Flexible swimmers: reverse engineering a jellyfish

Dabiri, John o .该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。这个项目将结合实验和计算来设计柔性推进器，也就是对水母进行逆向工程。为了成功地复制观察到的水母游泳性能，重要的是首先要了解生物推进系统中普遍存在的推进器柔韧性和非线性弹性的动力学作用。水母是一个引人注目的模型，因为它们代表了生物推进器最简单的例子之一，但却表现出耦合的流固相互作用、大变形和非线性弹性。因此，从这项研究中提取的设计原则可以潜在地应用于高等生物和工程推进系统。此外，最近编制了600多种水母的形态学数据库，可以将工程设计优化的结果与自然界中发现的解决方案进行比较。实验工具将为数值模型的验证和改进、设计优化的初始输入和最优解的评估提供必要的新数据。特别是，新的实验方案已经开发量化肌肉结构和活水母的激活动力学。数字粒子图像测速（DPIV）测量将在自由游动的水母产生的流场的多个平面上同时和依次收集。与UIUC的Jon Freund的持续合作有望为这项研究增加计算方面的内容。在这个项目中开发的方法将通过基于网络的教程传播，就像以前pi所做的那样。这个项目的跨学科性质将被利用来暴露学生从工程和生物学背景的研究方法。加州理工学院最近开设了一门名为“生物推进”的课程，将作为这项研究的教育渠道。PI还将继续担任加州理工学院新生暑期研究所（FSI）研究项目的协调员，该项目旨在向代表性不足的新生介绍研究型大学的环境。最后，两位pi将指导本科生和研究生的日常研究活动。

CBET - 0931413 Dabiri, John O.This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This project will combine experiments and computations in the design of flexible propulsors, i.e., to reverse engineer a jellyfish. To successfully replicate the observed swimming performance of jellyfish, it is important to first understand the dynamical role of propulsor flexibility and nonlinear elasticity, characteristics that are ubiquitous in biological propulsion systems. Jellyfish are a compelling model because they represent one of the simplest examples of a biological propulsor, and yet exhibit coupled fluid-structure interactions, large deformations, and nonlinear elasticity. Hence, the design principles extracted from this study can potentially be applied to higher organisms and engineered propulsion systems. Furthermore, a recently compiled morphological database of over 600 species of jellyfish is available to compare the results of the engineering design optimization with the solutions found in nature. Experimental tools will provide essential new data for validation and refinement of the numerical model, initial inputs to the design optimization, and evaluation of the optimal solutions. In particular, new experimental protocols have been developed to quantify the muscle architecture and activation dynamics of live jellyfish. Digital particle image velocimetry (DPIV) measurements will be collected both simultaneously and sequentially in multiple planes of the flow field created by free-swimming jellyfish. Continuing collaboration with Jon Freund at UIUC is expected to add a computational aspect to this study. The methods developed during this project will be disseminated via web-based tutorials, as has been done previously by the PIs. The interdisciplinary nature of this project will be leveraged to expose students from engineering and biology backgrounds to research methods. A recently developed course on 'Biological Propulsion' at Caltech will serve as an educational outlet for this research. The PI will also continue in his role as Coordinator of the Freshmen Summer Institute (FSI) Research Program at Caltech that introduces underrepresented incoming freshman to the environment of a research university. Finally, both PIs will mentor undergraduate and graduate students in the day-to-day research activities.