Collaborative Research: Three-Dimensional Flow-Structure Interaction During Phonation

1066962/1067286Luo/DoyleVoice的产生是喉部流动-结构相互作用过程的结果，在此过程中，声门气流导致声带组织每秒振动超过100次。本研究的目的是开发一种准确而有效的数值方法来模拟流致声带振动，并量化声门流动和声带动力学的三维特征。该数值方法将基于具有复杂/移动边界的不可压缩流动的浸没边界方法和能够表示软材料大变形的非线性有限元方法。我们将采用理想的喉部几何学来简化问题，并捕捉生物物理学的关键要素。包括分层组织结构、超弹性组织行为、大组织应变和声带冲击在内的几个重要因素将被结合在一起来产生逼真的模型。声门流动和声带振动都是高度三维的，它们有趣的特征在很大程度上决定了一个人的声音的独特特征(例如，女高音或男高音)。这项拟议的研究将揭示导致喉部动力学显著变化的潜在机制。具体地说，将研究流动中的涡旋结构、声带的振荡模式以及声带表面的冲击应力，并将喉部几何形状和组织的材料特性的影响量化。这项研究得出的结论将为发声的生物物理学提供更清晰的理解，并将为未来开发更先进的模型提供重要的指导方针，这些模型适用于语音障碍的临床治疗。此外，数值模拟中产生的流场数据可以直接用于喉部发声的声学分析。为了丰富研究生和本科生的教育，将创建一门包含多物理建模的计算课程，该课程将讨论流体、热学、结构和电学的相互作用。将开发交互式在线学习模块，以接触到K-12学生，让他们学习流体动力学的有趣应用。

1066962/1067286Luo/DoyleVoice production is a result of the flow-structure interaction process in the larynx during which the glottal airflow causes the vocal fold tissue to vibrate more than 100 times per second. The objective of this research is to develop an accurate and yet efficient numerical approach to model the flow-induced vocal fold vibration and quantify the three-dimensional characteristics of the glottal flow and vocal fold dynamics. The numerical method will be based on an immersed-boundary method for incompressible flows with complex/moving boundaries and a nonlinear finite-element method capable of representing large deformations of soft materials. Idealized geometry of the larynx will be adopted to simply the problem and to capture the key elements of the biophysics. Several important factors including the layered tissue structure, hyperelastic tissue behavior, large tissue strains, and vocal fold impact, will be incorporated to produce a realistic model. Both the glottal flow and vocal fold vibration are highly three-dimensional, and their intriguing characteristics largely determine the unique features of an individual's voice (e.g., a soprano or tenor). The proposed research will reveal the underlying mechanisms that lead to the significant variations in the laryngeal dynamics. Specifically, the vortical structures in the flow, the oscillation mode of the vocal folds, and the impact stress on the vocal fold surface will be studied, and the effects of the laryngeal geometry and material properties of the tissue will be quantified. The conclusion drawn from the research will provide a much clearer understanding of the biophysics of phonation and will generate important guidelines for the future development of more advanced models useful in the clinical treatment of voice disorders. In addition, the flow field data produced in the numerical simulations can be used directly in the acoustic analysis of sound production in the larynx. To enrich the education of graduate and undergraduate students, a computational course incorporating multiphysics modeling will be created, which will address the interaction of fluids, thermal, structures, and electricity. Interactive online learning modules will be developed to reach out to K-12 students for them to learn interesting applications of fluid dynamics.