高水头冲沙放空洞边墙空蚀破坏原因探讨  

Cavitation damage to sidewalls in a sand flushing tunnel under high head

作　　者：张建民[1] 许唯临[1] 王韦[1] 刘善均[1] 

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室,成都610065

出　　处：《水力发电学报》2010年第5期197-201,共5页Journal of Hydroelectric Engineering

基　　金：教育部重点项目(2008108111);"973"项目(2007CB714105)

摘　　要：有压接无压突扩突跌掺气设施掺气效果关系到工程泄洪安全。结合工程实例,通过模型试验对突扩突跌掺气水流流态、掺气空腔形态、壁面压力分布及水流空化特性等水力特性进行测试与分析。研究表明,高速水流突扩后冲击渐扩边墙起点附近,水流反射脱离壁面后引起局部压力条件恶化,同时,该处掺气空腔长度不足,边壁掺气浓度偏小,没有很好起到掺气减蚀作用,从而导致边墙空化空蚀发生。研究成果可为工程成功修复提供重要参考。The performance of flow,which related to the safety of flood discharge engineering,was studied near the sudden expansion and sudden drop aerator when the pressure flow changed the water surface flow in tunnel.The aerated flow pattern,wall pressure distribution and characteristics of flow are measured and analyzed in a physical model.Research shows that when the high speed flow from the pressure tunnel impacting the gradual enlarging wall the flow reflect and disengage from the side wall,so the local pressure situation is worsening.At the same time,as the aerated cavity length is not enough and the aeration concentration is lower,so the effect of aeration to reduce the cavitation damage is not prominent and the cavitation damage was happened at the side wall.The research is a reference for the repair of the project.

关 键 词：水力学 空蚀 试验研究 突扩突跌掺气设施 

分 类 号：TV131.32[水利工程—水力学及河流动力学]