Characteristics of hydraulic jumps over rough beds – an experimental study

An experimental study of wave and current interaction over ripples is presented in this paper. The campaign was carried out at the shallow water tank at the Danish Hydraulic Institute (DHI, Denmark), in the framework of the TA WINGS (Waves plus currents INteracting at a right anGle over rough bedS), funded by the European Union (EU) through the Hydralab+ program. Mean velocity profiles, measured with acoustic Doppler velocimeters for different flow conditions including current only, wave only and wave plus current were recorded and allowed to recover flow and vorticity fields. Recirculating cells in both wave only and wave plus current conditions form but they flatten when the current superposes over the wave. It was found that the superposition of current reduces the undertow present in the case of only waves and leads to an increase of vorticity outside the boundary layer. Instead, inside the boundary layer, the vorticity is dumped by the effect of current.

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An experimental study of air–water flows in hydraulic jumps on flat slopes

Journal of Hydraulic Research ◽

10.1080/00221686.2019.1671512 ◽

2019 ◽

Vol 58 (5) ◽

pp. 767-777 ◽

Cited By ~ 1

Author(s):

Laura Montano ◽

Stefan Felder

Keyword(s):

Experimental Study ◽

Hydraulic Jumps ◽

Water Flows

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Effect of roughness on sequent depth in hydraulic jumps over rough bed

Journal of the Croatian Association of Civil Engineers ◽

10.14256/jce.2017.2017 ◽

2019 ◽

Vol 71 (2) ◽

pp. 105-111

Author(s):

Arpan Arunrao Deshmukh ◽

Naveen Sudharsan ◽

Avinash D Vasudeo ◽

Aniruddha Dattatraya Ghare

Keyword(s):

Energy Dissipation ◽

Kinetic Energy ◽

Hydraulic Jump ◽

Open Channel ◽

Hydraulic Jumps ◽

Open Channel Flows ◽

Downstream Side ◽

Rough Bed ◽

Sequent Depth ◽

Rough Beds

Hydraulic jump is an important phenomenon in open channel flows such as rivers and spillways. Hydraulic jump is mainly used for kinetic energy dissipation at the downstream side of a spillway with the assist of baffle blocks. It has been demonstrated that corrugated or rough beds show considerably more energy dissipation than smooth beds. The experimental research evaluating the effect of crushed stones on the hydraulic jump is presented in this paper. Five different-size sets of crushed stones were used. Results show that the effect of rough bed does not increase after a certain height of crushed stone is reached.

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An experimental study of turbulent two-phase flow in hydraulic jumps and application of a triple decomposition technique

Experiments in Fluids ◽

10.1007/s00348-014-1775-8 ◽

2014 ◽

Vol 55 (7) ◽

Cited By ~ 22

Author(s):

Hang Wang ◽

Stefan Felder ◽

Hubert Chanson

Keyword(s):

Experimental Study ◽

Two Phase Flow ◽

Phase Flow ◽

Hydraulic Jumps ◽

Decomposition Technique ◽

Two Phase ◽

Turbulent Two Phase Flow

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Velocity Distribution and Attenuation Characteristic in Hydraulic Jumps on Rough Beds

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2019-0536 ◽

2021 ◽

Author(s):

Lei Wang ◽

Ming-jun Diao

Keyword(s):

Velocity Distribution ◽

Hydraulic Jump ◽

Maximum Velocity ◽

Hydraulic Jumps ◽

Attenuation Characteristic ◽

Jump Length ◽

Attenuation Rate ◽

Rough Bed ◽

Velocity Attenuation ◽

Rough Beds

This study was conducted to investigate the velocity distribution and attenuation in free jumps on rough beds. Based on the length scale of jump length Lj, the velocity distribution of the free jump on a rough bed can be divided into four parts by three typical sections where are in the position of x=0.4Lj, x=0.8Lj, and x=1.2Lj. It seems that the velocity distribution near section x=0.4Lj is the most uneven. The velocity attenuation rate in the bottom half of the water is larger than that in the top half of the water. The attenuation of the maximum velocity um is mainly done from x=0 to x=0.8Lj. The results show the mixed triangular corrugated floor increases the resistance of hydraulic jump development and is very efficient in energy dissipation.

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EXPERIMENTAL STUDY ON THE SIDE CHANNEL SPILLWAY AND ITS IMPACT ON THE JUMP, CROSS FLOW AND ENERGY DISSIPATION

Jurnal Teknologi ◽

10.11113/jt.v81.13811 ◽

2019 ◽

Vol 81 (6) ◽

Author(s):

Djoko Legono ◽

Roby Hambali ◽

Denik Sri Krisnayanti

Keyword(s):

Experimental Study ◽

Energy Dissipation ◽

Water Surface ◽

Cross Flow ◽

Side Channel ◽

Hydraulic Jumps ◽

Stilling Basin ◽

Energy Dissipater ◽

Design Discharge ◽

The Cross

The utilization of the side channel spillway as the primary component of dam is generally due to the limitation of the available space to construct conventional spillway with design discharge capacity. Some impacts may only be identified through the hydraulic physical model study; these include the presence of the chaotic jumps at the downstream of the spillway crest, the cross flow on the steep channel, as well as the performance of the energy dissipation in the stilling basin. This paper presents the result of the experimental study of three-dimensional behaviour of flow over the entire components of the side channel spillway of Bener Dam, Indonesia. The main dam and its appurtenant components, i.e., the reservoir, the spillway crest, the spillway channel, and the energy dissipaters were built, and various discharges were introduced to study the hydraulic performance of the spillway crest, the stilling basin, the chute, and the energy dissipater. The observed data were collected and then analysed. The results show that firstly, some chaotic hydraulic jumps were found at the stilling basin at downstream spillway crest. These chaotic hydraulic jumps would produce significant vibration that may endanger the nearby structures. Secondly, the presence of the cross flow along the steep channel downstream of the stilling basin may also need to be eliminated in such that its impact on the rise of water surface level does not create any objection. This may be carried out through the installation of baffles along the spillway channel bed. Thirdly, the presence of the hydraulic jumps at the energy dissipater basin under the design discharge has proven that the energy dissipater has performed well where local scour around the downstream structure was found to be not significant. However, to anticipate the raising of the water surface elevation at the energy dissipater basin, increasing the elevation of energy dissipater wall from +212.50 m to +215.00 m is highly recommended.

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