The Spectacular Undular Bore in Iowa on 2 October 2007

Unsteady Turbulence Characteristics in an Undular Bore

When a river mouth has a flat converging shape with a tidal range exceeding 6 to 9 m, the river may experience a tidal bore. A tidal bore is a positive surge, and the aim of the study is to detail the turbulent field beneath an undular bore. New unsteady experiments were conducted in a large channel. Turbulence measurements were performed with high-temporal resolution using side-looking acousti...

A bound on oscillations in an unsteady undular bore

The tidal bore is a well-known phenomenon in fluid mechanics, having been observed in many rivers around the world. Two of the better known rivers where bores regularly appear are the Severn River in England [1] and the Qiantang River in China [2]. The usual circumstances in which a bore can appear develop when a tidal swell causes a difference in surface elevation in the mouth of a river or fu...

Cover Vol.4 No.2, October 2007

Undular tidal bore dynamics in the Daly Estuary, Northern Australia

Measurements in the macro-tidal Daly Estuary show that the presence of an undular tidal bore contributed negligibly to the dissipation of tidal energy. No recirculation bubble was observed between a trough and the following wave crest in the lee waves following the undular bore. This differs to stationary undular bores in laboratory experiments at larger Froude numbers where a recirculation bub...

Undular bore solution of the Camassa-Holm equation.

Modulation theory is developed for a periodic peakon solution of the Camassa-Holm equation. An explicit simple wave solution of these modulation equations is then derived; this simple wave describing the evolution into an undular bore of an initial step. The characteristic on which the expansion fan occurs (propagating at a nonlinear group velocity) has a turning point, illustrating the fact th...