紊流风特性参数对近流线形桥梁表面风压分布影响
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摘要
风洞试验时紊流风特性参数的模拟精度会对桥梁结构的抖振、颤振、涡振等试验结果产生影响,为了提高试验精度,分析紊流风特性参数模拟误差所带来的影响、总结桥梁结构表面风压分布受紊流风参数的影响规律,在风洞中采用格栅紊流,分别形成了紊流强度相同但积分尺度不同与积分尺度相同但紊流强度不同的几种局部紊流风场,以此来研究紊流风特性参数单独变化对桥梁结构表面风压分布规律的影响。结果表明:紊流强度增大会使桥梁表面平均风压系数绝对值减小,减小的幅度会受结构表面位置、风攻角等因素的影响。当位置或风攻角发生变化后,紊流强度增大导致平均风压系数绝对值减小的幅度也会发生变化,很难进行定量修正。大部分位置的脉动风压系数会随紊流强度增大而增大。但受栏杆、风嘴、检修车轨道等附属结构影响,这种趋势可能出现相反的变化。紊流积分尺度增大会使近流线形桥梁表面平均风荷载增大,对脉动风荷载影响很小。进行桥梁气弹模型试验时,应首先保证准确模拟紊流强度,在条件许可的情况下再准确模拟紊流积分尺度。积分尺度越小,表面压力相关系数也越小。相邻位置的脉动风压相关系数主要受特征紊流影响,与来流的积分尺度无关。
The buffeting,flutter and VIV test results of bridge structure in wind tunnel is affected by the simulation precision of turbulent wind characteristic parameters. To improve the test accuracy,analyze the influence of simulation error of turbulent wind parameters and summarize the influence rule of the turbulent wind parameters on the wind pressure distribution on surface of the bridge structure,the grid turbulence is used in the wind tunnel,which composed some partial wind fields with the same turbulence intensity but different integral scales and others with the same integral scale but different turbulence intensities,the influence of the turbulent wind parameters on the wind pressure distribution rule on the bridge structure is studied. The result shows that( 1) The increase of turbulent intensity will reduce the absolute value of the mean wind pressure coefficient on the bridge surface,and the decreasing amplitude will be affected by the factors such as structural surface position,wind attack angle. When the position or wind attack angle changes,the absolute value reduction amplitude of the mean wind pressure coefficient due to the increase ofturbulence intensity will also change,it is difficult to make quantitative correction.( 2) The fluctuating wind pressure coefficient increases with the increase of turbulence intensity in most positions. However,this trend may be reversed due to the influence of railings,wind fairings,orbits of maintenance car and other attachment structures.( 3) The increase of turbulence integral scale will increase the mean wind load on the approximate streamlined bridge surface,while it has little effect on the fluctuating wind load.( 4) When carrying out the aeroelastic model test of bridge,the turbulence intensity should be accurately simulated at first,and the turbulence integral scale should be accurately simulated when conditions permit. The smaller the turbulence integral scale is,the less the surface pressure correlation coefficient is.( 5) The fluctuating wind pressure correlation coefficient at adjacent positions is mainly affected by signature turbulence and is independent of integral scale of inlet flow.
The buffeting,flutter and VIV test results of bridge structure in wind tunnel is affected by the simulation precision of turbulent wind characteristic parameters. To improve the test accuracy,analyze the influence of simulation error of turbulent wind parameters and summarize the influence rule of the turbulent wind parameters on the wind pressure distribution on surface of the bridge structure,the grid turbulence is used in the wind tunnel,which composed some partial wind fields with the same turbulence intensity but different integral scales and others with the same integral scale but different turbulence intensities,the influence of the turbulent wind parameters on the wind pressure distribution rule on the bridge structure is studied. The result shows that( 1) The increase of turbulent intensity will reduce the absolute value of the mean wind pressure coefficient on the bridge surface,and the decreasing amplitude will be affected by the factors such as structural surface position,wind attack angle. When the position or wind attack angle changes,the absolute value reduction amplitude of the mean wind pressure coefficient due to the increase ofturbulence intensity will also change,it is difficult to make quantitative correction.( 2) The fluctuating wind pressure coefficient increases with the increase of turbulence intensity in most positions. However,this trend may be reversed due to the influence of railings,wind fairings,orbits of maintenance car and other attachment structures.( 3) The increase of turbulence integral scale will increase the mean wind load on the approximate streamlined bridge surface,while it has little effect on the fluctuating wind load.( 4) When carrying out the aeroelastic model test of bridge,the turbulence intensity should be accurately simulated at first,and the turbulence integral scale should be accurately simulated when conditions permit. The smaller the turbulence integral scale is,the less the surface pressure correlation coefficient is.( 5) The fluctuating wind pressure correlation coefficient at adjacent positions is mainly affected by signature turbulence and is independent of integral scale of inlet flow.
