Flowfield Analysis of a Scramjet Combustor with a Coaxial Fuel Jet

A calculation procedure for predicting turbulent mixing and burning.and skin friction and wall heat transfer in a scramjet combustor with a central fuel jet from a gas generator has been developed. All the important physical and chemical processes have been modeled, including the upstream influence of heat release on the initial conditions and the pressure distribution in the duct. Calculations for a representative engine with Shelldyne H fuel at Mach 4 and 7 indicate that a combustor 1 to 2 m long is sufficient to insure complete heat release but that substantial nonuniformity of the combustor exit flow would still exist. The skin friction and wall heat transfer are both shown to be very sensitive to the local pressure gradient and to the impingement of combustion products and turbulence from the central jet mixing and burning zone. However, the responses of these two quantities are not of the same importance, and they are not in phase.