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hydraulic jump basins with wedge-shaped baffles

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第7期13卷 519-525页

作者： Ashraf Fathy ELLAYN Institute of Port Coastal and Offshore Engineering Zhejiang University

This laboratory study deals with the hydraulic jump properties for an artificially roughened bed with wedge-shaped baffle blocks. The experiments were conducted for both smooth and rough beds with a Froude number in the range of 3.06≤F1≤10.95 and a relative bed roughness ranging 0.22≤KR≤1.4. The data from this study were compared with those of rectangular baffle blocks. New experimental formulae were developed for determining the sequent depth ratio and the hydraulic jump length in terms of the inflow Froude number and relative bed roughness. Bélanger's jump equation of a rectangular channel was extended to account for the implications of the bed shear stress coefficient attributable to channel bed roughness. It was found that, in comparison with the smooth bed, the wedge-shaped bed roughness reduced the sequent depth of the hydraulic jump by approximately 16.5% to 30% and the hydraulic jump length by approximately 30% to 53%.

关键词： Energy dissipater hydraulic jump Stilling basins Wedge-shaped bed roughness

Local hydraulic jump effects on sediment deposition in open-channel flume experiments

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Journal of Hydrodynamics 2023年第2期35卷 268-277页

作者： Shi-hao Fu Mao-lin Zhou Wei-lin Xu Wang-ru Wei Guo-guang Wang State Key Laboratory of hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China

When a river channel is narrow,bifurcated,or intersected,or when extreme weather or geological disasters cause shed rock masses to occupy a river flood channel,local hydraulic jumps may develop in the *** disasters such as landslides,floods,and debris flows occur upstream,will result in large transport rate of large-sized gravel *** particles may be blocked in hydraulic jump areas,causing river channel water depth to *** this study,the effect of local hydraulic jumps on the sediment deposition rate was investigated in flume *** ratio of upstream and downstream Froude numbers,particle size,Sediment supply intensity,and flow discharge all affected the sediment deposition *** increases in the ratio of upstream and downstream Froude numbers,particle size,and sediment supply intensity,the sediment deposition rate *** sediment deposition rate decreased with an increase in flow *** hydraulic conditions and particle properties jointly determined the sediment deposition rate in a hydraulic jump section,and an empirical formula was developed using those parameters to calculate the sediment deposition ***,to identify risks and prevent disasters in mountain rivers,local changes in hydraulic conditions and particle properties need to be jointly evaluated.

关键词： hydraulic jump sediment deposition particle size upstream/downstream Froude numbers ratio sediment supply intensity flowdischarge

Air entrainment of hydraulic jump aeration basin

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Journal of Hydrodynamics 2018年第5期30卷 962-965页

作者： Jian-hua Wu Yu Zhou Fei Ma College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China

In order to avoid the cavitation damage and the decrease of the energy dissipation of the stepped spillways with a large unit discharge, the air entrainments of the hydraulic jump aeration basin （HJAB） are theoretically and experimentally investigated for the hydraulic-jump-stepped spillway developed by the authors. It is shown that the submerged degree of the hydraulic jump and the air concentration in the measuring section are all functions of the dimensionless discharge, the length and the end sill height of the H JAB. The submerged degree odecreases with the increase of the dimensionless discharge or the dimensionless length of the H JAB, but increases with the increase of the dimensionless height of the end sill of the HJAB. The flow regimes near the critical hydraulic jump, namely, at or= 1.0, have the best effect of the air entrainment for the flow at the measuring section and then that of the stepped spillway.

关键词： Air entrainment hydraulic jump hydraulic jump aeration basin stepped spillway submerged degree

A GENERALIZED EXPLICIT SOLUTION OF THE SEQUENT DEPTH RATIO FOR THE hydraulic jump

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Journal of Hydrodynamics 2005年第5期17卷 596-600页

作者： NI Han-gen LIU Ya-kun State Key Laboratory of Coastal and Offshore Enginccring Dalian University of Technology Dalian 116024 China

By use of the property of the momentum equation describing the hydraulic jump in rectangular channels, a generalized solution of the sequent depth ratio was given. On the basis of the generalized solution the explicit solutions of the sequent depth ratio were obtained for the hydraulic jump in gradual enlargements, the corresponding relative energy losses were also presented, and a method to determine the location of hydraulic jump in gradual enlargements was proposed.

