Strong Baroclinic Effects in a Light Jet in a Pulsed Coflow

The role of strong baroclinic effects in a light jet injected into a pulsed coflow is analyzed. This case is believed to be a model situation because the induced baroclinic torque competes with the jet shear. Phase-averaged mean and turbulent properties are presented. A correct scaling is obtained from physical analysis. The striking observation is here a transition from a jet to a wake behavior during the deceleration phase. This has a dramatic influence on the evolution of the Reynolds stresses.We show that indirect effects (production terms) caused by the modification of the mean flow by the unsteady body force strongly dominate the direct coupling of the turbulence with the unsteady pressure field in this situation.[PUBLICATION ABSTRACT]