Coupled simulation of fluid flow and propellant burning surface regression in a solid rocket motor

Propellant burning surface regression is one of the most distinguishing characteristics of solid rocket motors. Simulation of this phenomenon, especially when coupled with a fluid flow, requires accurate mathematical models and robust and efficient numerical techniques to determine the evolution of the propellant burning surface as it regresses with speed as determined by solid propellant combustion. In this paper, an integrated framework is presented for the coupled simulation of propellant burning surface regression and internal fluid flow in a solid rocket motor. The arbitrary-Lagrangian-Eulerian scheme is employed to formulate the compressible viscous fluid flow on moving meshes. Face-offsetting method is used to model the propellant burning surface regression of solid rocket motor. Automatic mesh smoothing and remeshing techniques are further utilized to address the deformation and distortion of fluid domain meshes. We present the theoretical foundation of our method and finally demonstrate its accuracy, efficiency, and flexibility for a laboratory-scale solid rocket motor.