Mechanism of air-trapped vertical vortices in long-corridor-shaped surge tank of hydropower station and their elimination

IF 3.4 3区工程技术 Q1 MECHANICS

水动力学研究与进展:英文版 Pub Date : 2017-10-01 DOI:10.1016/S1001-6058(16)60796-5

Fang Cai (蔡芳) , Yong-guang Cheng (程永光) , Lin-sheng Xia (夏林生) , Yong-qi Jiang (蒋永琪)

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引用次数: 4

Abstract

The air-trapped vertical vortices (ATVVs) are easy to form above the throttled orifices in the widely used long-corridor-shaped surge tanks (LCSSTs), when the tank water level decreases rapidly during hydraulic transients. These ATVVs may jeopardize the operation safety of the hydropower stations and should be avoided. This study elucidates the formation mechanism of the ATVVs and proposes some simple measures to eliminate them. The 3-D CFD model for predicting the ATVVs is validated first by physical model tests in a model tailrace LCSST, and then the formation mechanism is analyzed based on the numerical results. It is shown that the main influence factor for the ATVVs is the critical submergence, which can be reduced by minimizing the velocity circulation around the throttled orifices. Two practical ATVV elimination measures through suppressing the velocity circulation are compared and verified, and the optimized one is recommended.

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水电站长廊道式调压池内空气困住垂直涡的形成机理及消除

摘要在应用广泛的长廊道式调压舱中，当罐内水位在液压瞬变过程中迅速下降时，极易在节流孔上方形成气阻垂直涡。这些全地形车可能危及水电站的运行安全，应避免使用。本研究阐明了ATVVs的形成机制，并提出了一些消除ATVVs的简单措施。首先通过模型尾流LCSST的物理模型试验验证了预测ATVVs的三维CFD模型，然后根据数值结果分析了ATVVs的形成机理。结果表明，影响atvv的主要因素是临界沉水，可通过减小节流孔周围的速度循环来降低临界沉水。对比验证了抑制速度循环消除ATVV的两种实用措施，并推荐了最优措施。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

水动力学研究与进展:英文版

CiteScore

5.90

自引率

0.00%

发文量

1240