自然风下大比例模型的雷诺数效应

发布时间：2018-05-11 12:42

本文选题：桥梁工程 + 雷诺数　；参考：《长安大学学报(自然科学版)》2014年06期

【摘要】：为了分析阻塞度和洞壁效应对大比例模型风洞试验结果精度的影响,通过制作缩尺比为1∶9的大比例尺流线型桥梁断面模型,安装到高速移动的汽车上,形成不同风速的自然风场。测量了不同车速下(即不同雷诺数)模型的表面压力,拟合了试验数据,研究了自然风作用下高雷诺数区的流线型断面的三分力系数的变化规律以及表面压力分布的特点,并将自然风场数据与风洞试验数据进行了对比。研究结果表明:阻塞度和洞壁效应将对大比例模型的雷诺数效应产生较大影响,其中,当Re3×105时,随着雷诺数Re的增加,考虑阻塞度和洞壁效应影响的阻力系数呈不断减小的变化趋势,而不考虑其影响的阻力系数呈上升的变化趋势;阻塞度和洞壁效应使得升力系数数值变小,而升力矩系数数值却变大;阻塞度和洞壁效应不会改变模型表面最小压力点出现的位置,但是会使模型表面压力系数数值变小。
[Abstract]:In order to analyze the influence of blocking degree and wall effect on the accuracy of wind tunnel test results of large scale model, a large scale streamlined bridge section model with 1:9 scale ratio was made and installed on a high speed moving vehicle. Natural wind fields with different wind speeds are formed. The surface pressure at different velocities (i.e. different Reynolds numbers) is measured, the experimental data are fitted, and the variation law of the three-point force coefficient and the characteristics of the surface pressure distribution of the streamline section in the high Reynolds number region under the natural wind are studied. The natural wind field data are compared with the wind tunnel test data. The results show that the blocking degree and wall effect will have a great effect on the Reynolds number effect of the large scale model. When Re3 脳 10 ~ 5, with the increase of Reynolds number re, The drag coefficient considering the influence of blocking degree and wall effect shows a decreasing trend, but the resistance coefficient without considering the influence of the drag coefficient increases, and the blocking degree and wall effect make the lift coefficient value smaller. However, the value of the lifting moment coefficient is larger, and the blocking degree and wall effect will not change the position of the minimum pressure point on the surface of the model, but it will make the pressure coefficient of the model surface smaller.
【作者单位】：长安大学公路学院;
【基金】：国家自然科学基金面上项目(51078038)
【分类号】：U442.59

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