射弹跨声速入水初期阶段多相流场特性数值研究

In order to study the multiphase flow characteristics during the initial water-entry process, the water-entry of a projectile at transonic speed was simulated. A temperature-adjusted Tait equation was used to describe the compressibility effects in water, and the air and vapor were treated as ideal gases. The computational methodology was validated through comparing the simulation results with the experimental measurements and the theoretical results. Based on the computational methodology, the evolution of the flow and the influences of the compressibility effect and entry height were studied. The results show that there is bow shock near the nose, and the shock angle decreases when the projectile penetrates deeperly; the projectile does not touch the free surface because of the surface depression; the impact phase occurs later and the impact pressure is bigger when the entry height is small, but the entry height has little influence on the flow when it is bigger than 10 mm.