Management of Stronger Wall Jet by a Streamwise Vortex with Periodic Perturbation (Analysis by Phase Averaging)

Abstract

In a stronger wall jet managed by a streamwise vortex, effect of periodic perturbation on the interaction and evolution processes has been investigated in the equations derived from phase averaging and triple decomposition. Transverse and spanwise locations of vortex center have time variations associated with variation in strength of streamwise vortex. Normal Reynolds stress difference (V2-W2) and shear stress VW generated by periodic perturbation reduce decay rate of maximum vorticity and accelerate growth rate of spanwise vortex radius in terms of production terms in transport equation for streamwise vorticity. Prediction of Reynolds shear stress component VW by taking account of time variation of both vortex center and strength successfully explains experimental data of conventional time average stress of vw.