Journal of Propulsion and Energy ISSN:2734-1887(Print) 2765-0049(Online)

Recently, there is a growing interest in the development of electric solid propellants (ESPs) because they offer multiple start/stop operations and variable combustion rates at different electrical power. However, the understanding of complex reaction mechanisms involved in decomposition/combustion of these ESPs is still limited. The present study attempts to obtain insights into the thermal decomposition and combustion behaviour of ESPs based on lithium perchlorate (LP) oxidizer and poly vinyl alcohol (PVA) binder, and to further investigate the influence of tungsten (W) at 15% as a metal additive. Different parameters such as heat of reaction, mass loss, and combustion rates are obtained for metallized ESP- M15 and compared with the non-metallized baseline ESP. The heat release and mass loss from the overall decomposition reaction of baseline ESP are obtained as 3729 J/g and 51%, respectively. Addition of W decreases this net heat release by 43% and mass loss by 29% for ESP-M15, when compared to the baseline case. Combustion rates of both ESPs increase considerably with the applied initial voltage in the range of 100-500 V. Furthermore, inclusion of W in ESPs enhances their combustion rates by 4.6 times at 100 V and by 1.3 times at 500 V. This suggests that substantial oxidation of W at actual burning conditions improves the combustion rates of ESPs, whereas such process may not be significant at low temperatures of 30-600 °C in thermal experiments, thus reducing the heat release of metallized formulation relative to the baseline propellant.