摘要
在低湍流度的均匀流场中,测量了4种圆角率(R/D=0%、5%、10%和15%)的断面宽厚比为2∶1的二维矩形柱体模型在雷诺数1.1?105≤Re≤6.8?105范围内的表面风压时程,通过对模型表面风压时程积分的方法获得了模型的气动力系数时程,分析了四个模型的气动力系数的雷诺数效应以及雷诺数对各模型的气动力系数功率谱的影响。结果表明,随着圆角率的增大,模型的平均阻力系数减小,且平均阻力系数对雷诺数越来越敏感。所有模型的均方根阻力系数和均方根升力系数都呈现明显的雷诺数效应,且模型的圆角率越大,其均方根阻力系数和均方根升力系数对雷诺数越敏感。圆角率为0%和5%模型的脉动阻力系数功率谱和脉动升力系数功率谱基本不随雷诺数而改变,但圆角率为10%和15%模型的脉动阻力系数功率谱和脉动升力系数功率谱呈现明显的雷诺数效应。此外,圆角率对断面宽厚比为2∶1的二维矩形断面模型的Strouhal数也有明显的影响。
The experiments on 2∶1 rectangular prisms with rounded corner ratios R/D of 0%, 5%, 10% and 15% are reported. The tests were performed in low-turbulence uniform flow to measure the surface pressure of four models for the Reynolds number ranging from 1.1 × 10^5 to 6.8 ×10^5. Aerodynamic force coefficients are obtained by pressures integration. The effects of the Reynolds number on aerodynamic force coefficients and their power spectrums are analyzed. The results are summarized as follows： As the rounded corner ratio increases, the drag coefficient of the model decreases and becomes more sensitive to the Reynolds number. The RMS values of drag and lift coefficients for the four models all have considerable Reynolds number effects, and the RMS values become more sensitive to the Reynolds number with the increase of rounded corner ratios. The power spectrums of drag and lift coefficients for rectangular prisms R/D=0% or 5% are not changed with the Reynolds number, but when R/D=10% or 15%, the power spectrums have considerable Reynolds number effects. In addition, the rounded corner has a significant influence on the Strouhal number of 2∶1 rectangular prisms.
出处
《工程力学》
EI
CSCD
北大核心
2016年第1期64-71,共8页
Engineering Mechanics
基金
国家自然科学基金重大研究计划重点项目(90715040
91215302)
Key project of State Key Lab.of Disaster Reduction in Civil Eng.(SLDRCE15-A-04)
关键词
风工程
矩形柱体
雷诺数效应
圆角
气动力
wind engineering
rectangular prisms
Reynolds number effects
rounded corner
aerodynamic force
