变坡长隧洞明满流水力特性研究

发布时间：2018-03-04 20:50

本文选题：变坡　切入点：长隧洞　出处：《人民黄河》2017年06期 　论文类型：期刊论文

【摘要】：明满流交替是长隧洞常遇到的不利水流流态,尤其是洞内截留气囊输移现象会对隧洞结构安全构成威胁。通过试验研究,阐述了变坡长导流隧洞洞内流态的演变过程,指出随着上游水位上升,洞内水流流态呈现由水跃转变为明满流交替、直至有压流的演变过程,分析了典型流态下隧洞的泄流能力,得到了明满流交替的流量系数介于无压流和有压流流量系数之间的结论。同时探讨了明满流交替过程的压力波动,发现明满流交替的压力波动持续时间较长、振幅较大,但压力峰值持续的时间很短,并且截留气囊可有效减缓隧洞底部压力波动。
[Abstract]:The alternation of open and full flow is the unfavorable water flow pattern often encountered in long tunnel, especially the phenomenon of air bag transportation in tunnel will threaten the safety of tunnel structure. Based on the experimental study, the evolution process of internal flow state in diversion tunnel with variable slope length is expounded. It is pointed out that with the rise of the upstream water level, the water flow pattern in the tunnel changes from water jump to open flow alternately until the pressure flow, and the discharge capacity of the tunnel under the typical flow state is analyzed. A conclusion is drawn that the flow coefficient of open flow alternation is between pressure free flow and pressure flow flow coefficient. At the same time, the pressure fluctuation of open full flow alternation process is discussed. It is found that the pressure fluctuation of open full flow alternation is longer and the amplitude is larger. However, the peak pressure duration is very short, and retaining the airbag can effectively slow the pressure fluctuation at the bottom of the tunnel.
【作者单位】：南京水利科学研究院;
【分类号】：TV134.3

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