Heat transfer in low pressure (high Knudsen number) developing flows through parallel plates

Low pressure heat transfer in developing flows of nitrogen gas through parallel plates is studied using the Direct Simulation Monte Carlo (DSMC) technique. Heat flux along the plates is calculated and compared with two continuum solutions, viz., the Graetz analytical solution and the compressible Navier-Stokes equations. Variation of the Knudsen number (Kn) is obtained by reducing the pressure (increasing the mean free path), while the channel width is held constant. Heat transfer from the heated wall rapidly decreases with increasing Kn. However, the axial variation of heat flux along the wall in the streamwise direction is minimized with increasing Kn. The results are of interest in the design and analysis of low pressure chemical vapor deposition reactors.