Drag model validation of slurry pipeline using CFD

A number of drag models have been suggested for the interaction of fluid particles in slurry flow over the previous centuries. It is necessary to examine the correctness and applicability of these models in the slurry transportation. Based on this concept, a comparative analysis of the different drag models is performed for the 0.0549 m diameter slurry pipeline. The research is carried out by using three drag models: Syamlal-obrien, Schiller-naumann and Gidaspow due to their accessibility in the Fluent commercial software. The simulation is performed at mean flow velocity range, Vm= 2–5 ms-1 and solid concentration range, Cvf = 10– 20% (by volume) using computational drag models. The simulated outcomes for solid particle size 440 μm having density 2470 kg/m3 are recorded using Eulerian two-phase model with selected drag models in the computational domain. It has been found that the Eulerian two-phase model with Syamlal O’brien drag model gives the accurate and meticulous results with the published data in the literature. Finally, the simulated outcomes of solid concentration contours, solid concentration profiles and pressure drop are predicted at distinct velocity and solid concentration range for chosen drag models.

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Two-fluid Modeling of Geldart A Particles in Gas-solid Bubbling Fluidized Bed: Assessment of Drag Models and Solid Viscosity Correlations

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2017-0016 ◽

2017 ◽

Vol 16 (3) ◽

Cited By ~ 1

Author(s):

Tian Tian ◽

Zhengrui Jia ◽

Shujun Geng ◽

Xiaoxing Liu

Keyword(s):

Fluidized Bed ◽

Viscosity Model ◽

Frictional Stress ◽

Concentration Profiles ◽

Solid Concentration ◽

Drag Model ◽

Bubbling Fluidized Bed ◽

Drag Models ◽

Bed Expansion ◽

Two Fluid

AbstractIn this work the influences of solid viscosity and the way to scale-down traditional drag models on the predicted hydrodynamics of Geldart A particles in a lab-scale gas-solid bubbling fluidized bed are investigated. To evaluate the effects of drag models, the modified Gibilaro et al. drag model (constant correction factor) and the EMMS drag model (non-constant correction factor) are tested. And the influences of solid viscosity are assessed by considering the empirical model proposed by Gidaspow et al. (1997, Turbulence, Viscosity and Numerical Simulation of FCC Particles in CFB. Fluidization and Fluid-particle Systems, AIChE Annual Meeting, Los Angeles, 58–62) and the models based on kinetic theory of granular flow (KTGF) with or without frictional stress. The resulting hydrodynamics by incorporating the different combinations of the drag model and solid viscosity model into two-fluid model (TFM) simulations are compared with the experimental data of Zhu et al. (2008, Detailed Measurements of Flow Structure inside a Dense Gas-Solids Fluidized Bed.”Powder Technological180:339–349). The simulation results show that the predicted hydrodynamics closely depends on the setting of solid viscosity. When solid viscosity is calculated from the empirical model of Gidaspow et al., both drag models can reasonably predict the radial solid concentration profiles and particle velocity profiles. When the KTGF viscosity model without frictional stress is adopted, the EMMS drag model significantly over-estimates the bed expansion, whereas the modified Gibilaro et al. drag model can still give acceptable radial solid concentration profiles but over-estimate particle upwards and downwards velocity. When KTGF viscosity model with frictional stress is chosen, both drag models predict the occurrence of slugging. At this time, the particle velocity profiles predicted by EMMS drag model are still in well agreement with the experimental data, but the bed expansion is under-estimated.