引文
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[12]卢占斌,魏庆鼎.网格紊流CAARC模型风洞实验[J].空气动力学学报,2001,19(1):16-23.LU Zhan-bin,WEI Qing-ding.An Experiment on a CAARC Model in Grid Turbulent Flow[J].Acta Aerodynamica Sinica,2001,19(1):16-23.
[13]王利娟,林志兴.紊流对桥梁颤振特性影响的试验研究[J].同济大学学报:自然科学版,2001,29(4):390-395.WANG Li-juan,LIN Zhi-xing.Experimental Study of Turbulence Effects on Bridge Flutter[J].Journal of Tongji University:Natural Science Edition,2001,29(4):390-395.
[14]李春光,张记,陈政清.紊流积分尺度对桥梁颤振导数影响的试验研究[J].公路交通科技,2016,33(11):69-75.LI Chun-guang,ZHANG Ji,CHEN Zheng-qing.Experimental Study on Influence of Turbulence Integral Scale on Flutter Derivatives of Bridge[J].Journal of Highway and Transportation Research and Development,2016,33(11):69-75.
[15]茅建校,王浩,陶天友,等.紊流空间相关系数对大跨度三塔悬索桥抖振响应的影响[J].振动与冲击,2016,35(10):202-206.MAO Jian-xiao,WANG Hao,TAO Tian-you,et al.Effects of the Turbulent Spatial Correlation Coefficient on Buffeting Responses of a Triple-tower Suspension Bridge[J].Journal of Vibration and Shock,2016,35(10):202-206.
[16]白桦.影响桥梁及建筑结构风洞试验结果若干因素研究[D].西安:长安大学,2012.BAI Hua.Research on Effect of Several Factors on Wind Tunnel Test Result of Bridge and Building Structure[D].Xi'an:Chang'an University,2012.
[17]王骑,廖海黎,李明水,等.流线型箱梁气动外形对桥梁颤振和涡振的影响[J].公路交通科技,2012,29(8):44-50,70.WANG Qi,LIAO Hai-li,LI Ming-shui,et al.Influence of Aerodynamic Shape of Streamline Box Girder on Bridge Flutter and Vortex-induced Vibration[J].Journal of Highway and Transportation Research and Development,2012,29(8):44-50,70.
[18]马文勇,邓然然,卢金玉.D形断面柱体驰振耦合气动力特性试验研究[J].振动工程学报,2017,30(5):755-763.MA Wen-yong,DENG Ran-ran,LU Jin-yu.Characteristics of Coupled Aerodynamic Forces of a Galloping Cylinder with D-section[J].Journal of Vibration Engineering,2017,30(5):755-763.
[2]TIELEMAN H W.Wind Tunnel Simulation of the Turbulence in the Surface Layer[J].Journal of Wind Engineering&Industrial Aerodynamics,1990,36(1):1309-1318.
[3]BEARMAN P W,MOREL T.Effect of Free Stream Turbulence on the Flow around Bluff Bodies[J].Progress in Aerospace Sciences,1983,20(2):97-123.
[4]LEE B E.Some Effect of Turbulence Scale on the Mean Forces on a Bluff Body[J].Journal of Wind Engineering&Industrial Aerodynamics,1975,1(4):361-370.
[5]SCHEWE G.Reynolds-number Effects in Flow around More-or-less Bluff Bodies[J].Journal of Wind Engineering&Industrial Aerodynamics,2001,89(14):1267-1289.
[6]BUCHER C G,LIN Y K.Effects of Wind Turbulence on Motion Stability of Long-span Bridges[J].Journal of Wind Engineering&Industrial Aerodynamics,1990,36(1):1355-1364.
