Computational Investigation of Jet Mixing Enhancement by C-D Nozzle with Arc Tabs

The present computational investigation of the nozzle exit flow from C-D nozzle investigates the augmentation in mixing, jet decay and flow characteristics of jet from the supersonic nozzle with arc tab and without tab at the nozzle outlet for a Mach 2. ANSYS Fluent software is used to design the convergent divergent nozzle with design modeler and to simulate if for the design Mach number. The simulations are also carried out for overexpanded and under-expanded conditions in both the cases with NPRs 6 and 7.4. The jets from the nozzle with arc tab and without tab are compared using pressure and Mach number contour plots. The shock-cell formation with alternate expansion waves and compression waves are observed clearly. As the arc tab is included at the nozzle exit, the length and quantity of shock cells decreases. This leads to a decrement in strength of the shock and results in a faster decay in the case of nozzle with tab. The shock diamond or Mach disks observed at the kink of the barrel shock reduces with increase in flow direction. The nozzle with arc tab has a superior mixing enhancement as compared to nozzle without tab.