The scale-up method for the hydrodynamic processes in a sorbent layer using CFD simulation with the Ergun’s equation-based models

2021 ◽  
Author(s):  
A. P. Khomyakov ◽  
S. V. Mordanov ◽  
O. L. Tashlykov ◽  
V. P. Remez
Keyword(s):  
Cfd Simulation ◽  
Scale Up ◽  
Sorbent Layer ◽  
Hydrodynamic Processes

scholarly journals Influence of inlet air distributor geometry on the fluid dynamics of conical spouted beds: A CFD study

2018 ◽  
Vol 24 (4) ◽  
pp. 369-378 ◽  
Author(s):  
J.N.M. Batista ◽  
R.C. Brito ◽  
R. Béttega
Keyword(s):  
Fluid Dynamics ◽  
Cfd Simulation ◽  
Low Cost ◽  
Scale Up ◽  
Straight Tube ◽  
Spouted Bed ◽  
Bed Height ◽  
Spouted Beds ◽  
Wide Range ◽  
Solid Dynamics

The spouted bed presents limitations in terms of scale-up. Furthermore, its stability depends on its geometry as well as the properties of the fluid and solid phases. CFD provides an important tool to improve understanding of these aspects, enabling a wide range of information to be obtained rapidly and at low cost. In this work, CFD simulation was used to evaluate the effects of different inlet air distributors (Venturi and straight tube) and the effects of static bed height on the fluid and solid dynamics of a conical spouted bed. Simulations were performed using the two-dimensional Euler-Euler approach. In order to evaluate the fluid dynamics model, static pressure data obtained by simulation were compared with experimental data obtained with the Venturi distributor. The fluid and solid dynamics of the conical spouted bed were obtained by CFD simulation. The results showed that the pressure drop was lower for the straight tube air distributor, while the Venturi air distributor provided higher stability and a more homogenous air distribution at the bed entrance.

scholarly journals The Efficient Application of an Impulse Source Wavemaker to CFD Simulations

2019 ◽  
Author(s):  
Pál Schmitt ◽  
Christian Windt ◽  
Josh Davidson ◽  
John V. Ringwood ◽  
Trevor Whittaker
Keyword(s):  
Shallow Water ◽  
Source Function ◽  
Cfd Simulation ◽  
Navier Stokes ◽  
Cfd Simulations ◽  
Wide Range ◽  
Rans Models ◽  
Hydrodynamic Processes ◽  
Computational Fluid Dynamics Cfd ◽  
Shallow Water Models

Computational Fluid Dynamics (CFD) simulations, based on Reynolds Averaged Navier Stokes (RANS) models, are a useful tool for a wide range of coastal and offshore applications, providing a high fidelity representation of the underlying hydrodynamic processes. Generating input waves in the CFD simulation is performed by a numerical wavemaker (NWM), with a variety of different NWM methods existing for this task. While NWMs, based on impulse source methods, have been widely applied for wave generation in depth averaged, shallow water models, they have not seen the same level of adoption in the more general RANS based CFD simulations, due to difficulties in relating the required impulse source function to the resulting free surface elevation for non-shallow water cases. This paper presents an implementation of an impulse source wavemaker, which is able to self-calibrate the impulse source function to produce a desired wave series in deep or shallow water at a specific point in time and space. Example applications are presented, for a numerical wave tank (NWT), based on the opensource CFD software OpenFOAM, for wave packets in deep and shallow water, highlighting the correct calibration of phase and amplitude. Also, the suitability for cases requiring very low reflection from NWT boundaries is demonstrated. Possible issues in the use of the method are discussed and guidance for good application is given.

CFD Simulation of Water Gas Shift Membrane Reactor--Pressure Effects on the Performance of the Reactor

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Byron Smith R.J. ◽  
Muruganandam Loganathan ◽  
Murthy Shekhar Shantha
Keyword(s):  
Membrane Reactor ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Scale Up ◽  
Pressure Effects ◽  
Water Gas Shift ◽  
Pure Hydrogen ◽  
Computational Fluid Dynamic Analysis ◽  
H2 Recovery ◽  
Water Gas

Membrane reactor is a process intensified equipment that carries out both the reaction and separation in a single vessel. The equilibrium limited water gas shift reaction is an ideal reaction to be carried out in a membrane reactor as it improves the conversion of the reaction and reduces the space requirement for the reactor. Computational fluid dynamics offers a virtual prototyping of the reactor and helps in design, optimization, and scale-up of the reactor. To obtain pure hydrogen from the membrane reactor, the pressure of the reactor needs to be optimized. Hence the water gas shift membrane reactor is subjected to computational fluid dynamic analysis to understand the role played by pressure on the performance of the reactor using three different gas mixtures. The CO conversion and H2 recovery for the different operating pressures are simulated and the effects of pressure are discussed in this paper.

