Flow separation in a forced oscillation glottal model

Abstract

Flow separation was investigated in pulsatile flow within a computational fluid dynamics (CFD) model of glottis motion. Two-dimensional time-dependent laminar flow was calculated for given dynamic wall geometries and flow boundary conditions. A Lagrangian–Eulerian method with a multiblock mesh was employed to allow grid points to move in space to conform to the boundaries. The glottal wall was approximated with two sinusoidal curves (one for the glottal entrance and one for glottal exit) connected with a straight line. The entrance and exit glottal diameters were changed as a sinusoidal function of time with a phase difference to generate the desired glottal wall movements. Results will be reported on the mean velocity and pressure distributions for various phase angles, frequencies, oscillation amplitudes, and Reynolds numbers. The locations of the flow separation points were obtained through a shear stress analysis using MATLAB. An increase in the glottal amplitude causes the separation points to move upstream. The study provides a better understanding of the effect of inferior–superior phase differences on the glottal flow. [Work supported by NIDCD Grant No. 1 R01 DC03566.]