Scars and Vortices Induced by Ship Bow and Shoulder Wave Breaking

Experimental data are provided for physical understanding and computational fluid dy- namics (CFD) validation for the surface combatant David-Taylor model basin Model 5415 bow and shoulder wave breaking. A photographic study was conducted using 5.72 m replica and 3.05 m geosim models of Model 5415 over a range of Froude num- bers (Fr) to identify Fr and scale effects on wave breaking and choose the best Fr for the local flow measurements, which include near- and far-field means and rms wave eleva- tion and mean velocity under the breaking waves. The larger model and Fr=0.35 were selected due to the large extents of quasisteady plunging bow and spilling shoulder wave breaking. A direct correlation is shown between regions of wave slope larger than 17 deg and regions of large rms in wave height variation. Scars characterized by sudden changes in the mean wave height and vortices induced by wave breaking were identified. Complementary CFD solutions fill the gaps in the relatively sparse measurements en- abling a more complete description of the bow and shoulder wave breaking and induced vortices and scars. The combined results have important implications regarding the mod- eling of the bubbly flow around surface ships, especially for bubble sources and entrainment.