CFD Simulation of Different Flow Regimes of the Spout Fluidized Bed with Draft Plates

2017 ◽  
Vol 899 ◽  
pp. 89-94
Author(s):  
Bruna Sene Alves Araújo ◽  
Kássia Graciele dos Santos
Keyword(s):  
Fluid Dynamics ◽  
Fluidized Bed ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Scale Up ◽  
Flow Regimes ◽  
Chemical Transformations ◽  
Experimental Fluid Dynamics ◽  
Computation Fluid Dynamics ◽  
Two Phases

Spout fluidized bed has shown promising for gas-solid contact operations with and without chemical reactions, such as drying, coating, granulation, gasification, pyrolysis, etc. This is because these beds combine features from both spouted and fluidized beds. The other point is the ability to treat chemical transformations involving both heat and mass transfer in combination with particles of various sizes. Therefore, it is extremely important the knowledge of fluid dynamic of the bed, mainly for scale-up projects, which makes computer simulation an essential tool. Researches using the Computation Fluid Dynamics (CFD) proved to be very effective in predicting of particles dynamic in this type of bed. In Computation Fluid Dynamics, the two phases are treated as interpenetration continuous, and these phases are described by equations of conservation of mass, momentum and energy. The goal of the present work was to simulate using CFD experimental fluid dynamics data of a spout fluidized bed. Eight distinct flow regimes were identified which showed up in good agreement with the regime map presented in literature. The results showed that the technique was efficient for the simulation of the hydrodynamic of the bed presented.

scholarly journals An Assessment of Drag Models in Eulerian–Eulerian CFD Simulation of Gas–Solid Flow Hydrodynamics in Circulating Fluidized Bed Riser

2020 ◽  
Vol 4 (2) ◽  
pp. 37 ◽  
Author(s):  
Mukesh Upadhyay ◽  
Ayeon Kim ◽  
Heehyang Kim ◽  
Dongjun Lim ◽  
Hankwon Lim
Keyword(s):  
Fluidized Bed ◽  
Cfd Simulation ◽  
Circulating Fluidized Bed ◽  
Model Simulation ◽  
Scale Up ◽  
Radial Profile ◽  
Momentum Exchange ◽  
Drag Model ◽  
Solid Holdup ◽  
Drag Models

Accurate prediction of the hydrodynamic profile is important for circulating fluidized bed (CFB) reactor design and scale-up. Multiphase computational fluid dynamics (CFD) simulation with interphase momentum exchange is key to accurately predict the gas-solid profile along the height of the riser. The present work deals with the assessment of six different drag model capability to accurately predict the riser section axial solid holdup distribution in bench scale circulating fluidized bed. The difference between six drag model predictions were validated against the experiment data. Two-dimensional geometry, transient solver and Eulerian–Eulerian multiphase models were used. Six drag model simulation predictions were discussed with respect to axial and radial profile. The comparison between CFD simulation and experimental data shows that the Syamlal-O’Brien, Gidaspow, Wen-Yu and Huilin-Gidaspow drag models were successfully able to predict the riser upper section solid holdup distribution with better accuracy, however unable to predict the solid holdup transition region. On the other hand, the Gibilaro model and Helland drag model were successfully able to predict the bottom dense region, but the upper section solid holdup distribution was overpredicted. The CFD simulation comparison of different drag model has clearly shown the limitation of the drag model to accurately predict overall axial heterogeneity with accuracy.

scholarly journals CFD Simulation of Dry Pressure Drop in a Cross-Flow Rotating Packed Bed

