Three-dimensional reversed horseshoe vortex structures under broken solitary waves

• Published in: Coastal engineering (Amsterdam) 2014-09, Vol.91, p.261-279
• Main Authors: Farahani, Rozita J., Dalrymple, Robert A.
• Format: Article
• Language: English
• Subjects: Computational fluid dynamics; Earth, ocean, space; Evolution; Exact sciences and technology; External geophysics; Fluid flow; Mathematical models; Obliquely descending eddies; Physics of the oceans; Reversed horseshoe vortices; Smoothed particle hydrodynamics method; Solitary wave; Surface waves, tides and sea level. Seiches; Three dimensional; Turbulence; Turbulent flow; Vortices
• ISSN: 0378-3839; 1872-7379
• DOI: 10.1016/j.coastaleng.2014.06.006

Turbulent vortical structures under broken solitary waves are studied using three-dimensional smoothed particle hydrodynamics (SPH) method. The numerical model predicts water surface evolution and horizontal velocity very well in comparison with the experimental results. The numerical results detect organized coherent structures characterized as reversed horseshoe (hairpin) vortices being generated at the back of the broken spilling wave and traveling downward. The counter rotating legs of the reversed horseshoe structures appear to be a continuous form of the previously found obliquely descending eddies. The reversed horseshoe structures are associated with the turbulence motion of sweep events (downwelling motion) and transport momentum and turbulent kinetic energy downward into the water column. Vortex turning play an important role on the generation and evolution of three dimensional reversed horseshoe structures from the spanwise breaking wave rollers. •We numerically modeled a solitary wave for both spilling and plunging.•We studied turbulent vortex structures generated under the broken solitary wave.•Reversed horseshoe vortices are detected at the back of the broken spilling wave.•We studied obliquely descending eddies and their generation mechanism.