Mixing and Combustion Analysis of a Hydrogen Fueled Scramjet Engine Using Strut with Alternating Wedge Injector

A major problem in supersonic combustion is the short residence time of the fluid inside the combustor due to high flow velocities. Thus techniques for mixing enhancement have to be used to achieve a fast and efficient fuel-air mixing. In this paper, strut with alternating wedge injector is investigated numerically. The combustor and strut dimensions are same as DLR Scramjet model. It consists of a divergent channel with a flame - holding, wedge shaped structure in the middle of the flow field from the base of which hydrogen is injected. Mixing and combustion calculations are performed at Mach 2 for air and Mach 1 for Fuel (hydrogen). The simulation has been carried out by using FLUENT. Standard k-epsilon model has been used for modelling turbulence and single step finite rate chemistry has been used for modelling the H2-Air kinetics. k-epsilon model is based on a finite volume discretization of the continuity, momentum, energy equations. Numerically predicted profiles of static pressure, axial velocity, turbulent kinetic energy and static temperature for both non-reacting as well as reacting flows are compared. Validation is done by comparing numerically predicated profiles with experimental profiles. The results shows that alternating wedge injector is affecting the flow field of combustor considerably, due to this length required for the combustion chamber is reduced and also mixing efficiency and combustion efficiency of the injector calculated.