Lift enhancement on spanwise oscillating flat-plates in low-Reynolds-number flows
Lift enhancement on spanwise oscillating flat-plates in low-Reynolds-number flows
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DOI：
10.1063/1.4922236
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发表时间：
2015-06
影响因子：
4.6
通讯作者：
Shizhao Wang;G. He;Xing Zhang
中科院分区：
文献类型：
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作者：
Shizhao Wang;G. He;Xing Zhang
通过数值模拟研究了展向振荡对雷诺数为 300 的低展弦比平板周围三维流动的影响。板的简谐展向振荡由两个参数控制：折减频率 k 和无量纲振幅 Ay。研究发现，在一定的参数空间（k，Ay）范围内，展向振荡能够有效提高平均升力和增大平均升阻比。为了阐明展向振荡导致升力增强的机制，比较了有和没有展向振荡的平板后面的尾流结构。据观察，展向振荡稳定了前缘涡并将其压到非常靠近上表面的位置。由于前缘涡对应于低压核心，稳定附着的前缘涡有利于升力产生。这种升力增强机制也通过使用简化的......
Numerical simulations are performed to study the influence of spanwise oscillations on the three-dimensional flows around low-aspect-ratio flat-plates at a low Reynolds number of 300. The harmonic spanwise oscillations of the plate are controlled by two parameters: the reduced frequency k and the dimensionless amplitude Ay. It is found that in a certain range of the parameter space (k, Ay), spanwise oscillations are effective in enhancing the average lift and augmenting the average lift-to-drag ratio. To elucidate the mechanism of lift enhancement due to the spanwise oscillations, the wake structures behind flat-plates with and without spanwise oscillations are compared. It is observed that the spanwise oscillation stabilizes the leading-edge vortex and presses it to a place very close to the upper surface. Since a leading-edge vortex corresponds to a low-pressure core, the stably attached leading-edge vortex benefits lift production. This lift-enhancement mechanism is also verified by using a simplified ...