全风向角下二维方柱绕流数值模拟  

Numerical simulation of flow around a two-dimensional square cylinder under all wind yaw angles

作　　者：邓燕华[1] 祝志文[1] 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《铁道科学与工程学报》2016年第9期1796-1802,共7页Journal of Railway Science and Engineering

基　　金：国家重点基础研究发展计划(973计划)项目(2015CB057701;2015CB057702);国家自然科学基金资助项目(51278191)

摘　　要：利用雷诺时均N-S方程和SST K-ω湍流模型对雷诺数Re=6×104的二维方柱在风向角α=0°-45°下的绕流开展CFD模拟,获得方柱涡脱斯托哈数、平均和脉动风荷载随来流风向角的变化,模拟结果与文献吻合较好。研究结果表明:风向角α=10°-15°时,阻力系数平均值最小,斯托哈数最大;但随风向角的增大,前者大幅升高后者小幅回落。当风向角α≤15°时,风压系数平均值在0°最大,10°时最小;当风向角α>15°后,背面和上侧面风压系数平均值均大于0°风向角,下侧面均小于0°风向角,且随风向角的增大前者大幅升高而后者大幅降低。背面风压系数脉动值大于0°风向角而侧面小于0°风向角,且风向角越大,风压系数脉动值越大。本文研究揭示了方柱在全风向角下的风荷载变化规律。The flow fields around a two-dimensional square cylinder under Reynolds number of 6x104, and wind yaw angle ranged from 0°-45°, are simulated based on the Reynolds-averaged Navier-Stokes equations and SST k-ω） turbulent model. The vortex-shedding Strouhal number, mean and fluctuating wind loads applied on the square cylinder under various wind yaw angles are obtained and compared with available references, which shows good agreement. The research results show that the minimum mean drag coefficient and maximum Strouhal number occur among wind yaw angle ranges of 10° - 15°. While increasing of wind yaw angle significantly increase the minimum mean drag coefficient and slightly decrease the maximum Strouhal number. When the wind yaw angle is smaller than 15°, the mean wind pressure coefficient can achieve the maximum at 0° wind yaw angle but the minimum at 10°. when the wind yaw angle a is larger than 15°, the mean wind pressure coefficient on back and upper side is bigger than the value at 0°wind yaw angle, and the lower side surface is smaller than those values. It is also found that the increases of wind yaw angle result in steep increase on the former value and slightly decrease of the latter value. Meanwhile, the fluctuating wind pressure coefficient increases with the increase of wind yaw angle. The present study provides the variation features of wind loads of the square cylinder under all wind yaw angles.

关 键 词：二维方柱 风荷载 湍流模型 漩涡脱落 

分 类 号：TH212[机械工程—机械制造及自动化] TH213.3