Effects of Jet-to-Jet Spacing of Air-Jet Vortex Generators in Shock-Induced Flow-Separation Control

Abstract Experiments were carried out to assess the influence of spanwise spacing between adjacent orifices an air-jet vortex-generator (AJVG) array on their separation-control effectiveness. The was applied a 24° compression-ramp-induced shock-wave / turbulent boundary-layer interaction at $$M_{\infty } = 2.52$$ M ? = 2.52 and $$Re_{\theta 8225$$ R e ? 8225 . Three oriented AJVG arrays small, intermediate, large jet spacings studied. Their mean-flow organisation turbulence quantities assessed using flow visualisations planar particle image velocimetry across multiple measurement planes. streamwise vortices induced by AJVGs incited different control effects depending degree vortices. with intermediate achieved most favourable reductions in separation length area about $$25\%$$ 25 % $$52\%$$ 52 , respectively. This reduction brought formation stable, interacting streamwise-elongated coherent downstream injection associated entrainment high-momentum fluid. smallest incites vortex interactions adverse strength, breaking up structures even increasing separation. largest display characteristics similar single jets crossflow, only local modification region. Turbulent are amplified both separation-inducing shock; reduces amplification shock-wave/boundary-layer is effective also here.