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

声音的产生是喉内流-结构相互作用过程的结果，在这个过程中，声门气流使声带组织每秒振动100次以上。本研究的目的是建立一种准确而有效的数值方法来模拟流动引起的声带振动，并量化声门流动和声带动力学的三维特征。数值方法将基于具有复杂/移动边界的不可压缩流的浸入边界法和能够表示软材料大变形的非线性有限元法。喉部的理想几何形状将被采用来简化问题并捕捉生物物理学的关键要素。几个重要的因素，包括分层组织结构，超弹性组织行为，大组织应变，声带冲击，将纳入产生一个现实的模型。声门流动和声带振动都是高度三维的，它们的有趣特征在很大程度上决定了个人声音的独特特征（例如，女高音或男高音）。提出的研究将揭示导致喉动力学显著变化的潜在机制。具体来说，我们将研究气流中的涡旋结构、声带的振荡模式和声带表面的冲击应力，并量化喉部几何形状和组织材料特性的影响。从研究中得出的结论将对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，这些模型对临床治疗声音障碍有用。此外，数值模拟产生的流场数据可以直接用于喉部发声的声学分析。为了丰富对研究生和本科生的教育，我们将开设一门结合多物理场建模的计算课程，该课程将讨论流体、热、结构和电的相互作用。将开发互动式在线学习模块，以接触到K-12学生，让他们学习有趣的流体动力学应用。

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 individuals 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.