The finite element method in acoustics

From the variational field equations for problems in acoustics one can derive the finite element approach to their solution. From this approach the application of a standard finite element method (FEM) program to a problem in room acoustics was performed. The role of the acoustic variables, the material constants, boundary conditions, etc., as required for the FEM program was examined. The need for complex arithmetic in the analysis of a nonconservative system and in the modeling of real sources was shown. The FEM eigenvectors and eigenvalues were then used to assemble the Green's function in the form of a data base. This Green's function was then to be used to examine the acoustic behavior of the room at low frequencies, i.e., below the Schroeder frequency.