Numerical simulation of irregular wave transformation due to wave-induced current

In order to investigate the effects of wave breaking-induced currents on the transformation of irregular waves over a shoal, two numerical model systems, a combination of SWAN plus SHORECIRC and a combination of REF/DIF S plus SHORECIRC, were constructed. The experimental results of irregular breaking waves conducted by Vincent and Briggs [1989, Refraction–diffraction of irregular waves over a mound. J. Waterway Port Coast. Ocean Eng. 115(2), 269-284.] were simulated using these two wave and current model combinations. Even though the two model combinations show a slight disagreement on the wave transformations, the numerical results indicate that it is necessary to take into account the effect of the breaking-induced currents when the waves are breaking over a shoal: The computed results agree much better with the experimental measurements than the simulation results obtained by neglecting the wave-current interaction.