ASA 124th Meeting New Orleans 1992 October

3pSP10. Numerical simulation of unsteady flow in the glottal constriction with moving boundaries.

Fariborz Alipour

Voice Acoust. and Biomech. Lab., Dept. of Speech Pathol. and Audiol., Univ. of Iowa, Iowa City, IA 52242

Jun Ni

University of Iowa, Iowa City, IA

The unsteady airflow in the larynx with moving boundaries was visualized using numerical simulation. By employing the method of computational fluid dynamics (CFD), a two-dimensional model of laminar flow in the glottal constriction was built considering the changes in the wall geometry with time at a given frequency. The glottal wall was approximated with two sinusoidal curves (one for inferior opening and one for superior opening) connected with a straight line. The height of the superior opening was changed as a sinusoidal function of time to generate the desired glottal wall movements. The Navier--Stokes equations with pressure boundary conditions was solved iteratively with the Phoenix CFD code. A shadow method with fixed grid points was used to avoid the complexities of the moving grids. Results were reported on the velocity pattern and pressure distributions at various time steps and also time variations of pressure and velocity at certain points were studied. The study provides a basis for further investigation of pulsatile flow in the larynx. [Work supported by NIDCD Grant No. DC00831-01A2.]