Noise radiation of a disc surrounded by air using mboct-fem-pkg and Gmsh

The data for this case was taken from the following paper: M. Maeder, R. D'Auria, E. Grasso, G. Petrone b, S. De Rosa, M. Klaerner, L. Kroll, S. Marburg
Numerical analysis of sound radiation from rotating discs
Journal of Sound and Vibration 468 (2020) 115085
mboct-fem-pkg ([github.com/oct...]) is used as a solver and Gmsh ([gmsh.info]) is used for pre- and post processing. Perfectly matched layers are used to implement non reflecting boundary conditions.