不同阻塞比旋流阻塞泄洪洞水力特性数值模拟研究  

Numerical Simulation of the Flow in the Swirling-blocking Spillway Tunnel with Different Blocking Ratios

作　　者：龙建 李奇龙[3] 李大贵 王立杰 LONG Jian;LI Qilong;LI Dagui;WANG Lijie(Hunan Provincial Key Laboratory of Hydropower Development Key Technology,Changsha 410014,Hunan,China;PowerChina Zhongnan Engineering Corporation Limited,Changsha 410014,Hunan,China;Institute of Water Resources and Hydro-electric Engineering,Xi an University of Technology,Xi an 710048,Shaanxi,China;Gansu Earthquake Agency,Lanzhou 730000,Gansu,China)

机构地区：[1]水能资源利用关键技术湖南省重点实验室,湖南长沙410014 [2]中国电建集团中南勘测设计研究院有限公司,湖南长沙410014 [3]西安理工大学水利水电学院,陕西西安710048 [4]甘肃省地震局,甘肃兰州730000

出　　处：《水力发电》2024年第10期53-58,73,共7页Water Power

基　　金：水能资源利用关键技术湖南省重点实验室开放研究基金资助项目(PKLHD201804);陕西省自然科学基础研究计划一般项目(青年)(2019JQ-064)。

摘　　要：水平旋流泄洪洞中设置阻塞可增大洞内压力并改善水流空化条件,同时还可提升消能率,在高水头泄洪消能中具有独特优势。为探究不同阻塞比阻塞对水平旋流洞水流水力特性的影响,采用Realizable k-ε紊流模型与VOF法,对阻塞比0.2、0.3、0.36、0.4、0.5等5组体形水流水力特性进行了数值模拟。结果表明:阻塞比m越大,空腔直径越小,m>0.4时,空腔沿程变化变大,空腔旋流不稳定,阻塞比m不宜超过0.4;空腔旋流横断面压强近似呈底部略大的同心圆分布,阻塞比0.5较0.2体形壁面压强增大约2/3,阻塞增压效果显著,且m>0.3时增压效果更为显著;空腔旋流呈三维流速分布,切向流速沿径向近似为中心对称分布,轴向流速近似为轴对称分布;阻塞比0.5较0.2体形断面平均流速减小约1/4,阻塞减速效果显著。阻塞的增压减速效应有助于改善洞内水流空化条件,使之适用于更高水头的泄洪消能。综合来看,阻塞比选择在0.3~0.4之间较为适宜。The blockage implied in the horizontal swirling spillway tunnel has a unique advantage in high head spillway energy dissipation,because it can increase internal pressure of the tunnel,improve cavitation conditions and obtain higher energy dissipation rate.In order to explore the influence of different blocking ratios on the hydraulic characteristics of the water flow in the tunnel,the hydraulic characteristics of the flow in the tunnel with five blocking ratios m=0.2,0.3,0.36,0.4 and 0.5 are studied in this paper by the Realizable k-εturbulence model and VOF method,respectively.The results show that,(a)the larger the m,the smaller the cavity diameter,and the m should not exceed 0.4 because of the unstable and fluctuant cavity swirl along the tunnel when the m is more than 0.4;(b)the pressure in the cross section of the cavity swirl is approximately concentric circle with a slightly larger at the bottom,and the pressure on the wall of tunnel with a m of 0.5 is about 2/3 larger than that of 0.2,that means a significant pressurization effect,and the pressurization effect is more obvious when the m is larger than 0.3;(c)the velocity distribution of swirling flow in the cavity is three-dimensional,in which,the tangential flow velocity is approximately centrally symmetric along the radial direction,and the axial flow velocity is approximately axisymmetric;and(d)the average velocity of the tunnel with a m of 0.5 is about 1/4 smaller than that of 0.2,so the deceleration effect is also significant.The pressurization and deceleration effect of blockage is helpful to improve the cavitation conditions of the flow in the tunnel,making it suitable for the flood discharge and energy dissipation with higher water head.In summary,the blocking ratio m between 0.3 and 0.4 is more suitable.

关 键 词：水平旋流 阻塞 阻塞比 空腔旋流 水力特性 泄洪洞 

分 类 号：TV135.2[水利工程—水力学及河流动力学]