90°弯管下游管路流场的非定常特性  

Unsteady characteristics of flowfield in downstream pipeline behind 90° bend

作　　者：杨从新[1,2] 杨焘 王玲[1,2] YANG Cong-xin;YANG Tao;WANG Ling(College of Energy and Power Engineering,Lanzhou Univ.of Tech.,Lanzhou 730050,China;Key Laboratory of Fluid Machinery and System of Gansu Province,Lanzhou Univ.of Tech.,Lanzhou 730050,China)

机构地区：[1]兰州理工大学能源与动力工程学院,甘肃兰州730050 [2]兰州理工大学甘肃省流体机械及系统重点实验室,甘肃兰州730050

出　　处：《兰州理工大学学报》2019年第4期43-48,共6页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(51469013)

摘　　要：借助分离涡模拟(DES)方法,对圆形截面90°弯管内部及下游管路内湍流流场的流动特性进行了研究.分析了不同入流速度、入流直径和弯管中心线半径对下游流动及壁面压力波动的影响.计算结果表明:弯管小半径附近区域发生边界层分离,在下游出现拟序结构及壁面压力波动;提升入流速度能使频谱特性向高频次发展;改变管路直径并不改变内部流场的主要特征;降低弯管曲率可有效降低下游管路壁面上的压力波动.The flow characteristics of turbulence field in 90° bend with circular cross-section and downstream pipeline are studied by means of detached-eddy simulation (DES).The effects of inlet flow velocity,inlet diameter and centerline radius of the bend on downstream flow and wall pressure fluctuation are analyzed.Computational results show that boundary-layer separation occurs near the inner side of the bend and a coherent structure as well as wall pressure fluctuation appear in downstream flow.Increasing inlet flow speed will make the spectral characteristics of velocity and pressure on pipe wall to develop toward high frequency.Changing pipeline diameter will not change the main feature of the flow field.Reducing the curvature of the bend will effectively reduce the pressure fluctuation on the downstream pipeline wall.

关 键 词：弯管 DES 流动结构 

分 类 号：TH313[机械工程—机械制造及自动化]