Scramjet fuel-air mixing establishment in a pulse facility

A numerical simulation of the temporally developing flow through a generic scramjet combustor duct is presented for stagnation conditions typical of flight at Mach 13. The particular focus is to examine the startup transients and to determine the time required for certain flow parameters to become established. The calculations were made with a Navier-Stokes solver SPARK with temporally relaxing inflow conditions derived from the operation of the T4 shock tunnel at the University of Queensland in Australia. The generic combustor geometry includes the injection of hydrogen fuel from the base of a centrally located strut. The flow was assumed laminar and fuel combustion was not included. The establishment process is presented for viscous parameters in the boundary layer and for parameters related to the fuel-air mixing.