Simulations of Slumping Propellant and Flexing Inhibitors in Solid Rocket Motors

Abstract

We describe and present results from GEN2, the second-generation three-dimensional solid rocket motor simulation package developed at CSAR. The internal gas dynamics, propellant combustion, and structural response are fully coupled. In addition to several test cases, we simulate propellant slumping at a joint slot due to uneven gas pressure loads in the Titan IV SRMU. We also study the motion of a flexible inhibitor and its effect on the gas flow near a joint slot in a section of a typical large solid rocket motor. IntroductionDetailed 3-D simulation of solid rocket motors requires solving a very complex, tightly coupled multiphysics problem that includes a wide range of length and time scales. Obtaining accurate numerical solutions for relatively simple geometries, physical models, and even fairly short burn times, requires enormous computational resources that are available today only at major supercomputing centers. Each physics module (gas dynamics, structural mechanics, etc.) must run efficiently in parallel on many processors and data must be exchanged frequently between modules in order to solve the tightly coupled system.

Assessment of conservative load transfer for fluid-solid interface with non-matching meshes

“…To assess the effects of load transfer schemes on aeroelastic problems involving large displacements, we now consider the aeroelastic deformations of a flexible beam subjected to a subsonic flow field. This problem is motivated by that of an inhibitor protruding into the core flow field of a solid rocket motor [17,18].…”

Flow Simulation in Solid Rocket Motors Using Advanced CFD

“…The idea is to encapsulate the three main tasks: flow solution, structural response and dynamic burning into separate libraries. The driver program is then responsible for the data exchange [2].…”

“…Nowadays, there is a growing demand for high-fidelity flow simulations in complex systems like in turbomachinery [1] or in solid rocket motors [2]. The goal is to obtain deep insight into the physical and chemical processes, which are difficult or impossible to measure.…”

Burning surfaces evolution in solid propellants: A numerical model

“…When the conservation equations (1) to (3) are solved, the combustion pressure is obtained from the gas state equation (4). The gas transpiration due to solid combustion contributes to mass, momentum and energy in the form of sources.…”

“…The first published methods for either quasi-static, e.g. [2,3] or dynamic [4][5][6], coupling between gas and solid require interfaces with interpolation techniques as well as separate flow solvers and mesh generators for each phase. The latter poses particular demands on the designer, especially in three dimensions, where generation of geometrically complex (e.g.…”