Numerical Analysis of Transient Compressible Flow over Backward-facing Step

The direct numerical simulation study has been performed to investigate the effect of compressibility on heat transfer and transient flow over backward-facing step. The problem was investigated for Reynolds numbers varied from 46 to 140. transient Continuity, Navier-Stokes, and energy equations in two dimensions were employed taking into account the compressibility effect. The total length of channel was ten times of step heights in the direction of stream-wise. Also, the step edge considered four times the step heights based on downstream from channel inlet. The expansion ratio (ER) of channel inlet selected to be equal to two. Results for the temperature contour and velocity contour at different time steps based on different Reynolds number observed an increase in temperature and axial velocity values. While the reattachment decreases.