Collaborative Research: The Roles of Inter-limb Jets and Body Angles in Metachronal Paddling

合作研究：肢体间射流和身体角度在异时划桨中的作用

• 批准号: 1706007
• 负责人: Donald Webster
• 金额: $ 25万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1706007&HistoricalAwards=false
• 关键词: Collaborative; Research; Roles; Inter; limb

Commercial underwater drones typically rely on a single propeller element. If this element were to fail, then the drone would be lost. In contrast, the existence of multiple propulsion elements would permit continued use upon failure of a single propeller. Natural aquatic organisms illustrate a unique opportunity to use multiple propulsion elements to generate small-scale jets. Krill, shrimp, and crayfish, all use several pairs of limbs in highly coordinated motion to swim. The animal rhythmically oscillates its limbs from the tail-to-head at low velocity, with the timing of each pair delayed relative to its neighbors. Nature?s design uses much less energy than our engineered underwater drones. Mechanical elements, such as gears and timing belts, could be used to cost effectively mimic nature?s design. However, the underlying fluid dynamics of this metachronal (sequential) paddling is not well-understood. A limited number of studies have suggested limb morphology, the precision timing of the paddling sequence, and the generation of jets in the wake of the organism all contribute to this unique propulsion mechanism. This research project examines how coordination of adjacent limbs interact with the flow past the body to generate propulsive jets in the wake. Uncovering the underlying fluid dynamic principles of metachronal paddling will enable scalability to engineered devices, allowing for efficient design of miniaturized, bio-inspired autonomous underwater drones. This research project examines how the coordinated motion of multiple oscillating paddles merge with large-scale flow past a submerged object to generate propulsive forces. A combination of experiments with both live animals and robotic models will be used. Tomographic particle image velocimetry measurements of free-swimming aquatic organisms will be used to validate flow fields predicted by physical models. Self-propelled metachronal swimming robots will be used to examine the flow for individual and collective motion of the robots. Mechanical performance with respect to body angles, swimming speeds, and neighbor distances in individual and small groups of metachronal paddling robots will be examined. A primary project outcome will be the fluid dynamics mechanism by which aquatic organisms achieve large body speeds by paddling individual limbs at low velocity. The outcomes of this research will enable engineers to design and coordinate the motion of multiple propellers on engineered devices. In addition, the research project trains undergraduate and graduate students to conduct interdisciplinary research in bioengineering. Existing mechanisms at both institutions (NSF-funded Oklahoma Louis-Stokes Alliance for Minority Participation and Georgia Tech FOCUS program) are being used to recruit under-represented students for the project, and the researchers are participating in outreach activities to high school students and their teachers.

商业水下无人机通常依靠单个螺旋桨元件。如果该元素失败，那么无人机将丢失。 相比之下，多个推进元件的存在将允许单个螺旋桨失败后继续使用。 天然水生生物说明了使用多个推进元素产生小规模喷气式的独特机会。 磷虾，虾和小龙虾都在高度协调的运动中使用几对四肢游泳。动物有节奏地从低速下的尾部到头振荡，每对的时机相对于邻居而言延迟。 大自然的设计比我们工程的水下无人机所使用的能量要少得多。机械元素（例如齿轮和正时皮带）可用于成本地模仿自然界的设计。 然而，这种基本（顺序）划桨的基本流体动力学并不是很好地理解。有限的研究表明，肢体形态，划桨序列的精确时机以及生物体后的喷气机的产生都有助于这种独特的推进机制。 该研究项目研究了相邻肢体的协调如何与人体经过的流动相互作用，以产生推进喷气机。揭示基础流体划桨的基本流体动态原理将使工程设备可扩展性，从而有效地设计了微型生物启发的自主水下无人机。该研究项目研究了多个振荡桨的协调运动如何与大规模流动的物体合并以产生推进力。 将使用与活动物和机器人模型的实验组合。自由迅速水生生物的层析成像粒子图像测量值将用于验证物理模型预测的流场。自行车的基质游泳机器人将用于检查机器人的个体和集体运动的流程。将检查有关身体角度，游泳速度和邻居距离的机械性能。一个主要的项目结果将是流体动力学机制，通过在低速下划桨单个肢体，水生生物可以实现较大的体速。这项研究的结果将使工程师能够设计和协调多个螺旋桨在工程设备上的运动。 此外，该研究项目还培训本科生和研究生在生物工程中进行跨学科研究。 两家机构的现有机制（NSF资助的俄克拉荷马州路易斯 - 斯托克斯 - 斯托克斯联盟（Louis-Stokes Alliance in Commination）和佐治亚理工学院焦点计划）都被用来招募该项目的代表性不足的学生，研究人员正在向高中生及其老师参加外展活动。