Ignition of cryogenic H2/LOX sprays

First results obtained during the investigation of the transient ignition process in a cryogenic model rocket combustion chamber are reported. Ignition of the propellants LOX and GH2 has been initiated with a pulsed laser and ignition and flame stabilization processes have been analyzed using high-speed visualization methods. Local flame velocities as well as local convection velocities at the point of ignition are determined by image displacement velocimetry methods. Depending on the injection conditions of the propellants, some distinct phases of the transient start-up process could be observed and are discussed in terms of Weber and Reynolds number.