[Boundary-layer damping of traveling waves in a three-dimensional passive finite-element model of the human cochlea]

Abstract

A passive three-dimensional model of the human cochlea is described and analysed in the present article. One of its features is the implementation of a thermo-viscous boundary layer as a physically approved mechanism of mechanical damping. The model is solved numerically with the finite element method in ANSYS® and the simulation results are analysed with the help of MATLAB®. In this way curves of the basilar membrane's amplitude, phase and velocity for frequencies between 1000Hz and 8000Hz are calculated. A traveling wave develops on the basilar membrane and is damped after reaching its frequency-dependent maximum due to the boundary layer damping. A plot of the frequency-to-space transformation can be obtained which fits to the experimental data found in the literature. Furthermore, the study shows an energy analysis of the simulation verifying the boundary layer damping as a relevant physical effect for 3D-models of the cochlea.

Keywords: Boundary-layer damping; Cochlea; Frequency-to-space transformation; Frequenz-Orts-Transformation; Greenwood-Funktion; Greenwood-function; Grenzschichtdämpfung; Traveling wave; Wanderwelle.