A Numerical Method for Burnback Analysis of UV-cured Solid Rocket Propellant Grains

Today, numerical simulations are utilized to model the shape evolution of burning grains in solid rocket motors. These simulations can be coupled with fluid dynamic models to depict the flow field and evaluate performance. While these techniques have traditionally been applied to grains designed and produced using conventional processes, new manufacturing methods necessitate appropriate tools to simulate propellant behavior. This includes considering the new possibilities and characteristics that can be achieved with additive manufacturing. Therefore, the numerical tools used to analyze grain burn-back and the fluid dynamic field must be suitably adapted. The objective of this work is to revise existing methodologies and develop an initial version of a comprehensive tool intended for modeling nonuniform propellant burning. The distribution of propellant composition within the grain has been modeled and evaluated to assess the numerical tool’s ability to accurately calculate grain burnback with a nonuniform burning rate. Representative geometries with available experimental data and numerical or analytical simulations have been considered as test cases to validate the tool. Obtained results demonstrate the tool’s effective performance and its good agreement with available reference data. Additionally, the tool has proven capable of handling the nonuniform ballistic properties of the propellant.