Radiative heating and erosive burn of a solid propellant subject to electrothermal plasma

Summary form only given. Electrothermal-chemical (ETC) devices have shown a growing interest for possible various applications that exhibit the generation of high density, high enthalpy flows. The interaction of electrothermal plasmas with solid or liquid propellants is not clearly understood. The question of whether the externally high heat flux produced from the electrothermal plasma will enhance the propellant burn rate, or the burn rate will be limited by the vapor shield at the combustion flame temperature (flame vapor shield) is still unanswered. Erosive burn experiments conducted on JA-2 solid propellant have shown enhanced burn rates through plasma erosion. In closed-bomb geometry, experiments showed little or no effect on the burn rates of JA-2. Erosive burn experiments at NCSU showed that JA2 burn rate with plasma injected normal to the grains of the propellant is a factor of 3 higher than that for conventional burn. These experiments suggest that plasma augmentation of JA2 solid propellant through erosive burn is possible. The effect of radiative heating from the plasma may provide increased burn rates at the plasma-propellant interface, but the question remains unanswered if radiative heating continues during the burn process or will be limited at the boundary due to limited transport in the growing optically-thick layer. This paper explores the erosive burn and radiative heating, their implication on the ETC performance, and whether they are sufficient as augmentation and control mechanisms in electrothermal-chemical devices.