DYNAMICS OF SONIC HYDROGEN JET INJECTION AND MIXING INSIDE SCRAMJET COMBUSTOR

This paper presents the application of a Finite Volume Godunov-type implicit large eddy simulation method to study fuel injection into the combustion chamber of HyShot-II scramjet engine without chemical reaction/combustion in order to understand the fuel injection and air-fuel (hydrogen) mixing. The study is carried out in two parts; part one presents analysis of 2D HyShot-II geometry (without fuel injection) incorporating high temperature gas formulation which is validated against the NASA Thermally-Perfect-Gas code in order to obtain the combustion chamber inlet conditions. These combustor initial conditions are then utilized in part two for 3D combustion chamber simulations with hydrogen injection but cold flow where a digital filter based turbulent inflow boundary condition has been utilized. The purpose of the study is to understand the flow physics, hydrogen jet penetration and air & fuel mixing inside the HyShot-II combustor which is vital at the design stages. Various flow features are investigated such as the Mach number, velocity, pressure distributions, temperature, turbulent kinetic energy, Reynolds stresses and the effect of counter rotating vortices on mixing. The results of full geometry simulations are compared with computational results from the German Aerospace Centre, DLR, whereas due to unavailability of any data for hydrogen cold flow the validity of the results is based upon a similar validation case presented earlier (Rana et al., 2011b).