Model for Asymmetry of Shock/Boundary Layer Interactions in Nozzle Flows

Abstract

The reason for the asymmetry phenomenon of shock/boundary layer interactions (SBLI) in a completely symmetric nozzle with symmetric flow conditions is still an open question. A model for the asymmetry of nozzle flows was proposed based on the properties of fluid entrainment in the mixing layer and momentum conservation. The asymmetry model is deduced based on the nozzle flow with restricted shock separation, and is still applicable for free shock separation. Flow deflection angle at nozzle exit is deduced from this model. Steady numerical simulations are conducted to model the asymmetry of the SBLIs in a planar convergent-divergent nozzle tested by previous researchers. The obtained values of deflection angle based on the numerical results of forced symmetric nozzle flows can judge the asymmetry of flows in a nozzle at some operations. It shows that the entrainment of shear layer on the separation induced by SBLTs is one of the reasons for the asymmetry in the confined SBLIs.