Impact of Phase transitions on the Flow Structure of Gaseous Jets Injected into Water

Abstract

The flow structure of gaseous jets injected into water is key element which determines the characteristics of the total thrust and other parameters of the solid propellant motor used in submarine-launched vehicles. The process of gaseous jets is an unsteady and turbulent process accompanied with phase transitions of the water. The phase transitions have a profound impact on the heat and mass transfer of the gas. The purpose of this paper is to simulate the flow structure of the gas jets underwater considering the phase transitions of the water surroundings. A 2D axial symmetric model which is based on the real launching process is utilized for the numerical simulation. The VOF multi-phase flow model is adopted to get the simulation results of the flow structure of gaseous jets injected into water, which is considered the process of phase transitions. To get a better understanding of the phase transitions, the conditions which neglect the phase transitions are also taken into account to make a comparison. The results indicate that the phase transitions have an influence on the flow structure of jets, which contributes to faster movement. Moreover, the higher of the total gas temperature is, the more intense of the production of vapor gas behaves. Further researches on the phase transitions of water will result in a more effective way of injection. Keyword: solid propellant; hot gas; underwater gas jets; phase transitions; numerical simulation; multi-phase flow model