考虑结构响应超空泡射弹的流体动力特性及稳定航行机理

The failure of rigidity assumption for supercavitating projectiles during the high-speed sailing results in non-negligible interactions among structural response, supercavitation flow and macroscopic motion of supercavitating projectiles, this changes hydrodynamic characteristic and stability mechanism of supercavitating projectiles. This project aims to investigate the scientific problem of motion modeling and stability mechanism of supercavitating projectiles by considering the structural response, where theoretical analysis, numerical simulation and experimental method are all utilized. The supercavitating flow and structural response of supercavitating projectiles is first established, respectively, the hydrodynamic forces acting supercavitating vehicles and the associated structural response are extracted, and the response of supercavitating projectiles under typical load conditions is obtain. The coupled numerical model for the supercavitating flow and structural response is then presented, the influence of structural response on the supercavitation flow and hydrodynamic characteristic is discussed, this results in the method to predict the hydrodynamic force of supercavitating projectiles by considering structural response. The motion modeling method and trajectory simulation technology of supercavitating projectiles under the high-speed sailing is finally investigated, and the stability mechanism is revealed, and the constraint on the initial condition is explored to maintain stable sailing. This project is beneficial to promote the advancement of underwater high-speed sailing technology and associated theory, and to provide theoretical basis and technical support to the high-speed supercavitating projectiles.

试验表明超空泡射弹在高速航行时“刚体假设”不再成立，随之发生的结构响应与超空泡流动、宏观运动相互耦合作用，致使超空泡射弹的流体动力特性与运动特性发生变化。本项目考虑结构响应的影响，研究高速超空泡射弹的运动特性和稳定机理这一核心科学问题，拟采用理论分析、数值仿真和试验测试相结合的方法开展研究。建立超空化流动和射弹结构响应的仿真分析方法，研究超空泡射弹的流体动力特性和结构响应特性，获得射弹对典型载荷的结构响应规律；建立超空泡流动与结构响应相耦合的仿真分析方法，研究结构响应对超空泡流动的影响规律，掌握超空泡射弹在结构动态响应过程中的流体动力特性预报方法；考虑结构响应的影响建立超空泡射弹运动特性的理论分析方法，揭示高速超空泡射弹的稳定航行机理，确定维持其稳定航行的初始约束。本项研究工作有助于超空泡射弹技术理论体系的完善，预期研究结果可为高速超空泡射弹的优化设计和工程应用提供理论依据和技术支撑。

超空泡射弹由机/舰载火炮发射，利用了超空化减阻技术，能够对水下目标实施跨介质打击，具有反应速度快、效价比高、适应性强等特点，是舰船对抗水雷、鱼雷等水下威胁的有力手段。为了扩大超空泡射弹的防御范围、增强杀伤能力，超空泡射弹的初始发射速度越来越大。高速超空泡射弹在巨大流体动力作用下表现出了显著的结构变形响应特性，为期理论分析和工程应用带来了挑战。本项目综合运用数值模拟、理论分析和试验研究的方法，研究了高速超空泡射弹的超空化流场、宏观运动和结构变形响应之间的耦合影响关系，揭示了“非刚性”超空泡射弹的稳定航行机理，探索了超空泡射弹高速稳定航行的初始约束。主要研究工作如下：.（1）基于水动力学仿真软件Fluent和结构动力学仿真软件Abaqus，分别建立了超空化流动和射弹结构响应的仿真分析方法，通过机理试验和数值计算，掌握了超空泡射弹的流体动力特性及结构响应特性，获得了射弹在典型载荷作用下的结构响应规律。.（2）基于多物理场耦合平台MPCCI解决水动力学仿真软件Fluent和结构动力学仿真软件Abaqus之间的数据双向传递问题，构建了超空泡流动与结构响应相耦合的仿真分析方法，掌握了结构动态响应对超空化流动的影响规律，形成了在结构响应条件下射弹的流体动力预报方法。.（3）通过联合超空化流场、流体动力、射弹结构动态变形、射弹宏观运动的仿真计算过程，构建了“非刚体”射弹的弹道特性和结构动态响应变形特性的预测模型，获得了高速超空泡射弹的运动和结构响应规律，揭示了超空泡射弹伴随着结构高频振动的宏观尾拍运动的稳定机理。.本项研究有助于完善超空泡射弹技术的理论体系，研究结果可为高速超空泡射弹的理论分析和工程应用提供理论依据和技术支撑。