Large-Eddy Simulation of Internal Flow through Human Vocal Folds

Abstract

Abstract. The phonatory process occurs when air is expelled from the lungs through the glottis and the pressure drop causes flow-induced oscillations of the vocal folds. The flow fields created in phonation are highly unsteady and the coherent vortex structures are also generated. For accuracy it is essential to compute on humanlike computational domain and appropriate mathematical model. The work deals with numerical simulation of air flow within the space between plicae vocales and plicae vestibulares. In addition to the dynamic width of the rima glottidis, where the sound is generated, there are lateral ventriculus laryngis and sacculus laryngis included in the computational domain as well. The paper presents the results from OpenFOAM which are obtained with a large-eddy simulation using second-order finite volume discretization of incompressible Navier-Stokes equations. Large-eddy simulations with different subgrid scale models are executed on structured mesh. In these cases are used only the subgrid scale models which model turbulence via turbulent viscosity and Boussinesq approximation in subglottal and supraglottal area in larynx.

Large-Eddy Simulation of Flow Through Human Larynx With a Turbulence Grid at Inlet

“…The second order CDS is non-dissipative and conservative, which is essential for LES. Upwind-based schemes are not used in LES, because of the production of high numerical dissipation [9]. For the spatial discretization of the convective term, a total variation diminishing scheme (TVD) is used.…”