Splash, Vortices and Turbulent Shears in Partial Dam-Break Flows -- Splash Model of Wave-Breaking and Overtopping --

Abstract

Three-dimensional evolution of local fluid flows and surface shapes under partial collapse of a water column is characterized during computational experiments using three-dimensional large eddy simulation in this paper. The free-surface behaviors highly depend on the collapse level and ambient water layer depth via mechanical interactions between the surface and vortices. It has been found major three modes of the splashing responses of the free-surfaces and vortex structures; (i) forward projection of secondary jets, which organizes a typical rib-like vortex structure stretched underneath the jets, (ii) backward jet projection with an inverse form of the rib structure, and (iii) blob-like waves induced by an array of the horizontal roller vortices. These findings provide new perspectives to understand wave breaking behaviors as well as practical assessments for the fluid responses in the splashing area for sea wall overflow and overtopping.