Specification of Modal Participation Factors in Acoustic Scattering Problems

Using the wet modes of a submerged structure as expansion functions, it is shown how the scattered far-field pressures induced by an incident harmonic wave may be modified in a prescribed manner. This is done by applying forces directly to the structural surface, which superposes a radiated pressure field on the scattered one. By appropriate choice of the applied nodal forces, modal participation factors associated with any combination of mode shapes may be controlled. The method is illustrated by a numerical example.