Journal of Hydraulic Research (J HYDRAUL RES )

Publisher: International Association for Hydraulic Research; International Association of Hydraulic Engineering and Research

Description

Published bimonthly, this is a leading international scientific Journal for peer-reviewed research and technical developments in hydraulics and water science. All papers are reviewed by at least two members of the Editorial Board, consisting of internationally renowned experts in their specific field. The Journal is free of charge for corporate and individual members.

  • Impact factor
    1.04
    Show impact factor history
     
    Impact factor
  • 5-year impact
    1.15
  • Cited half-life
    0.00
  • Immediacy index
    0.23
  • Eigenfactor
    0.00
  • Article influence
    0.50
  • Website
    Journal of Hydraulic Research website
  • Other titles
    Journal of hydraulic research, Journal de recherches hydrauliques, Journal of the I.A.H.R., Journal de l'A.I.R.H., IAHR/AIHR journal
  • ISSN
    0022-1686
  • OCLC
    3910556
  • Material type
    Periodical
  • Document type
    Journal / Magazine / Newspaper

Publications in this journal

  • Journal of Hydraulic Research 09/2014;
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    ABSTRACT: Unstructured block ramps (UBR) are fish-friendly structures to stabilize a river bed. They are increasingly used to replace drops and represent large macro-roughness elements randomly placed on the river bed. Laser Doppler Anemometry measurements were conducted to determine the mean flow characteristics in a laboratory channel covered by block ramps. The resulting local time-averaged flow quantities allow for considerations of the flow field heterogeneity and for the identification of migration corridors for a certain target fish. Double-averaging (in time and in space) was applied to characterize the flow conditions taking into account the strongly heterogeneous bed of an unstructured block ramp. By applying this method, the characteristic vertical profiles describing the general flow conditions are presented. Based on geometrical and physical considerations, a suggestion is made to sub-divide the interfacial sublayer of macro-rough beds into upper and lower parts. The aim of this research is to present not only the flow field, but also to highlight the ecological value of UBR.
    Journal of Hydraulic Research 09/2014; 52(5).
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    ABSTRACT: A mathematical model for the simulation of dispersed turbulent liquid–solid flows in vertical pipes is presented. The model is based on the Eulerian–Eulerian approach and solves the averaged mass and momentum conservation equations for both phases, coupled by means of interfacial momentum transfer terms. Its distinctive feature is the modelling of interphase friction and turbulence modulation. In particular, specific source terms which generalize some existing correlations originally developed for gas–solid flows are introduced in the conservation equations for the turbulent kinetic energy of the fluid and its dissipation rate to account for turbulence modulation. By comparison with experimental data available in the literature for different flow conditions, the model revealed that it is capable of reproducing the main features of the flow. Moreover, it proved capable of predicting the effect of particle size on turbulence modulation in liquid–solid flows.
    Journal of Hydraulic Research 09/2014; 52(5).
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    ABSTRACT: The effect of an upstream obstacle – a backward-facing step (BFS) – on a very low head (VLH) water-turbine model has been investigated. The motivation of this study was to quantify the interaction between the VLH turbine and BFS, an abstraction of typical obstacles present in existing channels. Power measurements were obtained for three configurations; the turbine in the absence of the BFS was first examined as a baseline test, followed by configurations with the BFS placed at distances of half a turbine diameter and one turbine diameter upstream. It was found that turbine efficiency is comparable between the case with no step upstream and when the step is placed at one diameter. However, the configuration at half a diameter exhibited an efficiency deficit of approximately 7%. Particle image velocimetry measurements were then used to quantity the flowfield associated with loss in efficiency from the no step to the half a diameter step configuration. It was determined that the losses could be attributed to a highly non-uniform inlet velocity profile, which results in unsteady loading across the turbine blades.
    Journal of Hydraulic Research 09/2014; 52(5).
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    ABSTRACT: Scale effects of round-crested weir flow originate from viscosity and surface tension. No general weir flow equation accounting for these is available in the literature. In this work an equation is developed accounting for scale effects. Given the lack of knowledge on the laminar boundary layer development for these flows, detailed two-dimensional and integral laminar boundary layer solutions were obtained, from which an analytical solution results. The surface tension effect is included by allowing for high streamline curvature effects, as is typical for flow over very small weir models. The developments were used to successfully predict the discharge characteristics of circular weirs of small crest radius of curvature. The research indicates a minimum of R=0.01 m. Provided that 0.01 mR Keywords: Experimentation; scale effects; surface tension; viscosity; weir flow Document Type: Research Article DOI: http://dx.doi.org/10.1080/00221686.2014.910277 Affiliations: 1: (IAHR Member), Professor, University of Cordoba, Campus Rabanales, Leonardo Da Vinci Building, E-14071, Cordoba, Spain 2: (IAHR Honorary Member), Professor, VAW, ETH Zurich, CH-8093, Zürich, Switzerland., Email: hager@vaw.baug.ethz.ch Publication date: September 3, 2014 $(document).ready(function() { var shortdescription = $(".originaldescription").text().replace(/\\&/g, '&').replace(/\\, '<').replace(/\\>/g, '>').replace(/\\t/g, ' ').replace(/\\n/g, ''); if (shortdescription.length > 350){ shortdescription = "" + shortdescription.substring(0,250) + "... more"; } $(".descriptionitem").prepend(shortdescription); $(".shortdescription a").click(function() { $(".shortdescription").hide(); $(".originaldescription").slideDown(); return false; }); }); Related content In this: publication By this: publisher By this author: Castro-Orgaz, Oscar ; Hager, Willi H. GA_googleFillSlot("Horizontal_banner_bottom");
