Simulation of Spouted Bed Using a Eulerian Multiphase Model

2005 ◽  
Vol 498-499 ◽  
pp. 270-277 ◽  
Author(s):  
Claudio Roberto Duarte ◽  
Valéria V. Murata ◽  
Marcos A.S. Barrozo
Keyword(s):  
Control Volume ◽  
Flow Behavior ◽  
Cfd Modeling ◽  
Gas Flows ◽  
Present Calculation ◽  
Multiphase Model ◽  
Spouted Bed ◽  
Particle Coating ◽  
Spouted Beds ◽  
Good Agreement

Spouted bed systems have emerged as very efficient fluid-particle contactors and find many applications in the chemical and biochemical industry. Some important applications of spouted beds include coal combustion, biochemical reactions, drying of solids, drying of solutions and suspensions, granulation, blending, grinding, and particle coating. An extensive overview can be found in Mathur and Epstein[1]. The pattern of solid and gas flows in a spouted bed was numerically simulated using a CFD modeling technique. The Eulerian-Eulerian multifluid modeling approach was applied to predict gas-solid flow behavior. A commercially available, control-volume-based code FLUENT 6.1 was chosen to carry out the computer simulations. In order to reduce computational times and required system resources, the 2D axisymmetric segregated solver was chosen. The typical flow pattern of the spouted bed was obtained in the present calculation. The simulated velocity and voidage profiles presented a good agreement qualitative and quantitative with the experimental results obtained by He et al. [4].

The Use of CFD Technique in the Study of the Spouted Bed

2006 ◽  
Vol 530-531 ◽  
pp. 382-387 ◽  
Author(s):  
Claudio Roberto Duarte ◽  
R.A.A. Rosa ◽  
Valéria V. Murata ◽  
Marcos A.S. Barrozo
Keyword(s):  
Flow Pattern ◽  
Gas Flows ◽  
Present Calculation ◽  
Multiphase Model ◽  
Catalytic Polymerization ◽  
Spouted Bed ◽  
Qualitative And Quantitative ◽  
Eulerian Multiphase Model ◽  
Good Agreement ◽  
Circulation Characteristics

The spouted bed has been used in drying, granulation, catalytic polymerization, residues treatment and coating of several materials. The success of its applications is attributable to the solids circulation characteristics and excellent gas-particle contact. The pattern of solid and gas flows in a spouted bed was numerically simulated using a Eulerian multiphase model. The typical flow pattern of the spouted bed was obtained in the present calculation for axisymetric gas-solid flows. The simulated velocity profiles and the voidage profiles presented a good agreement qualitative and quantitative with the experimental results obtained by He et al. [4].

Study on the Flow Behavior in Thin Cavity during Water-Assisted Injection Molding

2011 ◽  
Vol 467-469 ◽  
pp. 80-83
Author(s):  
Tang Qing Kuang ◽  
Kun Han
Keyword(s):  
Injection Molding ◽  
Control Volume ◽  
Fluid Model ◽  
Flow Behavior ◽  
Experimental Result ◽  
Bulk Temperature ◽  
Injection Molding Process ◽  
Molding Process ◽  
Injection Location ◽  
Good Agreement

A numerical simulation model for the flow behavior of fluids in thin cavity during water assisted injection molding process is built up by adopting general Newtonian fluid model for the filling stage and non-Newtonian and compressible fluid model for the packing stage separately. Finite element/finite difference/control volume methods are adopted for the simulation of melt front, pressure variation at injection location, water thickness fraction and bulk temperature about a plate with trapezoidal cross-section. The simulated melt front location and shape have good agreement with experimental result. In comparison with the simulation results of conventional injection molding, it turns out that water assisted injection molding can obtain parts with low pressure requirement, perfect surface quality and rapid cooling.

Study on the Flow Behavior in a Tubular Cavity during Water-Assisted Injection Molding

2010 ◽  
Vol 154-155 ◽  
pp. 359-362
Author(s):  
Tang Qing Kuang
Keyword(s):  
Injection Molding ◽  
Control Volume ◽  
Flow Behavior ◽  
Polymer Melt ◽  
Bulk Temperature ◽  
Curved Pipe ◽  
Fluid Behavior ◽  
Simulation Results ◽  
Injection Location ◽  
Good Agreement

A simulation model for the filling of a tubular cavity during water assisted injection molding is proposed. The polymer melt and water are assumed to be incompressible and to follow a Hele-Shaw fluid behavior. The finite element/finite difference/control volume methods are adopted for numerical simulation of the melt front, pressure at injection location variation, water thickness fraction and bulk temperature about a curved pipe, the simulation results have good agreement with the results presented in the former experiment. In comparison with the simulation result of gas-assisted injection molding, water assisted injection molding can give parts with thinner and more uniform walls and more rapid cooling.

