管道悬索跨越绕流特性及三分力系数变化规律

1. 西南交通大学土木工程学院;2. 中国石油天然气管道工程有限公司;3. 中国石油西南管道公司贵阳输油气分公司

管道悬索跨越;数值风洞;绕流特性;三分力系数

Characteristics of bypass flow of pipeline suspension bridge and variation rules of mean aerodynamic force coefficients
ZUO Leibin1, 2, MA Cunming1, LI Guohui2, WANG Wenjin1, 2, NI Na2, GONG Yuliang3

1. School of Civil Engineering, Southwest Jiaotong University; 2. China Petroleum Pipeline Engineering Corporation;3. Guiyang Oil & Gas Transportation Sub-Company, PetroChina Southwest Pipeline Company

pipeline suspension bridge, numerical wind tunnel, bypass flow characteristics, three component coefficients

备注

为了准确获取管道悬索跨越结构的气动参数,建立油气管道悬索跨越典型主梁断面数值风洞模型,并选取SST k -ε 模型作为数值风洞湍流模型。数值风洞获取的绕流压力场分布显示,管道上、下表面的负压区较为明显,最大的正压区出现在管道的迎风侧面,位于入流方向的桁架梁迎风面和背风面的压力差最为明显;绕流速度场分布显示,管道和桁架梁对风速的阻挡效果明显,且管道、迎风侧栏杆、桁架梁均产生明显的流动分离和漩涡脱落现象,结合绕流场均方根压力可知,入流侧桁架最易发生涡振。通过对-3°、0°、3°风攻角下不同管径和不同主梁宽度的三分力系数分析,结果表明:主梁宽度对阻力系数和升力系数的影响较小,-3°风攻角下扭转系数随主梁宽度增加而减小;管径对三分力系数有决定性影响,随管径增大,阻力系数逐渐增大,而升力系数和扭转系数逐渐减小。研究结果可为悬索跨越桥面结构设计以及管道布置方式提供抗风方面的数据支持。(图 14表1,参[22]

For acquisition of accurate aerodynamic parameters of the pipeline suspension bridge, the numerical wind tunnel model for the typical girder section of the oil and gas pipeline suspension bridge was built, and SST k -ε model was used as the numerical wind tunnel turbulence model. The bypass flow pressure field distribution acquired from the numerical wind tunnel shows that the negative pressure area on the upper and lower surfaces of the pipeline is obvious, the largest positive pressure area appears on the windward side of the pipeline, and the pressure difference between the windward side and the leeward side of the truss girder in the inflow direction is particularly obvious. The bypass flow velocity field distribution shows that the pipeline and truss girder exert significant blocking effect on the wind speed, and the flow separation and vortex shedding phenomena occur apparently on the pipeline, windward railings and truss girder. According to the root mean square pressure of the flow field, vortex vibration is most likely to occur in the inflow side truss. Through the analysis of the three component coefficients of different pipeline diameters and different girder widths at the wind attack angles of -3°, 0° and 3°, it is concluded that the girder width has little influence on resistance coefficient and lift coefficient, and the torsion coefficient decreases with the increase of the girder width at -3° wind attack angle. The pipeline diameter definitively influences the three component coefficients, that is, with the increase of pipeline diameter, the resistance coefficient increases gradually, while the lift coefficient and torsion coefficient decrease gradually. The research results are expected to provide wind-resistant data support for the design of suspension bridge deck structure and the piping layout. (14 Figures, 1 Table, 22 References)