ACOUSTIC RADIATION FROM FINITE LENGTH CYLINDRICAL SHELLS USING BOUNDARY ELEMENT METHOD

摘要

The radiation efficiency of an acoustically thick circular cylindrical shell has been examined by calculations using the boundary element method for three different boundary conditions, and by conducting experiments using point excitation with the boundary conditions being free at both ends. Both the numerical and experimental results indicate that the radiation efficiency attains a value of unity at frequencies well below the critical frequency. Analysis has been made to explain the behaviour of acoustically thick shells.