In contrast to common continuous wings, microscopic flying insects such as fairyfly and thrips possess extraordinary wings that comprise several bristles. In the low-Reynolds-number environment inhabited by these insects, a bristled wing benefits from the formation of virtual fluid barriers that prevent flow leakage in the gaps of bristles. In this study, the optimal configuration regarding the aerodynamic performance of simple bristled-wing models is investigated numerically in terms of the Reynolds number and the distance between bristles, which are known to be important parameters for determining the effectiveness of a virtual fluid barrier. Inspired by the inherent characteristics of low-Reynolds-number flow, we provide new insights into the aerodynamics of a bristled wing by using a scaling parameter that combines these two independent parameters: effective gap width. In addition, the force ratio is scaled with the Reynolds number to better characterize the generation of drag and lift by a bristled wing. Despite the Reynolds number and the gap width varying by several orders of magnitude, the scaled drag force converges asymptotically beyond a specific effective gap width, and the lift force ratio has a peak within a very narrow range of the effective gap width. The trend of the lift with the effective gap width is correlated with changes in the asymmetric distributions of pressure and vorticity on the surface of the bristles. In addition, the drag and lift predicted theoretically, by invoking the linear superposition of creeping flows, agree well with numerical results, in particular for large effective gap width.

中文翻译：

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二维刚毛翼的优化构型

与普通的连续翅膀相比，飞蛾和蓟马等微型飞行昆虫拥有由数根刚毛组成的非凡翅膀。在这些昆虫居住的低雷诺数环境中，毛茸茸的翅膀受益于虚拟流体屏障的形成，可防止刷毛间隙中的流动泄漏。在这项研究中，关于简单刚毛翼模型的空气动力学性能的最佳配置在雷诺数和刚毛之间的距离方面进行了数值研究，这些距离是确定虚拟流体屏障有效性的重要参数。受低雷诺数流固有特性的启发，我们通过使用结合了这两个独立参数的缩放参数，提供了对刚毛机翼空气动力学的新见解：有效间隙宽度。此外，力比与雷诺数成比例，以更好地表征由刚毛机翼产生的阻力和升力。尽管雷诺数和间隙宽度有几个数量级的变化，但缩放阻力逐渐收敛到超过特定的有效间隙宽度，升力比在有效间隙宽度的非常窄的范围内具有峰值。有效间隙宽度的升力趋势与刷毛表面压力和涡量的不对称分布的变化有关。此外，理论上预测的阻力和升力，通过调用蠕动流的线性叠加，