Modeling and Analysis of Fluid-structure Interaction in Biomimetic Undulatory Swimming

这笔赠款将支持水上推进机制的基础研究。这项研究将有利于科学和工程领域，如勘探，运输和国防，通过促进基于使鱼类游泳高效和敏捷的基本原理的生物启发运动的发展。精确建模柔性体与周围流体之间的相互作用对于理解和优化能耗、速度和机动性至关重要。现有的波动游泳模型在运动形式和水流条件方面都存在一定的局限性。这项研究将有助于克服这些限制，通过引入更真实的身体运动和流动条件。一个新的身体鳍动力学模型将开发，包括以前忽略的关键因素，游泳性能的重要。本研究结合了振动理论、流体和固体力学、数值分析和实验分析，为研究生和本科生提供跨学科研究，并为K-12推广活动提供创意活动，包括鱼类设计比赛。波动游泳是身体与周围流体之间非线性相互作用的结果。内强迫和身体变形的细微变化可能会导致游泳成绩的显着差异。该奖项支持的研究，将解决准确的流体结构建模的基本挑战下，不同的身体鳍配置与不同的游泳步态和条件。一个细长体的波动游泳运动作为一个被迫的水弹性振荡器的降阶模型将开发连接内部肌肉强迫，外部流体力，和身体运动的有效方法的基础上状态变量模态分析。鳍上的非完整约束将用于绕过基于经典流体动力学模型的流体力预测，该模型仅限于理想化的几何形状和流动条件。非同步模式的使用将使一般体波与随时间变化的属性的描述。高保真计算流体-结构模拟，以及基于折射率匹配的创新水洞测量，再加上结构分析，将用于研究流体，结构和神经肌肉激活之间相互作用的详细特征，并改进降阶模型。然后，该模型将被用来评估优化的形态和内部强迫模式在粘性惯性游泳制度，为均匀和复杂的background flow.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

This grant will support fundamental research in aquatic propulsion mechanisms. This study will benefit science and engineering fields such as exploration, transportation, and defense, by boosting the development of bio-inspired locomotion based on the fundamental principles that make fish-swimming highly efficient and agile. Accurate modeling of the interplay between a flexible body and the surrounding fluid is crucial to understanding and optimizing energy consumption, speed, and maneuverability. Existing models of undulatory swimming are restrictive in the forms of motion and the flow conditions they can describe accurately. This study will help to overcome those restrictions by introducing more realistic body motion and flow conditions. A novel body-fin dynamical model will be developed that includes previously ignored key elements important for swimming performance. This research combines vibration theory, fluid and solid mechanics, and both numerical and experimental analyses, offering interdisciplinary research for graduate and undergraduate students, as well as creative activities for K-12 outreach including fish-design competitions.Undulatory swimming is a result of the nonlinear interaction between the body and surrounding fluid. Subtle changes in internal forcing and body deformation may induce significant differences in swimming performance. This award supports research that will address the fundamental challenges of accurate fluid-structure modeling under variable body-fin configurations with diverse swim gaits and conditions. A reduced-order model of undulatory swimming motion of a slender body as a forced hydroelastic oscillator will be developed to connect internal muscle forcing, external fluid forces, and body motion in an efficient approach based on state-variable modal analysis. Nonholonomic constraints on fins will be used to bypass the fluid-force prediction based on classical hydrodynamic models, which are restricted to idealized geometry and flow conditions. The use of nonsynchronous modes will enable the description of general body waves with longitudinally-varying properties. High-fidelity computational fluid-structure simulations, and innovative water-tunnel measurements based on refractive index matching, coupled with the structural analysis, will be used to investigate detailed features of the interactions between the fluid, structure, and neuromuscular activation and improve the reduced-order model. Then, the model will be used to evaluate optimized morphology and internal forcing patterns in viscous to inertial swim regimes, for uniform and complex background flows.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.