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| Format: | Thesis |
| Language: | English |
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Centre for Bioprocess Engineering Research
2014
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| _version_ | 1867613764591812608 |
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| access_status_str | Open Access |
| author | Coetzee, Waldo |
| author2 | Rawatlal, Randhir |
| author_browse | Coetzee, Waldo Rawatlal, Randhir |
| author_facet | Rawatlal, Randhir Coetzee, Waldo |
| author_sort | Coetzee, Waldo |
| collection | Thesis |
| description | Includes abstract. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/5368 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:41:20.258Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Centre for Bioprocess Engineering Research |
| publisherStr | Centre for Bioprocess Engineering Research |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/5368 Development of a computationally efficient bubble column simulation approach by way of statistical bubble micro-flow modelling Coetzee, Waldo Rawatlal, Randhir Coetzer, Roelof LJ Bioprocess Engineering Includes abstract. Includes bibliographical references. The intimate contact achieved between the gas and liquid phases in bubble columns, coupled with the inherent efficient mixing these reactors offer, yield excellent heat and mass transfer characteristics. These attributes have been exploited commercially for decades, however, due to the complexity of the underlying hydrodynamics, the prediction of bubble columns based on empirical models can be unreliable outside of the operating ranges used to fit these models. Computational Fluid Dynamics (CFD) has emerged as an attractive tool for simulating these reactors and is based on numerically approximating the fundamentally based Navier-Stokes equations on a discretized domain. The application of CFD has become more practical as the cost of computational resources has declined and has lead to the establishment of three distinct modelling approaches which have been evaluated for the purpose of bubble column simulation in a number of research papers over the past two decades. Here the Euler-Euler approach has been recommended for the simulation of large scale columns, however, this approach is based on the most assumptions and yields the least amount of flow field information. The Euler-Lagrange approach treats bubbles as discrete particles which allows for the incorporation of a deterministic bubble size distribution and the direct consideration of heat and mass transfer effects. The most fundamental approach, Direct Numerical Simulation (DNS), predicts flow properties at the bubble scale, however, is extremely computationally expensive and is therefore only practically applicable to the investigation of a very small number of bubbles. The objective of this study is to contribute to the simulation of gasliquid flow interaction occurring in bubble columns by proposing a novel technique for simulating bubble scale flow information at a significantly reduced computational expense. For this purpose, it is proposed to predict the micro-flow fields around individual bubbles, within an Euler-Lagrange framework, with an algebraic model termed the Bubble Cell Model (BCM). The high gradient regions around individual bubbles are thereby accounted for with an algebraic flow model that can be rapidly evaluated as opposed to the two-phase partial differential Navier-Stokes equations, thereby reducing the numerical complexity of the problem. Since no such flow models currently exist and accuracy and fast evaluation are imperative, a statistical approach to the construction of the BCM is justified. 2014-07-31T11:13:15Z 2014-07-31T11:13:15Z 2013 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/5368 eng application/pdf Centre for Bioprocess Engineering Research Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Bioprocess Engineering Coetzee, Waldo Development of a computationally efficient bubble column simulation approach by way of statistical bubble micro-flow modelling |
| thesis_degree_str | Doctoral |
| title | Development of a computationally efficient bubble column simulation approach by way of statistical bubble micro-flow modelling |
| title_full | Development of a computationally efficient bubble column simulation approach by way of statistical bubble micro-flow modelling |
| title_fullStr | Development of a computationally efficient bubble column simulation approach by way of statistical bubble micro-flow modelling |
| title_full_unstemmed | Development of a computationally efficient bubble column simulation approach by way of statistical bubble micro-flow modelling |
| title_short | Development of a computationally efficient bubble column simulation approach by way of statistical bubble micro-flow modelling |
| title_sort | development of a computationally efficient bubble column simulation approach by way of statistical bubble micro flow modelling |
| topic | Bioprocess Engineering |
| url | http://hdl.handle.net/11427/5368 |
| work_keys_str_mv | AT coetzeewaldo developmentofacomputationallyefficientbubblecolumnsimulationapproachbywayofstatisticalbubblemicroflowmodelling |