Numerical Simulation of Muzzle Flow Field Based on Calculation ofCombustion Productions in Bore

Liang Wang, Houqian Xu, Wei Wu , Rui Xue

(School of Power Engineering, Nanjing University of Science＆ Technology, Nanjing 210094, China)



Abstract:

To improve the accuracy of numerical simulation of muzzle chemical flow field, and study the gunpowder combustion productions, the muzzle flow field is simulated coupled with the calculation of combustion productions in bore. The calculation in bore uses the gibbs free-energy minimization method and the classical interior ballistics model. The simulation of the muzzle flow field employs the multi-component ALE(Arbitrary Lagrange-Euler)equations. Computations are performed for a 12.7 mm gun. From 2.48 ms to 3.14 ms, the projectile moves in the gun barrel. CO and H₂O masses decrease by 3.37％ and 6.51％, and H₂ and CO₂ masses increase by 11.11％ and 10.58％. The changes conform to the fact that the water-gas equilibrium reaction of all reactions plays a dominant role in this phase. After the projectile leaves the barrel, the masses of H₂ and CO decrease, and the masses of H₂O and CO₂ increase. When it moves to 80d away from the muzzle, the decreases are 12.75％ and 8.05％, and the increases are 12.76％ and 36.26％, which tallies with the existence of muzzle flame. Further, CO and H₂ burn more and more fiercely with the muzzle pressure p_g increasing, and burn more and more weakly with the altitude rising. When two projectiles launch in series, the combustion of the second projectile muzzle flow field is fiercer than the first projectile. Analysis results have shown that the proposed method is effective for simulating the muzzle flow filed.

Key words:  combustion  gibbs free-energy  muzzle flow field

DOI：10.11916/j.issn.1005-9113.2015.04.010

Clc Number:TJ012.2

Fund: