小柯机器人

意大利罗马大学Giacomo Falcucci课题组利用极端流动模拟揭示了深海海绵的骨骼适应性。2021年7月21日，国际学术期刊《自然》在线发表了这一成果。

研究人员解决了一个悬而未决的问题：除了改善其机械性能外，玻璃海绵的骨架形态是否是优化其体腔内外流体力学的基础。使用基于“格子玻尔兹曼”的极端流动模拟，研究发现具有超过500亿个网格点并跨越四个空间和时间。这些计算机模拟实验再现了生活在深海海底玻璃海绵的流体动力学特征。

该研究结果表明，骨架排布降低了整体流体动力应力，并支撑低流速下连贯的内部再循环模式。这种模式有利于生物体选择性滤食和有性生殖。该研究揭示了生活在深海中生物体的非凡适应机制，为此类在流体力学、生物学和功能生态学上的交叉科学研究进一步铺平了道路。

据悉，自玻璃海绵 Euplectella aspergillum被发现以来，人们对其机械性能和美学就产生了兴趣。它的骨架系统由无定形的水合二氧化硅组成，排列在高度规则和分层的圆柱形晶格中，具有优越的柔韧性和抗损伤能力。多数文献专注于对其结构进行分析，但围绕海绵的流体动力学在很大程度上仍然未知。

附：英文原文

Title: Extreme flow simulations reveal skeletal adaptations of deep-sea sponges

Author: Giacomo Falcucci, Giorgio Amati, Pierluigi Fanelli, Vesselin K. Krastev, Giovanni Polverino, Maurizio Porfiri, Sauro Succi

Issue&Volume: 2021-07-21

Abstract: Since its discovery1,2, the deep-sea glass sponge Euplectella aspergillum has attracted interest in its mechanical properties and beauty. Its skeletal system is composed of amorphous hydrated silica and is arranged in a highly regular and hierarchical cylindrical lattice that begets exceptional flexibility and resilience to damage3,4,5,6. Structural analyses dominate the literature, but hydrodynamic fields that surround and penetrate the sponge have remained largely unexplored. Here we address an unanswered question: whether, besides improving its mechanical properties, the skeletal motifs of E. aspergillum underlie the optimization of the flow physics within and beyond its body cavity. We use extreme flow simulations based on the ‘lattice Boltzmann’ method7, featuring over fifty billion grid points and spanning four spatial decades. These in silico experiments reproduce the hydrodynamic conditions on the deep-sea floor where E. aspergillum lives8,9,10. Our results indicate that the skeletal motifs reduce the overall hydrodynamic stress and support coherent internal recirculation patterns at low flow velocity. These patterns are arguably beneficial to the organism for selective filter feeding and sexual reproduction11,12. The present study reveals mechanisms of extraordinary adaptation to live in the abyss, paving the way towards further studies of this type at the intersection between fluid mechanics, organism biology and functional ecology.

DOI: 10.1038/s41586-021-03658-1

Source: https://www.nature.com/articles/s41586-021-03658-1

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
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