Coupling of Level Set and Volume of Fluid Methods for Simulations of Transient Internal Flow Field in Solid Rocket Motors

This study entails the analysis of the working performance of solid rocket motors (SRM), featuring the essential element of internal ballistic analysis. Therefore, the internal flow field under the condition of burning surface regression needs to be calculated. The boundary of the internal flow field of the SRM moves with the combustion of the propellant; therefore, it is necessary to accurately track the mobile interface to provide boundary conditions for the flow field calculation. The coupling of the level set method and the volume fraction method is utilized to track the burning surface, and the porous media model is used to divide the fluid and solid calculation domains. The interface between the two calculation domains is used to characterize the burning surface, and then, the area of the burning surface is obtained by solving the area of the interface. The calculation and analysis are carried out for SRM with tubular charge and star charge. The results verify that the calculation model can accurately calculate the transient internal flow field of SRM under the condition of burning surface regression.