摘要
矩形断面在实际工程中应用广泛,对其角部进行圆角化处理可有效减小风荷载并改善风致振动性能,然而圆角矩形断面的气动特性存在明显的雷诺数效应。为研究宽厚比为2:1的圆角矩形断面气动特性的雷诺数效应,减小在这类断面结构的风荷载和风致振动分析中因雷诺数原因引起的误差,对5种不同圆角率(0.1、0.2、0.3、0.4和0.5)的刚性模型进行了测压风洞试验,试验雷诺数范围为0.8×10^(5)~3.6×10^(5)。通过风洞试验得到并分析了不同圆角率矩形断面的平均阻力系数、平均风压系数和斯特罗哈数随雷诺数的变化规律,并与标准矩形断面进行对比。研究结果表明:不同于标准矩形断面,5种圆角矩形断面的气动特性均表现了一定的雷诺数效应,这种雷诺数效应随圆角率的增大先增强后减弱,当圆角率为0.2时最强,其在雷诺数为2.8×10^(5)时发生了明显跳跃;不同圆角矩形断面的平均阻力系数均随雷诺数的增加而减小。与其它位置相比,圆角矩形断面侧面和圆角位置处的风压系数受雷诺数影响更明显,其中圆角位置处最为显著。圆角矩形断面的斯特罗哈数在圆角率为0.1时基本稳定在0.22左右,圆角率为0.2时在跳跃前后分别在0.24和0.31附近,在其它圆角率时则随雷诺数的增加先增大后稳定。
Rectangular prisms are widely used in practical engineering.Rounding corner treatments can effectively reduce the wind load and improve wind-induced vibration performance.However,the aerodynamic characteristics of rectangular prisms with round corners experience an obvious Reynolds number effect.In order to study the Reynolds number effect of aerodynamic characteristics of 2:1 rectangular prism with round corners and reduce the error caused by Reynolds number in the analysis of wind load and wind-induced vibration of such prism structure,pressure-measured wind tunnel tests were carried out on five rigid models with different rounded corner ratios(0.1,0.2,0.3,0.4 and 0.5).The Reynolds number ranges from 0.8×10^(5)to 3.6×10^(5).The mean drag coefficients,mean wind pressure coefficients,and Strouhal number of rectangular prisms with different rounded corner ratios were obtained and analyzed by wind tunnel test,and compared with the standard rectangular prism.The results show that different from the standard rectangular prism,the aerodynamic characteristics of the five rectangular prisms with round corners show a certain Reynolds number effect,which increases first and then decreases with the increase of the rounded corner ratio.The Reynolds number effect is the strongest when the rounded corner ratio is 0.2,and the obvious jump occurs when the Reynolds number is 2.8×10^(5).The mean drag coefficients of different rectangular prisms with round corners decrease with the increase of the Reynolds number.Compared with other positions,the mean wind pressure coefficients at the side face and corner positions of the rectangular prisms with round corners are more obviously affected by Reynolds number,and the corner positions are the most obvious.The Strouhal number of the rectangle prisms with round corners is basically stable around 0.22 when the rounded corner ratio is 0.1,and around 0.24 and 0.31 before and after the jump when the rounded corner ratio is 0.2.At other rounded corner ratios,it increases first and then sta
作者
刘小兵
田学东
姜会民
杨群
LIU Xiaobing;TIAN Xuedong;JIANG Huimin;YANG Qun(State Key Lab of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Innovation Center for Wind Engineering and Wind Energy Technology of Hebei Province,Shijiazhuang 050043,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2023年第7期1-7,17,共8页
Journal of Vibration and Shock
基金
国家自然科学基金项目(52008273,52078313)
河北省自然科学基金项目(E2020210083)
河北省高等学校科学技术研究项目(ZD2019118)
省部共建交通工程结构力学行为与系统安全国家重点实验室自主课题(ZZ2020-14)。
关键词
矩形断面
圆角率
气动特性
雷诺数效应
风洞试验
rectangular prism
rounded corner ratio
aerodynamic characteristics
Reynolds number effect
wind tunnel test
