scholarly journals Retraction: Velocity distribution and attenuation characteristic in hydraulic jumps on rough beds (cjce-2019-0536)

2021 ◽  
pp. 1-1
Keyword(s):  
Velocity Distribution ◽  
Hydraulic Jumps ◽  
Attenuation Characteristic ◽  
Rough Beds

Velocity Distribution and Attenuation Characteristic in Hydraulic Jumps on Rough Beds

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.

scholarly journals Numerical Simulation of Hydraulic Jump over Rough Beds

2020 ◽  
Author(s):  
Saman Nikmehr ◽  
Younes Aminpour
Keyword(s):  
Numerical Model ◽  
Velocity Distribution ◽  
Hydraulic Jump ◽  
Surface Profile ◽  
Jump Length ◽  
Rough Bed ◽  
Sequent Depth ◽  
Rough Beds ◽  
Different Characteristics ◽  
Good Agreement

In this study, the hydraulic jumps over rough beds are numerically simulated. In order to calibrate the numerical model, the experimental data were used, which performed in a rectangular flume in various roughness arrangements and different Froude numbers. The effect of the distance (s) and the height (t) of the roughness on different characteristics of the hydraulic jump, including the sequent depth ratio, water surface profile, jump’s length, roller’s length, and velocity distribution were evaluated and compared. The results showed that the numerical model is fairly well able to simulate the hydraulic jump characteristics. The results also showed that the height and distance of roughness slightly reduced the sequent depth ratios for all Froude numbers. Also, the hydraulic jump length is reduced at the presence of the rough bed. Velocity profiles in different experiments were similar and there was a good agreement between simulated and measured results. Also, increasing the distance and the height of the roughness will slow down the velocity near the bed, increase the shear stress, and increase the gradient of the velocity distribution near the bed.

Hydraulic Jumps on Rough Beds

2007 ◽  
Vol 133 (9) ◽  
pp. 989-999 ◽  
Author(s):  
Francesco Giuseppe Carollo ◽  
Vito Ferro ◽  
Vincenzo Pampalone
Keyword(s):  
Hydraulic Jumps ◽  
Rough Beds

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

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.

Analysis of the submerged radial hydraulic jump

1985 ◽  
Vol 12 (3) ◽  
pp. 593-602 ◽  
Author(s):  
Sameh M. Abdel-Gawad ◽  
John A. McCorquodale
Keyword(s):  
Velocity Distribution ◽  
Internal Flow ◽  
Operating Conditions ◽  
Surface Velocity ◽  
Velocity Variation ◽  
Experimental Program ◽  
Hydraulic Jumps ◽  
Jump Length ◽  
Depth Ratio ◽  
Sequent Depth

Most of the research work on hydraulic jumps has dealt with their macroscopic behaviour. The important parameters in these studies were the sequent depth ratio and the jump length required for stilling basin design. Unfortunately, the internal flow in submerged radial hydraulic jumps has received very little attention. A complete mathematical model of the internal flow would permit the modeller to assess the possible scale effects in a physical model and to better estimate the cavitation potential.This study treats the internal flow characteristics of the submerged radial hydraulic jumps under different submergence and operating conditions. A numerical model based on the strip integral method is used to solve the governing momentum and continuity equations. The numerical technique uses velocity shape functions to permit the partial integration of the equations of motion. A Gaussian velocity distribution is used in the mixing zone and the power law is used in the inner layer. The model predicts the velocity distribution, water surface profile, decay of the maximum velocity, variation of the surface velocity, sequent depth ratio, jump length, and energy loss.A comprehensive experimental program was conducted in an expanding Plexiglas flume with a total angle of divergence of 13.5°. The results were used to calibrate and validate the model. The model predictions also compared well with the results of other studies.

scholarly journals Characteristics of hydraulic jumps over rough beds – an experimental study

2013 ◽  
Vol 46 (3) ◽  
pp. 1
Author(s):  
N.G.P.B. Neluwala ◽  
K.T.S. Karunanayake ◽  
K.B.G.M. Sandaruwan ◽  
K.P.P. Pathirana
Keyword(s):  
Experimental Study ◽  
Hydraulic Jumps ◽  
Rough Beds

Experimental Research on Velocity Distribution and Attenuation Characteristic of Spiral Flow by Laser Doppler Velocimeter

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Rao Yongchao ◽  
Wang Shuli ◽  
Zhou Shidong ◽  
Li Entian ◽  
Liu Wenming
Keyword(s):  
Velocity Distribution ◽  
Tangential Velocity ◽  
Hydrate Formation ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Spiral Flow ◽  
Horizontal Pipe ◽  
Attenuation Characteristic ◽  
Working Medium ◽  
Gas Hydrate Formation

An experimental study was conducted to get more insight into the flowing characteristics of single phase spiral flow in the horizontal pipe by the use of a laser Doppler velocimeter (LDV). Water was used as the working medium, and the spiral motion was produced by a vane. The vanes with different spiral angles and vane area were self-made. Influence of flow attenuation, average Reynolds number, spiral angle, and vane area on axial velocity distribution and tangential velocity distribution were studied. Turbulence intensity distribution was studied, and the spiral strength attenuation law was analyzed. The experimental results show that the vane is an efficient spiral device with low pressure drop, and it is used in pipeline, natural gas hydrate formation, and so on.

Dynamics of comets in the collapsing protosolar nebula

1999 ◽  
Vol 173 ◽  
pp. 45-50
Author(s):  
L. Neslušan
Keyword(s):  
Solar System ◽  
Velocity Distribution ◽  
Oort Cloud ◽  
Interstellar Clouds ◽  
Protosolar Nebula ◽  
Moving Bodies

AbstractComets are created in the cool, dense regions of interstellar clouds. These macroscopic bodies take place in the collapse of protostar cloud as mechanically moving bodies in contrast to the gas and miscroscopic dust holding the laws of hydrodynamics. In the presented contribution, there is given an evidence concerning the Solar system comets: if the velocity distribution of comets before the collapse was similar to that in the Oort cloud at the present, then the comets remained at large cloud-centric distances. Hence, the comets in the solar Oort cloud represent a relict of the nebular stage of the Solar system.

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