000004909 001__ 4909
000004909 005__ 20141119144604.0
000004909 04107 $$aeng
000004909 046__ $$k2002-06-02
000004909 100__ $$aAquino, Leslie J.
000004909 24500 $$aMOMENTUM BASED MODEL FOR SEDIMENT TRANSPORT

000004909 24630 $$n15.$$pProceedings of the 15th ASCE Engineering Mechanics Division Conference
000004909 260__ $$bColumbia University in the City of New York
000004909 506__ $$arestricted
000004909 520__ $$2eng$$aMany current models of sediment transport use single-phase flow equations to determine liquid flow velocity profiles and then use these to compute suspended load and bed load transport. A two-phase or two-fluid approach is more desirable because it allows mechanistic modeling of interfacial effects as well as turbulence effects within the near-bed layer. This also seems to be a more natural approach than some existing two-fluid models, which often couple a conservation of momentum equation for the liquid (continuous) phase and includes a diffusive flux of dispersed material in the conservation of mass equation for the dispersed phase. The basic equations for two-phase flow are presented and applied to the simplified case of steady-state two-dimensional fully-developed flow in a rectangular channel over a flat bottom. The equations for balance of mass and momentum are discussed for low sediment concentration, and a k − ε turbulence model is considered. Parameters which affect the sediment volume fraction are determined through nondimensionalization of the model equations. The k − ε system is found to be singularly perturbed, with a boundary layer near the bottom. Singular perturbation analysis of the k − ε system is performed, with “law of the wall” boundary conditions coming from the near-bottom analysis. Subsequent numerical solutions for the sediment volume fraction show that this treatment of the k − ε equations produces reasonable results when compared with experimental data.

000004909 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000004909 653__ $$aSediment transport, mathematical models

000004909 7112_ $$a15th ASCE Engineering Mechanics Division Conference$$cNew York (US)$$d2002-06-02 / 2002-06-05$$gEM2002
000004909 720__ $$aAquino, Leslie J.$$iDrew, Donald A.
000004909 8560_ $$ffischerc@itam.cas.cz
000004909 8564_ $$s125905$$uhttp://invenio.itam.cas.cz/record/4909/files/525.pdf$$yOriginal version of the author's contribution as presented on CD, .
000004909 962__ $$r4594
000004909 980__ $$aPAPER