雷诺数对不同圆角率3∶1二维矩形柱体气动力的影响

Reynolds Number Effects on Aerodynamic Force Coefficients of 3∶1 Rectangular Prisms with Various Rounded Corners

摘要:

在低紊流度的均匀流场中对4种圆角率（R/D=0，5%，10%，15%）的3∶1二维矩形柱体模型进行了刚性模型测压试验.试验雷诺数的变化范围为1.1×105~6.8×105，通过风压时程积分的方法获得了模型的气动力系数时程.研究了4个模型的气动力系数及其功率谱随雷诺数的变化规律.研究表明，圆角率为R/D=0和5%的模型的平均阻力系数随雷诺数的增大而增大，而圆角率为10%和15%的模型的平均阻力系数、均方根阻力系数和均方根升力系数随雷诺数地增大出现了明显地跳跃.圆角率为R/D=0和5%的模型的气动力系数功率谱曲线随雷诺数的变化较小，但圆角率为10%和15%的模型的气动力系数功率谱曲线呈现了明显的雷诺数效应.此外，3∶1二维矩形柱体模型的Strouhal数随着圆角率的增大而增大.

Abstract:

Experiments were performed on 3∶1 rectangular prisms with various rounded corners (R/D=0, 5%, 10%, 15%) in low turbulence uniform flow to measure the surface pressures of four models for the testing Reynolds number ranging from 1.1×105 to 6.8×105. The aerodynamic forces were obtained by integrating the wind pressures on the model surface. Reynolds number effects on the aerodynamic force coefficients and their power spectrums are presented. The results show that drag coefficients of rectangular prisms with R/D=0 and 5% increase with the increasing Reynolds numbers, whereas sudden decreases of the drag coefficients root mean square(RMS) drag coefficients and RMS lift coefficients are observed for the rectangular prisms with R/D=10% and 15%. The power spectrums of drag and lift coefficients for rectangular prisms with R/D=0 and 5% change slightly with the increasing Reynolds numbers, whereas significant influences of the Reynolds number on the power spectrums of areodynamic force coefficients are found for the models with R/D=10% and 15%. Besides, Strouhal numbers of the 3∶1 rectangular prisms obviously increase with the increasing rounded corner ratio.