Gemmell Brad J, Colin Sean P, Costello John H, Dabiri John O
Department of Integrative Biology, University of South Florida, Tampa, Florida 33620, USA.
Eugene Bell Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA.
Nat Commun. 2015 Nov 3;6:8790. doi: 10.1038/ncomms9790.
A central and long-standing tenet in the conceptualization of animal swimming is the idea that propulsive thrust is generated by pushing the surrounding water rearward. Inherent in this perspective is the assumption that locomotion involves the generation of locally elevated pressures in the fluid to achieve the expected downstream push of the surrounding water mass. Here we show that rather than pushing against the surrounding fluid, efficient swimming animals primarily pull themselves through the water via suction. This distinction is manifested in dominant low-pressure regions generated in the fluid surrounding the animal body, which are observed by using particle image velocimetry and a pressure calculation algorithm applied to freely swimming lampreys and jellyfish. These results suggest a rethinking of the evolutionary adaptations observed in swimming animals as well as the mechanistic basis for bio-inspired and biomimetic engineered vehicles.
在动物游泳概念化过程中，一个核心且长期存在的原则是，推进力是通过将周围的水向后推而产生的。这种观点内在的假设是，运动涉及在流体中产生局部升高的压力，以实现对周围水体预期的下游推力。在这里，我们表明，高效游泳的动物不是向后推周围的流体，而是主要通过吸力在水中拉动自己。这种区别体现在动物身体周围流体中产生的占主导地位的低压区域，这是通过使用粒子图像测速技术和应用于自由游动的七鳃鳗和水母的压力计算算法观察到的。这些结果表明，需要重新思考在游泳动物中观察到的进化适应性，以及生物启发和仿生工程车辆的机械基础。
