Abstract
We conducted Direct Numerical Simulation (DNS) to investigate the turbulent flow in a planar asymmetric diffuser. Unsteady separation from smooth wall and re-attachment make this case attractive concerning to analysis and prediction of turbulence phenomena under the influence of adverse pressure gradient. Comparison with experiment indicated that the critical Reynolds number of mean-flow separation is strongly influenced by the side walls. Our result suggested that the active redistribution among Reynolds stress components just after the expansion contribute a significant increase of shear stress.
