Pressure measurements in a scramjet combustor with film cooling

Experiments have been performed on a 500 mm long cylindrical scramjet, combustor in the T4 free piston shock tunnel at The University of Queensland. Four different fuel injectors designed to provide varying slot equivalence ratios were tested at a nominal freestream Mach number of AA and stagnation enthalpy of 5.8 MJ/kg. Each fuel injector was tested over a range of total equivalence ratios and pressure measurements were made along the length of the combustor. The stagnation pressure and enthalpy of the flow were also varied to investigate the effects of changes in flight altitude and speed respectively. Supersonic combustion was observed for all injectors at the nominal test condition. As expected, the pressure in the combustor increased with total equivalence ratio. However, the pressure in the combustor was found to be independent of how the fuel was distributed. The results obtained for stagnation pressure and enthalpy agreed with the expected trends, except at their lowest values, where no combustion was observed