| Summary:
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Human phonation process represents an interesting and complex problem of fluid-structure-acoustic interaction, where the deformation of the vocal folds (elastic body) are interplaying with the fluid flow (air stream) and the acoustics. Due to its high complexity, two simplified mathematical models are described - the fluid-structure interaction (FSI) problem describing the self-induced vibrations of the vocal folds, and the fluid-structure-acoustic interaction (FSAI) problem, which also involves aeroacoustic phenomena. The FSI model is based on the incompressible Navier-Stokes equations in the ALE formulation coupled with the linear elasticity model. Both the fluid and structural models are approximated using finite element methods, and the influence of different inlet boundary conditions is discussed in detail. For the FSAI model, an aeroacoustic hybrid approach is used, incorporating the Lighthill analogy or the perturbed convective wave equation. The acoustic results strongly depend on the proper choice of the computational acoustic domain (i.e. vocal tract model). Further, the spatial and frequency distributions of sound sources computed from the FSI solution are compared for both used approaches. The final frequency spectra of acoustic pressure at the mouth position are also analyzed for both approaches. (English) |
