超常规流速下栅条涡脱频率影响因素研究  

Study on the influencing factors of vortex shedding frequency of grid bar under unconventional flow velocity

作　　者：张述淼 朱慧 胡梦溪 赵建平[1] 刘珂 韩昌海[1] ZHANG Shumiao;ZHU Hui;HU Mengxi;ZHAO Jianping;LIU Ke;HAN Changhai(Nanjing Hydraulic Research Institute,Nanjing 210029,China;Management Division of Qinhuai River Hydraulic Engineering of Jiangsu Province,Nanjing 210022,China;Power China Huadong Engineering Co.,Ltd.,Hangzhou 311122,China)

机构地区：[1]南京水利科学研究院,江苏南京210029 [2]江苏省秦淮河水利工程管理处,江苏南京210022 [3]中国电建集团华东勘测设计研究院有限公司,浙江杭州311122

出　　处：《江苏水利》2025年第3期17-22,28,共7页Jiangsu Water Resources

摘　　要：栅后的周期性尾流是导致拦污栅损坏的主要因素之一,当周期性尾流的脱落涡频率与栅体结构的自振频率一致时,由脱落涡引发的结构共振会导致拦污栅结构的严重破坏。采用数值模拟方法,结合SAS湍流模型计算不同过栅流速下的脱落涡频率,分析常规流速(小于1.2m/s)和超常规流速(1.5~2.5m/s)下斯特劳哈尔数的变化规律,以及不同长宽比、不同截面形状等因素对斯特劳哈尔数的影响。结果表明:对固定断面形状的栅条,脱落涡频率随过栅流速的增加而增大,即脱落频率与过栅流速成正比。不同过栅流速下斯特劳哈尔数为一固定常数。栅条的截面形状是影响涡脱频率的一个重要因素,其中两缘半圆形栅条的脱落涡频率最大,矩形栅条的脱落涡频率最小。The periodic wake flow behind the grid is one of the main factors causing damage to the trash rack.When the vortex shedding frequency of the periodic wake is consistent with the natural frequency of the grid structure,the structural resonance caused by the shedding vortex will lead to serious damage to the trash rack structure.This article uses numerical simulation methods combined with the SAS turbulence model to calculate the vortex shedding frequency under different flow velocities,analyzes the variation of the Strouhal number under conventional flow velocities(less than 1.2 m/s)and unconventional flow velocities(1.5~2.5 m/s),and the influence of different aspect ratios,cross-sectional shapes,and other factors on the Strouhal number.The results show that for grid bars with a fixed cross-sectional shape,the vortex shedding frequency increases with the increase of the flow velocity passing through the bar,that is,the shedding frequency is directly proportional to the flow velocity passing through the grid bar.The Strouhal number is a fixed constant at different flow velocities through the grid bar.The cross-sectional shape of the grid bars is an important factor affecting the vortex shedding frequency.Among them,the grid bars with semicircular edges at both ends have the highest vortex shedding frequency,while the rectangular grid bars have the lowest vortex shedding frequency.

关 键 词：拦污栅 脱落涡频率 过栅流速 斯特劳哈尔数 

分 类 号：TV663[水利工程—水利水电工程]