Testing of Refractory Composites for Scramjet Combustors

Flat panels of carbon/carbon-silicon carbide and carbon/carbon were installed downstream of a hydrogen-fueled dual-mode scramjet combustor and tested for several minutes at conditions simulating flight at Mach 5 and Mach 6. The most severe test involved a carbon/carbon-silicon carbide panel that experienced three cycles totaling over 153s at Mach 6 enthalpy, with fueling at an equivalence ratio of 1.0 for 118s. Based on embedded thermocouple measurements and one-dimensional transient thermal analysis, the inside wall temperature was calculated to reach a maximum of 1400 degrees C during the test program. Both the carbon/carbon-silicon carbide and carbon/carbon panels experienced minimal erosion during the tests, giving strong confidence that both would be a viable material system for use in a scramjet combustor for short-duration test flights.