Three-dimensional CFD simulation and experimental validation of particle segregation in CFB riser

Purpose The purpose of this paper is to perform the computational fluid dynamics (CFD) simulation with experimental validation to investigate the particle segregation effect in abrupt and smooth shapes circulating fluidized bed (CFB) risers. Design/methodology/approach The experimental investigations were carried out in lab-scale CFB systems and the CFD simulations were performed by using commercial software BARRACUDA. Special attention was paid to investigate the gas-particle flow behavior at the top of the riser with three different superficial velocities, namely, 4, 6 and 7.7 m/s. Here, a CFD-based noble simulation approach called multi-phase particle in cell (MP-PIC) was used to investigate the effect of traditional drag models (Wen-Yu, Ergun, Wen-Yu-Ergun and Richardson-Davidson-Harrison) on particle flow characteristics in CFB riser. Findings Findings from the experimentations revealed that the increase in gas velocity leads to decrease the mixing index inside the riser. Moreover, the solid holdup found more in abrupt riser than smooth riser at the constant gas velocity. Despite the more experimental investigations, the findings with CFD simulations revealed that the MP-PIC approach, which was combined with different drag models could be more effective for the practical (industrial) design of CFB riser. Well agreement was found between the simulation and experimental outputs. The simulation work was compared with experimental data, which shows the good agreement (<4%). Originality/value The experimental and simulation study performed in this research study constitutes an easy-to-use with different drag coefficient. The proposed MP-PIC model is more effective for large particles fluidized bed, which can be helpful for further research on industrial gas-particle fluidized bed reactors. This study is expected to give throughout the analysis of CFB hydrodynamics with further exploration of overall fluidization.

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3D Numerical Simulation of Polydisperse Pressurized Gas-Solid Fluidized Bed

ASME-JSME-KSME 2011 Joint Fluids Engineering Conference: Volume 1, Symposia – Parts A, B, C, and D ◽

10.1115/ajk2011-12016 ◽

2011 ◽

Cited By ~ 3

Author(s):

P. Fede ◽

O. Simonin ◽

I. Ghouila

Keyword(s):

Numerical Simulation ◽

Fluidized Bed ◽

Ethylene Polymerization ◽

Solid Phase ◽

Three Dimensional ◽

Gas Velocity ◽

Particle Segregation ◽

3D Numerical Simulation ◽

Model Predictions ◽

The Mean

Three dimensional unsteady numerical simulations of dense pressurized polydisperse fluidized bed have been carried out. The geometry is a medium-scale industrial pilot for ethylene polymerization. The numerical simulation have been performed with a polydisperse collision model. The consistency of the polydisperse model predictions with the monodisperse ones is shown. The results show that the pressure distribution and the mean vertical gas velocity are not modified by polydispersion of the solid phase. In contrast, the solid particle species are not identically distributed in the fluidized bed indicating the presence of particle segregation.

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CFD simulations of gas–solid flow in an industrial-scale circulating fluidized bed furnace using subgrid-scale drag models

Particuology ◽

10.1016/j.partic.2014.05.008 ◽

2015 ◽

Vol 18 ◽

pp. 66-75 ◽

Cited By ~ 19

Author(s):

Srujal Shah ◽

Kari Myöhänen ◽

Sirpa Kallio ◽

Timo Hyppänen

Keyword(s):

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Industrial Scale ◽

Subgrid Scale ◽

Cfd Simulations ◽

Solid Flow ◽

Drag Models

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Network modelling of dry-type transformer cooling systems

COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ◽

10.1108/compel-12-2016-0534 ◽

2018 ◽

Vol 37 (3) ◽

pp. 1039-1053 ◽

Cited By ~ 1

Author(s):

Andrea Cremasco ◽

Wei Wu ◽

Andreas Blaszczyk ◽

Bogdan Cranganu-Cretu

Keyword(s):

Network Model ◽

Thermal Model ◽

Cfd Simulation ◽

Cooling System ◽

Cfd Simulations ◽

Network Modelling ◽

Cooling Systems ◽

Content Type ◽

System Configurations ◽

Dielectric Insulation

Purpose The application of dry-type transformers is growing in the market because the technology is non-flammable, safer and environmentally friendly. However, the unit dimensions are normally larger and material costs become higher, as no oil is present for dielectric insulation or cooling. At designing stage, a transformer thermal model used for predicting temperature rise is fundamental and the modelling of cooling system is particularly important. This paper aims to describe a thermal model used to compute dry transformers with different cooling system configurations. Design/methodology/approach The paper introduces a fast-calculating thermal and pressure network model for dry-transformer cooling systems, preliminarily verified by analytical methods and advanced CFD simulations, and finally validated with experimental results. Findings This paper provides an overview of the network model of dry-transformer cooling system, describing its topology and its main variants including natural or forced ventilation, with or without cooling duct in the core, enclosure with roof and floor ventilation openings and air barriers. Finally, it presents a formulation for the new heat exchanger element. Originality/value The network approach presented in this paper allows to model efficiently the cooling system of dry-type transformers. This model is based on physical principles rather than empirical assessments that are valid only for specific transformer technologies. In comparison with CFD simulation approach, the network model runs much faster and the accuracies still fall in acceptable range; therefore, one is able to utilize this method in optimization procedures included in transformer design systems.

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CFD simulation of empty fuel tanks separation from a trainer jet

Aircraft Engineering and Aerospace Technology ◽

10.1108/aeat-12-2019-0247 ◽

2020 ◽

Vol 92 (10) ◽

pp. 1459-1468

Author(s):

Aleksander Olejnik ◽

Adam Dziubiński ◽

Łukasz Kiszkowiak

Keyword(s):

Cfd Simulation ◽

Body Movement ◽

Cfd Simulations ◽

Content Type ◽

Sequential Release ◽

Wind Tunnel Data ◽

Computational Fluid Dynamics Cfd ◽

External Forces ◽

Additional Value ◽

Control Surfaces

Purpose This study aims to create 6-degree of freedom (SDOF) for computational fluid dynamics (CFD) simulations of body movement, and to validate using the experimental data for empty tank separation from I-22 Iryda jet trainer. The procedure has an ability to be modified or extended, to simulate, for example, a sequential release from the joints. Design/methodology/approach A set of CFD simulations are calculated. Both the SDOF procedure and the CFD simulation settings are validated using the wind tunnel data available for the aircraft. Findings The simulation using designed procedure gives predictable results, but offers availability to be modified to represent external forces, i.e. from body interaction or control system without necessity to model the control surfaces. Practical implications The procedure could be used to model the separation of external stores and design the deployment of anti-radar chaff, flares or ejection seats. Originality/value The work presents original work, caused by insufficient abilities of original SDOF procedure in ANSYS code. Additional value is the ability of the procedure to be easily modified.

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