Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Multiphase CFD modelling of stirred tanks
Includes bibliographical references (p. 67-70).
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Mechanical Engineering
2014
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613344279560193 |
|---|---|
| access_status_str | Open Access |
| author | Appa, Harish |
| author2 | Deglon, David |
| author_browse | Appa, Harish Deglon, David |
| author_facet | Deglon, David Appa, Harish |
| author_sort | Appa, Harish |
| collection | Thesis |
| description | Includes bibliographical references (p. 67-70). |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/5548 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:39.078Z |
| 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 | Department of Mechanical Engineering |
| publisherStr | Department of Mechanical Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/5548 Multiphase CFD modelling of stirred tanks Appa, Harish Deglon, David Meyer, CJ Mechanical Engineering Includes bibliographical references (p. 67-70). Stirred tanks agitated with Rushton turbines are commonly used in industry, for instance mixing processes and flotation systems. The need for more efficient systems in industries has led to the study of fluid flow within the tanks upon agitation; so that a better understanding of the phenomena can help in the optimisation of the tanks. In the recent years, efforts have been made towards the development of predictive methods using computational fluid dynamics (CFD). Among the various numerical works presented, emphasis was laid mainly on single phase systems. However, due to the various processes involving gas-liquid systems, the need for multiphase modelling of stirred tanks became increasingly important. This has led to more research studies involving multiphase flows. Most of the work reported showed good prediction of the velocity data and the power draw, reasonable turbulence parameters. But, the prediction of the gas hold-up was rarely well established. Therefore, the aim of this thesis, based on the numerical work presented by Engelbrecht (2006), is to investigate the discrepancies reported and to develop a multiphase model of a stirred tank agitated by a Rushton turbine. The commercially available CFD code FLUENT@ was used to model the agitated gas-liquid system. The results were validated with the numerical work of Engelbrecht (2006) and the experimental work presented by Deglon (1998). Two main cases were investigated, with a steady state and a transient approach. The QUICK scheme was used for the discretisation of the volume fraction and momentum and the first order upwind scheme for the discretisation of the turbulent kinetic energy and dissipation rate. The standard k - E turbulence model was used to account for the turbulent flow regime. A steady state MRF model was used for the investigation of the discrepancy reported by Engelbrecht (2006). The author reported that no convergence was achieved with such models. Solving the problem would have resulted in a good modelling approach for the prediction of gas dispersion, since steady state models are not computationally intensive. Three different boundary conditions, namely, a pressure outlet, an outflow and a velocity inlet, were used to model the outlet of the tank. The Euler-Euler multiphase model was used to simulate the gas-liquid system for the steady state model. 2014-07-31T11:22:22Z 2014-07-31T11:22:22Z 2007 Master Thesis Masters MSc http://hdl.handle.net/11427/5548 eng application/pdf Department of Mechanical Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Mechanical Engineering Appa, Harish Multiphase CFD modelling of stirred tanks |
| thesis_degree_str | Master's |
| title | Multiphase CFD modelling of stirred tanks |
| title_full | Multiphase CFD modelling of stirred tanks |
| title_fullStr | Multiphase CFD modelling of stirred tanks |
| title_full_unstemmed | Multiphase CFD modelling of stirred tanks |
| title_short | Multiphase CFD modelling of stirred tanks |
| title_sort | multiphase cfd modelling of stirred tanks |
| topic | Mechanical Engineering |
| url | http://hdl.handle.net/11427/5548 |
| work_keys_str_mv | AT appaharish multiphasecfdmodellingofstirredtanks |