CFD simulations of tapered bubbling/turbulent fluidized beds with/without gas distributor based on the structure-based drag model

2019 ◽  
Vol 202 ◽  
pp. 157-168 ◽  
Author(s):  
Zheng Zou ◽  
Wenming Liu ◽  
Dong Yan ◽  
Zhaohui Xie ◽  
Hongzhong Li ◽  
...  
Keyword(s):  
Fluidized Beds ◽  
Cfd Simulations ◽  
Drag Model ◽  
Gas Distributor

A CFD Study of Existing Drag Models for Geldart A Particles in Bubbling Fluidized Beds

2014 ◽  
Author(s):  
Bahareh Estejab ◽  
Francine Battaglia
Keyword(s):  
Experimental Data ◽  
Fluidized Beds ◽  
Fine Particles ◽  
The Other ◽  
Particle Interactions ◽  
Model Group ◽  
Drag Model ◽  
Numerical Studies ◽  
Solid Phases ◽  
Drag Models

In this study, seven drag models are examined to determine how they affect fluidization behavior of Geldart A particles of biomass and coal. Notwithstanding the notable number of numerical studies to find the best drag model for larger particles, there is a dearth of information related to drag models for finer Geldart A particles. Additionally, to our knowledge, these drag models have not been tested with a binary mixture of Geldart A particles. Computational fluid dynamics was used to model the gas and solid phases in an Eulerian-Eulerain approach to simulate the particle-particle interactions of coal-biomass mixtures and compare the predictions with experimental data. In spite of the previous findings that bode badly for using predominately Geldart B drag models for fine particles, the results of our study reveal that if static regions of mass in the fluidized beds are considered, these drag models work well with Geldart A particles. It was found that the seven drag models could be divided into two categories based on their performance. One category included the Gidaspow family of drag models (Gidaspow, Gidaspow-Blend, and Wen-Yu) and the Syamlal-O’Brien drag model; these models closely predicted the experiments for single solids phase fluidization. For binary mixtures, however, the other drag model group (BVK, HYS, Koch and Hill) yielded better predictions.

Comparison of heat transfer models in DEM-CFD simulations of fluidized beds with an immersed probe

2009 ◽  
Vol 193 (3) ◽  
pp. 257-265 ◽  
Author(s):  
Francesco Paolo Di Maio ◽  
Alberto Di Renzo ◽  
Daniela Trevisan
Keyword(s):  
Heat Transfer ◽  
Fluidized Beds ◽  
Cfd Simulations ◽  
Transfer Models

Assessment of Drag Models for Geldart A Particles in Bubbling Fluidized Beds

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Bahareh Estejab ◽  
Francine Battaglia
Keyword(s):  
Binary Mixtures ◽  
Fluidized Beds ◽  
Fine Particles ◽  
Poplar Wood ◽  
Hydrodynamic Behavior ◽  
Empirical Relationships ◽  
Drag Model ◽  
Model Predictions ◽  
Solid Phases ◽  
Drag Models

In order to accurately predict the hydrodynamic behavior of gas and solid phases using an Eulerian–Eulerian approach, it is crucial to use appropriate drag models to capture the correct physics. In this study, the performance of seven drag models for fluidization of Geldart A particles of coal, poplar wood, and their mixtures was assessed. In spite of the previous findings that bode badly for using predominately Geldart B drag models for fine particles, the results of our study revealed that if static regions of mass in the fluidized beds are considered, these drag models work well with Geldart A particles. It was found that drag models derived from empirical relationships adopt better with Geldart A particles compared to drag models that were numerically developed. Overall, the Huilin–Gidaspow drag model showed the best performance for both single solid phases and binary mixtures, however, for binary mixtures, Wen–Yu model predictions were also accurate.

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