Self-ignition and supersonic reaction of pylon-injected hydrogen fuel

The flame stabilization and reaction processes in a scramjet combustion chamber have been experimentally investigated. Hydrogen was injected into a vitiated Mach 2.15 airstream by means of pylon-like fuel injectors. The supersonic flame was stabilized in a purely kinetical way; i.e., by means of fuel self-ignition. The flame-stabilization mechanisms have been studied. The interaction between the gasdynamics and the reaction kinetics are discussed. A small wedge has been mounted into the test combustor to modify the oblique shock structure. The response of the reacting how on this change has been observed. To assess the reacting how, only nonintrusive, optical measurement techniques have been employed: the schlieren technique to visualize the how structure, the Rayleigh scattering technique to study the injected mixing jets, as well as the self-fluorescence of the OH radical to determine location and intensity of the reaction zones. Additionally, the wall static pressure has been measured.