Rigorous formulation of an open-boundary condition in green-function analysis of a wave field

The Green-function method provides a powerful tool for analyzing diffraction and multiple reflection of waves. In treating a basin with complicated configuration, however, the accuracy of wave field analysis has been often reduced because of irrational open-boundary conditions introduced. This paper presents the most rigorous formulation of continuation conditions for an open-boundary. Validity and use fulness of the revised method are demonstrated through computation of wave diffraction behind a breakwater gap.