水科学进展2024，Vol.35Issue(1)：132-144,13.DOI:10.14042/j.cnki.32.1309.2024.01.012
侧式进/出水口偏流出流下的大涡模拟
Study on large eddy simulation of lateral inlet/outlet under bending outflow
摘要
Abstract
Due to the influence of topography and geology in actual engineering projects,water tunnels often have horizontal bends.These bends result in non-uniform inflow conditions,complicating the turbulence characteristics at the inlet and outlet compared to straight-line tunnels.This study employs Large Eddy Simulation to analyze a real engineering problem.The calculated results are compared with experimental data,revealing close agreement in flow velocity and probability density distribution.The findings show that under outflow conditions,the flow-split ratios for each channel are 0.64,0.81,1.26,and 1.29,indicating a highly non-uniform horizontal velocity distribution.In the vertical direction,the main flow occurred primarily in the lower middle section,and the vertical Reynolds shear stress in the diffusion segment exhibits a distinctive pattern with alternating positive and negative peaks.This phenomenon is primarily attributed to flow separation in the upper middle area and wall shearing near the bottom.The recirculation region's height in the two middle channels was found to be greater than that in the side channels,indicating that trash racks in the central channels are more susceptible to reverse flow velocities.Additionally,flow separation near the trash rack gives rise to a three-axis vortex,while two energy-concentrated pulsations occur in the upper middle section and near the bottom.Moreover,under bending flow conditions,turbulence intensities in different channels increase by 11％,25％,29％,and 3％,respectively,compared to those in uniform flow situations.Consequently,the unfavorable flow regime and high turbulence intensity associated with bending flow pose a threat to the trash rack.关键词
侧式进/出水口/偏流出流/雷诺切应力/流动分离/低频脉动Key words
lateral inlet/outlet/bending flow/Reynolds shear stress/flow separation/low frequency pulsation分类
建筑与水利引用本文复制引用
郭港归,刘亚坤,魏杰,曹泽,张帝..侧式进/出水口偏流出流下的大涡模拟[J].水科学进展,2024,35(1):132-144,13.基金项目
国家自然科学基金资助项目(52179060 （）
51909024)The study is financially supported by the National Natural Science Foundation of China(No.52179060 （）
No.51909024). （）
