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

1511761（Erath）本提案的目的是通过实验和数值方法研究流体绕柔性梁流动时的流体结构相互作用。这是气流通过声带的代表性模型。这项研究将不仅关注代表健康声带的条件，而且主要关注声带不健康的情况。因此，拟议研究的结果可以影响语音康复，并且可以被美国大约30%的人口中的许多人所感受到，这些人估计在他们生命中的某个时候患有声音病理学。拟议研究的主要目标是确定柔性梁上的一列涡流平流煽动结构中的运动的机制，参数化地探索这个基本的流体-结构相互作用问题。 建议量化如何在语音过程中产生的涡流影响声带动力学在正常的，以及病理性的讲话。目前，对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的理解还不完全。这一不足将通过实验和理论/数值研究涡流梁的相互作用，所产生的相干结构通过一个灵活的梁。假设相干涡结构是由剪切层中的Kelvin-Helmholtz不稳定性形成的。梁的激发将在一个范围内的无量纲梁，流体和几何参数进行研究。实验结果将验证涡束相互作用的理论流动模型，然后将用于扩展和探索超出实验设备的限制的参数空间。该理论模型最终将应用于有声语音的数值模型，以量化涡流组织相互作用对发声结果的作用。与可变形表面相互作用的涡流的基本问题也与使用可变形电活性装置从流体中收获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外展计划，PI将与高中合唱团总监合作，提供与声音和歌唱有关的课堂演示。

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.