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Brandspoedkatalise, eienskappe en toepassings van hoë-energie materiale
Dissertation (doctoral) -- University of Stellenbosch, 1993.
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| Other Authors: | |
| Format: | Thesis |
| Language: | Afrikaans |
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Stellenbosch : Stellenbosch University
2012
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| _version_ | 1867614118397083648 |
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| access_status_str | Open Access |
| author | De Wet, Hendrik Francois |
| author2 | Engelbrecht, W. J. |
| author_browse | De Wet, Hendrik Francois Engelbrecht, W. J. |
| author_facet | Engelbrecht, W. J. De Wet, Hendrik Francois |
| author_sort | De Wet, Hendrik Francois |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Dissertation (doctoral) -- University of Stellenbosch, 1993. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/49643 |
| institution | Stellenbosch University (South Africa) |
| language | Afrikaans |
| last_indexed | 2026-06-10T12:46:57.306Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2012 |
| publishDateRange | 2012 |
| publishDateSort | 2012 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/49643 Brandspoedkatalise, eienskappe en toepassings van hoë-energie materiale De Wet, Hendrik Francois Engelbrecht, W. J. Van der Merwe, S. W. J. Stellenbosch University. Faculty of Science. Dept. of Chemistry and Polymer Science. Solid propellants Rockets (Aeronautics) -- Fuel Combustion Dissertations -- Chemistry Dissertation (doctoral) -- University of Stellenbosch, 1993. The main constraint in impulse performance of conventional double-base propellants, is that the most energetic substance (nitroglycerine), is limited to a maximum content of ca 43%. Because nitroglycerine is a liquid, unacceptable mechanical properties are obtained if the above limit is breached. The maximum energy of conventional double-base propellants produced at Somchem, is ca. 4 200 J/g, with a density of ca. 1,60 g/cm³. One of the main advantages of double-base propellants is the temperature and pressure insensitivity thereof. This is obtained by the catalysis of the propellant burn rate in such a way that the burn rate is constant in a specific pressure region and it is illustrated by a plato or mesa in the burn rate/pressure curves. The continuous demand for higher performance rocket and missile systems resulted in the need for higher performance double-base rocket propellants. High energy, high density, platonised burn rate curves and acceptable mechanical properties, were the directives for the development of new high performance propellants. Though the addition of up to 22% (m/m) of the solid oxidizer RDX, the maximum energy value of platonised double-base rocket propellants is increased by ca. 25% and the density by ca. 6%, in comparison with conventional propellants with similar burn rate characteristics. These improvements resulted in considerable higher total impulse performances for the RDX-containing propellants. These propellants were manufactured by the solventless extrusion process. A series of platonised propellant compositions have been developed with burn rates as low as 4 mm/s at pressures of 1 to 3 MPa and as high as 40 mm/s at 15 to 25 MPa. The energy values ranged from 4 200 to 5 100 J/g. The burn rate catalysis was explained in terms of the proposed reaction mechanisms, especially by means of a modified carbon theory, as proposed by Youfang (1987). Due to the knowhow developed in this investigation, high performance double base propellants with nearly any burn rate – as required by different propulsion systems – can be manufactured locally. RDX-containing propellant is further characterized in terms of friction, impact, initiation and bullet impact sensitivities. The results obtained compares well with that of conventional double-base propellant. The chemical and physical shelf life were determined by extensive tests and are sufficient for use in weapon systems (> 20 years). The influence of environmental factors, cultivar and type of cut of cotton linters on the properties of nitrocellulose and eventually on the mechanical and even ballistic properties, has been shown. Furthermore, it was found for a specific RDX-containing composition that variation in process parameters during propellant manufacturing do not influence the mechanical and ballistic properties significantly. Such properties are advantageous for the production of a specific propellant. One of the RDX-containing compositions has already found an application as a high performance propellant in the Somchem Extended range 127 mm Rocket system. The energy of the existing propellant has been increased by 27% (3 620 to 4 620 J/g) and the density by 6%. The upgraded system has been qualified and the new propellant made a substantial contribution to the improvement in maximum range from 22 km to 36 km at sea level. The series of RDX-containing compositions that have been developed may be used in future as a basis for full scale development of specific propellants for rocket and missile systems where high performance double base propellants are needed. Doctoral 2012-08-27T11:33:01Z 2012-08-27T11:33:01Z 1993 Thesis http://hdl.handle.net/10019.1/49643 af Stellenbosch University 273 pages : ill. application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Solid propellants Rockets (Aeronautics) -- Fuel Combustion Dissertations -- Chemistry De Wet, Hendrik Francois Brandspoedkatalise, eienskappe en toepassings van hoë-energie materiale |
| title | Brandspoedkatalise, eienskappe en toepassings van hoë-energie materiale |
| title_full | Brandspoedkatalise, eienskappe en toepassings van hoë-energie materiale |
| title_fullStr | Brandspoedkatalise, eienskappe en toepassings van hoë-energie materiale |
| title_full_unstemmed | Brandspoedkatalise, eienskappe en toepassings van hoë-energie materiale |
| title_short | Brandspoedkatalise, eienskappe en toepassings van hoë-energie materiale |
| title_sort | brandspoedkatalise eienskappe en toepassings van hoe energie materiale |
| topic | Solid propellants Rockets (Aeronautics) -- Fuel Combustion Dissertations -- Chemistry |
| url | http://hdl.handle.net/10019.1/49643 |
| work_keys_str_mv | AT dewethendrikfrancois brandspoedkataliseeienskappeentoepassingsvanhoeenergiemateriale |