Water Engineering Research

Korea Water Resources Association (한국수자원학회)
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NUMERICAL MODELLING OF SHEET-FLOW TRANSPORT UNDER WAVE AND CURRENT

  • Bakhtiary, Abbas-Yeganeh (Research Center for Disaster Environment, Disaster Prevention Research Inst., Kyoto University, Uji, Kyoto 611-0011, Japan) ;
  • Hotoshi Gotoh (Department of Civil Engineering, Kyoto University, Uji, Kyoto 611-0011, Japan) ;
  • Tetsuo Sakai (Department of Civil Engineering, Kyoto University, Uji, Kyoto 611-0011, Japan)
  • Published : 2002.04.01
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Abstract

An Euler-Lagrange two-phase flow model is presented fur simulation sheet-flow transport under wave and current. The flow is computed by solving the Reynolds Averaged Navier-Stokes equation in conjunction with the k-$\varepsilon$ turbulence model for turbulence closure. The sediment transport is introduced as a motion of granular media under the action of unsteady flow from the Lagragian point of view. In other word, motion of every single particle is numerically traced with Movable Bed Simulator (MBS) code based on the Distinct Element Method (DEM), in which the frequent interparticle collision of the moving particles during the sheet-flow transport is sophisticatedly taken into account. The particle diameter effect on time-dependent developing process of sheet-flow transport is investigated, by using three different diameter sizes of sediment. The influence of an imposed current on oscillatory sheet-flow transport is also investigated. It is concluded that the sediment transport rate increases due to the relaxation process related to the time-lag between flow velocity and sediment motion.

Keywords

References

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