在湍流来流中，矩形柱绕流流场具有不同于均匀流中的流动形态。为深入了解顺向脉动来流对矩形柱绕流流场的影响，采用三维大涡模拟（large-eddy simulations，LES）方法，对不同频率顺向正弦来流下宽高比4:1矩形柱气动力和流场特性进行研究，深入探讨了升阻力系数、背压系数、斯托罗哈数、回流长度和再附长度等参数的变化规律，并比较了均匀流与正弦来流下4:1矩形柱的流场结构及演化过程。研究表明：矩形柱绕流流场结构受来流条件影响显著。在顺向正弦来流下，4:1矩形柱阻力系数主频与来流频率基本一致，当 时，在升力方向上正弦来流占据主导地位，交替旋涡脱落被强烈抑制。当来流频率 增大时，回流长度保持增大态势，而再附长度先增大后减小，在 时达到最大值。在正弦来流中，矩形柱前缘上下两侧旋涡对称分离，尾部旋涡脱落与前缘不同步，尾缘旋涡交替脱落并在尾流中破碎为小尺度旋涡。
Abstract
The flow field pattern around a rectangular cylinder in turbulent flow show discrepancies with those in uniform flow. To further understand the influence of streamwise gust inflow on flow field around a rectangular cylinder, three-dimensional Large-Eddy Simulations (LES) were conducted to investigate the influence of streamwise sinusoidal flow with different frequencies on the aerodynamic forces and flow field characteristics of a 4:1 rectangular cylinder. Changing pattern of some parameters, include lift and drag force coefficient, base suction coefficient, Strouhal number, recirculation length and reattachment length, were analyzed in detail, mean structure and evolution of the flow field around the cylinder in unform flow and sinusoidal flow were also compared. The results indicate that the oncoming flow conditions has a significant effect on the structure of flow field around the rectangular cylinder. In streamwise sinusoidal flow, the dominant frequency of drag coefficient is basically same with the inflow frequency. When , streamwise sinusoidal flow hold a dominant position on the lift force direction, while alternating vortex shedding was strongly suppressed. As the inflow frequency increased, the recirculation length also kept increasing, while the reattachment length increased first and then decreased, reached a maximum value when . The vortices above and below the leading edge of the rectangular cylinder are symmetrically separated in streamwise sinusoidal flow, when the trailing vortex shedding is not synchronized with the leading edge. The trailing edge vortices are alternately shed and broken up into small-scale vortices in the wake.
关键词
顺向正弦来流 /
4:1矩形柱 /
大涡模拟 /
气动力特性 /
流场
{{custom_keyword}} /
Key words
streamwise sinusoidal flow /
4:1 rectangular cylinder /
Large-Eddy Simulation /
aerodynamic characteristics /
flow field
{{custom_keyword}} /
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 刘庆宽, 任若松, 孙一飞, 等. 扁平流线型箱梁涡激振动雷诺数效应研究[J]. 振动与冲击, 2022, 41(4): 117-123.
LIU Qingkuan, REN Ruosong, SUN Yifei, et al. A study of Reynolds number effect on vortex-induced vibrations of a flat streamline box girder[J]. Journal of Vibration and Shock, 2022, 41(4): 117-123.
[2] 王仰雪, 刘庆宽, 靖洪淼, 等. 倾斜栏杆对流线型箱梁涡激振动性能影响的试验研究[J]. 振动与冲击, 2023, 42(6): 232-239.
WANG Yangxue, LIU Qingkuan, JING Hongmiao, et al. Experimental study on the influence of inclined railings on the vortex-induced vibration performance of a streamlined box girder[J]. Journal of Vibration and Shock, 2023, 42(6): 232-239.
[3] GE Y, ZHAO L, CAO J. Case study of vortex-induced vibration and mitigation mechanism for a long-span suspension bridge[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2022, 220: 104866.
[4] 李少鹏, 廖志伟, 李鑫, 等. 宽高比2:1矩形断面横风向抖振力紊流三维畸变效应及风洞试验修正方法研究[J]. 建筑结构学报, 2023, 44(5): 68-77.
LI Shaopeng, LIAO Zhiwei, LI Xin, et al. Study of three-dimensional distortion effect of turbulence on lateral buffeting force acting on a 2:1 rectangular cylinder and wind tunnel correction method[J]. Journal of Building Structures, 2023, 44(5): 68-77.
