LES of Human Vocal Tract Model Flow
Computational aeroacoustics studies of flow through the human vocal tract, here modeled as a planar channel with an orifice, hence referred to as the glottis, are conducted using large eddy simulation (LES). Comparisons between LES predictions and experimental wall pressure measurements and particle-imaging-velocimetry flow fields will be presented. The compressible Navier-Stokes equations are accurately and efficiently integrated for the low Mach number flow through the use of an additive semi-implicit Runge-Kutta method and high-order compact finite-difference schemes for spatial discretization. Characteristic-based non-reflecting boundary conditions are used together with an exit zone in the context of a multi-block approach. An acoustic analogy based on the Ffowcs Williams-Hawkings equation will be applied to decompose the near-field acoustic source into its monopole, dipole, and quadrupole contributions to assess glottal geometry effects on far-field sound.
- Grid used for human vocal tract model flow; color shows computational blocks in multi-block
simulation.
- Instantaneous vortical structure near the glottis of human vocal tract model indentified by second invariant Q=0.05; colored by streamwise velocity.
- Snapshot of streamwise velocity showing turbulent transition
and Coanda Effect
- Instantaneous dilatation
