Executive Summary : | Metal-based propellants, such as Refrigerated Solid Propellants (RSPs) and Gelled Composite Propellants (GCPs), are attractive due to their high energy densities, safety, and green exhaust. These propellant formulations, which consist of metal particles and liquid oxidizers, offer performance comparable to liquid propellants without compromising the simplicity of solid rocket motor design. However, combustion studies and static fire-motor experiments have revealed inefficiencies associated with combustion and propulsion, affecting overall propulsive performance. This project aims to simulate multiphase flow dynamics in a rocket motor for metal-based refrigerated and gelled composite propellants. A theoretical framework will be developed by modeling relevant physicochemical phenomena, including multiphase flow, chemical reactions, viscous and diffusion effects, and flow turbulence. Numerical treatment of convective fluxes will be performed using shock-capturing schemes, and boundary conditions will be implemented based on the Method of Characteristics (MOC) procedure. Various grain configurations will be considered, and simulations will be conducted for a diverse set of propellant formulations. The time evolution of pressure, thrust, specific impulse, characteristic velocity, and efficiencies will be computed, and model predictions will be compared with available experimental data. The proposed work aims to achieve a proper understanding of the underlying physicochemical processes and explain the reported performance of RSP and GCP formulations. The proposed work is expected to guide the design and development of rocket motors based on RSP and GCP propellant formulations. |