[5] CAO S Y, LI M. Numerical study of flow over a circular cylinder in oscillatory flows with zero-mean and non-zero-mean velocities[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2015, 144: 42-52.
[6] MORISON J R, JOHNSON J W, SCHAAF S A. The Force Exerted by Surface Waves on Piles, Petroleum Trans[J]. Journal of Petroleum Technology, 1950, 2(5):0-0.
[7] 于春放, 靖洪淼, 王仰雪, 等. 顺向正弦来流条件下圆柱气动力和绕流流场数值模拟研究[J]. 振动与冲击, 2024, 43(6): 216-224.
YU Chunfang, JING Hongmiao, WANG Yangxue, et al. Numerical study on aerodynamic forces and flow around a circular cylinder under streamwise sinusoidal inflow condition[J]. Journal of Vibration and Shock, 2024, 43(6): 216-224.
[8] WU B, LI S P, CAO S Y, et al. Numerical investigation of the separated and reattaching flow over a 5:1 rectangular cylinder in streamwise sinusoidal flow[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2020, 198: 104120.
[9] WU B, LI S P, Li K, et al. Large-eddy simulation of the near wake of a 5:1 rectangular cylinder in oscillating flows at Re=670[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2020, 196: 104050.
[10] MA R W, ZHOU Q, WANG P Y, et al. Effects of sinusoidal streamwise gust on the vortex-induced force on an oscillating 5:1 rectangular cylinder[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2021, 213: 104642.
[11] MA R W, ZHOU Q, WANG P Y, et al. Numerical studies of unsteady flow field and aerodynamic forces on an oscillating 5:1 rectangular cylinder in a sinusoidal streamwise flow[J]. Wind and Structures, 2022, 34(1): 91-100.
[12] YU D, KAREEM A. Parametric study of flow around rectangular prisms using LES[J]. Journal of Wind Engineering and Industrial Aerodynamics, 1998, 77: 653-662.
[13] SOHANKAR A. Large eddy simulation of flow past rectangular-section cylinders: Side ratio effects[J]. Journal of wind engineering and industrial aerodynamics, 2008, 96(5): 640-655.
[14] TAMURA T, MIYAGI T, KITAGISHI T. Numerical prediction of unsteady pressures on a square cylinder with various corner shapes[J]. Journal of Wind Engineering and Industrial Aerodynamics, 1998, 74(2): 531-542.
[15] MANNINI C, ŠODA A, GÜNTER SCHEWE. Numerical investigation on the three-dimensional unsteady flow past a 5:1 rectangular cylinder[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2011, 99(4): 469-482.
[16] BRUNO L, FRANSOS D, COSTE N, et al. 3D flow around a rectangular cylinder: A computational study[J]. Journal of Wind Engineering & Industrial Aerodynamics, 2010, 98(6-7): 263-276.
[17] GUISSART A, ANDRIANNE T, DIMITRIADIS G, et al. Numerical and experimental study of the flow around a 4: 1 rectangular cylinder at moderate Reynolds number[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2019, 189: 289-303.
[18] ÁLVAREZ A J, NIETO F, NGUYEN D T, et al. 3D LES simulations of a static and vertically free-to-oscillate 4: 1 rectangular cylinder: Effects of the grid resolution[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2019, 192: 31-44.
[19] MATSUMOTO M, YAGI T, TAMAKI H, et al. Vortex-induced vibration and its effect on torsional flutter instability in the case of B/D = 4 rectangular cylinder[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2008, 96(6-7):971-983.
[20] MATSUMOTO M, SHIRAISHI N, SHIRATO H, et al. Mechanism of, and turbulence effect on vortex-induced oscillations for bridge box girders[J]. Journal of Wind Engineering & Industrial Aerodynamics, 1993, 49(1-3):467-476.
[21] DANIELS S J, CASTRO I P, XIE Z T. Numerical analysis of freestream turbulence effects on the vortex-induced vibrations of a rectangular cylinder - ScienceDirect[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2016, 153:13-25.
[22] LI M, LI Q, SHI H. Aerodynamic pressures on a 5:1 rectangular cylinder in sinusoidal streamwise oscillatory flows with non-zero mean velocities[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2021, 208: 104440.
[23] NAKAGUCHI H, HASHIMOTO K, MUTO S. An Experimental Study on Aerodynamic Drag of Rectangular Cylinders[J]. Journal of the Japan Society for Aeronautical and Space Sciences, 1968, 16(168): 1-5.
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}
PDF(5216 KB)
