Large flow rate shear-coaxial gas-gas injector

Based on the previous results of studies in single-element condition, an optimal design single-element GO₂/GH₂ injector was designed and tested at a large flow rate condition firstly, and the result shows that this injector can complete combustion in the nominal combustor. Furthermore, to investigate the combustion characteristics of large flow rate injector in the multi-element injector chamber which have the interaction between the elements, an optimal design multi-element shear mixing injector equipped with seven elements was deigned. The shear mixing element had high H₂/O₂ velocity ratio and flared O₂ post tip. Numerical simulation and repeat hot-fire tests were carried out with the injector. Steady operations were obtained without any stability aids, and the injector showed benign heat environments on the faceplate and cylinder wall. The combustion efficiency of this injector exceeds 99% in the flow rate of 3.7 times than that of SSME main injection element in the nominal combustor.