Fully-coupled aeroelastic simulation with fluid compressibility — For application to vocal fold vibration

Abstract

In this study, a fully-coupled fluid–structure interaction model is developed for studying dynamic interactions between compressible fluid and aeroelastic structures. The technique is built based on the modified Immersed Finite Element Method (mIFEM), a robust numerical technique to simulate fluid–structure interactions that has capabilities to simulate high Reynolds number flows and handles large density disparities between the fluid and the solid. For accurate assessment of this intricate dynamic process between compressible fluid, such as air and aeroelastic structures, we included in the model the fluid compressibility in an isentropic process and a solid contact model. The accuracy of the compressible fluid solver is verified by examining acoustic wave propagations in a closed and an open duct, respectively. The fully-coupled fluid–structure interaction model is then used to simulate and analyze vocal folds vibrations using compressible air interacting with vocal folds that are represented as layered viscoelastic structures. Using physiological geometric and parametric setup, we are able to obtain a self-sustained vocal fold vibration with a constant inflow pressure. Parametric studies are also performed to study the effects of lung pressure and vocal fold tissue stiffness in vocal folds vibrations. All the case studies produce expected airflow behavior and a sustained vibration, which provide verification and confidence in our future studies of realistic acoustical studies of the phonation process.

Immersed Methods for Fluid–Structure Interaction

“…Immersed methods have also been used in other biological and biomedical modeling applications, including flows of cells and capsules (Eggleton & Popel 1998;Fogelson & Guy 2008;Le 2010;Pranay et al 2010Pranay et al , 2012Crowl & Fogelson 2011;Fai et al 2013Fai et al , 2017Zhu & Brandt 2015;Banaei et al 2017;Saadat et al 2018), cell migration and locomotion (Lewis et al 2015, Li et al 2017, insect flight (Miller & Peskin 2005Bergou et al 2007;Vargas et al 2008), and phonation (Luo et al 2008, Yang et al 2017.…”

Evaluation of aerodynamic characteristics of a coupled fluid-structure system using generalized Bernoulli's principle: An application to vocal folds vibration

“…The detailed algorithm, methodology, simulation setup and validation can be found in our previous work. (50) …”

An immersed transitional interface finite element method for fluid interacting with rigid/deformable solid

“…where σ s is the Cauchy stress tensor of the solid, ρ s is the density, v s is the velocity vector, f s is the body force vector, s is the constant in the Rayleigh damping model (Chowdhury & Dasgupta, 2003) that is used to describe the damping effect of the solid vibration in the FSI system (Yang, Wang, Krane, & Zhang, 2016). In small deformation, the Cauchy stress of the solid is expressed as…”