Volumetric measurements and simulations of the vortex structures generated by low aspect ratio plunging wings
Volumetric measurements and simulations of the vortex structures generated by low aspect ratio plunging wings
复制标题
低展弦比俯冲翼产生的涡结构的体积测量和模拟
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
M. Visbal
中科院分区：
文献类型：
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作者：
D. Calderon;Zhijin Wang;I. Gursul;M. Visbal
体积三分量测速测量已在经历小幅度纯俯冲运动的低展弦比机翼上进行。本研究重点关注设置为固定几何迎角 α = 20° 的矩形和椭圆形机翼产生的涡流。对斯特劳哈尔数影响的研究说明了前缘涡流的高度三维性质及其提高升力性能的固有能力。计算模拟与实验结果吻合良好，两者都证明了每个循环中产生的前涡、尾涡和尖端涡之间的复杂相互作用。特别是前缘涡流可能在整个周期中显着变形，在某些情况下会产生强烈的展向波动。这些至少与斯特劳哈尔数和平面形状相关。根据纵横比和斯特劳哈尔数，可能会形成一两个拱形涡旋结构。在斯特劳哈尔数足够高的情况下，也可能会形成尖端涡环，由于自感速度而将其自身推离翼展方向。
Volumetric three-component velocimetry measurements have been performed on low aspect ratio wings undergoing a small amplitude pure plunging motion. This study focuses on the vortex flows generated by rectangular and elliptical wings set to a fixed geometric angle of attack of α = 20°. An investigation into the effect of Strouhal number illustrates the highly three-dimensional nature of the leading edge vortex as well as its inherent ability to improve lift performance. Computational simulations show good agreement with experimental results, both demonstrating the complex interaction between leading, trailing, and tip vortices generated in each cycle. The leading edge vortex, in particular, may deform significantly throughout the cycle, in some cases developing strong spanwise undulations. These are at least both Strouhal number and planform dependent. One or two arch-type vortical structures may develop, depending on the aspect ratio and Strouhal number. At sufficiently high Strouhal numbers, a tip vortex ring may also develop, propelling itself away from the wing in the spanwise direction due to self-induced velocity.