Experimental investigations of coaxial injectors in a laboratory-scale rocket combustor

摘要: Abstract An investigation is performed through experiments of a laboratory-scale optically accessible combustor equipped with single-element shear coaxial injector. Various optical diagnostics approaches, such as hydroxyl (OH) planar laser-induced fluorescence (OH-PLIF), high-speed imaging and infrared imaging, are simultaneously used to determine the OH radical spatial distribution, flame instantaneous fluctuations, temperature fields outside nozzle. This study emphasizes combustion characteristics stabilizations two propellant combinations under same thrust level, including gaseous hydrogen/gaseous oxygen (GH2/GO2) methane/gaseous (GCH4/GO2). Moreover, validate pressure-scaling criterion, different pressure conditions also considered. Based on results OH-PLIF images, similarities evident chamber pressures for each couple. The kinds seen be stabilized in vicinity oxidizer injector lip but anchor region GCH4/GH2 cases found change dynamically near lip. lift-off GCH4/GO2 exhibits unsteady phenomenon combustor. Experimental data indicates that stabilization hard achieve compared GH2/GO2 flame. Furthermore, has greater heat releasing intensity gentler reaction zone distribution. relative flame, causes major issues regard protection inner wall Meanwhile, according plume lower outlet core larger gradient, which an advantage employment future space engines. study, identifying preliminary behavior differences between flames, will applicable engine design.