Mixing Enhancement by Pulsed Energy Deposition in Jet/Shock Wave Interaction

Abstract

The mechanism of the supersonic round jet mixing enhancement by a pulsed energy deposition is studied numerically by solving the three-dimensional unsteady Reynolds-averaged Navier–Stokes equations with the second-order scheme in space and time. A round jet at different Mach numbers (, 1.76, 3.00) is parallelly injected into a coflowing air stream of Mach number 2.5, interacting with the oblique shock generated by a compression ramp of 20°. The density ratio between the jet and external flow is 0.5. The laser pulse with at 20 kHz is modeled as an ellipsoid for the energy addition, and proposed to put above or inside the jet for jet mixing control. It is found that the energy deposition inside the jet is much more effective for the jet mixing amplification compared with that above the jet. The jet mixing enhancement is achieved through the large-scale vortices, initiated by the energy deposition zone interacting with the oblique shock wave. It is shown that the jet cross-sectional area is doubled, and the turbulent kinetic energy is increased, even reaching 10 times the original level at the downstream location. However, a slight decrease about 0.3% of the total pressure recovery coefficient is observed far downstream.