【作者】 王英奎；

【导师】 江春波；

【作者基本信息】 清华大学 ， 水利工程， 2011， 博士

【摘要】 立轴漩涡是泄洪洞进水口前比较常见的一种流动现象，对泄洪洞的泄洪安全具有很大的危害，因此在工程实际中需要尽量避免出现。本文结合溪洛渡电站水利工程实际，以消除实际工程中的立轴漩涡现象为目标，从模型试验、理论分析、工程应用等三个方面，对立轴漩涡进行了深入研究。建立溪洛渡电站水力学整体模型，对泄洪洞进口处的立轴漩涡进行了试验观测，包括立轴漩涡形态观测和表面流场观测。形态观测是在不同淹没水深情况下，对不同进口体型、不同进口边界、不同下泄流量等条件下的立轴漩涡产生及发展变化过程进行了详细观测。对立轴漩涡的形态特征及水力因素进行了总结分析，并且对立轴漩涡的产生和发展的机理进行了理论研究。利用粒子图像跟踪测速技术对泄洪洞进口前表面流场进行了试验观测，得到了不同水位情况下的流场变化情况，并且根据流场数据计算得到了漩涡环量随淹没水深的变化规律。表面流场分布和临界淹没水深是立轴漩涡的两个重要影响因素，本文重点对这两个方面进行了理论研究。针对立轴漩涡表面流场分布，对比分析了之前相关研究的理论和经验公式。根据试验观测及理论分析，改进了立轴漩涡表面流场的计算公式，提高了计算精度，并用漩涡模型实验结果对其进行了验证，在立轴漩涡的理论研究方面具有一定的进步。同时，通过“镜像法”理论，能够考虑侧壁对漩涡的影响，将立轴漩涡的研究理论从无限水域的自由漩涡拓宽到有边壁限制的受限漩涡，理论研究结果更容易应用到水电站的工程实际，研究不仅具有理论意义，而且具有工程应用价值。利用溪洛渡电站水工模型试验数据，对表面流场公式进行了对比分析，进一步验证了改进公式的精度和“镜像法”的适用性。总结分析了对漩涡产生起主要作用的影响因素，对立轴漩涡产生和发展机理进行了讨论。同时，对立轴漩涡的临界淹没水深进行了细致深入的研究，探讨了临界淹没水深的判定方法，并且利用模型试验数据对其进行了验证。在此基础上，进一步对泄洪洞进口体型进行了优化分析，提出了一个更有利于消除立轴漩涡的进口体型设计，可以在工程设计上作为参考。最后，本文系统地总结了工程实际中常用的消涡措施，并对其消涡原理进行了探讨。从临界淹没水深和表面流场两个方面尝试对消涡措施进行理论上的分析，以期对工程实际中选择合适的消涡措施提供参考。更多还原

【Abstract】 The vertical vortex frequently occurs in the spillway tunnel intake, which is aserious damage to the safety of flood discharge, so it must be avoided in the engineeringpractice. In this paper, the research is aimed to avoid the vertical vortex phenomenon onXiluodu hydraulic project via the study on experiment investigation, theory analysis andengineering application.The experiment study was carried out on the huge hydraulic model of Xiluoduproject. The vortex shape evolution was observed under different submergence depthswith different intake types, different intake boundaries and different flow discharges.The form characteristics and hydraulic effects were analyzed, and the formation andevolution of vertical vortex were studied theoretically. The flow field velocitydistribution was measured by the Particle Tracking Velocimetry (PTV) technology infront of spillway tunnel intake. The development of surface velocity distribution wasobtained with different submergence depths and the changing of velocity circulationwas calculated with different submergence depths.Surface velocity distribution and critical submergence depth are two importantaffects to vertical vortex, which have been studied theoretically in this paper. Since allthe related velocity formulas have disadvantage, a new formula of surface velocitydistribution was proposed based on the Navier-Stokes Equations and the experimentresults, whose advantage has been confirmed by comparing with former formulas. Theproposed formula is applied to engineering practice via the “method of images”, whichcan consider the effect of boundary. The vortex theory was developed from free vortexto bounded vortex within boundary, and it is more easily to apply the research theory tothe engineering practice. Moreover, the experiment results certified the precision ofproposed formula and the applicability of “method of images”.Based on the theory of “Critical Spherical Sink Surface (CSSS)”, the mechanismabout formation and evolution of vertical vortex was analyzed theoretically. A criterionof critical submergence depth was proposed which is modified by the model experimentresults. Meanwhile, the optimizing research was put forward on spillway tunnel intake,and an optimal type was proposed, which should be more helpful to anti-vortex inengineering practice. The purpose of experiment investigation and theoretical research in this paper is toavoid or reduce the vertical vortex phenomenon in engineering practice. Therefore, thecommon anti-vortex measurements were systematic generalized, and the relatedmechanism was discussed. The theoretical analyses were mainly focused on surfacevelocity distribution and critical submergence depth, so as to give suggestions to theengineering practice.更多还原