Free Surface Length Scale Estimation in Hydraulic Jumps

Two-Phase Flow Properties and Free-Surface Deformations in Hydraulic Jumps

In an open channel, a hydraulic jump is a sudden transition from a high-velocity to slower, fluvial flow motion. The impinging flow forms a turbulent roller with a highly fluctuating free-surface, while a large amount of air bubbles is entrapped at the jump toe. The present work presents some physical investigations of hydraulic jumps based upon a wide range of inflow Froude numbers (3.8 < Fr1 ...

Averaging theory for the structure of hydraulic jumps and separation in laminar free-surface flows

We present a simple viscous theory of free-surface flows in boundary layers, which can accommodate regions of separated flow. In particular this yields the structure of stationary hydraulic jumps, both in their circular and linear versions, as well as structures moving with a constant speed. Finally we show how the fundamental hydraulic concepts of subcritical and supercritical flow, originatin...

Air Entrainment and Turbulence in Hydraulic Jumps: Free- Surface Fluctuations and Integral Turbulent Scales

An open channel flow can change from a supercritical to subcritical flow with a strong dissipative process: a hydraulic jump. Herein some new measurements of free-surface fluctuations next to the jump toe and integral turbulent scales in the roller are presented with a focus on turbulent hydraulic jumps with a marked roller. The results highlighted the fluctuating nature of the impingement peri...

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...

Two-dimensional bubble clustering in hydraulic jumps