Control effects on coherent structures in a non-uniform adverse-pressure-gradient boundary layer

We examine the effects of three basic but effective control strategies, namely uniform blowing, suction, and body-force damping, on intense Reynolds-stress events in turbulent boundary layer (TBL) developing suction side a NACA4412 airfoil. This flow is subjected to non-uniform adverse pressure gradient (APG), which substantially modifies its turbulence statistics with respect zero-pressure-gradient (ZPG) layer, it also changes how strategies affect flow. The strong APG results that are shorter more often detached from wall than ZPG TBLs. In quadrant analysis, ejections remain most relevant structures, sweeps become important TBLs, fact lower contribution wall-normal velocity events. Control relatively less statistics. Uniform blowing has an impact similar even APG, while complex effects, likely due particular behavior component near wall. Body-force damping reduces probability occurrence very-large attached structures proximity actuation region. Our show robust features If do not target directly these their pronounced mean • makes slightly shorter. longer. wall-attached structures.