2021 ◽  
Vol 11 (21) ◽  
pp. 10099
Author(s):  
Chao Zhang ◽  
Weizhou Jiao ◽  
Youzhi Liu ◽  
Guisheng Qi ◽  
Zhiguo Yuan ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Complex Structure ◽  
Scale Up ◽  
Cross Flow ◽  
Packed Bed ◽  
Rotating Packed Bed ◽  
Porous Media Model ◽  
The Cross

The cross-flow rotating packed bed (RPB) has attracted wide attention in recent years because of its advantages of large gas capacity, low pressure drop and lack of flooding limitation. However, the complex structure of the packing makes it difficult to obtain the gas flow characteristics in the cross-flow RPB by experiments. In this study, the dry pressure drop in the cross-flow RPB was investigated by computational fluid dynamics (CFD). The packing was modeled by the porous media model and the rotation of the packing was simulated by the sliding mesh model. The simulation results obtained by three turbulence models were compared with experimental results, and the RNG k-ε model was found to best describe the turbulence behaviors in the cross-flow RPB. Then, the effects of gas flow rate and rotating speed on dry pressure drop in different parts of the cross-flow RPB were analyzed. The results of this study can provide important insights into the design and scale-up of cross-flow RPB.

Numerical Simulation of the Swirl Flow Effect on the Cold Condition Characteristic of Entrained Flow Gasifier

2012 ◽  
Vol 524-527 ◽  
pp. 1943-1946
Author(s):  
Zhi Qiang Wu ◽  
Shu Zhong Wang ◽  
Lin Chen ◽  
Jun Zhao ◽  
Hai Yu Meng
Keyword(s):  
Numerical Simulation ◽  
Flow Characteristic ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Scale Up ◽  
Swirl Flow ◽  
Injection Velocity ◽  
Cold Flow ◽  
Entrained Flow ◽  
Entrained Flow Gasifier

The swirl flow could enhance the turbulent mixing and promote the slagging in the entrained flow gasifier. In recent research, the effect of swirl flow on cold flow characteristic of entrained flow gasifier was neglected or simplified. To address this, a three-dimensional computational fluid dynamic (CFD) simulation was presented to investigate the effect of swirl flow on the cold flow characteristic of entrained flow gasifier. Several control parameters, i.e., the diameter and injection velocity of nozzles, were found to significantly affect swirl intensity and velocity distribution in the entrained flow gasifier. Our numerical simulation provides an effective way for researchers or engineers to optimize and scale up the gasifier and nozzle.

scholarly journals The Efficient Application of an Impulse Source Wavemaker to CFD Simulations

2019 ◽  
Vol 7 (3) ◽  
pp. 71 ◽  
Author(s):  
Pal Schmitt ◽  
Christian Windt ◽  
Josh Davidson ◽  
John V Ringwood ◽  
Trevor Whittaker
Keyword(s):  
Shallow Water ◽  
Source Function ◽  
Cfd Simulation ◽  
Free Surface Elevation ◽  
Cfd Simulations ◽  
Wide Range ◽  
Rans Models ◽  
Hydrodynamic Processes ◽  
Computational Fluid Dynamics Cfd ◽  
Shallow Water Models

Computational Fluid Dynamics (CFD) simulations, based on Reynolds-AveragedNavier–Stokes (RANS) models, are a useful tool for a wide range of coastal and offshore applications,providing a high fidelity representation of the underlying hydrodynamic processes. Generating inputwaves in the CFD simulation is performed by a Numerical Wavemaker (NWM), with a variety ofdifferent NWM methods existing for this task. While NWMs, based on impulse source methods, havebeen widely applied for wave generation in depth averaged, shallow water models, they have notseen the same level of adoption in the more general RANS-based CFD simulations, due to difficultiesin relating the required impulse source function to the resulting free surface elevation for non-shallowwater cases. This paper presents an implementation of an impulse source wavemaker, which is ableto self-calibrate the impulse source function to produce a desired wave series in deep or shallowwater at a specific point in time and space. Example applications are presented, for a NumericalWave Tank (NWT), based on the open-source CFD software OpenFOAM, for wave packets in deepand shallow water, highlighting the correct calibration of phase and amplitude. Furthermore, thesuitability for cases requiring very low reflection from NWT boundaries is demonstrated. Possibleissues in the use of the method are discussed, and guidance for accurate application is given.

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