Optimization of Solid Rocket Motor Grains Exploiting Non-Uniform Ballistic Properties of 3D-Printed Propellants

This work explores Solid Rocket Motor grain design, leveraging the possibilities offered by innovative additive manufacturing techniques based on slurry deposition and UV-curing. The primary objective is to create an automated design procedure capable of finding optimal solutions that match the specific mission requirements. This is achieved by exploiting new geometric and ballistic configurations that are attainable because of the absence of constraints imposed by the classical mix-cast-cure manufacturing process. The design optimization procedure is based on a stochastic optimization approach coupled with surrogate modeling of the grain pressure-time response at variation of geometrical and ballistic parameters. After automating the creation of geometric models and the computation of pressure-time routines to produce suitable databases, various surrogate models were tested. The selected surrogate model is then applied to evaluate different individuals in stochastic optimizer routines. The optimizer identifies the most suitable solution to obtain the desired pressure-time response and to meet the motor performance requirements. The results obtained show the ability of the procedures to automate the modified design process, handle novel design parameters, and obtain an adequate response to the expressed requirements.