FIV2018 Paper Management System, FIV2018 Conference

Font Size: 
Modeling of glottis closure during vocal folds self-oscillation
Petr Sváček, Jaromír Horáček

Last modified: 2018-04-19

Abstract


Numerical simulation of self-oscillations of the vocal folds in the glottal channel by finite element (FE) method brings a problem how to correctly model the glottis closure when the airflow in the channel periodically stops during the vocal folds impacts. The problem is not only associated with a possible destruction of the FE mesh of the fluid flow domain in the very narrow glottal gap before vocal folds contact, but also with the resulting airflow velocity and pressure waveforms at the channel inlet and outlet, where due to unsuitably prescribed inlet and outlet boundary conditions these waveforms can be unrealistic.

The contribution presents the mathematical model and numerical simulation of interaction of the vibrating human vocal folds model with the incompressible viscous airflow in a channel modeling the vocal folds self-sustained vibrations. The flow is governed by the 2D Navier–Stokes equations written in the Arbitrary Lagrangian–Eulerian form. The stabilized FE method is applied for numerical approximation of the flow and modified inlet boundary condition motivated by the penalization approach is implemented. The three-mass lumped model of the vocal folds vibration is used and the Hertz impact theory is applied for treating the vocal folds contact.

Newly developed modification of the boundary condition is used at the inlet containing a penalty parameter. It enables to treat the complete periodic closures of the channel. In this way more realistic numerically simulated time signals of pressure and airflow velocity at the channel inlet and outlet can be obtained.


Keywords


Numerical simulation, computational fluid dynamics, FEM

Full Text: PDF