Computation of the Eigenfrequencies of Acoustic Cavities: A New Penalty Method

A new penalty method for determining the natural frequencies and normal modes of acoustic cavities is presented. The acoustic medium is described in terms of the displacement field. A new easy-to-implement penalty function method is employed to enforce the irrotationality condition. This new method has significant advantages when compared to classical penalty function methods since it is more stable with respect to the penalty parameter.