Experimental Thermal and Fluid Science

In an estuary, a tidal bore may be generated at the leading edge of the flood tidal wave during the early flood tide under spring tide conditions into a narrow funnelled channel. For Froude numbers greater than 1.4–1.6, the leading edge of the bore is characterised by a breaking roller. The roller is characterised by a sudden increase in water depth, a highly turbulent flow with large-scale vortical structures, some kinetic energy dissipation, a two-phase air–water flow region and strong turbulence interactions. New experiments were conducted in a large canal with a focus on breaking bore roller propagation. The upstream propagation of the roller toe was highly turbulent. The toe perimeter shape fluctuated…