CFD Analysis of Mixing and Combustion of a Hydrogen Fueled Scramjet Combustor with a Strut Injector by Using Fluent Software

Abstract

A numerical study of combustion enhancement has been performed for a Mach 2 model scramjet (supersonic combustion ramjet) combustor. The configuration used is similar to the DLR (German Aerospace Center) scramjet model and it is consists of a one-sided divergent channel with a wedge-shaped flame holder. Fuel (hydrogen) is injected at supersonic speed through the rear of a circular strut injector located at the channel symmetry axis. The shape of the strut is chosen in a way to produce strong stream wise vorticity and thus to enhance the hydrogen/air mixing. Strength and size of the vortices are defined by the strut geometry and may be modified. Numerically predicted profiles of static pressure, axial velocity, and static temperature for both non-reacting as well as reacting flows are compared with the experimental data. The RANS calculations are able to predict the mean and fluctuating quantities reasonably well in most regions of the flow field. Subsonic regions at the channel symmetry axis are responsible for flame holding. If the combustor geometry is chosen in a favorable way these subsonic zones may be kept small. The k-e computations are capable of predicting mixing and combustion simulations well and good.