Simulation of unsteady compressible flow in a channel with vibrating walls Influence of the frequency
This study deals with the numerical solution of a 20 unsteady flow of a compressible viscous fluid in a channel for low inlet airflow velocity. The unsteadiness of the flow is caused by a prescribed periodic motion of a part of the channel wall with large amplitudes, nearly closing the channel during oscillations. The channel is a simplified model of the glottal space in the human vocal tract and the flow can represent a model of airflow coming from the trachea, through the glottal region with periodically vibrating vocal folds to the human vocal tract. The flow is described by the system of Navier-Stokes equations for laminar flows. The numerical solution is implemented using the finite volume method (FVM) and the predictor-corrector MacCormack scheme with Jameson artificial viscosity using a grid of quadrilateral cells. Due to the motion of the grid, the basic system of conservation laws is considered in the Arbitrary Lagrangian-Eulerian (ALE) form. The authors present the numerical simulations of flow fields in the channel, acquired from a program developed exclusively for this purpose. The numerical results for unsteady flows in the channel are presented for inlet Mach number M-infinity = 0.012, Reynolds number Re-infinity = 4.5 x 10(3) and the wall motion frequency 20 and 100 Hz. (C) 2010 Elsevier Ltd. All rights reserved.
unsteady flow finite volume method cfd low mach number viscous compressible fluid