The influence of micro air jets on mixing augmentation of fuel in cavity flameholder at supersonic flow

Abstract

In this study, numerical simulations are performed to study the effect of micro air jets on the mixing of fuel in the cavity flameholder of the scramjet. This research mainly focused the optimum position of fuel (C2H4) injection on the mixing rate inside the cavity. In order to simulate the cavity flameholder with micro air/fuel jets, a three-dimensional model is chosen and computational fluid dynamic approach is used for the simulations. The effect of significant parameters is studied by using the Reynolds-averaged Navier–Stokes equations with Menter's Shear Stress Transport (SST) turbulence model. In this work, the transient study is also performed to reveal the flow feature and mass distribution inside the cavity in the supersonic free stream (M=2.2). Results show that the injection of the fuel in the middle of the vertical wall significantly enhances the mixing of fuel in the cavity. The obtained results reveal that the injection of micro air jets distributes the fuel uniformly inside the cavity. Therefore, an enhanced mixing zone occurs in the downstream of the injection slots which lead to flame-holding.