scholarly journals TWO-PHASE FLOW SIMULATIONS OF SCOUR AROUND VERTICAL AND HORIZONTAL CYLINDERS

2018 ◽  
pp. 22
Author(s):  
Tim Nagel ◽  
Julien Chauchat ◽  
Cyrille Bonamy ◽  
Antoine Mathieu ◽  
Xiaofeng Liu ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Two Phase Flow ◽  
Numerical Data ◽  
Horizontal Cylinder ◽  
Transport Processes ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Solver ◽  
Sediment Bed ◽  
Horizontal Cylinders

Scour around structures is a major engineering issue that requires a detailed description of the flow field as well as sediment transport processes. Due to enhanced suspended load associated with vortices generated around structures, sediment transport cannot be solely related to bed shear stress, such as Shields parameter based formula. In order to address this issue, we used a multi-dimensional two-phase flow solver, sedFoam-2.0 (Chauchat et al., GMD 2017) implemented under the open-source CFD toolbox OpenFOAM. Three configurations are studied and compared with experimental and numerical data from the literature. First, the 2D configurations of an horizontal cylinder lying on a sediment bed (Mao, 1986; Sumer et al., 2001) are investigated. Then, the 3D configuration of the scour around a vertical cylindrical pile reported by Roulund et al. (2005) for rigid-bed and live bed cases is investigated.

scholarly journals SedFoam-2.0: a 3-D two-phase flow numerical model for sediment transport

2017 ◽  
Vol 10 (12) ◽  
pp. 4367-4392 ◽  
Author(s):  
Julien Chauchat ◽  
Zhen Cheng ◽  
Tim Nagel ◽  
Cyrille Bonamy ◽  
Tian-Jian Hsu
Keyword(s):  
Sediment Transport ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Test Cases ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Solver ◽  
Transport Problems ◽  
Stress Models

Abstract. In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver is extended from twoPhaseEulerFoam available in the 2.1.0 release of the open-source CFD (computational fluid dynamics) toolbox OpenFOAM. In this approach the sediment phase is modeled as a continuum, and constitutive laws have to be prescribed for the sediment stresses. In the proposed solver, two different intergranular stress models are implemented: the kinetic theory of granular flows and the dense granular flow rheology μ(I). For the fluid stress, laminar or turbulent flow regimes can be simulated and three different turbulence models are available for sediment transport: a simple mixing length model (one-dimensional configuration only), a k − ε, and a k − ω model. The numerical implementation is demonstrated on four test cases: sedimentation of suspended particles, laminar bed load, sheet flow, and scour at an apron. These test cases illustrate the capabilities of SedFoam-2.0 to deal with complex turbulent sediment transport problems with different combinations of intergranular stress and turbulence models.

scholarly journals SedFoam-2.0: a 3D two-phase flow numerical model for sediment transport

2017 ◽  
Author(s):  
Julien Chauchat ◽  
Zhen Cheng ◽  
Tim Nagel ◽  
Cyrille Bonamy ◽  
Tian-Jian Hsu
Keyword(s):  
Sediment Transport ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Solver ◽  
Dense Granular Flow ◽  
Transport Problems ◽  
Stress Models

Abstract. In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver is extended upon twoPhaseEulerFoam available in the 2.1.0 release of the open-source CFD toolbox OpenFOAM. In this approach the sediment phase is modeled as a continuum, and constitutive laws have to be prescribed for the sediment stresses. In the proposed solver, two different inter-granular stress models are implemented: the kinetic theory of granular flows and the dense granular flow rheology μ(I). For the fluid stress, laminar or turbulent flow regimes can be simulated and three different turbulence models are available for sediment transport: a simple mixing length model (one-dimensional configuration only), a k-ϵ and a k-ω model. The numerical implementation is first demonstrated by two validation test cases, sedimentation of suspended particles and laminar bed-load. Two applications are then investigated to illustrate the capabilities of SedFoam-2.0 to deal with complex turbulent sediment transport problems with different combinations of inter-granular stress and turbulence models.

Evaluating the performance of the two-phase flow solver interFoam

2012 ◽  
Vol 5 (1) ◽  
pp. 014016 ◽  
Author(s):  
Suraj S Deshpande ◽  
Lakshman Anumolu ◽  
Mario F Trujillo
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Solver

scholarly journals Numerical simulation of two-phase flow for sediment transport in the inner-surf and swash zones

2010 ◽  
Vol 33 (3) ◽  
pp. 277-290 ◽  
Author(s):  
R. Bakhtyar ◽  
D.A. Barry ◽  
A. Yeganeh-Bakhtiary ◽  
L. Li ◽  
J.-Y. Parlange ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Sediment Transport ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase

scholarly journals A two-phase flow model of sediment transport: transition from bedload to suspended load

2014 ◽  
Vol 755 ◽  
pp. 561-581 ◽  
Author(s):  
Filippo Chiodi ◽  
Philippe Claudin ◽  
Bruno Andreotti
Keyword(s):  
Sediment Transport ◽  
Flow Model ◽  
Two Phase Flow ◽  
Suspended Load ◽  
Particle Migration ◽  
Turbulent Shear ◽  
Phase Flow ◽  
Dimensionless Numbers ◽  
Two Phase ◽  
Rouse Number

AbstractThe transport of dense particles by a turbulent flow depends on two dimensionless numbers. Depending on the ratio of the shear velocity of the flow to the settling velocity of the particles (or the Rouse number), sediment transport takes place in a thin layer localized at the surface of the sediment bed (bedload) or over the whole water depth (suspended load). Moreover, depending on the sedimentation Reynolds number, the bedload layer is embedded in the viscous sublayer or is larger. We propose here a two-phase flow model able to describe both viscous and turbulent shear flows. Particle migration is described as resulting from normal stresses, but is limited by turbulent mixing and shear-induced diffusion of particles. Using this framework, we theoretically investigate the transition between bedload and suspended load.

Modeling Sediment-Turbulent Flow Interactions

1995 ◽  
Vol 48 (9) ◽  
pp. 601-609 ◽  
Author(s):  
C. Villaret ◽  
A. G. Davies
Keyword(s):  
Eddy Viscosity ◽  
Two Phase Flow ◽  
Passive Scalar ◽  
Sediment Concentration ◽  
Transport Processes ◽  
Phase Flow ◽  
High Concentration ◽  
Two Phase ◽  
Hindered Settling ◽  
Flow Models

Models of widely differing complexity have been used in recent years to quantify sediment transport processes for engineering applications. This paper presents a review of these model types, from simple eddy viscosity models involving the “passive scalar hypothesis” for sediment predication, to complex two-phase flow models. The specific points addressed in this review include, for the suspension layer, the bottom boundary conditions, the relationship between the turbulent eddy viscosity and particle diffusivity, the damping of turbulence by vertical gradients in suspended sediment concentration, and hindered settling. For the high-concentration near-bed layer, the modeling of particle interactions is discussed mainly with reference to two-phase flow models. The paper concludes with a comparison between the predictions of both a classical, one-equation, turbulence k-model and a two-phase flow model, with “starved bed” experimental data sets obtained in steady, open-channel flow.

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