Two-dimensional numerical simulation on gas-solid two-phase flow induced by combustion gas flow in a chamber based on a fifth-order WENO scheme

In order to explore the flow characteristics and propagation law of combustion gas from the central ignition tube in the initial stage of internal ballistic, a visual experimental platform was designed to carry out ignition experiments with the substituted particle bed in the chamber. A high-speed camera system was used to capture the gas flow and flame propagation in the chamber, and a dynamic data acquisition and analysis system with pressure sensors was applied to record the pressure data at characteristic positions in the chamber. A two-dimensional, axisymmetrical, two-phase flow model of internal ballistics was constructed to simulate the flow process of the gas in the substituted particle bed based on a weighted essentially non-oscillatory (WENO) scheme, and the time term was determined by the third-order TVD Runge-Kuta method. The calculated results are in good agreement with the visual experimental results, and the global pressure average error is 5.35%. It indicates that the numerical simulation can accurately describe the gas flow characteristics and present the development process of the gas from the ignition tube in the substituted particle bed. The radial effect of the chamber pressure is obvious, and the gas moves rapidly along the radial direction, and the substituted particle basically does not move in the initial stage of ignition. Moreover, with the gradual propagation of the gas in the chamber, the chamber pressure is characterized by a radial uniformity and an axial gradient distribution. Under the action of the pressure gradient, the axial velocity of the gas phase begins to dominate, and furthermore, the radial velocity decreases to zero in the bottom and the middle region of the chamber, while the solid phase velocity varies with the gas phase velocity. In addition, before the gas reaches the bottom of the right end, the inverse velocity fluctuation appears in advance due to the solid particle congestion.