and height is 200. The stagnation pressure, p stg is chosen in such a way that the Mach number at the exit ranges from 0.1 to 0.7. The outlet pressure is fixed at the atmosphere. The heat transfer characteristics in micro-channels are obtained. And comparisons with available experimental values were conducted. The wall and bulk temperatures in micro-channels are compared with those of the incompressible flow in the conventional sized parallel plate channel. A correlation for the prediction of the wall temperature of the gaseous flow in the micro-channel is proposed. And supplementary runs with slip boundary conditions for h = 10 μm conducted and slip effect is discussed.