侧缩结构对阶梯泄水道水力特性的影响研究  

Influence of side contraction structure on the hydraulic characteristics of stepped discharge channel

作　　者：杨涛 YANG Tao(Shanghai Investigation Design and Research Institute Limited Company,Shanghai 200080,China)

机构地区：[1]上海勘测设计研究院有限公司,上海200080

出　　处：《水科学与工程技术》2021年第3期41-44,共4页Water Sciences and Engineering Technology

摘　　要：为进一步提高阶梯消能工消能效果、掺气效果,以及减少空化空蚀发生的风险,在阶梯泄水道的基础上,增设侧缩结构(突缩结构和渐缩结构),利用物理模型试验的方法,研究了此阶梯泄水道的水力特性。结果表明,在设置突缩结构的阶梯面上可形成跌落水流和水跃的组合流态,在设置渐缩结构的阶梯面上可形成扩散型流态,有效提高了阶梯泄水道的掺气效果和消能效果,减少了阶梯泄水道发生空化空蚀的风险。相比于突缩结构,渐缩结构水流对渐缩结构迎水面的冲击力更小,水流排泄更流畅,可作为提高阶梯泄水道掺气效果和消能效果的一项有效措施。In order to further improve the energy dissipation and air entrainment characteristics of stepped discharge channel and reduce the cavitation risk,this paper proposes to add side contraction structure(abrupt contraction structure and gradual contraction structure)on the basis of stepped discharge channel,and studies the hydraulic characteristics of this stepped discharge channel in detail by means of physical model,including flow regime,energy dissipation,time-average pressure,etc.The results show that the combinations of nappe flow and hydraulic jump flow regimes are formed thanks to the abrupt contraction structure,and the diffusion flow regimes are formed thanks to the gradual contraction structure.These special flow regimes strengthen the water air mixing in the discharge channel.Effectively improve the air entrainment and energy dissipation of the stepped discharge channel,and reduce the cavitation risk.At the same time,compared with the abrupt contraction structure,the time-average pressure of the gradual contraction structure is lower.The impact force of water flow on the gradual contraction structure is smaller,and the flow discharge is more smooth.Therefore,the gradual contraction structure can be used as an effective measure to improve air entrainment and energy dissipation of stepped discharge channel.

关 键 词：阶梯泄水道 水力特性 侧缩结构 

分 类 号：TV135[水利工程—水力学及河流动力学]