Control of Separation Using Pulsed Wall Jets: Numerical Investigations Using DNS and LES

摘要

In a numerical effort, the dynamics of coherent structures in unforced, and periodically forced, turbulent weak wall jets has been investigated. The objective of this research is to better understand the effect of pulsed blowing used for separation control on airfoils. The focus has been on flat plate geometries. In the simulations, weak wall jets are generated by steady and/or pulsed wall-tangential blowing through a wall-slot into a constant pressure or adverse pressure gradient boundary layer. Numerical approaches taken are Direct Numerical Simulations (DNS), Large-Eddy Simulations (LES), and Unsteady Reynolds-Averaged Navier-Stokes calculations (URANS). Using three- dimensional LES, it was shown that large-amplitude pulsed blowing can prevent flow separation.