Particle-Impact Ignition Measurements in a High-Pressure Oxygen Shock Tube

Metal particle contamination is a concern for liquid rocket engines that use enriched O

2

at high pressure. It is believed that under some engine conditions contaminant particle impact could release sufficient kinetic energy to initiate combustion, providing an ignition source for engine components (e.g., turbine blades) impacted by the particles, and subsequently a combustion event that eventually consumes structural materials of the engine. It is important that the combustion properties of these candidate metal particles be studied for their propensity to cause ignition under rocket-like conditions, to reduce the risk of engine failure. Laboratory study of such a mechanism under realistic engine conditions is difficult, and data are lacking. Data that reveal the influence of particle mass, kinetic energy, impacted-surface composition, and environmental conditions on ignition propensity are valuable for launch programs involving oxidizer-rich, staged combustion engines.