跌坎消力池尾坎坡度对泄洪消能影响的三维数值模拟  

3D numerical simulation of influence of slope of end sill on hydraulic characteristics of discharge and energy dissipation of stilling pool

作　　者：刁奕 田忠[1] DIAO Yi;TIAN Zhong(State Key Laboratory of Hydraulics and Mountain Rivers Engineering,Sichuan University,Chengdu 610065,China)

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：《西南民族大学学报（自然科学版）》2023年第3期348-354,共7页Journal of Southwest Minzu University(Natural Science Edition)

基　　金：国家自然科学基金项目(51879178)。

摘　　要：采用的k-ε双方程紊流数学模型与VOF法追踪自由水面,对中低水头胸墙闸坝式跌坎型消力池在三个尾坎坡度下的泄洪消能进行了三维数值模拟研究.模拟计算了正常和设计水位情况下三种局开运行工况的消力池水力特性,获得了消力池底板压力、流场分布、沿程水面线、紊动能及紊动能耗散率等水力参数的变化规律.数模计算结果显示,尾坎坡度对消力池的泄洪消能效果较为敏感.尾坎坡度变陡会明显提高消能效果,对来流无推移质的消力池可适当加大尾坎坡度,有助于提高消能率及适当缩短消力池长度,但尾坎坡度越大,出池水流向上壅水的趋势越明显,如果尾坎下游河道水位偏低,则出池水流可能形成较明显的二次跌落,对尾坎后河床造成一定的冲刷,因此消力池的尾坎坡度需要结合下游河道水位情况综合考虑,做到在提高消力池的消能率的同时,尽量避免出池水流较大的二次跌落,确保出池水流与下游河道水流平顺衔接.论文研究成果可供类似工程参考.Using the k-ε two-equation turbulence model and the VOF method to trace the free water surface,the three dimensional numerical simulation of the flood discharge and energy dissipation of the middle and low water head sluice dam with step-down stilling pool under the slope of three end sill is carried out.The hydraulic characteristics of the pool under normal and design water levels were simulated and calculated,and the variation laws of hydraulic parameters such as the botom pressure,flow velocity distribution,water surface,turbulent kinetic energy and turbulent kinetic energy dissipation rate were obtained.The numerical simulation results show that the slope change of the end sill is sensitive to the discharge and energy dissipation effect of the pool.A steeper slope can significantly improve the effect of energy dissipation,If the flow into the pool basically does not carry bed load,the slope can be designed steeper,which will help to improve the energy dissipation and appropriate to shorten the length of the pool,However,the steeper the slope of the end sill,the more obvious the upward trend of the water flowing out of the pool is.When the water level of the downstream channel is relatively low,the outflow water may form a more obvious secondary fall,which will cause serious scour.Therefore,the slope of the end sill of the pool should be comprehensively considered in combination with the water level of the downstream river.While improving the energy dissipation of the pool,the secondary drop of the outflow water flow should be avoided as far as possible,so as to ensure the smooth connection between the outflow water flow and the downstream river flow.The research results can be used as reference for similar projects.

关 键 词：跌坎消力池 尾坎坡度 泄洪消能 水力特性 出池流速 数值模拟 

分 类 号：TV135.2[水利工程—水力学及河流动力学]