公伯峡水电站旋流泄洪洞空化特性的原型观测与反演模型试验的对比分析

Contrastive Analysis through Prototype Observation and Inversion Model Experiment of Rotary Flow Dissipation Tunnel Cavitation Characteristic in Gongboxia Hydropower Station

依据公伯峡水电站旋流泄洪洞原型观测和反演模型试验的成果,对此类新型旋流内消能泄洪洞的空化特性进行了对比分析。分析表明:旋流洞起始段收缩环突扩断面上存在空化现象,但其程度并不足以造成壁面的空蚀破坏;原型观测观察到的旋流洞末端的沟槽破坏有可能是空蚀的结果;水垫塘进口突扩部位、水垫塘末端三角墩部位的原、模型观测结果有一定的差异,缩尺效应导致了泄洪洞内的某些水力特性不相似,小比尺减压模型试验表现出更为严重的空化特性。公伯峡旋流泄洪洞的这些关键部位的空化空蚀特性尚需进一步观测和检验。

This article makes an cavitation characteristics contrastive analysis of this new type rotary flow inner energy dissipation tunnel through achievements of prototype observation and inversion model experiment of Gongboxia hydropower station rotary flow energy dissipation tunnel.Analysis shows that： sections on the sudden expansion of retraction ring at initial segment of swirl holes are presented with cavitation phenomenon,but its extent is not sufficient to cause the wall cavitation;groove damage at the end of swirl holes may be the result of cavitation via prototype observation;There are some differences between model observations and original one at the inlet of sudden expansion site and the end of the triangle pier area of plunge pool.Scale effect has led to some of the dissimilarity of hydraulic characteristics in discharge hole and small scale pressure reduction model test shows more severe cavitation.The key parts of the cavitation characteristics of Gongboxia rotary flow tunnel still need further observation and testing.