4 research outputs found
A study on the scale dependence of mixing indices for Eulerian multiphase models
No full textMixing can vary based on the scale at which the system is observed, and a mixing index that can capture the features at different length scales is desirable. In this article, we analyze the scale dependence of the mixing indices developed for Eulerian multiphase models. Relevant length scales are distinguished by filtering solid fraction fields. The scale-dependence study is first done on manufactured fields of solid fraction to assess the performance of the mixing indices. The study is extended to a two-dimensional CFD simulation of the segregation of a bidisperse gas–solid mixture. The local mixing index performs well in capturing the spatial variation of mixing at different scales. The scale dependence of two global mixing indices is considered in the study, where the state of mixing is defined based on statistical measures. We demonstrate that the choice of measures influences the sensitivity of mixing indices to mixing at different scales.This article is published as Nagawkar, Barlev R., Alberto Passalacqua, and Shankar Subramaniam. "A study on the scale dependence of mixing indices for Eulerian multiphase models." AIChE Journal (2024): e18589. doi: https://doi.org/10.1002/aic.18589. © 2024 The Author(s).This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs (http://creativecommons.org/licenses/by-nc-nd/4.0/)
An index to characterize gas-solid and solid-solid mixing from average volume fraction fields
No full textA mixing index based on solid volume fraction fields is developed for gas-solid flows. Conventional mixing indices are based on particle realizations of granular mixing and are applicable to experimental data or DEM simulations. However, these indices cannot be used as-is for multi-fluid models, and an index for characterizing mixing in gas-solid flows from continuous fields is needed. The performance of the mixing index is tested in two applications. The first is a 3D simulation of the mixing of biomass and sand in a fluidized bed reactor, and the second is a 2D simulation of binary particle segregation in a fluidized bed. The simulations are performed using OpenFOAM®. The mixing index is used to quantify gas-solid mixing using solid volume fractions and solid-solid mixing using solid fractions. The formulation of conventional mixing indices is extended to be used with solid volume fractions fields, and methods for performance improvement are presented.This is the peer-reviewed version of the following article: Nagawkar, Barlev R., Venkata P. Kotrike, Alberto Passalacqua, and Shankar Subramaniam. "An index to characterize gas‐solid and solid‐solid mixing from average volume fraction fields." AIChE Journal (2022): e17639., which has been published in final form at DOI: 10.1002/aic.17639. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Copyright 2022 American Institute of Chemical Engineers. Posted with permission
Computational models for the prediction of yields in the autothermal pyrolysis of biomass
No full textAutothermal pyrolysis of biomass, conducted in fluidized bed reactors, addresses the heat transfer challenges of conventional fast pyrolysis by injecting a small amount of oxygen to allow for partial oxidation of pyrolysis products. This article presents two computational models for predicting yields in autothermal pyrolysis using a comprehensive chemical kinetic mechanism for devolatilization, char combustion, and secondary gas-phase reactions. Initially, the reaction mechanism is studied in stages using a homogeneous model in OpenFOAM®, excluding the fluidized bed hydrodynamics. The model performs well to estimate yields based on biomass feedstock and operating conditions. An Euler-Euler multiphase model is then used to describe the fluidized bed hydrodynamics coupled with the kinetic model. Early-stage simulations are compared to experimental data, showing that secondary gas-phase reactions can be omitted in lab-scale devices. However, homogenous models show that such reactions are useful when considering longer residence times typical of plant-scale devices.This is a manuscript of an article published as Nagawkar, Barlev R., Shankar Subramaniam, Robert C. Brown, and Alberto Passalacqua. "Computational models for the prediction of yields in the autothermal pyrolysis of biomass." Chemical Engineering Science (2025): 121599. doi: https://doi.org/10.1016/j.ces.2025.121599
Clinician Concepts of Cure in Adult Relapsed and Refractory Philadelphia-Negative B Cell Precursor Acute Lymphoblastic Leukemia – A Delphi Study
No full textFull copyright for enhanced digital
features is owned by the authors.
Article full
text
The full text of this article can be found here.
Provide enhanced digital features for this article
If you are an author of this publication and would like to provide additional
enhanced digital features for your article then please contact [email protected].
The journal offers a range of additional features designed to increase
visibility and readership. All features will be thoroughly peer reviewed to
ensure the content is of the highest scientific standard and all features are
marked as ‘peer reviewed’ to ensure readers are aware that the content has been
reviewed to the same level as the articles they are being presented alongside.
Moreover, all sponsorship and disclosure information is included to provide
complete transparency and adherence to good publication practices. This ensures
that however the content is reached the reader has a full understanding of its
origin. No fees are charged for hosting additional open access content.
Other enhanced features include, but are not limited to:
• Slide decks
• Videos and animations
• Audio abstracts
• Audio slides</p
