万米级深海陶瓷耐压结构水下内爆流场数值模拟

耐压结构是深海潜器的重要组成部分，但在深海的高压环境中却存在内爆的风险。为研究陶瓷耐压结构水下内爆的流场特性，使用针对可压缩多相流问题开发的开源代码，采用直接数值模拟，应用自适应直角网格，对两种压力条件下的耐压结构水下内爆进行了数值模拟。通过低压模拟结果与理论解和试验值比较，验证了模拟方法的有效性，进而开展万米级深海陶瓷耐压结构水下内爆模拟。分析发现：陶瓷耐压结构发生内爆后，其内部气腔存在多次压缩—反弹现象，深海环境压力越大则反弹越不明显；气腔反弹阶段，在结构外部将产生数倍于深海环境压力的冲击波，且传播速度接近声速；冲击波压力峰值与到球心距离呈负指数幂函数关系；在相同深海环境压力下，耐压结构外部监测点的冲击波压力与球体半径呈正比例关系。

Numerical simulation of flow field of underwater implosion of full-ocean-depth ceramic pressure hull

Pressure hull plays an important role in deep-sea submersibles, but it bears the risk of implosion in the high-pressure environment. In order to study the characteristics of the flow field of the underwater implosion of the ceramic pressure hull, an open-source code developed for the compressible multiphase flow problem, direct numerical simulation, and adaptive Cartesian mesh are used to numerically simulate the underwater implosion of pressure hull under two pressure conditions. The implosion simulation result with low deep-sea environment pressure is compared with theoretical solutions and experimental results to verify the effectiveness of the simulation, then the numerical simulation of flow field of underwater implosion of full-ocean-depth ceramic pressure hull is carried out. There are repeated compression-rebound processes of the internal air cavity after the implosion. The greater the ambient pressure, the less obvious the rebound. In the rebound stage, a shock wave several times the ambient pressure is generated outside the structure, and the propagation speed is close to the speed of sound. The peak pressure of the shock wave has a negative exponential power function relationship with the distance to the center of the sphere. The pressure of the shock wave at the monitoring point outside the pressure hull is proportional to the radius of the sphere under the same ambient pressure.