Numerical Analysis Of Two Phases Fluid Characters In The Combustor Of Liquid-Rocket Engine

Numerical simulation is a good method to investigate hydrodynamic in liquid rocket engine chamber. The mechanism of gas-liquid two-phase fluid was not so clear due to the complexity of influential factors of fluid in scramjet engine. With the rapid development of hardware and calculation technique, numerical simulation combined computational mathematics with computational fluid dynamics had been become an important research approach from the aspect of numerical simulation.This paper built up gas phase and liquid phase dynamic equations with the base of gas-liquid two-phase fluid dynamic theory. Interaction between gas-liquid two-phase in hypersonic two-phase flow was considered in two-phase flow model, two-fluid model and dispersed droplets model were used, turbulence kinetic energy, turbulence dissipation and the turbulent products caused by viscosity and buoyancy were considered in the calculations by including 3μtitem and"freezing pressure"hypotheses into the equations.In the dispersed droplets model, suppose that the dispersed droplets travels throng continuous fluid medium. The factors affects on the droplets acceleration are the different velocities between two phases and the displacement of fluid medium caused by droplets kinetic. At the same time, the chemical reactions and radiation energy given out by the burning of fuel are considered in the combustor using a P1 model by solving the radiation problem.By investigating on the influence of improving inflow structure, changing different velocities of inflow and equivalence ratio of fuel which may affect the characteristic of fluid dynamics in the chamber. This paper indicates the influence of shock wave and the ways of its spread. At high Mach number of inflow, the length of the shock wave increases and the echo decreases in the chamber. Introducing a high equivalence ratio in the former injection part, it has not too much influence on the flow in the chamber. The second part of injections affect on the mixing of fuel and air. Large diameter drops are difficult to be carried away because they have a larger resistance on the whole, and have a similar velocity both in the beginning and the end in the chamber, and have an asymmetry distribution in the chamber. Small diameters are easy to be carried away by airflow, and have higher velocity at the end than at the beginning, and distributing equally on the whole.In the chamber of scramjet engine, the influence of radiation energy was given by the combustion of fuel upon fluid situation and density distribution of the system. By comparing with non-combustion case, results indicate that the given energy by fuel combustion has great influence on the flow. The fuel-air mixture expands when crossing the laryngeal and mixture more symmetry, combustion to be more sufficient, so the combustion is more fierce at the end of the chamber.