斜置拉索表面脉动风力特性研究

Characteristics of fluctuating forces on inclined stay cable

采用一套可调节拉索模型倾角和风向角的试验装置,通过同步测压风洞试验,测得了三维拉索(考虑了拉索的倾角和风向角)表面的脉动风压分布。风洞试验考虑了风向角和Re数的影响,试验风向角为0°～45°,试验Re数为1.17×105和2.34×105,两种Re数分别处在亚临界区和临界区内。通过进一步的分析,得到了两种Re数下风压功率谱、脉动风力和风力功率谱随风向角的变化情况。研究表明:随着风向角的增大,斜拉索的Strouhal数逐渐减小;当Re数进入临界区后,拉索的脉动风压分布和脉动风力将发生很大变化。

With the help of a specially designed test set-up,a series of wind tunnel tests were carried out on an inclined and yawing cable model to obtain its fluctuating pressure distributions.The effects of Reynolds number and wind angle on fluctuating forces of the cable model were investigated.In tests,the wind angle ranges from 0° to 45°,and the Reynolds number tates 1.17×105（at a subcritical regime） or 2.34×105（at a critical regime）.Furthermore,RMS（root mean square） of aerodynamic forces and power spectrums of fluctuating pressures and fluctuating forces were presented at several different wind angles.It is found that Strouhal number will decrease with the increase of wind angle.Moreover,characteristics of fluctuating pressures and fluctuating forces will change dramatically when the Reynolds number increases from subcritical regime to critical regime.