HEAT TRANSFER CHARACTERISTICS OF GASEOUS FLOWS IN MICROCHANNELS

Two-dimensional compressible momentum and energy equations are solved to obtain the heat transfer characteristics of gaseous flows in parallel-plate microchannels. The numerical methodology is based on the arbitrary-Lagrangian-Eulerian (ALE) method. The computations were performed for channels with adiabatic walls to obtain the adiabatic wall temperature. The channel height ranges from 10 to 100 μm and the channel length is fixed at 30 mm. The stagnation pressure varies from 1.1 × 10⁵ to 4 × 10⁶ Pa. The outlet pressure is fixed at the atmosphere. The computations were also performed for channels with isothermal walls. The aspect ratio of the channel length and height is 100 or 200. The channel height also ranges from 10 to 100 μm. The bulk and total temperatures are compared with that of the incompressible flow in the conventional-sized parallel plate channel.