不同宽高比双边箱梁气动特性试验研究

Experimental Study on Aerodynamic Characteristics of Double-Sided Box Girder with Different Width-Height Ratios

为了对实际工程中双边箱梁的抗风设计提供参考,采用节段模型风洞测压和测力试验相结合的方法研究了双边箱梁的气动特性。首先,对比分析了不同宽高比双边箱梁的三分力系数随风攻角的变化规律;然后,通过分析风压分布规律初步探讨了三分力系数变化的机理;最后,通过对比分析升力系数的傅里叶幅值谱,揭示不同宽高比双边箱梁的旋涡脱落特性。结果表明,宽高比对阻力系数的影响主要体现在较大的正攻角,对升力系数和扭矩系数的影响主要体现在较大的负攻角。旋涡脱落特性与双边箱梁的宽高比和风攻角均密切相关。

In order to provide a reference for the wind resistance design of the double-sided box girder in practical engineering,the aerodynamic characteristics of the double-sided box girder were studied with the method of sectional model wind tunnel pressure measurement and force measurement test.Firstly,the variation law of the three-component force coefficients of the double-sided box girder with different width-height ratios at different wind attack angles was compared and analyzed.Then,the mechanism of the variation of the three-component force coefficients was preliminarily discussed by analyzing the distribution law of wind pressure.Finally,the vortex shedding characteristics of the double-sided box girder with different width-height ratios were revealed by comparing and analyzing the Fourier amplitude spectrum of the lift coefficient.The results show that the influence of the width-height ratio on the drag coefficient is mainly reflected in the large positive angle of attack,and the influence on the lift coefficient and torque coefficient is mainly reflected in the large negative angle of attack.The vortex shedding characteristics are closely related to the double-sided box girder’s width-height ratio and wind attack angle.