Experimental and simulation investigation on partially catalyzed ignition process of hydrogen peroxide/kerosene in a lab-scale rocket engine

The hydrogen peroxide/kerosene rocket engine utilizing partially catalytic autoignition demonstrates potential advantages in ignition enhancement, engine weight reduction, and combustion efficiency, positioning it as a promising green alternative to traditional toxic hypergolic propellant engines. This study investigates the partially catalytic ignition process of hydrogen peroxide/kerosene through experimental and simulation approaches. A laboratory-scale optical engine was designed to visualize the ignition process. Optical diagnostics based on chemiluminescence were used to capture the spatiotemporal evolution of autoignition kernel initiation and flame propagation, while ignition delay times were measured across varying catalytic ratios. The simulation results, regarding combustion field establishment and ignition delay, show good agreement with experimental data. The findings reveal that the fully catalytic ignition process undergoes an unstable combustion stage with pressure decrease and fluctuations. In the partially catalytic scheme, the injection of non-catalyzed hydrogen peroxide significantly enhances flame propagation stability, resulting in smoother and more stable pressure buildup. In the HP/kerosene engine, ignition delay times below 1 ms were achieved, with a trend of initial decrease, followed by an increase, and then a decrease again as the catalytic ratio decreased from 100 % to 70 %. The optimal catalytic ratio for the partially catalytic ignition scheme is approximately 85 %, achieving the shortest ignition delay and the fastest pressure buildup. This study aims to provide insights into the catalytic ratio's influence on partially catalytic ignition characteristics, offering guidance for the optimization of engine ignition strategies.