高压补燃循环液体火箭发动机主燃烧室自点火研究

For oxygen-rich staged combustion cycle，the high-temperature hydrogen-rich products from the gas generator is injected into the main combustion chamber together with cryogenic liquid oxygen. Due to the high reactivity of the high-temperature products and the high-pressure environment of the main combustion chamber，auto-ignition is highly likely to occur in the main combustion chamber. The interaction between autoignition and flame can lead to a phenomenon similar to the‘knocking’，and it is urgent to study the parameter boundaries of auto-ignition. In response to this，this study developed a trans/supercritical unsteady flamelet model，conducted trans/supercritical unsteady flamelet calculations，and explored the auto-ignition characteristics of high-temperature hydrogen-rich products and liquid oxygen. The results indicate that the global equivalence ratio and scalar dissipation rate of the gas generator significantly affect the auto-ignition delay time of the mixture in the main combustion chamber. Through extensive calculations of operating conditions，the auto-ignition delay in the main combustion chamber was determined to be in the range of 0.143 4 ms to 5.892 5 ms，and the boundary of auto-ignition occurrence was determined in the space of the gas generator global equivalence ratio and the scalar dissipation rate.