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

  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper reports the results of detailed numerical simulations of the flow over a submerged bridge. The method of Large Eddy Simulation (LES) is applied, which allows elucidation of the instantaneous flow and an accurate quantification of its turbulence statistics. The in-house LES code employs a free surface algorithm based on the Level Set Method (LSM) to determine the complex water surface profile over the bridge, which is validated with data from a physical model of the bridge under analogous flow conditions. Numerically predicted water surface profiles showed good agreement with measured data. The water surface resembles that of the flow over a broad-crested weir with a plunging nappe and a standing wave downstream of the bridge. The mean flow is characterized by a multitude of complex flow features including horizontal recirculation zones upstream and downstream of the bridge abutment and vertical recirculation zones of the separated plunging flow. The latter influences significantly the near-bed turbulence and the bed shear stress.
    Journal of Hydraulic Research 03/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hydraulic turbines are frequently used to maintain electrical grid parameters. An angular movement of the guide vanes (GVs) during transients such as load acceptance and rejection within short time raised significant concerns for increased wear and instabilities. The present work focuses on the pressure variations in a high-head Francis turbine during the transients. Six transient conditions were investigated including time-domain rotor–stator interaction. The measurements in the vaneless space and runner indicated the presence of unsteady vortical flow during transients. The vortices travelled to the runner and affected the flow in the blade channels. The GVs angular movement increases the pressure difference between the pressure and suction sides of the blade. The largest pressure variation was observed during the partial load rejection at the trailing edge of the blade. Preliminary results indicated that an appropriate closure of the GVs may minimize large pressure fluctuations in the runner.
    Journal of Hydraulic Research 03/2014; 52(2):1-15.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Flow–structure–seabed interaction in coastal and marine environments is a rapidly growing area of research and applications. In this vision paper, this area is discussed with a view of identifying its state of the art and current research challenges. The discussion draws attention to key issues related to structures such as marine pipelines, offshore windfarms, and multiuse offshore platforms. Tsunamis, which received considerable attention after two recent extreme events (2004 Indonesia tsunami and 2011 Japan tsunami) are also included in the discussion. Marine hydro-geomechanics is highlighted, among other areas, as an emerging branch of Marine Civil Engineering. Predictions of the field development for the forthcoming years are also briefly outlined.
    Journal of Hydraulic Research 01/2014; 52(1).
  • [Show abstract] [Hide abstract]
    ABSTRACT: Drop manholes are widely employed in urban drainage systems. They experience operating conditions in which insufficient energy dissipation leads to hydraulic problems that are enhanced by particular configurations of the manhole bottom. Therefore, specific jet-breaker devices were considered to improve the flow conditions. Two different types of jet-breakers have been tested in the present work: plane jet-breaker (PJB) and wedge jet-breaker (WJB). Both have proved to be effective in inducing adequate energy loss, if properly sized, and to improve the overall drop manhole performance. The selection of a jet-breaker element should account for additional features of the drop manhole hydraulics, including the pool depth, the air entrainment phenomena, as well as further practical aspects including cost-effectiveness, simplicity of realization and clogging risk. This study provides the hydraulic basis for the design of the jet-breakers, particularly of the PJB, which has an overall optimum performance, as laboratory experiments have shown.
    Journal of Hydraulic Research 01/2014; 52(3).
  • [Show abstract] [Hide abstract]
    ABSTRACT: Phase-shift tidal power system with a dam deployed perpendicularly to a coastline in the sea is considered. The tidal power is extracted from water level difference on both sides of the dam, which originates from different propagation path of the tidal wave and the phase shift in water levels. This study focuses on hydrodynamic characteristics of a Y-shaped dam under the action of the tidal waves and explores the effects of the dam parameters on the phase shift of the tidal waves on both sides of a main dam and water head. A two-dimensional model is used to simulate tidal flows in the Taiwan Strait and Qiongzhou Strait. The model is validated by comparing the numerical results with previous studies and available measurements. The influence of the angle between the main dam and the branch dam, branch dam length, and dam types on phase difference in water levels and water head over the main dam is discussed.
    Journal of Hydraulic Research 01/2014; 52(3).
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ski jumps are frequently applied as spillways of high dams. The resulting jet impact location on the plunge pool surface is often distant from the dam toe so that the latter is protected from scouring. Furthermore, the jet disintegrates and disperses prior to its impact, thereby reducing the specific energy addition to the plunge pool. The present research addresses four aspects, based on three physical modelling campaigns: (1) geometry of upper and lower jet trajectories; (2) virtual jet take-off angles for the trajectory computations; (3) average and minimum cross-sectional air concentrations along the jet; and (4) general jet air concentration profiles. It is shown that the trajectory parabola may also be applied for negative jet take-off angles, and that these are smaller than the bucket angle. As for the air concentration distribution along the jet, tests indicate that the latter depends exclusively on the relative jet black-water core length.
