Optimization of Finocyl Grain Geometries of Solid Rocket Boosters

Abstract

A common propellant grain geometry for solid rocket motors consisting of a combined cylindrical and finocyl geometry is explained. The burn-off is simulated by a DLR simulation tool, which gives amongst others a thrust curve as the result. The burn-off simulator was coupled with an optimizer, which uses a Mesh Adaptive Direct Search method to find an optimal solution using a black box program. The assessment function and several constraints are explained. A propellant grain for a possible booster stage for a hypothetical space launcher is designed using the combination of the burn-off simulator and the optimizer. The combination of both tools produces suffcient results for the predesign phase of a solid rocket motor.