掺气分流墩三维流场数值模拟  

Numerical Simulation of Three-dimensional Flow Field of the Aerated Flow Splitting Pier

作　　者：雷鹏帅[1,2] 武福平[2] 孙建[1] 

机构地区：[1]西安理工大学水利水电学院,陕西西安710048 [2]兰州交通大学环境与市政工程学院,甘肃兰州730070

出　　处：《兰州交通大学学报》2015年第1期136-141,共6页Journal of Lanzhou Jiaotong University

摘　　要：采用RNGk-ε三维紊流模型和VOF方法,1:1几何建模,对柘林水电站左岸泄洪洞下游掺气分流墩的三维流场进行了数值模拟.在与原型观测试验对比验证的基础上,对该流场的流态、水面、流速分布和压强分布进行了分析.结果表明:流态模拟正确,水面、流速与原型观测结果均能较好吻合;联合作用下的流场,在三维涡体的形成、增强掺气效果和空化空蚀的防止等方面均明显优于无掺气分流墩的流场;三维涡体主要由两股入水主流与池内前部淹没水跃的水体相互摩擦形成;被抛向高空的水翅在下落入水时卷入大量空气,具有较深穿透力,使得波动坎及坎下区域充分掺气,从而破坏空化,防止空蚀.In order to fully understand the cavitation erosion decrease mechanism of aerated flow splitting pier,and to provide design reference for cavitation damage prevention of engineering stilling pools,RNG turbulence model and VOF method are adopted to numerically simulate 3-D flow field of the aerated flow splitting pier downstream of flood discharging tunnel on the left bank of Zhelin Hydropower Station by 1∶1geometric model.Based on the comparison of prototype measurement data,the flow state,water surface,velocity distribution and pressure distribution are analyzed.The results show that the flow state of the simulation results is correct,and both water surface and velocity data agree well with the prototype measurement results.The flow field under the joint effect is obviously superior to that without aerated flow splitting pier in three-dimensional vortex formation,the enhancement effects of aeration and cavitation prevention.Three dimensional vortexes are mainly formed by mutual friction between two mainstreams into the water and water of submerged hydraulic jump in front of the pool.A great quantity of air is involved into the water during its dropping highly from the air,and it has deep penetration,so the area above and below the fluctuating ridge is fully aerated,and thus the cavitation is destroyed and the cavitation erosion is avoided.

关 键 词：掺气分流墩 RNGk-ε紊流模型 VOF 数值模拟 

分 类 号：TV131.3[水利工程—水力学及河流动力学]