    Journal of Hydraulic Research 01/2014; 52(3).
  • [Show abstract] [Hide abstract]
    ABSTRACT: The potential flow theory is a good mathematical approximation to various problems in the fields of free surface open channel and groundwater flows. In both fields, second-order equations are commonly derived using perturbation methods to account for the non-hydrostatic pressure distribution. However, an alternative technique is Picard's iteration approach, used by Matthew for steady open channel flows. Regretfully, this technique was not expanded to unsteady potential flow, limiting its full impact. The purpose of this work is to generalize the theory of Matthew to unsteady potential free surface flow, both for open channels and groundwater. The new development is an alternative to perturbation techniques, highlighting the relevance of Matthew's work. To illustrate the widespread problems to which the theory applies, simulations are made for a dambreak wave and for flow in sloping and curved aquifers. In both cases one-dimensional results are in good agreement with two-dimensional data.
    Journal of Hydraulic Research 01/2014; 52(1).
  • [Show abstract] [Hide abstract]
    ABSTRACT: Experimental results for fish-friendly trashracks placed in an open-water channel are presented. Eighteen angled trashracks were used to test different bar spacings, bar shapes and rack angles. Each model trashrack comprised two horizontal supports with regularly spaced slots adjusted to compensate for the trashrack angle, i.e. maintain the vertical bars “streamwise” (parallel to flow). Water depths and velocity profiles were acquired upstream and downstream of each rack configuration. The results reveal that the head-loss coefficient for angled racks with streamwise bars does not depend on the rack angle and can be calculated with equations for racks perpendicular to the channel. Upstream velocity profiles along the rack are not significantly affected by the rack angle and downstream transverse profiles are nearly uniform. A comparison with conventional angled trashracks with bars set perpendicular to the rack revealed the many advantages of streamwise bars.
    Journal of Hydraulic Research 01/2014; 52(3).
  • [Show abstract] [Hide abstract]
    ABSTRACT: Gates are one of the most important hydraulic structures extensively investigated by physical and two-dimensional (2D) numerical research in the past. However, the hydraulics of free gate flow features of engineering interest, including the water surface profile, the force on the gate, or the bottom pressure distribution, were overlooked in the literature, so that the current knowledge is incomplete. In this work this gap is filled in using a higher order one-dimensional model based on a Boussinesq-type closure. The proposed model provides the free surface profile of the approach flow as a cnoidal wave, and the free jet portion as a generalized solitary wave, which compare well with 2D results. The model further provides as a part of the theoretical computation the pressure distribution on the gate. Bottom pressure features were also determined resulting in a good agreement with potential flow data. Boussinesq-type equations for submerged jets are presented and solved for the submerged hydraulic jump.
    Journal of Hydraulic Research 01/2014; 52(2).
  • [Show abstract] [Hide abstract]
    ABSTRACT: Various forms of mass balance equations are commonly used in sediment transport studies and applications. However, the quantities involved in such equations are not always clearly defined, with sediment flux (or solid discharge) as a typical example. Starting with the fundamental definitions, this paper provides a general and consistent framework for integral (Eulerian) mass balances and gives scale-consistent definitions for instantaneous and time-averaged variables. In particular, alternative expressions for the instantaneous and averaged solid discharge are proposed and compared with the existing formulations. Conceptual developments of this study are illustrated using sediment transport data from laboratory experiments.
    Journal of Hydraulic Research 01/2014; 52(2).
  • Journal of Hydraulic Research 01/2014; 52(1).
  • [Show abstract] [Hide abstract]
    ABSTRACT: Smooth rectangular open channel flow is a benchmark for studying river hydraulics and sediment transport. Such a flow is more complicated than the classic boundary layer flow at least in two ways: (i) the maximum velocity occurs below the water surface, which is called the velocity-dip-phenomenon and (ii) the velocity distribution is affected not only by the channel bottom but also by the side-walls and the free surface. This fundamental flow is approximated herein by three hypotheses: (i) the velocity-dip-position shifts exponentially from the water surface to half flow depth as the width–depth ratio decreases from infinity to zero; (ii) the conventional wake-law for the centreline velocity distribution results from boundary shear stresses including the bottom, side-walls, and water surface in terms of secondary currents; and (iii) the cross-sectional velocity distribution is described by Guo and Julien's modified log-wake-law. These hypotheses are well supported by flume data.
    Journal of Hydraulic Research 01/2014; 52(1).

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