Self-Ignition and Supersonic Reaction of Pylon-Injected Hydrogen Fuel

The e ame 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 supersonice amewasstabilizedina purelykineticalway;i.e.,bymeansoffuelself-ignition.Thee ame-stabilization mechanisms have been studied. The interaction between the gasdynamics and the reaction kinetics are discussed. A small wedgehas beenmounted into thetestcombustorto modify theobliqueshockstructure.Theresponseofthe reacting e ow on this changehas been observed. To assessthereacting e ow, only nonintrusive, optical measurement techniques have been employed: the schlieren technique to visualize the e ow structure, the Rayleigh scattering technique to study the injected mixing jets, as well as the self-e uorescence of the OH radical to determine location and intensity of the reaction zones. Additionally, the wall static pressure has been measured.