Integrated Fluid-Structure Simulation for Coupled Phenomena of a Solid Propellant Rocket Interior

Abstract

The interior phenomena in solid rocket exhibit highly unsteady, multi-scale, and multi-physics features because fluid, structure, and combustion generates a non-linear feedback cycle by influencing one another inside the combustion chamber. In order to integrated fluid-structure-combustion simulation to understand the highly unsteady, multi-physics phenomena inside of solid rocket motor interior, fully integrated computational simulations inside solid propellant rocket are carried out to examine the nonlinear feedback interaction between fluid, structure and combustion module. The Arbitrary Lagrangian Eulerian (ALE) description is employed to efficiently tracking the burning process along grain surface. An automatic re-meshing algorithm is added to the FSbI process to accurately analyze unsteady fluid-structure coupling phenomena with deforming solid grain during simulation. The developed solver is then applied to the full-burning simulation of a solid propellant grain, which is a highly-coupled unsteady phenomenon between gas flow and propellant structure. Based on the integrated computed results, detailed ignition mechanism and flame propagation process along propellant grain surface are investigated. In particular, flame propagation delay and secondary burning phenomena are explained from the physical and numerical perspectives. Furthermore, virtual contact line method is introduced to overcome the boots contact problem occurring in the gas flow-propellant interaction, and the deforming behavior of full-burning solid propellant is examined.