为获取超空泡射弹不同攻角入水时的空泡演化与运动特性变化规律,基于RANS方程、Schnerr-Sauer空化模型、k-ε湍流模型,采用重叠网格技术,针对入水速度400 m/s不变,入水攻角不同时,静水与波浪环境下的超空泡射弹入水过程开展了数值模拟研究。研究结果表明:攻角大于2°时,弹丸将在入水过程中出现尾拍现象,尾拍时尾翼划破空泡壁,会造成空泡在此区域的扩张,并对弹道稳定性产生不利影响;尾拍现象发生时,阻力系数和升力系数均会上升,且攻角越大,上升的幅值越大;在波浪环境下,弹丸入水过程中仍然会发生尾拍运动,但与静水环境相比,在尾拍发生的时间上有一定区别。攻角为正时尾拍出现的时间提前,反之则尾拍出现的时间延后。

To obtain the water-entry cavitation evolution and motion characteristics of supercavitation projectiles in different attack angle, the water-entry process of constant water-entry speed and different attack angle in hydrostatic and wave environment is simulated by using RANS equation, k-ε turbulence model, Schnerr-Sauer cavitation model and overset mesh. The result shows that the projectile will have an obvious tail-slap phenomenon in the process of water-entry when the attack angle is larger than 2°. When tail-slap phenomenon occurs, the tail wing cuts through the cavity wall, which cause the expansion of the cavity in this area and adversely affect the trajectory stability. Furthermore, both the drag and lift coefficients will rise, and the higher the angle of attack, the greater the rise. In the wave environment, the tail-slap phenomenon will still occur in the process of the projectile entering the water, but compared with the static water environment, there is a certain difference in the time of the tail-slap. When the attack angle is positive, the time of the tail-slap is advanced, otherwise it will be delayed.