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Shaping a heliostat facet by applying a bending moment to a circular flat mirror
Thesis (MEng)--Stellenbosch University, 2023.
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| Format: | Thesis |
| Language: | en_ZA en_ZA |
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Stellenbosch : Stellenbosch University
2023
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| _version_ | 1867613897349922816 |
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| access_status_str | Open Access |
| author | Hanekom, J. |
| author2 | Smit, W. J. |
| author_browse | Hanekom, J. Smit, W. J. |
| author_facet | Smit, W. J. Hanekom, J. |
| author_sort | Hanekom, J. |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2023. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/127308 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA en_ZA |
| last_indexed | 2026-06-10T12:43:26.328Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2023 |
| publishDateRange | 2023 |
| publishDateSort | 2023 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/127308 Shaping a heliostat facet by applying a bending moment to a circular flat mirror Hanekom, J. Smit, W. J. Venter, M. P. Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. Heliostat Bending moment Finite element method Ray tracing algorithms Paraboloid Thesis (MEng)--Stellenbosch University, 2023. ENGLISH ABSTRACT: This research investigates a novel heliostat shaping method. Roark’s formulas predict that thin circular discs with uniform thickness with a uniform line moment applied at the circumference will deform into a paraboloid. The aim of the research is thus to gather novel information regarding the shaping method. This will be accomplished with the following by firstly, confirming that the surface of a circular facet with a uniform line moment applied to the circumference conforms to the shape of a paraboloid. Thereafter, an analytical model is developed to calculate the resultant deformation of the facet. This model is then compared to a paraboloid. This is followed by the development of a computational model which is also compared to the analytical model. Lastly, different heliostat concepts are designed, experimentally tested and compared to the analytical model, computational model as well as the paraboloid. The analytical model is calculated using Roark’s formulas for thin circular flat plates. The computational model consists of a finite element (FE) and a ray tracing model. The analytical model predicted that a paraboloid is a good representation of the heliostat facet shaped with the novel method. The FE-model was simulated under different loading conditions and the results used to compare with a paraboloid. These results also predicted good performance for the heliostat facet. The FE-analysis results were also used to generate the ray tracing model which was used to compare with the paraboloid available in the ray tracing software, Tonatiuh. These results were, again suggesting that the shaping method is represented closely by a paraboloid. Lastly, experimental analyses were completed which consisted of testing a concept and capturing the reflected image. These results showed that the heliostat concept accomplish the main goal of concentrating sunlight. Another experimental analysis was concluded with a second concept with the main goal to be compared with the FE-model to use for model verification. The FE-model predicted, again, facet profiles that resembles a paraboloid very closely. 3D scanning was this time used together with a load cell to determine the optical performance of the heliostat, which can be compared with the FE-model. These results, again, showed that the heliostat surface conform to a paraboloid. AFRIKAANS OPSOMMING: Hierdie navorsing ondersoek 'n nuwe heliostaat-vormingsmetode. Roark se formules voorspel dat dun sirkelvormige skyfies, met eenvormige dikte, met 'n eenvormige lynmoment wat by die omtrek toegepas word, sal in 'n paraboloïed vervorm. Die doel van die navorsing is dus om nuwe inligting rakende die vormingsmetode in te samel. Dit sal met die volgende bewerkstellig word deur eerstens te bevestig dat die oppervlak van 'n sirkelvormige faset met 'n eenvormige lynmoment wat op die omtrek toegepas word, ooreenstem met die vorm van 'n paraboloïed. Daarna word 'n analitiese model ontwikkel om die gevolglike vervorming van die faset te bereken. Hierdie model word dan met 'n paraboloïed vergelyk. Dit word gevolg deur die ontwikkeling van 'n berekeningsmodel wat ook met die analitiese model vergelyk word. Laastens word verskillende heliostaatkonsepte ontwerp, eksperimenteel getoets en vergelyk met die analitiese model, berekeningsmodel sowel as die paraboloïed. Die analitiese model word bereken met behulp van Roark se formules vir dun sirkelvormige plat plate. Die berekeningsmodel bestaan uit 'n eindige-element- en 'n straalspoor-model. Die analitiese model het voorspel dat 'n paraboloïed 'n goeie voorstelling is van die heliostaatfaset wat met die nuwe metode gevorm is. Die 'n eindige-element-model is onder verskillende lastoestande gesimuleer en die resultate is gebruik om met 'n paraboloïed te vergelyk. Hierdie resultate het ook goeie prestasie vir die heliostaatfaset voorspel. Die eindige-element-analise resultate is ook gebruik om die straalspoormodel te genereer wat gebruik is om te vergelyk met die paraboloïed wat beskikbaar is in die straalnasporingsagteware, Tonatiuh. Hierdie resultate dui weer daarop dat die vormingsmetode deur 'n paraboloïed voorgestel word. Laastens is eksperimentele ontledings voltooi wat bestaan het uit die toets van 'n konsep en die vaslegging van die gereflekteerde beeld. Hierdie resultate het getoon dat die heliostaatkonsep die hoofdoel bereik om sonlig te konsentreer. Nog 'n eksperimentele analise is afgesluit met 'n tweede konsep met die hoofdoel om vergelyk te word met die eindige-element-model om vir modelverifikasie te gebruik. Die eindige-element-model het weereens fasetprofiele voorspel wat baie na aan 'n paraboloïed lyk. 3D-skandering is hierdie keer saam met 'n laaisel gebruik om die optiese werkverrigting van die heliostaat te bepaal, wat met die FE-model vergelyk kan word. Hierdie resultate het weereens getoon dat die heliostaatoppervlak ooreenstem met 'n paraboloïed. Masters 2023-03-02T09:03:14Z 2023-05-18T07:15:17Z 2023-03-02T09:03:14Z 2023-05-18T07:15:17Z 2023-03-02 Thesis http://hdl.handle.net/10019.1/127308 en_ZA en_ZA Stellenbosch University 112 pages : illustrations. application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Heliostat Bending moment Finite element method Ray tracing algorithms Paraboloid Hanekom, J. Shaping a heliostat facet by applying a bending moment to a circular flat mirror |
| title | Shaping a heliostat facet by applying a bending moment to a circular flat mirror |
| title_full | Shaping a heliostat facet by applying a bending moment to a circular flat mirror |
| title_fullStr | Shaping a heliostat facet by applying a bending moment to a circular flat mirror |
| title_full_unstemmed | Shaping a heliostat facet by applying a bending moment to a circular flat mirror |
| title_short | Shaping a heliostat facet by applying a bending moment to a circular flat mirror |
| title_sort | shaping a heliostat facet by applying a bending moment to a circular flat mirror |
| topic | Heliostat Bending moment Finite element method Ray tracing algorithms Paraboloid |
| url | http://hdl.handle.net/10019.1/127308 |
| work_keys_str_mv | AT hanekomj shapingaheliostatfacetbyapplyingabendingmomenttoacircularflatmirror |