超空泡射弹尾翼流体动力特性实验分析

Hydynamic characteristic of fins of supercavitation projectile

为研究尾翼对超空泡流型发展及射弹流体动力的影响,在高速水洞中进行了通气条件下的超空泡射弹尾翼流体动力特性实验.首先基于高速水洞搭建了通气空化绕流实验测试系统,同时根据射弹基本外形,按照相似理论设计了尾翼测力实验模型,为改变空泡壁面与尾翼的相对位置关系,用以研究穿刺高度对射弹尾翼流体动力特性的影响,实验中采用调整空泡尺寸或模型安装姿态来改变尾翼穿刺高度,最后对实验方案的合理性进行了充分的论证.通过改变测试工况对超空泡射弹尾翼的流体动力特性开展实验研究,得到了不同穿刺条件下尾翼对空泡流型的影响规律及其流体动力特性.研究结果表明:尾翼穿刺空泡以后,在其顶部和侧面生成的二次空泡将显著改变主体空泡的形态,且随着穿刺高度的增加,尾翼对主体空泡的影响更加明显;尾翼的流体动力主要产生于前缘沾湿部位,且随着穿刺高度的增加升力系数和阻力系数均显著增加;在尾翼穿刺空泡的条件下,其阻力系数和升力系数随攻角的增大而线性增加.

To study the influence regularity of the tail fin on the bubble flow pattern,the hydrodynamic characteristics of fins of supercavitation projectile were performed in water tunnel.The rationality of the test scheme was fully demonstrated.The test system of ventilation cavitation flow was constructed based on the high-speed water tunnel.Base on the basic shape of the projectile and the similarity theory,the tail force measurement test model was designed.Meanwhile,to change the relative location between the fins and the cavitation,the cavitation size or the model attitude was adjusted.The hydrodynamic characteristics of fins of supercavitation projectile were studied by changing the test conditions.The influence regularity of the tail fin on the bubble flow pattern and its hydrodynamic characteristics under different puncture conditions were obtained.The results show that the formation of secondary cavitation at the top and the side of the tail fin after the puncture of the tail significantly changed the shape of the main cavitation,and the impact of the tail fin on the main cavitation became more obvious with the increase of the puncture height.The hydrodynamic characteristics of the tail fin mainly came from the wetting part of the leading edge,and the lift coefficient and the drag coefficient increased significantly with the increase of the puncture height.The drag coefficient and the lift coefficient under puncture conditions increased linearly with the attack angle.The results can provide references for the optimization design of the shape of the supercavitation projectile and trajectory prediction.