Analysis of the Flow past Airfoils with Gurney Flaps at Low Reynolds Numbers
Analysis of the Flow past Airfoils with Gurney Flaps at Low Reynolds Numbers
复制标题
低雷诺数下带有格尼襟翼的翼型的流动分析
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
V. Roy
中科院分区：
文献类型：
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作者：
D. Mateescu;A. Panahi;V. Roy
本文对安装了格尼襟翼的低雷诺数固定翼型进行了非定常流动分析。格尼襟翼是一种简单而高效的增升装置。由于其机械简单，利用轮尼襟翼是特别感兴趣的小尺寸微型飞行器（MAV）在低速和非常低的雷诺数飞行。本文采用作者提出的求解低雷诺数下NavierStokes方程的有效时准数值方法进行了气动分析，该方法在时间和空间上都是二阶精确的。本文给出了几种对称和弧形翼型的升力和阻力气动系数及升阻比的求解方法。研究发现，虽然翼型被认为是静止的，但从一个相对较小的发生率（约8度）开始，由于在低雷诺数下发生的流动分离的不稳定，流动变得不稳定，气动系数在时间上显示周期性振荡。本文详细研究了轮尼襟翼高度、雷诺数、翼型相对厚度和相对弧度等几何参数和流动参数对升力、阻力和升阻比气动系数的影响。还借助流动可视化技术研究了流动分离，说明了不同时刻流型的变化。
This paper presents the unsteady flow analysis of the low-Reynolds-number flows past stationary airfoils equipped with Gurney flaps, which are simple but very efficient liftincreasing devices. Due to its mechanical simplicity, the utilization of Gurney flaps is of particular interest for the small size micro-air-vehicles (MAV) flying at low speed and very low Reynolds number. The aerodynamic analysis is performed in the paper with an efficient time-accurate numerical method developed by the authors for the solution of the NavierStokes equations at low Reynolds numbers, which is second-order-accurate in time and space. The paper presents solutions for the aerodynamic coefficients of lift and drag and for the lift-to-drag ratio of several symmetric and cambered airfoils. It was found that although the airfoil is considered stationary, starting from a relatively small incidence (about 8 degrees) the flow becomes unsteady due to the unsteadiness of the flow separations occurring at low Reynolds numbers, and the aerodynamic coefficients display periodic oscillations in time. A detailed study is presented in the paper on the influence of various geometric and flow parameters, such as the Gurney flap height, Reynolds number, airfoil relative thickness and relative camber, on the aerodynamic coefficients of lift, drag and lift-to-drag ratio. The flow separation is also studied with the aid of flow visualizations illustrating the changes in the flow pattern at various moments in time.