Birds morph their wings and tail in order to glide under a wide range of aerodynamic conditions. Gross wing morphing has been described in a multitude of studies, but the finer details of wing morphing are still unknown. Here, we measured the changes in wing shape and pose in a barn owl, Tyto alba, when gliding across a range of fifteen self-selected speeds. We found that T. alba does not use fine-wing shape control to glide at slow speeds in steady conditions, with the measured wing shapes being highly consistent across all flights. Instead, T. alba relied upon wing postural control (gross pitch) and changes in both tail shape and pose to modulate aerodynamic force. A consistent wing shape provides an exceptional aerodynamic tool for understanding gliding flight in birds through postural change and tail morphing. This geometry was used as the basis for computational fluid dynamics simulations which gave very similar wake measurements and weight support to those measured in flight. This geometry is provided here to assist other researchers interested in exploring the fluid dynamics behind gliding flight in birds.

中文翻译：

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从机翼形状到仓中的流体动力学（Tyto alba）

鸟类使翅膀和尾巴变形，以便在各种空气动力学条件下滑行。在许多研究中都描述了机翼的总体变形，但是机翼变形的更详细的细节仍然未知。在这里，我们测量了在十五种自选速度范围内滑行时，仓bar Tyto alba的机翼形状和姿势的变化。我们发现，阿尔巴T. alba并未使用细翼形状控制来在稳定条件下以低速滑行，而测得的翼形在所有飞行中都是高度一致的。相反，T。alba依靠机翼姿势控制（总音高）并改变尾巴的形状和姿势来调节空气动力。一致的机翼形状提供了一种出色的空气动力学工具，可用于通过姿势变化和尾巴变形了解鸟类的滑行飞行。这种几何形状被用作计算流体动力学仿真的基础，该仿真提供了与飞行中的测量非常相似的尾流测量和重量支持。这里提供了这种几何形状，以协助其他有兴趣探索鸟类滑翔飞行背后的流体动力学的研究人员。