scholarly journals Two-Phase Flow Simulation of Tunnel and Lee-Wake Erosion of Scour below a Submarine Pipeline

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1727 ◽  
Author(s):  
Antoine Mathieu ◽  
Julien Chauchat ◽  
Cyrille Bonamy ◽  
Tim Nagel
Keyword(s):  
Sediment Transport ◽  
Turbulence Model ◽  
Flow Model ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Stress Model ◽  
Submarine Pipeline ◽  
Two Phase ◽  
Diffusion Term ◽  
Cross Diffusion

This paper presents a numerical investigation of the scour phenomenon around a submarine pipeline. The numerical simulations are performed using SedFoam, a two-phase flow model for sediment transport implemented in the open source Computational Fluid Dynamics (CFD) toolbox OpenFOAM. The paper focuses on the sensitivity of the granular stress model and the turbulence model with respect to the predictive capability of the two-phase flow model. The quality of the simulation results is estimated using a statistical estimator: the Brier Skill Score. The numerical results show no sensitivity to the granular stress model. However, the results strongly depend on the choice of the turbulence model, especially through the different implementations of the cross-diffusion term in the dissipation equation between the k − ε and the k − ω 2006 models. The influence of the cross-diffusion term tends to indicate that the sediment transport layer behaves more as a shear layer than as a boundary layer, for which the k − ε model is more suitable.

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.

scholarly journals A Numerical Study on Oscillatory Flow-Induced Sediment Motion over Vortex Ripples

2015 ◽  
Vol 45 (1) ◽  
pp. 228-246 ◽  
Author(s):  
Xin Chen ◽  
Xiping Yu
Keyword(s):  
Turbulence Model ◽  
Oscillatory Flow ◽  
Flow Model ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Laboratory Data ◽  
Phase Flow ◽  
Mass Force ◽  
Two Phase ◽  
Reference Concentration

AbstractA two-dimensional, two-phase flow model is applied to the study of sediment motion over vortex ripples under oscillatory flow conditions. The Reynolds-averaged continuity equations and momentum equations for both the fluid and sediment phases, which include the drag force, the added mass force, the lift force for interphase coupling, and the standard k–ε turbulence model as well as the Henze–Tchen particle turbulence model for closure, are numerically solved with a finite-volume method. The model is effective over the whole depth from the undisturbed sandy bed to the low concentration region above the ripples. Neither a reference concentration nor a pickup function is required over the ripple bed as in a conventional advection–diffusion model. There is also no need to identify the bed load and the suspended load. The study focuses on the effects of erodible ripples on the intrawave flow and sediment motion over the ripples. The computational results show reasonable agreement with the available laboratory data. It is demonstrated that the formation–ejection process of vortices and the trapping–lifting process of sediment over vortex ripples can be well described by the two-phase flow model. The numerical model can also accurately predict the vertical distribution of the mean sediment concentration.

scholarly journals Application of a Eulerian two-phase flow model to scour processes

2018 ◽  
Vol 40 ◽  
pp. 05015 ◽  
Author(s):  
Antoine Mathieu ◽  
Tim Nagel ◽  
Cyrille Bonamy ◽  
Julien Chauchat ◽  
Zhen Cheng ◽  
...  
Keyword(s):  
Experimental Data ◽  
Vortex Shedding ◽  
Flow Model ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Submarine Pipeline ◽  
Sheet Flow ◽  
Two Phase ◽  
One Dimensional ◽  
Quantitative Results

In this paper, the application of a two-phase flow model to scour processes is presented. The model is first calibrated against experimental data of unidirectional sheet-flow (one-dimensional configuration). The model is then applied to multi-dimensional configurations for the scour under a submarine pipeline and around a vertical pile. The results show that quantitative results can be obtained at the upstream sides of structures, the lee-wake erosion driven by the vortex shedding deserves further research.

scholarly journals Global existence for a two-phase flow model with cross-diffusion

2020 ◽  
Vol 25 (3) ◽  
pp. 957-979
Author(s):  
Esther S. Daus ◽  
◽  
Josipa-Pina Milišić ◽  
Nicola Zamponi ◽  
Keyword(s):  
Global Existence ◽  
Flow Model ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Cross Diffusion

A ONE-DIMENSIONAL TWO-PHASE FLOW MODEL AND EXPERIMENTAL VALIDATION FOR A FLASHING VISCOUS LIQUID IN A SPLASH PLATE NOZZLE

2015 ◽  
Vol 25 (9) ◽  
pp. 795-817 ◽  
Author(s):  
Mika P. Jarvinen ◽  
A. E. P. Kankkunen ◽  
R. Virtanen ◽  
P. H. Miikkulainen ◽  
V. P. Heikkila
Keyword(s):  
Viscous Liquid ◽  
Experimental Validation ◽  
Flow Model ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional

Status of Advanced Two-Phase Flow Model Development for SRM Chamber Flow Field and Combustion Modeling

2004 ◽  
Author(s):  
Gary Luke ◽  
Mark Eagar ◽  
Michael Sears ◽  
Scott Felt ◽  
Bob Prozan
Keyword(s):  
Flow Field ◽  
Flow Model ◽  
Two Phase Flow ◽  
Model Development ◽  
Phase Flow ◽  
Two Phase ◽  
Combustion Modeling

scholarly journals Experimental Investigation and Prediction on Pressure Drop during Flow Boiling in Horizontal Microchannels

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 510
Author(s):  
Yan Huang ◽  
Bifen Shu ◽  
Shengnan Zhou ◽  
Qi Shi
Keyword(s):  
Pressure Drop ◽  
Flow Model ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Separated Flow ◽  
Heat Fluxes ◽  
Phase Flow ◽  
Vapor Quality ◽  
Two Phase ◽  
Gas Flux

In this paper, two-phase pressure drop data were obtained for boiling in horizontal rectangular microchannels with a hydraulic diameter of 0.55 mm for R-134a over mass velocities from 790 to 1122, heat fluxes from 0 to 31.08 kW/m2 and vapor qualities from 0 to 0.25. The experimental results show that the Chisholm parameter in the separated flow model relies heavily on the vapor quality, especially in the low vapor quality region (from 0 to 0.1), where the two-phase flow pattern is mainly bubbly and slug flow. Then, the measured pressure drop data are compared with those from six separated flow models. Based on the comparison result, the superficial gas flux is introduced in this paper to consider the comprehensive influence of mass velocity and vapor quality on two-phase flow pressure drop, and a new equation for the Chisholm parameter in the separated flow model is proposed as a function of the superficial gas flux . The mean absolute error (MAE ) of the new flow correlation is 16.82%, which is significantly lower than the other correlations. Moreover, the applicability of the new expression has been verified by the experimental data in other literatures.

A prospective study of anti-vibration mechanism of microfluidic fuel cell via novel two-phase flow model

Energy ◽  
2021 ◽  
Vol 218 ◽  
pp. 119543
Author(s):  
Jingxian Chen ◽  
Peihang Xu ◽  
Jie Lu ◽  
Tiancheng Ouyang ◽  
Chunlan Mo
Keyword(s):  
Fuel Cell ◽  
Prospective Study ◽  
Flow Model ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Vibration Mechanism ◽  
Microfluidic Fuel Cell ◽  
A Prospective Study
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