Model for polygonal hydraulic jumps

Model for polygonal hydraulic jumps.

We propose a phenomenological model for the polygonal hydraulic jumps discovered by Ellegaard and co-workers [Nature (London) 392, 767 (1998); Nonlinearity 12, 1 (1999); Physica B 228, 1 (1996)], based on the known flow structure for the type-II hydraulic jumps with a "roller" (separation eddy) near the free surface in the jump region. The model consists of mass conservation and radial force ba...

Depth-averaged model for hydraulic jumps on an inclined plate.

We examine the dynamics of a layer of viscous liquid on an inclined plate. If the layer's upstream depth h(-) exceeds the downstream depth h(+), a smooth hydraulic jump (bore) forms and starts propagating down the slope. If the ratio η = h(+)/h(-) is sufficiently small and/or the plate's inclination angle is sufficiently large, the bore overturns and no smooth steadily propagating solution exis...

Thin-film fluid flows over microdecorated surfaces: observation of polygonal hydraulic jumps.

Liquid films flowing over rough substrates are influenced by asperities whose sizes are comparable to the film thickness. We investigate flows driven by jet impact on a regular array of micron-size posts. We show that the topography modifies the size and the shape of the observed hydraulic jumps: in addition to circular jumps, we obtain a variety of stable polygonal shapes. We rationalize our r...

Two-dimensional bubble clustering in hydraulic jumps

Hydraulic jumps: turbulence and air bubble entrainment

-A free-surface flow can change from a supercritical to subcritical flow with a strong dissipative phenomenon called a hydraulic jump. Herein the progress and development in turbulent hydraulic jumps are reviewed with a focus on hydraulic jumps operating at large Reynolds numbers typically encountered in natural streams and hydraulic structures. The key features of the turbulent hydraulic jumps...