基于二维非定常Euler方程,结合高精度Roe格式及结构化动网格技术,对弹丸从膛底飞离不同膛口装置过程中膛口流场的发展过程进行了数值模拟。数值计算结果清晰地揭示了光膛口以及分别加装开腔式和多孔制退器后膛口流场的不同波系结构,同时计算纹影图清楚地显示了其与弹丸相互作用及演变过程。计算结果与本课题组先前相关试验阴影照片相符。另外,根据数值流场结果,详细探讨了制退器降低后坐冲量的机理与膛口周围超压区域的分布,为制退器改进设计提供重要参考。
The processes of a high-speed projectile flying away from the bores through different muzzle brakes were numerically simulated by using the high resolution Roe scheme and the structured dynamic mesh techniques based on the two-dimensional unsteady Euler equation.The calculated results describe the evolution process of muzzle blast wave structures of different muzzle brakes(without muzzle brake,a three-way muzzle brake and a multi-cavity muzzle brake),and the interaction and evolution processes of them and the projectile are visualized clearly in the computational schlieren images.The numerical results agree well with our previous corresponding experimental shadowgraphs.Moreover,the reducing mechanism of recoil impulse of muzzle brake and the distribution of overpressure areas around the muzzle were discussed in detail,which can praide important guidance for improving the muzzle brake design.