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Direct Measurement of the Mean Flow Velocity Vector

Journal of Fluids Engineering ◽

10.1115/1.3448471 ◽

1976 ◽

Vol 98 (4) ◽

pp. 736-739 ◽

Cited By ~ 1

Author(s):

R. H. Kirchhoff ◽

R. M. Struziak

Keyword(s):

Flow Velocity ◽

Fundamental Frequency ◽

Velocity Vector ◽

Mean Flow ◽

Two Phase ◽

Response Equation ◽

The Mean ◽

Lock In ◽

Mean Flow Velocity

The response of a single inclined rotating hot wire anemometer was analyzed. The mean flow anemometer response equation was expanded in a Fourier Series about the fundamental frequency of rotation. Utilizing the d-c level and the first two harmonics of the response it is possible to construct the mean flow velocity vector within a solid angle determined by the mounting angle of the wire. The rotating anemometer response was measured using the technique of two phase lock-in detection to determine the first two harmonics and their phases relative to the fundamental frequency of rotation. Determination of the mean flow velocity vector using this technique was found to be feasible.

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Two-phase model for human classical conditioning.

Journal of Experimental Psychology ◽

10.1037/h0026448 ◽

1968 ◽

Vol 78 (3, Pt.1) ◽

pp. 359-368 ◽

Cited By ~ 6

Author(s):

William F. Prokasy ◽

Martha A. Harsanyi

Keyword(s):

Classical Conditioning ◽

Phase Model ◽

Two Phase

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A Study on Temporal Information Processing and the Two-Phase Model of Time Shifts Processing

Advances in Psychological Science ◽

10.3724/sp.j.1042.2012.00963 ◽

2013 ◽

Vol 20 (7) ◽

pp. 963-970

Author(s):

Xian-You HE ◽

Hui YANG ◽

Yu-Mei DENG ◽

Shuang WU

Keyword(s):

Information Processing ◽

Temporal Information ◽

Phase Model ◽

Two Phase ◽

Temporal Information Processing

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Transport of organochlorine pesticides in soil columns enhanced by dissolved organic carbon

Water Science & Technology ◽

10.2166/wst.1997.0270 ◽

1997 ◽

Vol 35 (7) ◽

pp. 139-145 ◽

Cited By ~ 10

Author(s):

Jiann-Yuan Ding ◽

Shian-Chee Wu

Keyword(s):

Organic Carbon ◽

Dissolved Organic Carbon ◽

Organochlorine Pesticides ◽

Transport Model ◽

Phase Model ◽

Soil Columns ◽

Two Phase ◽

Three Phase ◽

Phase Transport ◽

Remediation Of Soil

The objective of this study is to quantify the effects of humic acid solution infiltration on the transport of organochlorine pesticides (OCPs) in soil columns using a three-phase transport model. From experimental results, it is found that the dissolved organic carbon enhances the transport of OCPs in the soil columns. In the OCPs-only column, the concentration profiles of OCPs can be simulated well using a two-phase transport model with numerical method or analytical solution. In the OCPs-DOC column, the migrations of aldrin, DDT and its daughter compounds are faster than those in the OCPs-only column. The simulation with the three-phase model is more accurate than that with the two-phase model. In addition, significant decrease of the fluid pore velocities of the OCPs-DOC column was found. When DOC leachate is applied for remediation of soil or groundwater pollution, the decrease of mean pore velocities will be a crucial affecting factor.

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Investigation of two-dimensional nonstationary processes of outflow a gas-saturated liquid from axisymmetric vessels

Proceedings of the Mavlyutov Institute of Mechanics ◽

10.21662/uim2012.1.008 ◽

2012 ◽

Vol 9 (1) ◽

pp. 47-52

Author(s):

R.Kh. Bolotnova ◽

V.A. Buzina

Keyword(s):

Comparative Analysis ◽

Numerical Model ◽

Liquid Mixture ◽

Phase Model ◽

Test Problems ◽

Two Dimensional ◽

Nonstationary Processes ◽

Saturated Liquid ◽

Two Phase ◽

One Dimensional

The two-dimensional and two-phase model of the gas-liquid mixture is constructed. The validity of numerical model realization is justified by using a comparative analysis of test problems solution with one-dimensional calculations. The regularities of gas-saturated liquid outflow from axisymmetric vessels for different geometries are established.

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