On the development and early observations from a towing tank-based transverse wing–gust encounter test rig
On the development and early observations from a towing tank-based transverse wing–gust encounter test rig
复制标题
基于拖曳水箱的横向机翼-阵风遭遇试验台的开发和早期观察
DOI：
10.1007/s00348-018-2586-0
复制
发表时间：
2018
影响因子：
2.4
通讯作者：
J. Harvey
中科院分区：
文献类型：
--
作者：
S. Corkery;H. Babinsky;J. Harvey
小型无人机和生物飞行器可能会遇到与飞行速度相当的阵风，这不利于飞行稳定性。对于一种遭遇类型，即低雷诺数横向阵风，人们对基本流体力学知之甚少，部分原因是难以通过实验或计算来复制该场景。因此，这项工作的目的是展示一种能够生成和测量大振幅横向机翼阵风遭遇的瞬态响应的设备的开发和表征。该系统旨在产生锋利的阵风剖面，以便与线性库斯纳模型直接进行比较。粒子图像测速（PIV）测量表明，该系统成功产生了稳定的礼帽形阵风。使用惯性传感器的技术已被用来最大限度地减少模型振动在测量不稳定力时的影响。还提出了与飞行速度相等的横流速度的机翼-阵风相互作用。对于这种相互作用，形成强烈的前缘涡旋，并且在后缘处散发出相反方向的涡量。后缘涡度保持相对平面，这类似于库斯纳模型的平面尾流假设。机翼进入时可以看到阵风剪切层的大变形，这与线性理论假设的“刚性”剪切层有偏差。尽管理论和实验之间的流动拓扑存在差异，但升力系数在进入阵风期间匹配得惊人地好，但在退出阵风时出现偏差。图形摘要
Small unmanned aerial vehicles and biological fliers can experience wind gusts of similar magnitude to the flight speed, which is detrimental to flight stability. For one encounter type, the low Reynolds number transverse gust, little is known about the fundamental fluid mechanics due in part to the difficulties in replicating the scenario experimentally or computationally. The aim of this work is thus to present the development and characterisation of an apparatus capable of generating and measuring the transient response of large amplitude transverse wing–gust encounters. The system is designed to produce a sharp-edged gust profile for direct comparison with the linear Küssner model. Particle image velocimetry (PIV) measurements show that the system successfully generated a steady top-hat shaped gust. A technique using inertial sensors has been used to minimise the effects of model vibration in measuring the unsteady forces. A wing–gust interaction with cross flow velocity equal to the flight speed is also presented. For this interaction, a strong leading edge vortex forms and vorticity of opposite sense is shed at the trailing edge. The trailing edge vorticity remains relatively planar, which is similar to the planar wake assumption of the Küssner model. Large deformation of the gust shear layers is visible upon wing entry, which is a deviation from the ‘rigid’ shear layers assumed by linear theory. Despite differences in flow topology between theory and experiment, the lift force coefficients match surprisingly well during entry into the gust, but deviate upon exit.Graphical abstract