Numerical Analysis on the Effect of Wedge and Diamond Injector in a Cavity based Scramjet Combustor

Abstract

The Scramjet engine's supersonic burning cycle is seen as a realistic propulsive framework for hypersonic vehicles. The stream has a very short residence period (milliseconds) inside the combustor since the ignition occurs at supersonic speeds. For comparison, a generic scramjet combustor (DLR) was used and an off-design analysis was performed to evaluate and to analyse the modifications. The impact of wedge and diamond shaped struts on fuel-air blending and combustion effectiveness has been investigated. The cavity is added to the same model for further investigation. To numerically simulate the flow field of the hydrogen fuelled. Scramjet combustor, the kε RNG turbulence model and the finite rate / eddy - dissipation reaction model was used. Ideal boundary condition for the current calculation work is taken to be at 833 K temperature with 115.299 Pa pressure. The research focused on improving the fuel air mixture in the combustion chamber in order to achieve optimal combustion efficiency. From the outcomes acquired the shocks and vorticity created in the combustor operate as a flame holder, extending the flow's residence period. Throughout the combustor's length, supersonic flow has been maintained along with the desired effects. It was observed that the wedge with cavity out of the four tested models produced the expected results with better mixing and combustion properties.