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| 泵站进水系统竖直进口空气吸入涡不稳定特性研究 |
| Instability characteristics of the air-core vortex at vertical pump intakes |
| 投稿时间：2025-07-21 修订日期：2026-01-27 |
| DOI： |
| 中文关键词: 空气吸入涡 竖直进口 不稳定特征 湍动能 本征正交分解 |
| 英文关键词: air-core vortex vertical hydraulic intake instability characteristics turbulent kinetic energy proper orthogonal decomposition |
| 基金项目:国家自然科学(U22A20238, 52009136)；中央高校基本科研业务费专项资金资助(2024TC081) |
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| 中文摘要: |
| 空气从泵站进水系统进入泵站进口，空气受到水泵抽吸作用产生连接自由表面至进水口的局部连贯涡旋，即空气吸入涡，它是影响泵站运行效率和安全稳定性的主要不利因素。本文采用大涡模拟结合CLSVOF界面追踪技术对竖直进口产生的空气吸入涡进行了数值研究。通过湍动能输运方程和本征正交分解（POD）方法分析了空气吸入涡演变过程中涡旋结构与湍流脉动场的相互作用特征。研究结果表明，竖直进口空气吸入涡的演化可分为V型表面旋流、表面凹陷和连贯空气芯三个阶段，湍动能分布与涡旋运动密切相关。流向和展向脉动速度与对应速度梯度的相互作用驱动局部湍动能生成，且湍动能扩散为随机涡旋向空气吸入涡演化提供能量输运途径。脉动速度场和涡量场的POD分析发现，前二阶模态流场存在旋转方向相反的涡旋对，使得空气吸入涡涡核一侧强度增大，而另一侧强度减小，从而诱导涡核移动。本文揭示的空气吸入涡不稳定性特征与机制丰富了空气吸入涡理论研究，也为空气吸入涡的控涡措施和泵站进水系统优化设计提供了依据。 |
| 英文摘要: |
| Air is entrained into the pump intake system by the pump suction, forming an air-core vortex that connects the free surface to the pipe intake. The air-core vortex is one of the adverse factors affecting the operational efficiency and safety stability of pumping stations. In this paper, we conduct numerical researches on air-core vortex phenomena at vertical hydraulic intakes using large-eddy simulation coupled with the CLSVOF interface-tracking technique. The interaction between vortex structures and turbulent flow fields during the air-core vortex formation was analyzed by implementing the turbulent kinetic energy transport equation and proper orthogonal decomposition (POD) method. The results indicate that the evolution of the air-core vortex in vertical hydraulic intakes can be categorized into three distinct phases: the V-shaped surface swirl, the surface dimple, and the coherent air core stages. The turbulent kinetic energy distribution exhibits a strong correlation with vortex dynamics. Analyses of the turbulent kinetic energy transport equation reveal that the interaction between the streamwise and spanwise components of fluctuation velocities and their corresponding velocity gradients drives local turbulent kinetic energy production, while turbulent kinetic energy diffusion provides an essential energy transport pathway for the evolution of random vortices into an air-core vortex. The POD analyses of the fluctuation velocity and vorticity fields reveal that the first two modes of the fluctuation fields exhibit a pair of vortices with opposite rotating directions, which causes the strength of the air-core vortex to increase on one side while decreasing on the other, thereby inducing a lateral displacement of the vortex core. The instability characteristics and mechanisms of the air-core vortex revealed in this paper enrich the theoretical understanding of such vortices and provide a basis for vortex control measures and the optimal design of pump station intake systems. |
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