摘要
为研究变截面覆冰对斜拉索气动力特性的影响,应用FLUENT中的SST k-ω模型对三维新月形变截面覆冰斜拉索绕流场进行数值模拟;将变截面覆冰斜拉索模型划分为6个节段,分别监测不同覆冰厚度节段的气动力,得到全攻角下各节段以及全索的阻力系数和升力系数;基于Den Hartog机制,获得驰振力系数,进而研究变截面覆冰斜拉索的驰振稳定性。结果表明:变截面覆冰形态对斜拉索的流场分布影响较大,其绕流场具有明显的三维流动特性;由于覆冰厚度的变化,变截面覆冰斜拉索各节段表现出不同的气动力特性和驰振稳定性;经过三维模拟计算,变截面覆冰斜拉索各节段及全索的部分驰振力系数小于0,拉索具有发生覆冰驰振的可能性,变截面覆冰对斜拉索的气动力特性影响较大。
In order to investigate the influence of variable cross-section ice accretion on the aerodynamic characteristic of stay cables, the flow field of 3D variable cross-section stay cables with crescent-shape ice accretion was numerical simulated by SST k-ω model of FLUENT. The model of variable cross-section stay cables with ice accretion was divided into six segments, and the aerodynamic forces of the segments with different ice accretion thicknesses were monitored. The drag and lift coefficients of each segment and the whole stay cable under full attack angle were obtained. The galloping coefficients were obtained based on Den Hartog criterion, and the galloping stability of variable cross-section stay cables with ice accretion was studied. The results show that the shape of variable cross-section ice accretion has important impact on the flow field of stay cables, and the flow field has obvious 3D flow characteristics. Each segment of variable cross-section stay cables with ice accretion exhibits different aerodynamic force characteristics and galloping stability due to the change of ice accretion thickness. Part of galloping force coefficients of variable cross-section stay cables with ice accretion computed by 3D simulation are less than zero, so the stay cables have the possibility of icing galloping. The variable cross-section ice accretion has important impact on aerodynamic characteristics of stay cables.
出处
《建筑科学与工程学报》
CAS
北大核心
2017年第3期66-72,共7页
Journal of Architecture and Civil Engineering
基金
国家自然科学基金项目(51408452)
道路桥梁与结构工程湖北省重点实验室开放基金项目(DQJJ201509)
关键词
变截面
覆冰
斜拉索
气动力参数
驰振
variable cross-section
ice accretion
stay cable
aerodynamic parameter
galloping
