Numerical investigation of the effect of aerodynamic fragmentation of condensate particles on the two-phase impulse losses in a solid-fuel rocket engine nozzle

The work is devoted to numerical investigation of the effect of aerodynamic fragmentation of aluminum oxide liquid particles on the characteristics of two-phase flow in a nozzle of solid-propellant rocket engine and to comparative analysis of the application of the fragmentation criterion in the form of a constant value or a functional dependency.
Combustion products of a metallized fuel form a mixture of gas and condensate particles. The flow is non-equilibrium, which induces two-phase impulse losses in the engine nozzle. The interaction of liquid condensate particles with a gas is accompanied by their fragmentation and coagulation. The interaction of the particles is described based on the continuous approach to variation in the size distribution function. The aerodynamic fragmentation of particles is characterized by a critical Weber number which is equal to 17 in the engineering calculations. The fragmentation is a complex process which depends both on parameters of the gas flow and parameters of the ensemble of liquid particles which change along the nozzle. Therefore, the critical Weber number must be multifunctional dependent.
An empirical functional dependence determining the critical Weber number is shown. The results of calculations of two-phase impulse losses with the fragmentation criterion in the form of a constant value or a functional dependence are presented.