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

旋涡在自然界中大量存在，从空气动力学(翼尖旋涡)到水生动物(鱼类和水母)的推进，再到人类发声时喉部的旋涡脱落，都有出现。虽然涡旋动力学已经被广泛研究了几十年，但考察和利用涡旋与可变形/活动结构之间的相互作用来控制流动、收集能量和生物激励/仿生已经重新活跃了该领域。这项建议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：即使用可变形的智能材料为包括遥感网络在内的微电子设备提供动力的小规模射流能量收集；以及理解人类语音中的声带机制并对其进行建模，长期目标是(10多年)帮助制定手术计划以进行病理补救。这两个研究轨迹的共同核心力学是涡流和柔顺表面的双向耦合；即表面(无论是能量收集器还是声带组织)由于相邻流体流动中的压力场而变形，进而改变流体边界条件。因此，这项研究计划设想通过理论分析、计算建模、实验测试和验证相结合的方式，建立对涡旋与可变形结构相互作用的彻底和基本的理解，以促进对能量收集和语音建模的理解。这一研究方案将侧重于开发适用于两个研究重点的工具，以及针对具体领域的研究问题具体实施这些工具。最初的模型开发将集中在(二维)涡偶极子和(三维)环上，(I)穿过柔顺床面，并将旋涡的压力场和频率与时变的壁面变形相关联；(Ii)以不同的角度冲击柔顺结构，并探索冲击机理。控制无量纲参数将按参数变化，并将探索三维现象的重要性，例如结构上的边缘效应和撞击过程中的涡旋拉伸以及随后的涡旋破裂。为了确保具体问题的结果，能量收集轨道将侧重于能量收集设备的开发和验证，以及最大限度地提高能量提取的最佳参数和性能标准的评估，而演讲轨道将调查通过声道的涡流对对称和非对称组织特性的声带自持续振荡的影响。该项目将带来优化的基于智能材料的能量收集设备和包含涡流效应的改进的语音模型。

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.