[7]张志田,陈政清,葛耀君,等.紊流中大跨度桥梁的扭转发散特性[J].工程力学,2010,27(2):108-116.ZHANG Zhi-tian,CHEN Zheng-qing,GE Yao-jun,et al.Torsional Divergence Characteristics of Long Span Bridge in Turbulence[J].Engineering Mechanics,2010,27(2):108-116.
[8]WANG T,HAN W,YANG F,et al.Wind-vehicle-bridge Coupled Vibration Analysis Based on Random Traffic Flow Simulation[J].Journal of Traffic and Transportation Engineering:English Edition,2014,1(4):293-308.
[9]SCANLAN R H,LIN W H.Effects of Turbulence on Bridge Flutter Derivatives[J].Journal of the Engineering Mechanics Division,1978,104(4):719-733.
[10]潘韬,赵林,曹曙阳,等.多风扇主动控制风洞类平板断面抖振力识别研究[J].振动与冲击,2010,29(6):178-183.PAN Tao,ZHAO Lin,CAO Shu-yang,et al.Buffeting Force Analysis of Thin Plate Section in Multiple Fans Active Control Wind Tunnel[J].Journal of Vibration and Shock,2010,29(6):178-183.
[11]华旭刚,陈政清,杨靖波,等.大缩尺比气弹模型风洞试验紊流积分尺度修正[J].建筑结构学报,2010,31(10):55-61.HUA Xu-gang,CHEN Zheng-qing,YANG Jing-bo,et al.Turbulence Integral Scale Corrections to Aeroelastic Wind Tunnel Experimental Results with Large Scale Model[J].Journal of Building Structures,2010,31(10):55-61.
[12]卢占斌,魏庆鼎.网格紊流CAARC模型风洞实验[J].空气动力学学报,2001,19(1):16-23.LU Zhan-bin,WEI Qing-ding.An Experiment on a CAARC Model in Grid Turbulent Flow[J].Acta Aerodynamica Sinica,2001,19(1):16-23.
[13]王利娟,林志兴.紊流对桥梁颤振特性影响的试验研究[J].同济大学学报:自然科学版,2001,29(4):390-395.WANG Li-juan,LIN Zhi-xing.Experimental Study of Turbulence Effects on Bridge Flutter[J].Journal of Tongji University:Natural Science Edition,2001,29(4):390-395.
[14]李春光,张记,陈政清.紊流积分尺度对桥梁颤振导数影响的试验研究[J].公路交通科技,2016,33(11):69-75.LI Chun-guang,ZHANG Ji,CHEN Zheng-qing.Experimental Study on Influence of Turbulence Integral Scale on Flutter Derivatives of Bridge[J].Journal of Highway and Transportation Research and Development,2016,33(11):69-75.
[15]茅建校,王浩,陶天友,等.紊流空间相关系数对大跨度三塔悬索桥抖振响应的影响[J].振动与冲击,2016,35(10):202-206.MAO Jian-xiao,WANG Hao,TAO Tian-you,et al.Effects of the Turbulent Spatial Correlation Coefficient on Buffeting Responses of a Triple-tower Suspension Bridge[J].Journal of Vibration and Shock,2016,35(10):202-206.
[16]白桦.影响桥梁及建筑结构风洞试验结果若干因素研究[D].西安:长安大学,2012.BAI Hua.Research on Effect of Several Factors on Wind Tunnel Test Result of Bridge and Building Structure[D].Xi'an:Chang'an University,2012.
[17]王骑,廖海黎,李明水,等.流线型箱梁气动外形对桥梁颤振和涡振的影响[J].公路交通科技,2012,29(8):44-50,70.WANG Qi,LIAO Hai-li,LI Ming-shui,et al.Influence of Aerodynamic Shape of Streamline Box Girder on Bridge Flutter and Vortex-induced Vibration[J].Journal of Highway and Transportation Research and Development,2012,29(8):44-50,70.
[18]马文勇,邓然然,卢金玉.D形断面柱体驰振耦合气动力特性试验研究[J].振动工程学报,2017,30(5):755-763.MA Wen-yong,DENG Ran-ran,LU Jin-yu.Characteristics of Coupled Aerodynamic Forces of a Galloping Cylinder with D-section[J].Journal of Vibration Engineering,2017,30(5):755-763.