P. Mciver et M. Mciver, TRAPPED MODES IN AN AXISYMMETRICAL WATER-WAVE PROBLEM, Quarterly Journal of Mechanics and Applied Mathematics, 50, 1997, pp. 165-178
Trapped-mode solutions, that is, examples of non-uniqueness, are given
for a class of axisymmetric problems in the linearized theory of the
interaction of water waves with structures. The solutions are construc
ted by placing an axisymmetric ring source in the free surface with th
e radius of the ring chosen to eliminate radial circular waves. The ri
ng-source potential then corresponds to a localized standing wave. Sui
table structural surfaces are obtained by looking for stream surfaces
of the flow.