Modifications To a Propagation Model for the Combinded Refraction-Diffraction of Stokes Waves; Shallow Water, Large Angle and Breaking Wave Effects

摘要

This report discusses several features of the combined refraction-diffraction model for Stokes waves (developed by Kirby, 1983) which limit its applicability in shallow water. Chapter 2 discusses a proposed dispersion relation for waves in arbitrary water depth, which provides a smooth patch between the lowest order Stokes dispersion relation and an approximate dispersion relation for shallow water, given originally by Hedges (1976). Chapter 3 extends the large-angle approximation of Kirby (1983) to the case of waves on currents, in order to allow for the calculation of waves which are refracted or diffracted to angles which deviate significantly from an initially preferred direction of propagation, due to the combined effect of varying depth and current. Finally, Chapter 4 provides some calculations of wave fields around surface-piercing islands, in order to illustrate the effect of wave breaking and the use of a thin-film approximation for dry areas in the model.