泄洪洞高落差连接段水力特性试验研究
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摘要
由于地形的限制,实际工程中泄洪洞的高落差连接是经常面临的问题,该问题主要的难点在于高水头、大流量可能引起水流的空化,进而引起泄洪洞内固体边壁的空蚀。对此采用模型试验和理论计算相结合的方法,来探究泄洪洞抛物线形(即俗称龙抬头)高落差连接段内的压力、沿程的水深以及气穴数的分布情况。结果表明:龙抬头式的高落差连接段存在低压,而且在抛物线段出现气蚀的可能性很大,但试验研究表明,此种连接方式对于水库的泄洪能力并没有太大的影响。
Because of the terrain constraints,a high fall connection segment of spillway tunnel is always encountered in the actual project.The key problem is the flow cavitation and cavitation erosion of solid boundary in the spillway tunnels caused by the high head and the large flow.The model test combining theoretical analysis methods has been applied in the research to observe the internal pressure of connecting section with high drops,water depth along the way and distribution of cavitations.The results indicate that low pressure exists in the high drop connecting section.It is possible that the cavitation erosion would appear in the parabolic section.But the connecting method had no obvious effect on the flood discharge capacity of the reservoir.
Because of the terrain constraints,a high fall connection segment of spillway tunnel is always encountered in the actual project.The key problem is the flow cavitation and cavitation erosion of solid boundary in the spillway tunnels caused by the high head and the large flow.The model test combining theoretical analysis methods has been applied in the research to observe the internal pressure of connecting section with high drops,water depth along the way and distribution of cavitations.The results indicate that low pressure exists in the high drop connecting section.It is possible that the cavitation erosion would appear in the parabolic section.But the connecting method had no obvious effect on the flood discharge capacity of the reservoir.
引文
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[4]郑秋文,罗书靖,张法星.反弧段体型对高流速泄洪洞水力特性的影响[J].中国农村水利水电.2012(4):133-138.
[5]郭军,张东,刘之平,等.大型泄洪洞高速水流的研究进展及风险分析[J].水利学报,2006,37(10):1193-1198.
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