The role of optimal vortex formation in biological fluid transport
The role of optimal vortex formation in biological fluid transport
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DOI：
10.1098/rspb.2005.3109
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发表时间：
2005-08-07
影响因子：
4.7
通讯作者：
Gharib, M
中科院分区：
文献类型：
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作者：
Dabiri, JO;Gharib, M
需要宏观流体运输才能发挥功能的动物门反复且经常独立地集中在喷射流的使用上。在流动启动过程中，这些射流形成流体涡环，有利于固定泵（例如心室）的质量传递和移动系统（例如喷射推进的游泳器）的动量传递。先前的研究表明，实验室产生的涡环可以根据射流长径比 (LID) 来优化效率或推力，峰值性能出现在 3.5 < L/D < 4.5 时。由于无法正确解释动物门中发现的喷射运动学的多样性，确定生物喷射是否实现这种优化的尝试尚未得出结论。我们将实验室实验、现场观察和将运动学简化为单个参数的框架相结合，以便定量地表明个体动物运动学可以根据最佳涡环形成进行调整。这种新方法确定了有效流体输送的简单规则，促进了跨动物门的射流的比较生物学研究，无论其具体功能如何，并且可以扩展以统一基于射流和扑动的涡环形成的最佳理论。
Animal phyla that require macro-scale fluid transport for functioning have repeatedly and often independently converged on the use of jet flows. During flow initiation these jets form fluid vortex rings, which facilitate mass transfer by stationary pumps (e.g. cardiac chambers) and momentum transfer by mobile systems (e.g. jet-propelled swimmers). Previous research has shown that vortex rings generated in the laboratory can be optimized for efficiency or thrust, based on the jet length-to-diameter ratio (LID), with peak performance occurring at 3.5 < L/D < 4.5. Attempts to determine if biological jets achieve this optimization have been inconclusive, due to the inability to properly account for the diversity of jet kinematics found across animal phyla. We combine laboratory experiments, in situ observations and a framework that reduces the kinematics to a single parameter in order to quantitatively show that individual animal kinematics can be tuned in correlation with optimal vortex ring formation. This new approach identifies simple rules for effective fluid transport, facilitates comparative biological studies of jet flows across animal phyla irrespective of their specific functions and can be extended to unify theories of optimal jet-based and flapping-based vortex ring formation.