Identification of the Spouted Bed Flow Regime by Simulation and Experimental Data

2008 ◽  
Vol 591-593 ◽  
pp. 329-334 ◽  
Author(s):  
R.O. Lourenço ◽  
Kássia Graciele dos Santos ◽  
Valéria V. Murata ◽  
Claudio Roberto Duarte ◽  
Humberto Molinar Henrique ◽  
...  
Keyword(s):  
Experimental Data ◽  
Cfd Simulation ◽  
Volume Fraction ◽  
Flow Regimes ◽  
Visual Observation ◽  
Circulation Rate ◽  
Multiphase Model ◽  
Spouted Bed ◽  
Spouted Beds ◽  
Experimental Apparatus

The particle circulation rate and gas–solid contacting efficiency are important parameters for the project of spouted beds, applied in many industrial processes. Due to the restrictions found in the identification of flow regimes through visual observation, new techniques have been developed to obtain a better gas and particle dynamics description, necessary for the evaluation of these parameters. One of these techniques has been the CFD simulation. In this work the pattern of solids and gas flows in a spouted bed was numerically simulated using a 3D Eulerian multiphase model. Soybean particles had been used in the attainment of data of pressure drop fluctuation and power spectrum as a function of gas velocity in an experimental apparatus. The 3D simulated solids volume fraction profiles allow the identification of the flow regimes showing a good agreement with the experimental data.

Mixture of Particles' Influence in Computer Simulations of a Spouted Bed

2010 ◽  
Vol 660-661 ◽  
pp. 448-453 ◽  
Author(s):  
D.A. Santos ◽  
I. Petri Junior ◽  
Marcos A.S. Barrozo ◽  
Claudio Roberto Duarte
Keyword(s):  
Experimental Data ◽  
High Speed ◽  
Fluid Dynamic ◽  
Computational Simulation ◽  
Particle Interaction ◽  
Multiphase Model ◽  
Spouted Bed ◽  
Air Concentration ◽  
Spouted Beds ◽  
Full Plane

This article aims to assess the influence of the way of simulating monoparticles as just monoparticles or as a mixture of particles, the latter, unlike the first, considering the effect of particle-particle interaction. The Eulerian–Eulerian multiphase model is used in the computational simulation of fluid dynamics of spouted beds and compared with experimental data. A half column of cylindrical spouted bed with a full plane glass attached to the front open surface of the bed as the transparent window was used for observation and photographing. Images of solid flows were recorded using a high speed camera (2000 frames per second). Glass beads with a diameter of 0.00368, 0.005 and 0.00252 mm are used as bed material. The simulated characteristic fluid dynamic curves of spouted bed for 0.15 m static bed heights (Ho) were obtained with good agreement with experimental data when the monoparticles was simulated as a mixture of particles with mixture’s percentage of 50%. The same occurred for the simulation of vertical velocities of particles profile, that is, when the monoparticles was simulated as a mixture of particles with mixture’s percentage of 50% we observed a more approach to the experimental data. It was also observed that the air concentration distribution seem to be independent of the changing of the composition.

Study of Measurement Methods of Particle Velocity in a Spouted Bed

2012 ◽  
Vol 727-728 ◽  
pp. 1842-1847
Author(s):  
D.A. Santos ◽  
G.C. Alves ◽  
M.A.S. Barrozo ◽  
Claudio Roberto Duarte
Keyword(s):  
Particle Velocity ◽  
High Speed ◽  
Measurement Techniques ◽  
Video Camera ◽  
Three Dimensions ◽  
Average Particle ◽  
Multiphase Model ◽  
Spouted Bed ◽  
Spouted Beds ◽  
Fiber Optical

Average particle velocity measurements were carried out in a conical-cylindrical spouted bed made of acrylic. In this study an intrusive fiber optical technique which is based on a cross-correlation function between signals from its two channels was used. For a non-intrusive measurement in order to compare with the intrusive technique, images of particle movement were recorded using a high-speed video camera. The experiments were conducted in differents air velocity conditions above the minimum spouting velocity. The latter method was limited in velocity measurement only near the spouted beds wall inasmuch as the spouted bed used was a three dimensions one. On the other hand, the fiber optical is a promising technique for measuring particle velocity distributions in a three dimensions spouted bed. To predict the minimum spouting velocity in order to use this result in the measurement techniques investigation, simulations were carried out using the Eulerian-Eulerian multiphase model.

