UNS: The Interaction of Coherent Structures in a Shear Layer with a Flexible Beam

UNS：剪切层中相干结构与柔性梁的相互作用

• 批准号: 1511761
• 负责人: Byron Erath
• 金额: $ 28万
• 依托单位: Clarkson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1511761&HistoricalAwards=false
• 关键词: UNS; Interaction; Coherent; Structures; Shear

1511761(Erath)The goal of this proposal is to investigate experimentally and numerically the fluid structure interaction when fluid passes around a flexible beam. This is a representative model of air flow past the vocal cords. The study will focus not only on conditions representing healthy vocal cords, but mainly on cases where the vocal cords are not healthy. Results from the proposed research can, thus, impact speech rehabilitation and could be felt by many people among the roughly 30% of the population of the US, who are estimated to suffer voice pathology at some point in their lives.The main objective of the proposed research is to identify the mechanisms by which a train of vortices advecting over a flexible beam incite motion in the structure, and parametrically explore this fundamental fluid- structure interaction problem. It is proposed to quantify how vortices produced during speech impact vocal fold dynamics in both normal, as well as pathological speech. Currently, there is incomplete understanding of the interplay between the aerodynamic loading as air comes to the vocal cords and the structural response of the tissue. This deficiency will be addressed by experimentally and theoretically/numerically investigating vortex-beam interactions that arise from coherent structures passing over a flexible beam. The hypothesis is that the coherent vortical structures are formed from the Kelvin-Helmholtz instability in the shear layer of the flow. The excitation of the beam will be investigated over a range of nondimensional beam, fluid, and geometrical parameters. The experimental results will validate the theoretical flow model of vortex-beam interactions, which will then be used to extend and explore the parameter space beyond the limitations of the experimental facility. The theoretical model will ultimately be applied to a numerical model of voiced speech to quantify the role of vortex-tissue interactions on vocal outcomes. The fundamental problem of vortices interacting with a deformable surface also has specific relevance to the topic of using deformable electroactive devices to harvest energy from fluids. In addition to graduate and undergraduate student education, a plan for K-12 outreach is proposed, where the PI will partner with high school choir directors to provide classroom demonstrations relating voice and singing to science.

1511761(Erath)该提案的目标是通过实验和数值研究流体绕过柔性梁时的流体结构相互作用。这是气流通过声带的代表性模型。该研究不仅关注代表健康声带的情况，而且主要关注声带不健康的情况。因此，拟议研究的结果可能会影响言语康复，并且大约 30% 的美国人口中的许多人都可以感受到，这些人估计在一生中的某个阶段患有嗓音疾病。该研究的主要目标拟议的研究旨在确定在柔性梁上平流的一系列涡流激发结构运动的机制，并以参数方式探索这一基本的流体-结构相互作用问题。 建议量化语音过程中产生的涡流如何影响正常和病态语音中的声带动态。目前，对于空气进入声带时的空气动力学载荷与组织的结构响应之间的相互作用尚不完全了解。这一缺陷将通过实验和理论/数值研究由穿过柔性梁的相干结构引起的涡旋梁相互作用来解决。假设是相干涡旋结构是由流动剪切层中的开尔文-亥姆霍兹不稳定性形成的。光束的激发将在一系列无量纲光束、流体和几何参数上进行研究。实验结果将验证涡流束相互作用的理论流动模型，然后将其用于扩展和探索超出实验设施限制的参数空间。该理论模型最终将应用于有声语音的数值模型，以量化涡旋-组织相互作用对发声结果的作用。涡流与可变形表面相互作用的基本问题也与使用可变形电活性装置从流体中获取能量的主题具有特定的相关性。除了研究生和本科生教育外，还提出了一项 K-12 推广计划，其中 PI 将与高中合唱团指挥合作，提供将声音和歌唱与科学相关的课堂演示。