Finite element method application for the impedance eduction problem in case of “Interferometer with the flow” installations

This paper deal with investigations of the Finite Element Method (FEM) application to sound propagation in "Interferometer with Flow" installations type in order to solve the problem of impedance eduction taking into account the inhomogeneity of the flow for the two-dimensional and three-dimensional geometries of the installation duct. The propagation of sound in a duct in the presence of a plane-parallel airflow is described by means of Linearized Euler equation, which is solved by FEM for a given sound frequency. Presented experimental and calculation results comparison demonstrates the influence of the calculated channel geometry on both the distribution of the sound field and the extracted impedance values.