旋流式竖井环形掺气坎的掺气空腔计算  

Calculation of the Cavity Length of Annular Aerator in the Vortex Drop Shaft Spillway

作　　者：李瑶[1] 张法星[1] 邓军[1] 许唯临[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,四川成都610065

出　　处：《四川大学学报（工程科学版）》2011年第2期28-33,共6页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金委员会;二滩水电开发有限责任公司雅砻江水电开发联合研究基金资助项目(50539060);"十一五"国家科技支撑计划资助项目(2008BAB29B04)

摘　　要：通过试验对旋流式竖井的竖井段流速、压强等进行测量,计算了水流空化数。通过分析,明确了有必要在高水头旋流式竖井泄洪洞中设置掺气减蚀设施。针对旋流竖井环形掺气坎掺气空腔长度的计算问题,从旋流式竖井中水流微团的运动特点出发,运用抛射体理论,推导出旋流式竖井环形掺气坎掺气空腔长度的计算方法,同时将计算结果与试验数据进行了对比,表明给出的计算方法具有一定的精度,可供工程设计参考。在设置环形掺气坎后,对下游竖井段时均压强影响较小,脉动压强有所增大但频率分布以5 Hz以内的低频为主,不会对井壁构成威胁。The pressure and velocity of vortex drop shaft spillway were experimentally studied,and the cavitation numbers of the flow in the drop shaft were calculated.Aeration is necessary to set in vortex drop shaft spillway through analysis.Based on the characteristics of flow in the vortex drop shaft spillway,a formula,established on the projectile theory,was presented to calculate the cavity length of annular aeration in the vortex drop shaft spillway.And experiments to survey the cavity length were also conducted.The comparison between the results of the formula and experiments indicated that the formula can be used to predicting the cavity length as a reference in engineering design.After adding the annular aerator,the change of the average-time pressure was not very much.The fluctuating pressure increased,but it was not dangerous to the wall of the shaft downstream,since the frequency distribution was mostly below 5 Hz.

关 键 词：旋流式竖井 环形掺气坎 空腔长度 掺气 

分 类 号：TV135.2[水利工程—水力学及河流动力学]