Dual functions of insect wings in an odor-guided aeronautic navigation.
Dual functions of insect wings in an odor-guided aeronautic navigation.
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昆虫翅膀在气味引导航空导航中的双重功能。
DOI：
10.1115/1.4045946
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Zhao,Kai
中科院分区：
文献类型：
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作者：
Li,Chengyu;Dong,Haibo;Zhao,Kai
昆虫可以检测和定位远处的气味来源(食物、配偶等)。通过跟踪气味羽流，这是它们生存的关键。在气味引导导航过程中，人们推测拍动翅膀会主动将气味吸引到触角上，并提高嗅觉敏感度。利用内部计算流体力学解算器，我们对果蝇前向飞行时的气味羽流结构进行了量化，并证实了拍打的翅膀在昆虫头部上方诱导了强烈的涡流，从而使触角周围的气味质量通量增加了约1.8倍。为了进一步了解不同机翼区域在空气动力学和嗅觉方面的功能，我们设计了一种改装的果蝇翅膀，去掉了它的后缘部分；随后的模拟表明，这种改装的机翼具有更高的升力，但诱导气味质量通量显著减少。与通常认为昆虫的翅膀形状只为空气动力学性能而优化相反，我们的结果表明，由于空气动力学和嗅觉功能在气味引导导航中都是不可或缺的，昆虫可能会牺牲一些空气动力学潜力来增强嗅觉检测；而翅膀的形状和大小可能是这两种功能之间的平衡。此外，我们还发现，较高的机翼拍频和机翼反转相位会导致较高的气味质量通量，而较低的拍频和下冲位相会产生较好的升力系数，这表明这两种功能之间存在着另一种平衡。
Insects can detect and locate distant odor sources (food, mate, etc.) by tracking odor plumes, which is key to their survival. During an odor-guided navigation, flapping wings have been speculated to actively draw odorants to the antennae and enhance olfactory sensitivity. Utilizing an in-house computational fluid dynamics solver, we have quantified the odor plume structures of a fruit fly in a forward flight motion and have confirmed that the flapping wings induce a strong vortex flow over the insect's head, thereby enhancing the odor mass flux around the antennae (by ~1.8 times). To further understand the function of different wing area in terms of aerodynamics and olfaction, we designed an altered fruit fly wing by removing its trailing-edge portion; subsequent simulations showed that this altered wing has an improved lift production but with significantly reduction of the induced odor mass flux. Contrary to the common belief that the wing shapes of an insect are optimized only for aerodynamic performance, our results suggest that, because both aerodynamic and olfactory functions are indispensable during the odor-guided navigation, insects may sacrifice some aerodynamic potential to enhance olfactory detection; and the shape and size of the wing may be a balance between the two functions. Furthermore, we found that higher wing beat frequency and wing reversal phase induce higher odor mass flux, while lower beat frequency and downstroke phase produce better lift coefficient, which indicates another balance between the two functions.