In an open channel, a hydraulic jump is the rapid transition from superto sub-critical flow associated with strong turbulence and air bubble entrainment in the mixing layer. New experiments were performed at relatively large Reynolds numbers using phase-detection probes. Some new signal analysis provided characteristic air–water time and length scales of the vortical structures advecting the ai...

Email alerting service here click or sign up in the box at the top right-hand corner of the article Receive free email alerts when new articles cite this article-An experimental study of the circular hydraulic jump (CHJ) was carried out to show how reducing gravity to 10 ¡ 2 times that of the Earth's normal gravity a¬ects the CHJ diameter and the downstream ®ow patterns. Water was the working ®...

The specific force equation has many applications in open channel flow problems. Quantifying of the hydraulic jump phenomenon is an important application of this equation. This equation has a direct solution only for the rectangular channels. The trial and error procedure as well as the graphical solution are the existing methods of solving hydraulic jump equations. No direct solutions are avai...

Both RaNS (Reynolds-averaged Navier-Stokes) and DES (Detached Eddy Simulation) type turbulence models were used in conjunction with a two-fluid model of bubbly flow and a new subgrid air entrainment model to predict air entrainment and transport in a hydraulic jump. It was found that the void fraction profiles predicted by both methods are in agreement with the experimental data in the lower sh...

Truncated sharp crested weirs are used to measure flow rate and control upstream water surface in irrigation canals and laboratory flumes. The main advantages of such weirs are ease of construction and capability of measuring a wide range of flows with sufficient accuracy. Artificial neural networks (ANNs) and genetic programming (GP) have recently been used for estimation of hydraulic data. In...

scour around hydraulic structures is an inevitable phenomenon . recognition of this phenomenon and dealing with it is an issue considering which will ensure the project success . local scour at piers has been reported as the most important factor in the destruction of the bridges . the use of submerged and non-submerged piles is one of the scour control methods . submerged piles have been rarel...

We report the results of a theoretical investigation of the stability of a toroidal vortex bound by an interface. Two distinct instability mechanisms are identified that rely on, respectively, surface tension and fluid inertia, either of which may prompt the transformation from a circular to a polygonal torus. Our results are discussed in the context of three experiments, a toroidal vortex ring...

The formation of orographic wakes and vortices is studied within the context of numerically simulated viscous flow with uniform basic-state wind and stability past elongated free-slip ridges. The viscosity and thermal diffusivity are sufficiently large that the onset of small-scale turbulence is suppressed. It is found in Part I of this study that wake formation in the viscous flow is closely t...