Sane Sanjay P
Department of Biology, University of Washington, Seattle, WA 98195, USA.
J Exp Biol. 2006 Jan;209(Pt 1):32-42. doi: 10.1242/jeb.01957.
A strong induced flow structure envelops the body of insects and birds during flight. This flow influences many physiological processes including delivery of odor and mechanical stimuli to the sensory organs, as well as mass flow processes including heat loss and gas exchange in flying animals. With recent advances in near-field aerodynamics of insect and bird flight, it is now possible to determine how wing kinematics affects induced flow over their body. In this paper, I develop a theoretical model based in rotor theory to estimate the mean induced flow over the body of flapping insects. This model is able to capture some key characteristics of mean induced flow over the body of a flying insect. Specifically, it predicts that induced flow is directly proportional to wing beat frequency and stroke amplitude and is also affected by a wing shape dependent parameter. The derivation of induced flow includes the determination of spanwise variation of circulation on flapping wings. These predictions are tested against the available data on the spanwise distribution of aerodynamic circulation along finite Drosophila melanogaster wings and mean flows over the body of Manduca sexta. To explicitly account for tip losses in finite wings, a formula previously proposed by Prandtl for a finite blade propeller system is tentatively included. Thus, the model described in this paper allows us to estimate how far-field flows are influenced by near-field events in flapping flight.
在飞行过程中，强烈的诱导流结构包裹着昆虫和鸟类的身体。这种流动影响着许多生理过程，包括向感觉器官传递气味和机械刺激，以及包括飞行动物的热量损失和气体交换在内的质量流动过程。随着昆虫和鸟类飞行近场空气动力学的最新进展，现在有可能确定翅膀运动学如何影响其身体上的诱导流。在本文中，我基于旋翼理论开发了一个理论模型，以估计扑翼昆虫身体上的平均诱导流。该模型能够捕捉飞行昆虫身体上平均诱导流的一些关键特征。具体而言，它预测诱导流与翅膀拍动频率和冲程幅度成正比，并且还受到一个与翅膀形状相关的参数的影响。诱导流的推导包括确定扑翼上环量的展向变化。这些预测与沿有限的黑腹果蝇翅膀的空气动力学环量展向分布以及烟草天蛾身体上的平均流的现有数据进行了对比测试。为了明确考虑有限翅膀中的梢部损失，暂时纳入了普朗特先前为有限叶片螺旋桨系统提出的一个公式。因此，本文描述的模型使我们能够估计远场流如何受到扑翼飞行中近场事件的影响。
