Integrated Fluid–Structure Simulation for Full Burning of a Solid-Propellant Rocket Interior

Fully integrated computational simulations inside solid-propellant rockets are carried out to examine the nonlinear feedback interaction between fluid, structure, and burning module. The arbitrary Lagrangian Eulerian description is employed to efficiently track the burning process along the grain surface. An automatic remeshing algorithm is added to the fluid, structure, and burning process to accurately analyze unsteady fluid–structure coupling phenomena with deforming solid grain during the 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 the gas flow and propellant structure. Based on the integrated computed results, the detailed burning mechanism and flame propagation process along the propellant grain surface are investigated. In particular, flame propagation delay and secondary burning phenomena are explained from the physical and numerical perspectives. Furthermore, the virtual contact line method is introduced to overcome the boots contact problem occurring in the gas flow–propellant interaction, and the deforming behavior of the full-burning solid propellant is examined.