Evaluation of large Eddy simulation and Euler-Euler CFD models for solids flow dynamics in a stirred tank reactor

AIChE Journal ◽  
2008 ◽  
Vol 54 (3) ◽  
pp. 766-778 ◽  
Author(s):  
Debangshu Guha ◽  
P. A. Ramachandran ◽  
M. P. Dudukovic ◽  
J. J. Derksen
Keyword(s):  
Large Eddy Simulation ◽  
Flow Dynamics ◽  
Stirred Tank ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Eddy Simulation ◽  
Cfd Models ◽  
Large Eddy

Large-eddy simulation of the turbulent free-surface flow in an unbaffled stirred tank reactor

2010 ◽  
Vol 65 (15) ◽  
pp. 4307-4322 ◽  
Author(s):  
N. Lamarque ◽  
B. Zoppé ◽  
O. Lebaigue ◽  
Y. Dolias ◽  
M. Bertrand ◽  
...  
Keyword(s):  
Free Surface ◽  
Large Eddy Simulation ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Stirred Tank ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Eddy Simulation ◽  
Large Eddy

scholarly journals The Process of the Intensification of Coal Fly Ash Flotation Using a Stirred Tank

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 597 ◽  
Author(s):  
Lu Yang ◽  
Zhenna Zhu ◽  
Xin Qi ◽  
Xiaokang Yan ◽  
Haijun Zhang
Keyword(s):  
Fly Ash ◽  
Kinetic Energy ◽  
Large Eddy Simulation ◽  
Rotation Speed ◽  
Coal Fly Ash ◽  
Stirred Tank ◽  
Turbulent Length Scale ◽  
Mineral Particles ◽  
Eddy Simulation ◽  
Large Eddy

Pulp preconditioning using a stirred tank as a pretreatment process is vital to the flotation system, which can be used to improve the flotation efficiency of mineral particles. The kinetic energy that is dissipated in the stirred tank could strengthen the interaction process between mineral particles and flotation reagents to improve the flotation efficiency in the presence of the preconditioning. In this paper, the effect of the conditioning speed on the coal fly ash flotation was investigated using numerical simulations and conditioning-flotation tests. The large eddy simulation coupled with the Smagorinsky-Lilly subgrid model was employed to simulate the turbulence flow field in the stirred tank, which was equipped with a six blade Rushton turbine. The impeller rotation was modelled using the sliding mesh. The simulation results showed that the large eddy simulation (LES) well matched the previous experimental data. The turbulence characteristics, such as the mean velocity, turbulent kinetic energy, power consumption and instantaneous structures of trailing vortices were analysed in detail. The turbulent length scale (η) decreased as the rotation speed increased, and the minimum value of η was almost unchanged when the rotation speed was more than 1200 rpm. The conditioning-flotation tests of coal fly ash were conducted using different conditioning speeds. The results showed that the removal of unburned carbon was greatly improved due to the strengthened turbulence in the stirred tank, and the optimal results were obtained with an LOI of 3.32%, a yield of 78.69% and an RUC of 80.89% when the conditioning speed was 1200 rpm.

Large Eddy Simulation Study of Flow Dynamics in a Multiswirler Model Combustor at Elevated Pressure and High Temperature

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Weijie Liu ◽  
Qian Yang ◽  
Ranran Xue ◽  
Huiru Wang
Keyword(s):  
High Temperature ◽  
Large Eddy Simulation ◽  
Elevated Pressure ◽  
Dominant Frequency ◽  
Flow Dynamics ◽  
Main Stage ◽  
Eddy Simulation ◽  
Precessing Vortex Core ◽  
Flow Interaction ◽  
Large Eddy

Large eddy simulation (LES) of nonreacting turbulent flow in a multiswirler model combustor is carried out at elevated pressure and high temperature. Flow interaction between the main stage and the pilot stage is discussed based on the time-averaged and instantaneous flowfield. Flow dynamics in the multiswirling flow are analyzed using a phase-averaged method. Proper orthogonal decomposition (POD) is used to extract dominant flow features in the multiswirling flow. Numerical results show that the main stage and the pilot stage flows interact with each other generating a complex flowfield. Flow interaction can be divided into three regions: converging region, merging region, and combined region. A precessing vortex core (PVC) is successfully captured in the pilot stage. PVC rotates with a first dominant frequency of 2756 Hz inducing asymmetric azimuthal flow instabilities in the pilot stage. POD analyses for the velocity fields also show dominant high-frequency modes (mode 1 and mode 2) in the pilot stage. However, the dominant energetic flow is damped rapidly downstream of the pilot stage such that it has a little effect on the main stage flow.

Large-Eddy Simulation of Single-Phase Flow Dynamics and Mixing in an Industrial Crystallizer

2007 ◽  
Vol 85 (2) ◽  
pp. 169-179 ◽  
Author(s):  
J.J. Derksen ◽  
K. Kontomaris ◽  
J.B. McLaughlin ◽  
H.E.A. Van den Akker
Keyword(s):  
Large Eddy Simulation ◽  
Single Phase ◽  
Flow Dynamics ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Eddy Simulation ◽  
Large Eddy

Shear improved Smagorinsky model for large eddy simulation of flow in a stirred tank with a Rushton disk turbine

2016 ◽  
Vol 108 ◽  
pp. 69-80 ◽  
Author(s):  
Satish Malik ◽  
Emmanuel Lévêque ◽  
Mounir Bouaifi ◽  
Lionel Gamet ◽  
Eglantine Flottes ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Stirred Tank ◽  
Smagorinsky Model ◽  
Eddy Simulation ◽  
Large Eddy
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