Multi-Dimensional Two-Phase Flow Modeling Applied to Interior Ballistics

Abstract

Complex phenomena occur in a combustion chamber during a ballistic cycle. From the ignition of the black powder in the primer to the exit of the projectile through the muzzle, two-phase gas-powder mix undertakes various transfers in different forms. A detailed comprehension of these effects is fundamental to predict the behavior of the whole system, considering performances and safety. Although the ignition of the powder bed is three-dimensional due to the primer’s geometry, simulations generally only deal with one- or two-dimensional problem. In this study, we propose a method to simulate the two-phase flows in 1, 2 or 3 dimensions with the same system of partial differential equations. A one-pressure, conditionally hyperbolic model [1] was used and solved by a nonconservative finite volume scheme associated to a fractional step method, where each step is hyperbolic. We extend our study to a two-pressure, unconditionally hyperbolic model [2] in which a relaxation technique was applied in order to recover the one-pressure model by using the granular stress. The second goal of this study is also to propose an improved ignition model of the powder grains, by taking into account simplified chemical kinetics for decomposition reactions in the two phases. Here we consider a 0th-order solid decomposition and an unimolecular, 2nd-order gas reaction. Validation of the algorithm on several test cases is presented.

Numerical simulation of gas-solid two-phase reaction flow with multiple moving boundaries

“…The two-phase reaction flow model for the launch system of multiple projectiles are established according to other researchers' and our previous work (Kuo and Summerfield, 1974;Gough and Zwarts, 1979;Baer and Nunziato, 1986;Zhang et al, 1996Zhang et al, , 2002Zhang et al, , 2006Saurel and Abgrall, 1999;Nussbaum et al, 2011;Jaramaz et al, 2011;Yuan and Zhang, 2005;Cheng and Zhang, 2013).…”

Study on Dynamic Burning Rate Equation of Propellant

“…The components of propellant charge structure are basically including the main propellant grain charge and center ignition-spread tube. The dynamics model of main propellant charge and basic hypothesis are as follows [21][22][23][24][25]:…”

“…Without considering the stumble movement of the gun.The basic equations of the interior ballistic two-phase flow of main propellant charge in chamber and gun barrel are as Eq. (1)[16,[21][22][23][24][25]:…”

Optimization Design for Detonation Powerplant Based on LS-DYNA Simulation

“…The process of the detonation powerplant doing work to outside can be divided into four stages. On the basis of the characteristic of each stage and classic ballistic theories such as internal ballistics gunpowder gas equation of state, burning equation, energy conservation law, and kinematic equation [13][14][15][16][17], the mathematical models of internal ballistics of the four stages are built. The first stage is the period from the ignition of gunpowder to the time when the cartridge and slide cylinder start to move.…”