关键词： cubic algebraic equation hydraulic jump sequent depth ratio jump in gradual enlargement

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Journal of Hydrodynamics 1992年第2期4卷 46-51页

作者： Zhang, Shengming Yangtze River Scientific Research Inst Wuhan China

For further study of the similarity law of fluctuating pressure, a series of model tests with more scales, covering a wide range of Reynolds number and Froude number have been completed. The data of the fluctuating pressure acting the floor level within 2-D free hydraulic jump were obtained. Froude number varied from 2.94 to 8.61, and Reynolds number ranged from 2×104 to 6×105. The tests were conducted in a glass flume with 0.2 m in width and six fluctuating pressure probes (Type CYG-01) were installed on the floor within the jump. Experimental results indicate that the amplitude scale of fluctuating pressure is the length of the model, i.e., Pr=Lr, which agrees with gravity similarity law. The frequency scale of the fluctuating pressure is an unity i.e., fr=1, which does not satisfy the gravity similarity law.

关键词： hydraulic jump

Analogy Between hydraulic jump in Films Formed by Impinging Liquid Jet and Critical Flow in Internal Flows

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Journal of Thermal Science 2003年第2期12卷 171-175页

作者： Jaroslaw Mikielewicz Institute of Fluid-Flow Machinery Polish Academy of SciencesGdaskPoland

Formulated are simple models for the flow in liquid film, formed by impinging jet, and a two-phase downward flow in pipe. The models are based on simplified equations of mass, momentum and energy. The solutions of such conservation equations may have regular points belonging to one integral curve only as well as turning points can be found amongst them, which refer to extreme values in the appropriate co-ordinate system. The solutions can also have singular points belonging to none or more than one integral curve. Both the turning and singular points have a clear physical meaning. They could be linked to critical flow conditions in the pipe flow or to the so-called hydraulic jump. Analogy existing between critical conditions in the pipe and the flow of liquid films formed by the liquid jet have been shown in the paper.

关键词： critical flow liquid film hydraulic jump singular points.

Study of a hydraulic jump in an Asymmetric Trapezoidal Channel with Different Sluice Gates

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Fluid Dynamics & Materials Processing 2024年第7期20卷 1499-1516页

作者： Bouthaina Debabeche Sonia Cherhabil Research Laboratory in Civil Engineering HydraulicsSustainable Development and Environment(LARGHYDE)University of BiskraBiskra7000Algeria Faculty of Sciences Applied Sciences Liege UniversityLiege4000Belgium Underground and Surface hydraulics Research Laboratory(LARHYSS) Biskra7000Algeria

In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and *** particular,an asymmetric trapezoidal flume with a length of 7 m and a width of 0.304 m is considered,with the bottom of the flume transversely inclined at an angle of m=0.296 and vertical lateral *** corresponding inflow Froude number is allowed to range in the interval(1.40jump are compared to those of hydraulic jumps in channels with other types of cross-sections.A relationship for calculating hydraulic jump efficiency is proposed for the considered *** F1>5,the hydraulic jump is found to be more effective than that occurring in triangular and symmetric trapezoidal ***,when■mes>8 and■>5,the hydraulic jump in the asymmetrical trapezoidal channel downstream of a parallelogram sluice gate is completely formed as opposed to the situation where a triangular sluice is considered.

关键词： Asymmetric trapezoidal channel characteristic lengths efficiency Froude hydraulic jump sequent depths sluice gate

STUDIES ON THE TWO-DIMENSIONAL FREE hydraulic jump TAKING ACCOUNT OF TURBULENCE INTENSITY AND OTHER FACTORS

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Journal of Hydrodynamics 1991年第2期3卷 71-74页

作者： Ding, Zhuo-yi Yangtze River Scientific Research Inst Wuhan China

Taking account of turbulence intensity, non-uniformity of velocity distribution at the initial and sequent section of hydraulic jump and frictional drag on the floor within jump range, this paper derives new formulas for calculating the ratio of conjugate depths and the efficiency of energy dissipation in the two-dimensional free hydraulic jump. It has been verified by test data that the new formulas are not only exact in theory but also still better in conformity with practice.

关键词： Flow Of Fluids Turbulent hydraulic jump Friction hydraulics

Theoretical Analysis of hydraulic jump on ExtremelySmall Size Liquid Jet Impingement

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Journal of Thermal Science 1998年第3期7卷 176-180页

作者： Dingwei Zhou Chongfang Ma Yutao Ren School of Energy and Power Engineering Xi’an Jiaotong University Xi’an China Department of Thermal Science and Engineering Beijing Polytechnic University Beijing China Second Rolling Mill Taiyuan Iron & Steel Group Corporation Taiyuan China

A theoretical study was conducted to characterize hydraulic jump of laminar circular liquid jets. The objective of this research was to determine the jump location in a simple explicit form. The effects of many factors were investigated including nozzle diameter, jet exit pressure, nozzle-to-plate spacing, jet velocity and Reynolds number. It was found that the theoretical data collapsed well over the range of jet Reynolds number 500 Re 1800 with previous data.

关键词： hydraulic jump jet impingement theoretical analysis