低弗劳德数水跃消能弱化机制及关键技术研究进展

Research progress on weakening mechanisms and key technologies of energy dissipation by hydraulic jumps with low Froude numbers

摘要

【目的】水跃作为一种重要的水力现象，在水利工程消能中被广泛应用。低弗劳德数下水跃易形成波状结构且消能率往往不理想，导致下游消能防冲设施受到严重冲刷破坏。【方法】因此分别从力学机制和外部条件作用分析总结了低弗劳德数水跃消能弱化机制，并结合水体结构与气泡引入及其相互作用角度，深化对低弗劳德数水跃结构和消能路径的理解。基于弱化机制的认识，对消力池设计、消力池结构优化、辅助消能工应用和掺气整流消能关键技术及机理进行梳理，以指导工程设计，同时指出了应对辅助消能工空化空蚀、消力池内泥沙淤积、水体过饱和气鱼类致死等衍生问题的关键技术。【结果】研究发现，当前低弗劳德数水跃消能研究由于水跃结构本身的复杂性以及现代流动测试技术局限性，水跃紊流结构与能量耗散机理研究仍存在系统性认知空缺；在工程应用中，目前缺乏普适性设计准则以指导工程优化，同时亟待建立工程生态影响评估体系。【结论】未来可利用物理信息神经网络和机器学习技术在水跃两相流机理的深入、消能工设计方法的优化、工程方案多目标评价体系的建立三方面开展进一步研究。

Abstract

[Objective] As an important hydraulic phenomenon, hydraulic jumps are widely used for energy dissipation in water conservancy projects. Hydraulic jumps with low Froude numbers tend to form wavy structures, and the energy dissipation rate is often unsatisfactory, resulting in severe scouring and damage to the downstream energy dissipation and anti-scouring facilities. [Methods] Therefore, the weakening mechanisms of energy dissipation by hydraulic jumps with low Froude numbers are analyzed and summarized from the perspectives of mechanical mechanisms and external conditions. The understanding of the structure and energy dissipation pathways of hydraulic jumps with low Froude numbers is deepened by considering water body structure, bubble entrainment, and their interactions. Based on the understanding of the weakening mechanisms, key technologies and mechanisms related to stilling basin design, stilling basin structure optimization, auxiliary energy dissipator application, and aeration rectification energy dissipation are reviewed to guide engineering design. Additionally, key technologies are highlighted for addressing derivative problems such as cavitation erosion of auxiliary energy dissipators, sediment deposition in stilling basins, and fish mortality caused by supersaturated dissolved gases in water. [Results] It is found that due to the inherent complexity of hydraulic jump structures and the limitations of modern flow measurement techniques, systematic knowledge gaps remain in the research on the turbulent structures and energy dissipation mechanisms of hydraulic jumps with low Froude numbers. In engineering applications, there is a lack of universal design criteria to guide engineering optimization, and the establishment of an engineering ecological impact assessment system is urgently needed. [Conclusion] In the future, physics-informed neural networks and machine learning technologies can be used to carry out further research in three aspects: in-depth investigation of two-phase flow mechanisms of hydraulic jumps, optimization of energy dissipator design method, and the establishment of multi-objective evaluation systems for engineering schemes.

关键词

低弗劳德数 / 水跃消能 / 弱化机制 / 关键技术 / 消能机理 / 消能率 / 水力特性 / 空化

Key words

low Froude number / energy dissipation by hydraulic jump / weakening mechanism / key technology / energy dissipation mechanism / energy dissipation rate / hydraulic characteristics / cavitation

基金资助

江苏省水利厅科研项目“淮河入海水道二期工程枢纽建设质量及安全保障提升关键技术研究”(RHSD2/FW-2024-03)

国家重点研发计划“长江中下游平原河网区水动力优化再构与自然动能高效利用”(2022YFC3202603)