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Lift and drag forces on a submarine pipeline in steady flow
Includes bibliography.
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| Main Author: | |
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Civil Engineering
2014
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| _version_ | 1867613282481733632 |
|---|---|
| access_status_str | Open Access |
| author | Kok, Nicolaas Johannes |
| author2 | Kilner, F A |
| author_browse | Kilner, F A Kok, Nicolaas Johannes |
| author_facet | Kilner, F A Kok, Nicolaas Johannes |
| author_sort | Kok, Nicolaas Johannes |
| collection | Thesis |
| description | Includes bibliography. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/8315 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:33:40.116Z |
| 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 Civil Engineering |
| publisherStr | Department of Civil Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/8315 Lift and drag forces on a submarine pipeline in steady flow Kok, Nicolaas Johannes Kilner, F A Civil Engineering Includes bibliography. This thesis describes an experimental investigation into the hydrodynamic forces induced on a cylinder placed transversely to a steady stream. Various cylinder locations near the bed of a water flume were considered. The work relates to pipeline design. The various flow phenomena around a cylinder are theoretically analysed and an explanation of the phenomenon of lift provided. A thorough literature review was undertaken regarding the classical theory, as well as experimental and theoretical studies carried out on the subject. This revealed that theoretical studies are virtually non-existent. Measurements have been done in intermediate water depths with both smooth and rough beds. Two different methods, comprising very simple yet novel techniques, were utilised in a water flume 18 m long x 600 mm wide x 450 mm deep. The methods involved a unique pressure determination method as well as the direct measurement of hydrodynamic forces, using a "weighing" method. Very ' accurate flow velocities were measured using a unique differential manometer. Experiments were performed in the Reynolds number range 6 000 to 26 000, using 30 and 50 mm diameter cylinders. comprehensive tests on cylinder roughening were carried out in a flow region which had not been well researched regarding this aspect. Cylinder locations were varied from a gap-to-cylinder diameter ratio of zero to 2,67. Results revealed that the force coefficients are not appreciably affected by bed roughness. Cylinder roughening produced somewhat contradicting results for the two different cylinders used. The influence on the lift coefficient was inconclusive, but the "rougher" 30 mm cylinder produced a slightly higher drag coefficient. Although the lift force was predominantly away from the bed, a downward lift force was measured on a few occasions with the cylinder situated further than one cylinder diameter away from the bed. A possible explanation is offered for this and other unexpected results. Flow visualisation tests were performed to confirm certain features of the flow around the cylinder. These as well as all the other results have been related to published work. 2014-10-11T12:00:00Z 2014-10-11T12:00:00Z 1988 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/8315 eng application/pdf Department of Civil Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Civil Engineering Kok, Nicolaas Johannes Lift and drag forces on a submarine pipeline in steady flow |
| thesis_degree_str | Doctoral |
| title | Lift and drag forces on a submarine pipeline in steady flow |
| title_full | Lift and drag forces on a submarine pipeline in steady flow |
| title_fullStr | Lift and drag forces on a submarine pipeline in steady flow |
| title_full_unstemmed | Lift and drag forces on a submarine pipeline in steady flow |
| title_short | Lift and drag forces on a submarine pipeline in steady flow |
| title_sort | lift and drag forces on a submarine pipeline in steady flow |
| topic | Civil Engineering |
| url | http://hdl.handle.net/11427/8315 |
| work_keys_str_mv | AT koknicolaasjohannes liftanddragforcesonasubmarinepipelineinsteadyflow |