    Journal of Hydraulic Research 09/2014; 52(5).
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    ABSTRACT: Three-dimensional hydrodynamic and ecological modelling was used to explore strategies to mitigate the impacts of high biomass algal blooms (Aulacoseira sp.) on the drinking water intakes of the city of Buenos Aires, in the Río de la Plata. An automated real-time and a four-day forecast warning system was implemented in 2010 in order to predict the occurrence of such blooms near the intakes. Since the adoption of the technology, blooms of Aulacoseira sp. were neither predicted nor observed, demonstrating that the system did not create a false positive. Further, a historical high biomass bloom event was successfully predicted and then used to test two engineering solutions, designed to mitigate the impact of strong blooms. It was found that extending the raw drinking water intakes offshore beyond the high algae concentration provided a 50% reduction in Aulacoseira sp. concentrations. Alternatively, placing groynes around the intake sites induced a dilution of the phytoplankton patch and reduced the concentrations by 40%.
    Journal of Hydraulic Research 09/2014; 52(5).
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    ABSTRACT: Floating box-type breakwaters are frequently used for small harbours and marinas. This paper reports a comparative experimental study of the performance of a rectangular floating breakwater with and without slotted barriers. Experimental results showed that the slotted barriers attached to the bottom of a floating box-type breakwater could improve the transmission performance without increasing both the heave and surge motion responses. It was also found that the slotted barriers could reduce the pitch motion responses for shorter waves and increase the pitch motion responses for longer waves.
    Journal of Hydraulic Research 09/2014; 52(5).
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    ABSTRACT: Pipe pressurization is examined experimentally by 144 laboratory experiments in a circular tilting pipe between two tanks, in which the transient was triggered by sudden closing of the downstream tank outlet. The experiments cover ranges of values of slope, velocity and filling ratio of the open-channel flow not explored in previous studies. Situations involving considerable air quantity and consequent intense pressure oscillations were also reproduced. Two different pressurization patterns, defined as “smooth” and “abrupt”, were observed, but only the abrupt pattern produced intense pressure oscillations. The comparison among all the abrupt pressurization surges showed how the oscillations changed in starting time, intensity and duration as the pipe slope, the flow rate and the free-surface flow filling ratio varied. The experimental results also stressed the major role of entrapped air in determining the oscillation characteristics, showing that oscillations were actually produced by the pulsating of large air pockets during their migration along the pipe and their release through the upstream manhole.
    Journal of Hydraulic Research 09/2014; 52(5).
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    ABSTRACT: China is developing a 21 km2 artificial island for the Dalian offshore airport in Jinzhou Bay, and a sea-crossing bridge traffic route scheme and an impervious seawall road traffic route scheme are under consideration. To compare the effects of the development of the airport island with these two schemes on the marine environment, a two-dimensional hydrodynamic model and a pollutant transport model have been developed. The data from field observations have been used for the calibration and validation of the models. The numerical simulation results of the effects on hydrodynamics, morphological evolution, water pollution, and biological losses indicate that the sea-crossing bridge traffic route scheme is less damaging to the marine environment than that of the seawall road scheme. This study's conclusions provide an important foundation for the Dalian offshore airport programme and can be used as a reference for similar coastal engineering and marine environmental protection programmes.
    Journal of Hydraulic Research 09/2014; 52(5).
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    ABSTRACT: This work presents an investigation on the effects of spatial and temporal averaging processes (filtering) implemented in Acoustic Doppler Velocimeter (ADV) on the computations of the turbulent kinetic energy, velocity variances, and Reynolds shear stresses. The averaging processes are implemented in the ADV technology in order to reduce the noise level inherent in acoustic measurements. A conceptual model, simulating the ADV operation and the turbulent flow field, is developed to assess the filtering effects on the turbulence parameter estimates of sampling volume heights, recording frequencies, and distances from the sampling volume to the channel bottom. The results of the conceptual model are compared with experimental data. The findings provide a criterion to examine the capability of ADV to characterize turbulent flows using different sampling configurations.
