The Vortex/Structure Dance: Exploring Coupled Interactions for Energy Harvesting and Speech Modeling Applications

涡旋在自然界中比比皆是，从空气动力学（翼尖涡旋）到水生动物（鱼和水母）的推进，再到人类发声时喉部的涡旋脱落，这些领域都有出现。虽然涡旋动力学已经被广泛研究了几十年，但研究和利用涡旋与流动控制、能量收集和生物启发/仿生学的可变形/主动结构的相互作用使该领域重新焕发活力。该提案侧重于工程和医学中两个看似不同但密切相关的重要领域：即，使用可变形智能材料为微电子设备供电的小型流体能量收集，包括遥感网络；理解和模拟人类语言的声带力学，长期目标（10年以上）帮助手术计划病理修复。这两个研究轨道的共同核心机制是涡载流体流动与柔顺表面的双向耦合；即表面（能量收集器或声带组织）由于邻近流体流动中的压力场而变形，从而改变流体边界条件。因此，本研究计划设想通过理论分析、计算建模、实验测试和验证的混合，建立对涡旋与可变形结构相互作用的彻底和基本理解，以促进对能量收集和语音建模的理解。该研究计划将侧重于开发适用于这两个研究焦点的工具，以及针对特定领域研究问题的这些工具的具体实施。最初的模型开发将侧重于（二维）涡旋偶极子和（三维）环(i)通过一个柔顺的床，并将涡旋的压力场和频率与时变壁面变形联系起来；（ii）以不同角度冲击柔顺结构并探索冲击力学。控制无量纲参数将参数化变化，并将探讨三维现象的重要性，例如边缘效应对结构的影响以及撞击过程中旋涡的拉伸和随后的旋涡破裂。为了确保特定问题的结果，能量收集轨道将专注于能量收集设备的开发和验证，以及最大限度地提取能量的最佳参数和性能标准的评估，而语音轨道将研究通过声道的涡流对声带的自我持续振荡的影响，包括对称和非对称组织特性。该项目将优化基于智能材料的能量收集设备，并改进包含涡旋效应的语音模型。

Vortices abound in nature, appearing in fields ranging from aerodynamics (wing tip vortices) to propulsion of aquatic animals (fish and jellyfish) to vortex shedding in the larynx during human phonation. While vortex dynamics has been studied extensively for decades, examining and exploiting the interaction of vortices with deformable/active structures for flow control, energy harvesting, and bio-inspiration/biomimicry has reinvigorated the field. This proposal focuses on two seemingly disparate but intimately related areas of importance in engineering and medicine: namely, small-scale fluidic energy harvesting using deformable smart-materials for powering micro-electronic devices, including remote sensing networks; and understanding and modeling vocal fold mechanics in human speech with the long term goal (10+ years) of aiding in surgical planning for pathology remediation. The shared core mechanics of these two research tracks is the bi-directional coupling of a vortex-laden fluid flow with a compliant surface; that is, the surface (either the energy harvester or the vocal fold tissue) deforms due to the pressure field in the adjacent fluid flow, which, in turn, alters the fluid boundary condition. As such, this research program envisions establishing a thorough and fundamental understanding of the interaction of vortices with deformable structures via a mix of theoretical analysis, computational modeling, and experimental testing and validation for advancing understanding of energy harvesting and speech modeling. This research program will focus on the development of tools applicable to both research foci, as well as the track-specific implementation of these tools for addressing field-specific research questions. Initial model development will focus on (two-dimensional) vortex dipoles and (three-dimensional) rings (i) passing over a compliant bed and relating the pressure field and frequency of the vortices to the time-variant wall deformation; and (ii) impacting a compliant structure at various angles and exploring the impact mechanics. The governing dimensionless parameters will be varied parametrically and the importance of three-dimensional phenomena, such as edge effects on the structure and vortex stretching during impact and subsequent vortex breakdown, will be explored.  To ensure problem-specific outcomes, the energy harvesting track will focus on development and validation of energy harvesting devices and evaluation of the optimal parameters and performance criteria for maximizing energy extraction, while the speech track will investigate the impact of vortices passing through the vocal tract on the self-sustained oscillations of the vocal folds for both symmetric and asymmetric tissue properties. This project will lead to optimized smart material-based energy harvesting devices and improved speech models incorporating vortex effects.