Numerical investigation of two-phase reactive flow with two moving boundaries in a two-stage combustion system

Abstract

Abstract The quest to achieve higher muzzle velocity is one of the key goals for researchers in the fields of propulsion and ballistic. Based on the conventional chemical propulsion, the two-stage combustion system as a new launch principle can provide higher muzzle velocity without exceeding the maximum pressure in the chamber. In this paper, the modified two-fluid model with two moving boundaries is proposed to simulate the detailed multi-dimensional flow and energy conversion behaviors of the combustion gas and propellant grains in the two-stage chamber. The dynamic self-adapting mesh update method is developed to expand and merge the computational domain for both projectile and piston motions. The application to a standard virtual gun as a standard benchmark for interior ballistic codes is used to validate the accuracy and reliability. The calculation results are in good agreement with those of codes in different countries. After that, a two-stage chamber system is set up based on the standard virtual gun. The numerical results present deep understanding of the two-phase flow behaviors in the two-stage chamber. Then the effects of design parameters on the performances in the additional chamber are numerically investigated. Finally, a suggested scheme of the additional chamber is proposed. The findings of the study put a further prediction tool for the understanding and design of the two-stage combustion system with moving boundaries.