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Modelling the external ballistics of tranquilliser darts
Thesis (MEng)--Stellenbosch University, 2021.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2021
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| _version_ | 1867613901648035840 |
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| access_status_str | Open Access |
| author | Cilliers, Aldert Johan |
| author2 | Els, D. N. J. |
| author_browse | Cilliers, Aldert Johan Els, D. N. J. |
| author_facet | Els, D. N. J. Cilliers, Aldert Johan |
| author_sort | Cilliers, Aldert Johan |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2021. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/109951 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:43:30.888Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2021 |
| publishDateRange | 2021 |
| publishDateSort | 2021 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/109951 Modelling the external ballistics of tranquilliser darts Cilliers, Aldert Johan Els, D. N. J. Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. Ballistics, Exterior Computational fluid dynamics Tranquilliser darts Rigid-body UCTD Thesis (MEng)--Stellenbosch University, 2021. ENGLISH ABSTRACT: To facilitate the design of tranquilliser darts, several ballistic models are investigated, derived, implemented and verified. Sensitivity analysis showed the required model fidelity and parameter accuracies are significantly less stringent for subsonic, flat trajectories. This agrees with doppler radar measurements suggesting drag stabilised darts have a near constant drag coefficient. This is further corroborated by computational fluid dynamics (CFD) analysis: aerodynamic coefficients are independent of velocity but sensitive to angle of attack. The tailpiece however ensures there is little to no pitching and/or yawing, eliminating non-linearities due to instability (the angle of attack). Consequently, a single CFD analysis at an average velocity can sufficiently estimate the aerodynamic forces and moments. For the same reasons, Point-mass and Modified point-mass approximations are qualitatively on par with Rigid-body approximations (in most cases). Due to drag stabilisation by the tailpiece, the drag coefficients measured and simulated are high (CD >= 0.9). Future designs' aerodynamic efficiency can be improved by rather using spin stabilisation. Point-mass and Modified pointmass approximations are however unable to account for instabilities. If considered, Rigid-body approximations are recommended to confirm initial stability. AFRIKAANSE OPSOMMING: Om die ontwerp van verdowingspyle te vergemaklik, is verskeie ballistiese modelle ondersoek, geïmplementeer en geverifieer. Sensitiwiteitsanalise toon modelgetrouheid asook dat parameterakkuraatheid minder streng is vir kort en plat trajekte. Dit stem ooreen met doppler radar metings waar die verdowingspyl se sleur koëffisiënt konstant is. Berekenings vloeimeganika (BVM) toon dat die verskeie koëffisiënte onafhanklik is van snelheid maar sensitief vir invalshoek. Die stert verseker 'n klein invalshoek en bevorder sodoende die konstante geaardheid van die koëffisiënte. Gevolglik sal 'n eenmalige BVM simulasie, by 'n gemiddelde snelheid voldoende wees om die aerodinamise kragte en momente te bepaal. Vir soortgelyke redes is Puntmassa en Gemodifiseerdepuntmassa analises kwalitatief gelykstaande aan Rigiede-liggaam analises. As gevolg van die stert, is die sleur koëffisiënt hoog (CD >= 0.9). Aerodinamies kan verdowingspyle vebeter word deur eerder gebruik te maak van spin stabilisasie. Puntmassa en Gemodifiseerde-puntmassa neem aan die verdowingspyl is stabiel, wat nie noodwendig die geval is nie. Indien spin stabilisasie oorweeg word, stel ons Rigiede-liggaam simulasie voor as 'n grondslag om stabiliteit te bevestig. Masters 2021-03-05T12:41:15Z 2021-04-21T14:33:34Z 2021-03-05T12:41:15Z 2021-04-21T14:33:34Z 2021-03 Thesis http://hdl.handle.net/10019.1/109951 en_ZA Stellenbosch University 133 pages application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Ballistics, Exterior Computational fluid dynamics Tranquilliser darts Rigid-body UCTD Cilliers, Aldert Johan Modelling the external ballistics of tranquilliser darts |
| title | Modelling the external ballistics of tranquilliser darts |
| title_full | Modelling the external ballistics of tranquilliser darts |
| title_fullStr | Modelling the external ballistics of tranquilliser darts |
| title_full_unstemmed | Modelling the external ballistics of tranquilliser darts |
| title_short | Modelling the external ballistics of tranquilliser darts |
| title_sort | modelling the external ballistics of tranquilliser darts |
| topic | Ballistics, Exterior Computational fluid dynamics Tranquilliser darts Rigid-body UCTD |
| url | http://hdl.handle.net/10019.1/109951 |
| work_keys_str_mv | AT cilliersaldertjohan modellingtheexternalballisticsoftranquilliserdarts |