摘要
为解决常规物理模型试验受观测手段限制难以全方位研究深尾水消力池内水力学参数的问题,借助RNGk-ε紊流模型结合VOF方法对比研究深尾水作用下平尾墩及非完全宽尾墩试验方案下游消力池内流场变化,并揭示非完全宽尾墩消能机理.研究结果表明:受溢流堰纵向长度及下游消力池内深尾水限制,平尾墩底流式淹没水跃逼近溢流堰顶,消力池内消能紊动不足,出池水流形成强烈二次水跃;非完全宽尾墩则束窄部分溢流堰闸室过流断面促使形成纵向拉伸挑射水舌,利用各相邻闸室非对称出闸水流、增强消力池内入池水流横向流速梯度和水位落差,加剧消力池内入池水流横向扩散、交汇,在消力池上游区域形成由底层至表层的大幅度立轴旋滚,显著增强消力池内能量耗散,降低出池水流流速,取得较好的消能效果.
Limited by measuring means,the conventional physical model test almost couldn′t comprehensively study the variation of hydraulics parameters in the deep tail water stilling basin.Based on the renormalization group(RNG)k-εturbulence model and the volume of fluid(VOF)method,the flow field variation in the deep tailwater stilling basin of the flat gate pier program and incomplete flaring gate pier program were respectively studied,and the energy dissipation mechanism of incomplete flaring gate pier was revealed.Research results show that restricted by the longitudinal overflow weir length and the deep tailwater in the stilling basin,the submerged hydraulic jump approaches weir crest in the flat gate pier program,leading to the insufficient energy dissipation turbulence in the stilling basin and strong secondary hydraulic jump outside the stilling basin.The incomplete flaring gate pier program restricts the overflow weir chamber width to result to the longitudinally stretched water jet,and the asymmetric water flow is utilized in the adjacent chamber to enhance the lateral flow velocity gradient and the water level drop.The large vertical axis rolling from the bottom to the surface is created in the upstream region of stilling basin by the intensified lateral diffusion and intersection,which significantly enhances energy dissipation in the stilling basin,inducing the flow rate of outlet water and achieving well energy dissipation effect.
引文
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