空泡扩展与水锤效应在容器尺寸约束下的相互作用机理研究

Study on the hydrodynamic ram pressure induced by projectiles penetrating water-filled vessels is a challenging problem in hydrodynamic ram research fields. This project conducts research on the problems of dynamic cavity expansion behaviours and associated HRam pressure in drag and cavitation stages induced by non-tumbling projectiles penetrating confined water-filled vessels with different size, establishes and develops a mechanical model and a theoretical method which can describe the interrelation between cavity dynamic behaviours and associated HRam pressure, by which the interaction mechanism between them is to be illustrated. This projectile makes research mainly in the following aspects:(1)Dimension constraint influence on the characteristics of projectile movement attenuation, cavity expansion and hydrodynamic ram pressure in drag and cavitation stages is quantitatively studied by experimental and numerical method, through which the changing rules of associated physical phenomenons under dimension constraint effects are to be definitized.(2)A theory model of the expansion evolution of cavity fields with dimension constraint effects is established, and the relationship among the cavity expansion, energy transforming and the energy distribution around flow field , as well as the process mechanism of the fluid acting on container walls are obtained.(3)Interrelation between the dynamic cavity expansion and HRam pressure of fluid acting on container walls under constraint conditions is built, by which the interaction mechanism between them is to be revealed. The achievement of the projectile is expected to enrich the theory in HRam effect research and to provide theoretical foundation for survival design of associated vulnerable vessel structures under projectile penetration.

弹体侵彻水容器时在阻滞和空化阶段的水锤压力问题研究是水锤效应研究领域中富有挑战性的课题。本项目对不翻转弹体侵彻不同尺寸水容器时在阻滞及空化阶段的空泡扩展动力学行为及其引起的水锤压力问题展开研究，建立并发展可以描述两者相互作用关系的力学模型和理论方法，阐述其相互作用机理。本项目主要对以下问题展开研究：（1）利用试验和数值模拟定量研究容器尺寸约束效应对阻滞和空化阶段弹体运动衰减、空泡扩展、水锤压力等特性的影响，明确两阶段下相关物理现象在此效应下的变化规律。（2）建立含尺寸约束效应的空泡场扩展演化理论模型，得到空泡扩展与周围流体能量转化和能量分布之间的关系及流体作用于容器壁的过程机制。（3）建立约束条件下空泡场动态扩展与流场对容器壁的水锤压力作用的相互关系，揭示两者相互作用机理。通过以上问题研究将丰富并完善水锤效应研究中的理论基础，并为相关易损容器结构在弹体侵彻下的抗毁伤设计提供理论依据。

弹体侵彻充液容器时的水锤问题研究，对军事民用相关易损结构的设计具有着重要的科学和理论应用价值。.本项目通过常规不翻转弹体侵彻液体不同尺寸容器，将水锤压力问题研究由入水初始阶段扩展至了阻滞和空化阶段，取得的一些主要成果如下：1)通过开展大量高速弹体侵彻不同尺寸充液容器的试验，定量分析了容器尺寸约束效应对入水相关物理现象如空泡扩展、空泡壁扩展平均速度、面闭合、深闭合及入水速度衰减特性等的影响规律，研究结果表明，容器尺寸约束对空泡的扩展有着重要的抑制作用，从而使得容器壁受到更大的空泡扩展动压力。.2)通过引入容器对最大空泡截面半径和空泡壁扩展平均速度的约束因子，提出了含有容器约束影响的空泡扩展演化模型，此模型可以预测弹体不同速度侵彻不同尺寸容器后的空泡扩展演化，且与实验结果吻合较好。.3)研究了不同容器尺寸下的壁压约束因子，结果表明此因数与弹体速度、容器尺寸以及容器壁变形刚度有关；提出了含有容器约束效应的由弹体速度衰减和空泡扩展引起的容器壁压力演化模型，解决了弹体入水后在阻滞和空化阶段产生的水锤压力分布问题。.通过以上问题的研究丰富并完善了水锤效应研究中的理论基础，并为相关易损容器结构在弹体侵彻下的抗毁伤设计提供理论依据。