Determining the transfer coefficient of natural turbulence near the solid-propellant gasification zone. I. Two-phase model of the gasification zone

A model for the gasification of solid propellants containing a two-phase medium in an intermediate stage. The formation of the gas phase proceeds in two ways: chemical reactions result in gas products, which, in turn, initiate the formation of bubbles, in which vapor forms from the liquid phase of the fuel. Gas products play an important role only at the earliest stage of bubble development; the minimum size of gas-phase nuclei is determined from their minimum pressure. The he bubble volume grows primarily by evaporation of the liquid phase. A kinetic equation for the bubble concentration and the necessary boundary conditions are formulated. Arguments are given to suggest that a maximum temperature cannot be formed in the gasification zone and that natural turbulence can be generated by collapsing bubbles. The sound produced by burning solid rocket propellants is explained by the collapse of a huge number of microscopic bubbles. If the processes in the two-phase zone are neglected, the formulated system of equations goes over into the Belyaev–Zel'dovich model equations.