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Eigenmodes of triaxial ellipsoidal acoustical cavities with mixed boundary conditions
M Willatzen1, L C Lew Yan Voon
1Mads Clausen Institute for Product Innovation, University of Southern Denmark, Grundtvigs Alle 150, DK-6400 Sønderborg, Denmark. willatzen@mci.sdu.dk
Abstract:
The linear acoustics problem of resonant vibrational modes in a triaxial ellipsoidal acoustic cavity with walls of arbitrary acoustic impedance has been quasi-analytically solved using the Frobenius power-series expansion method. Eigenmode results are presented for the lowest two eigenmodes in cases with pressure-release, rigid-wall, and lossy-wall boundary conditions. A mode crossing is obtained as a function of the specific acoustic impedance of the wall; the degeneracy is not symmetry related. Furthermore, the damping of the wave is found to be maximal near the crossing.
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