Plasma-propellant interactions studies: measurements of heat flux produced by hydrocarbon ablation-supported plasmas

An investigation is underway to determine the mechanisms which contribute to the enhanced performance of electro-thermal chemical (ETC) ignition systems. Measurements of the plasma properties are difficult due to the hot, low density, ionized plasma flow which interfered with the data acquisition system. The present study utilizes an infrared (IR) camera to measure the temperature of both a copper disk and propellant grains exposed to a plasma. Use of the IR camera minimizes the electrical noise interference experienced in past experiments. The copper disk was used to determine the total energy flux produced by the plasma and the propellant grains were used to determine the energy flux absorbed by the propellant. A larger average energy appears to be transferred to JA2 compared to M30 propellant with similar plasma energy inputs. While it is likely that this is due to the higher absorption coefficient of JA2, the JA2 experiments also showed a significant amount of particles on the propellant face which may have contributed to the higher energy measured.