Characteristics of breaking vorticity in spilling and plunging waves investigated numerically by SPH

The present paper, places emphasis on the vorticity induced by wave breaking, which greatly contributes to sediments pick up and suspension as well as to air–water exchange at the wave interface, thus deserving a thorough study. A weakly-compressible smoothed particle (WCSPH) model, coupled with a two-equation model for turbulent stresses, has been employed for this scope. A careful calibration of the SPH’s numerical parameters has been first performed, based on experiments carried out in a sloped wave channel, specifically using wave elevation and velocity data. Once proved the reliable performance of the model, the characteristics of vorticity induced just prior and post breaking for both the cases of a spilling and a plunging wave have been numerically studied. The main and detailed results indicate that for both the types of breakers there is a cause-effect relation observed between the stream wise flow deceleration and the vorticity generation.