CFD modeling of the gas–particle flow behavior in spouted beds

2008 ◽  
Vol 183 (2) ◽  
pp. 260-272 ◽  
Author(s):  
Wu Zhonghua ◽  
Arun S. Mujumdar
Keyword(s):  
Flow Behavior ◽  
Particle Flow ◽  
Cfd Modeling ◽  
Spouted Beds

scholarly journals Research on the viscosity of stabilized emulsions in different pipe diameters using pressure drop and phase inversion

2021 ◽  
Author(s):  
Jose Plasencia ◽  
Nathanael Inkson ◽  
Ole Jørgen Nydal
Keyword(s):  
Pressure Drop ◽  
Salt Water ◽  
Flow Behavior ◽  
Turbulent Viscosity ◽  
Relative Viscosity ◽  
Cfd Modeling ◽  
Water Fraction ◽  
Water Fractions ◽  
Oil Emulsions ◽  
Mixture Velocity

AbstractThis paper reports experimental research on the flow behavior of oil-water surfactant stabilized emulsions in different pipe diameters along with theoretical and computational fluid dynamics (CFD) modeling of the relative viscosity and inversion properties. The pipe flow of emulsions was studied in turbulent and laminar conditions in four pipe diameters (16, 32, 60, and 90 mm) at different mixture velocities and increasing water fractions. Salt water (3.5% NaCl w/v, pH = 7.3) and a mineral oil premixed with a lipophilic surfactant (Exxsol D80 + 0.25% v/v of Span 80) were used as the test fluids. The formation of water-in-oil emulsions was observed from low water fractions up to the inversion point. After inversion, unstable water-in-oil in water multiple emulsions were observed under different flow regimes. These regimes depend on the mixture velocity and the local water fraction of the water-in-oil emulsion. The eddy turbulent viscosity calculated using an elliptic-blending k-ε model and the relative viscosity in combination act to explain the enhanced pressure drop observed in the experiments. The inversion process occurred at a constant water fraction (90%) and was triggered by an increase of mixture velocity. No drag reduction effect was detected for the water-in-oil emulsions obtained before inversion.

Upward Vertical Two-Phase Flow Through an Annulus—Part II: Modeling Bubble, Slug, and Annular Flow

1992 ◽  
Vol 114 (1) ◽  
pp. 14-30 ◽  
Author(s):  
E. F. Caetano ◽  
O. Shoham ◽  
J. P. Brill
Keyword(s):  
Flow Pattern ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Bubble Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through ◽  
Physical Phenomena ◽  
Good Agreement

Mechanistic models have been developed for each of the existing two-phase flow patterns in an annulus, namely bubble flow, dispersed bubble flow, slug flow, and annular flow. These models are based on two-phase flow physical phenomena and incorporate annulus characteristics such as casing and tubing diameters and degree of eccentricity. The models also apply the new predictive means for friction factor and Taylor bubble rise velocity presented in Part I. Given a set of flow conditions, the existing flow pattern in the system can be predicted. The developed models are applied next for predicting the flow behavior, including the average volumetric liquid holdup and the average total pressure gradient for the existing flow pattern. In general, good agreement was observed between the experimental data and model predictions.

Thermo-Mechanical Modeling and Analysis of Equal Channel Angular Pressing

2005 ◽  
Vol 23 ◽  
pp. 263-266 ◽  
Author(s):  
Qing Xiang Pei ◽  
B.H. Hu ◽  
C. Lu
Keyword(s):  
Equal Channel Angular Pressing ◽  
Temperature Rise ◽  
Flow Behavior ◽  
Material Model ◽  
Workpiece Material ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Die Geometry ◽  
Angular Pressing ◽  
Good Agreement

Thermo-mechanical finite element analysis was carried out to study the deformation behavior and temperature distribution during equal channel angular pressing (ECAP). The material model used is the Johnson-Cook constitution model that can consider the multiplication effect of strain, strain rate, and temperature on the flow stress. The effects of pressing speed, pressing temperature, workpiece material and die geometry on the temperature rise and flow behavior during ECAP process were investigated. The simulated temperature rise due to deformation heating was compared with published experimental results and a good agreement was obtained. Among the various die geometries studied, the two-turn die with 0° round corner generates the highest and most uniform plastic strain in the workpiece.

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