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Performance characteristics of a deep tilling rotavator
Thesis (PhD)--University of Pretoria, 2010.
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University of Pretoria
2013
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| _version_ | 1867613564896804864 |
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| access_status_str | Open Access |
| author2 | Du Plessis, Hanli |
| author_browse | Du Plessis, Hanli |
| author_facet | Du Plessis, Hanli |
| collection | Thesis |
| dc_rights_str_mv | © 2009, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Thesis (PhD)--University of Pretoria, 2010. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/25458 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:38:09.710Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/25458 Performance characteristics of a deep tilling rotavator Du Plessis, Hanli moses.marenya@univen.ac.za Marenya, Moses Okoth Tillage performance Soil shear strength Soil-metal friction Bite length Kinematic parameter Down-cut rotavator Power Specific energy Soil-failure modelling Deep-tilling Rotavator UCTD Thesis (PhD)--University of Pretoria, 2010. This study was undertaken to develop an analytical model that is capable of predicting the torque requirements of a rotavator fitted with commercially available L-shaped blades. An analytical approach based on the limit equilibrium analysis was used to develop the proposed model. The proposed model was verified by comparing the model and measured torque requirements at predetermined rotavator blade angular positions from the horizontal for a down-cut rotavator. The study findings indicated that there was an optimum set tillage depth for each rotavator configuration and operational conditions at which the resultant horizontal thrust generated was greatest. This unique depth was influenced by the bite length. The validation of the proposed model showed that the predicted and measured torque requirements, at different angular blade positions from the horizontal, correlated reasonably well for all the set tillage depths. As the depth of tillage increased, however, the curve for the measured torque requirements exhibited a cyclic behaviour after the peak torque requirements value had been recorded. The cyclic behaviour was probably due to the re-tilling and the instability of the tool-frame carrier, which increased with the set tillage depth. The knowledge contributed by this research will afford the designers of active tillage tools a better understanding of the operations of the rotavator, particularly in deep tillage. The modelling approach, and instrumentation technique used in this research, can be extended to analyze the performance of rotavators fitted with other types of commercial blades. Civil Engineering unrestricted 2013-09-06T21:38:31Z 2010-06-14 2013-09-06T21:38:31Z 2010-04-16 2010-06-14 2010-06-11 Thesis Marenya, MO 2009, Performance characteristics of a deep tilling rotavator, PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/25458 > D10/438/ag http://hdl.handle.net/2263/25458 http://upetd.up.ac.za/thesis/available/etd-06112010-193036/ © 2009, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf University of Pretoria |
| spellingShingle | Tillage performance Soil shear strength Soil-metal friction Bite length Kinematic parameter Down-cut rotavator Power Specific energy Soil-failure modelling Deep-tilling Rotavator UCTD Performance characteristics of a deep tilling rotavator |
| title | Performance characteristics of a deep tilling rotavator |
| title_full | Performance characteristics of a deep tilling rotavator |
| title_fullStr | Performance characteristics of a deep tilling rotavator |
| title_full_unstemmed | Performance characteristics of a deep tilling rotavator |
| title_short | Performance characteristics of a deep tilling rotavator |
| title_sort | performance characteristics of a deep tilling rotavator |
| topic | Tillage performance Soil shear strength Soil-metal friction Bite length Kinematic parameter Down-cut rotavator Power Specific energy Soil-failure modelling Deep-tilling Rotavator UCTD |
| url | http://hdl.handle.net/2263/25458 http://upetd.up.ac.za/thesis/available/etd-06112010-193036/ |