Aerodynamic forces on fixed and rotating plates
Aerodynamic forces on fixed and rotating plates
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DOI：
10.12989/was.2010.13.2.127
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发表时间：
2010-03
影响因子：
1.6
通讯作者：
P. Martinez-Vazquez;C. Baker;M. Sterling;A. Quinn;P. Richards
中科院分区：
文献类型：
--
作者：
P. Martinez-Vazquez;C. Baker;M. Sterling;A. Quinn;P. Richards
林等人最近报道了静态平板和自转平板上的压力测量。(2006)，Holmes等人。(2006)，和Richards等人。(2008)等。总体而言，法向力相对于迎角的变化在中攻角范围内似乎是失速的，在尾迹中有大尺度的分离。然而，到目前为止，还没有在自动旋转板上测量到表面压力，这是某一类碎片的典型特征。本文介绍了一种测量平板上气动力的实验结果，该平板与气流成不同的角度保持不动，并允许平板自动旋转。力是通过用内部安装的压力传感器和数据记录系统测量平板两侧的差压来确定的。给出了表面压力分布和板上总积分力和力矩的系数形式的结果。计算的静力系数显示了中程迎角的失速效应，以及不同雷诺数时的变化。自转实验测得的法向力在一个周期内高于大多数俯仰角的静态值。由此得到的力矩系数与目前的分析公式不能很好地比较，这些公式表明存在一种不能通过静态试验完全描述的流动机制。
Pressure measurements on static and autorotating flat plates have been recently reported by Lin et al. (2006), Holmes, et al. (2006), and Richards, et al. (2008), amongst others. In general, the variation of the normal force with respect to the angle of attack appears to stall in the mid attack angle range with a large scale separation in the wake. To date however, no surface pressures have been measured on auto-rotating plates that are typical of a certain class of debris. This paper presents the results of an experiment to measure the aerodynamic forces on a flat plate held stationary at different angles to the flow and allowing the plate to auto-rotate. The forces were determined through the measurement of differential pressures on either side of the plate with internally mounted pressure transducers and data logging systems. Results are presented for surface pressure distributions and overall integrated forces and moments on the plates in coefficient form. Computed static force coefficients show the stall effect at the mid range angle of attack and some variation for different Reynolds numbers. Normal forces determined from autorotational experiments are higher than the static values at most pitch angles over a cycle. The resulting moment coefficient does not compare well with current analytical formulations which suggest the existence of a flow mechanism that cannot be completely described through static tests.