    Journal of Hydraulic Research 08/2014;
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    ABSTRACT: The paper reports on the experimental results of a vertical slot fishway (VSF) study. Particle image velocimetry and Acoustic Doppler Velocimetry were used to estimate the effects of a supplementary cylinder, appropriately positioned inside existing VSFs, on the hydraulic parameters and the instantaneous flow patterns. Special attention was paid to the analysis of the spatial flow distribution and to the instantaneous flow dynamics initiated by the addition of a cylinder. Modifications of velocity amplitudes, flow fluctuations and vorticity values were quantified for two dimensions of VSF. The contribution of a supplementary cylinder has been quantified in order to “smooth” the effects of turbulence and to facilitate the passage of the largest number of fish irrespective of their size or swimming capacity. The results provided insights on the control of the fishway turbulence, which might help engineers to develop effective systems for the passage of fish with low swimming capabilities.
    Journal of Hydraulic Research 07/2014; 52(5):614-629.
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    ABSTRACT: Axially stretched free-surface vortices occur at low-head hydropower intakes under specific flow and geometric conditions. When they are sufficiently strong, they can harm performance or cause premature failure of mechanical components such as turbine blades or guide vanes. Laboratory-scale experimental models are currently used to assess the risk of vortex formation during the design phase, but uncertainty remains as to how vortex characteristics translate from the laboratory scale to the much larger scale of an actual hydropower plant. This paper proposes a semi-empirical model that roughly predicts how the approach flow and intake geometry determine the key vortex characteristics (the core radius, bulk circulation and the depth of the free surface depression). The model is developed using detailed velocity measurements of the approach flow and the flow inside the vortex in a laboratory-scale physical model, using analytical models and insights drawn from previous work.
    Journal of Hydraulic Research 07/2014; 52(4).
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    ABSTRACT: Intake free-surface vortices can cause efficiency losses, flow fluctuations and even structural damages. Experiments were performed to examine the effect of entrance shapes on the critical submergence. Seven entrance shapes were devised and tested, including a square-edged, a bell-mouthed, three symmetrical conical and two conical profiles with eccentricity. The focus of the study was on a range of Froude numbers from 0.25 to 0.65. The square-edged shape appeared to show the highest local head-loss compared to other shapes. Steady counter-clockwise vortices characterize all the intake profiles except in a narrow water tank. The experiments show both discrepancy and similarity between the intake profiles. The critical submergence of the bell-mouthed intake is lower when compared to the square-edged shape. For the other profiles, it is proportional to the Froude number. A closer sidewall may lead to larger critical submergence in the case of weak circulations. The results demonstrate that the intake-entrance profile has an important effect on the critical submergence.
    Journal of Hydraulic Research 07/2014; 52(4).
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    ABSTRACT: The paper describes two different ways of defining the terrain roughness in smoothed particle hydrodynamics (SPH) simulations performed with the Tis Isat model, developed at the University of Ljubljana. The model introduces into the SPH method a non-discrete boundary condition with friction. Two basic definitions of terrain roughness are used: (a) as a hydraulically smooth wall, where roughness was controlled by the wall–particle eddy viscosity coefficient; and (b) as a hydraulically rough terrain by elevating the mesh-nodes. The undertaken SPH simulations relate to a dam break at the upper storage reservoir of the pumped-storage hydro power plant Kolarjev vrh in Slovenia. For the first time, such study was performed on a real topography. Water depths at the gauges along the valley were compared with measurements on a physical model and to results obtained using a finite volume (FV) model. The comparison showed satisfactory agreement with the measurements, which are comparable with the FV model simulations.
    Journal of Hydraulic Research 07/2014; 52(4).
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    ABSTRACT: In hydraulic research, numerical modelling of complex flows is essential for managing water risks. High-resolution finite volume schemes have become popular for shallow water flow modelling due to their mass and momentum balance characteristics and their ability to capture shocks. These methods use slope limiters to suppress numerical oscillations near discontinuities. However, one-dimensional limiters do not assure numerical accuracy in multidimensional applications, occasionally leading to excessive or insufficient numerical dissipation. For this reason, a multidimensional limiting process (MLP) was developed for oscillation control in multidimensional compressible flows. In this paper, we implement MLP on adaptive quadtree grids for shallow water flow simulations and compare MLP performance with simulations using conventional limiters. Four simulation cases show that MLP outperforms conventional limiters, and yield more accurate and stable solutions on adaptive quadtree grids. The capability of MLP for oscillation control is more noticeable on quadtree than on uniform grids.
    Journal of Hydraulic Research 07/2014; 52(4).