Numerical modeling of the solid fuel sublimation in a high-temperature gas flow in the continuum approach and with boundary separation between two media

Two approaches are proposed for the numerical simulation of two-phase flows in a porous medium, taking into account the gasification of the solid phase. In the first case, the mathematical model of a porous medium is represented in a two-phase formulation using the model of interpenetrating continuums. Arrhenius kinetics was used to take into account the sublimation of fuel. In the second case, the porous medium was specified explicitly with separation of the boundary between the two media, and an approach based on the melting and crystallization model was used to simulate the sublimation of a solid. For both approaches, computational technologies have been created to simulate the sublimation of a solid fuel in a high-temperature oxidizer flow. Parametric calculations of the flow dynamics in a porous medium during sublimation of the solid phase have been carried out. It is shown that the continual equilibrium mathematical model, in which the temperatures of the gaseous and solid phases are assumed to be equal, makes it possible to qualitatively correctly describe the dynamics of the process of gasification of a solid fuel in a high-temperature oxidizer flow. The similarity of the characteristic times of the sublimation process calculated using two approaches is revealed.