Effect of an H$_2$O$_2$ additive on hydrogen ignition and combustion in a supersonic air flow

The effect of small amounts of inert and reacting additives (such as hydrogen peroxide, its decomposition products,CO$_2$, etc.) on the ignition and combustion of hydrogen in a high-temperature supersonic air flow was studied experimentally. It is shown that direct doping of the fuel has little effect on the combustion of H$_2$, whereas injection of hydrogen peroxide or small amounts of pure hydrogen ahead of the nozzle decreases suddenly the ignition delay, indicating the profound effect of the reaction products. Comparative experiments with inert additives showed that these additives only lead to a decrease in the air-flow temperature.