Investigation of CFD-PBM simulations based on fixed pivot method : influence of the moment closure
The fixed pivot method can only conserve two moments while other moments suffer from inherent errors caused by internal inconsistency. In this work, we present a comprehensive investigation regarding the influence of moment closure on population balance and hydrodynamics in the coupled CFD-PBM simul...
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sg-ntu-dr.10356-832422023-03-04T17:23:14Z Investigation of CFD-PBM simulations based on fixed pivot method : influence of the moment closure Shang, Xiaopeng Ng, Bing Feng Wan, Man Pun Ding, Shirun School of Mechanical and Aerospace Engineering Population Balance Modeling Engineering Engineering::Mechanical engineering The fixed pivot method can only conserve two moments while other moments suffer from inherent errors caused by internal inconsistency. In this work, we present a comprehensive investigation regarding the influence of moment closure on population balance and hydrodynamics in the coupled CFD-PBM simulations. The CFD-PBM model, which conserves the surface area and volume (second and third moment, i.e. CFD-PBM-SV model), and the number and volume (zeroth and third moment, i.e. CFD-PBM-NV model), has been developed based on a two-fluid model. To assess the accuracy of Sauter Mean Diameter (SMD) with different moment closures, a transient and homogeneous case is first simulated by the single PBM model, which conserves the surface area-volume (i.e. PBM-SV model) and number-volume (i.e. PBM-NV model), respectively. It shows that in comparison with the analytical solution, the SMD predicted by the PBM-SV model shows higher accuracy than the PBM-NV model with identical sectioning resolution, and the PBM-NV model can give satisfactory results only on very fine sectioning grids. A rectangular bubble column is then simulated by the CFD-PBM-SV and CFD-PBM-NV model, respectively. It is found that both models can capture the oscillating bubble plume of the gas-liquid flow inside the column reactor. The flow features predicted by the CFD-PBM-SV model show better agreement with experimental data, in terms of the time-averaged vertical liquid velocity, gas hold-up and plume oscillation period, than the CFD-PBM-NV model. It is speculated that the better performance of the CFD-PBM-SV model is ascribed to more accurate predictions of interfacial forces and momentum transfer between the two phases due to internal consistency of the local SMD compared to the CFD-PBM-NV model. Accepted version 2019-10-10T07:50:28Z 2019-12-06T15:18:12Z 2019-10-10T07:50:28Z 2019-12-06T15:18:12Z 2019 Journal Article Shang, X., Ng, B. F., Wan, M. P., & Ding, S. (2019). Investigation of CFD-PBM simulations based on fixed pivot method : influence of the moment closure. Chemical Engineering Journal, 122882-. doi:10.1016/j.cej.2019.122882 1385-8947 https://hdl.handle.net/10356/83242 http://hdl.handle.net/10220/50136 10.1016/j.cej.2019.122882 en Chemical Engineering Journal © 2019 Elsevier. All rights reserved. This paper was published in Chemical Engineering Journal and is made available with permission of Elsevier. 56 p. application/pdf |
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Population Balance Modeling Engineering Engineering::Mechanical engineering Shang, Xiaopeng Ng, Bing Feng Wan, Man Pun Ding, Shirun Investigation of CFD-PBM simulations based on fixed pivot method : influence of the moment closure |
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The fixed pivot method can only conserve two moments while other moments suffer from inherent errors caused by internal inconsistency. In this work, we present a comprehensive investigation regarding the influence of moment closure on population balance and hydrodynamics in the coupled CFD-PBM simulations. The CFD-PBM model, which conserves the surface area and volume (second and third moment, i.e. CFD-PBM-SV model), and the number and volume (zeroth and third moment, i.e. CFD-PBM-NV model), has been developed based on a two-fluid model. To assess the accuracy of Sauter Mean Diameter (SMD) with different moment closures, a transient and homogeneous case is first simulated by the single PBM model, which conserves the surface area-volume (i.e. PBM-SV model) and number-volume (i.e. PBM-NV model), respectively. It shows that in comparison with the analytical solution, the SMD predicted by the PBM-SV model shows higher accuracy than the PBM-NV model with identical sectioning resolution, and the PBM-NV model can give satisfactory results only on very fine sectioning grids. A rectangular bubble column is then simulated by the CFD-PBM-SV and CFD-PBM-NV model, respectively. It is found that both models can capture the oscillating bubble plume of the gas-liquid flow inside the column reactor. The flow features predicted by the CFD-PBM-SV model show better agreement with experimental data, in terms of the time-averaged vertical liquid velocity, gas hold-up and plume oscillation period, than the CFD-PBM-NV model. It is speculated that the better performance of the CFD-PBM-SV model is ascribed to more accurate predictions of interfacial forces and momentum transfer between the two phases due to internal consistency of the local SMD compared to the CFD-PBM-NV model. |
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School of Mechanical and Aerospace Engineering |
author_facet |
School of Mechanical and Aerospace Engineering Shang, Xiaopeng Ng, Bing Feng Wan, Man Pun Ding, Shirun |
format |
Article |
author |
Shang, Xiaopeng Ng, Bing Feng Wan, Man Pun Ding, Shirun |
author_sort |
Shang, Xiaopeng |
title |
Investigation of CFD-PBM simulations based on fixed pivot method : influence of the moment closure |
title_short |
Investigation of CFD-PBM simulations based on fixed pivot method : influence of the moment closure |
title_full |
Investigation of CFD-PBM simulations based on fixed pivot method : influence of the moment closure |
title_fullStr |
Investigation of CFD-PBM simulations based on fixed pivot method : influence of the moment closure |
title_full_unstemmed |
Investigation of CFD-PBM simulations based on fixed pivot method : influence of the moment closure |
title_sort |
investigation of cfd-pbm simulations based on fixed pivot method : influence of the moment closure |
publishDate |
2019 |
url |
https://hdl.handle.net/10356/83242 http://hdl.handle.net/10220/50136 |
_version_ |
1759856396171476992 |