{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/17351"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/17351","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"The design of a prototype Otto-Atkinson engine and evaluation of the part load fuel efficiency","abstract":"This thesis is an investigation into the application of the hybrid Otto-Atkinson cycle, as a means of improving the part load fuel efficiency of spark-ignition engines. The primary objective of this thesis was to investigate the technical feasibility of the modified Atkinson cycle as a spark-ignition engine concept and thus to quantify the associated potential for greater fuel efficiency. The modified Atkinson cycle is a hybrid cycle which approximates the Otto cycle at full load but tends to emulate the Atkinson cycle at part load, and therefore it is referred to as the Otto-Atkinson cycle. In order to fulfil this objective, a single cylinder engine which operated on the Otto-Atkinson cycle, was designed and constructed. This unusual cycle was achieved by a crank linkage which allowed the power output to be controlled by varying the inlet and compression strokes rather than by the more conventional method of throttling the induced fuel-air mixture. Thus the pumping losses associated with throttled part-load operation are eliminated. Furthermore, the expansion stroke is always greater than the compression stroke, the difference being greatest at part loads. This results in a cycle which approximates the Atkinson cycle for part-load operation. A simplified thermodynamic simulation of the cycle was formulated. Theoretical predictions were made based on this simulation.","abstract_html":"This thesis is an investigation into the application of the hybrid Otto-Atkinson cycle, as a means of improving the part load fuel efficiency of spark-ignition engines. The primary objective of this thesis was to investigate the technical feasibility of the modified Atkinson cycle as a spark-ignition engine concept and thus to quantify the associated potential for greater fuel efficiency. The modified Atkinson cycle is a hybrid cycle which approximates the Otto cycle at full load but tends to emulate the Atkinson cycle at part load, and therefore it is referred to as the Otto-Atkinson cycle. In order to fulfil this objective, a single cylinder engine which operated on the Otto-Atkinson cycle, was designed and constructed. This unusual cycle was achieved by a crank linkage which allowed the power output to be controlled by varying the inlet and compression strokes rather than by the more conventional method of throttling the induced fuel-air mixture. Thus the pumping losses associated with throttled part-load operation are eliminated. Furthermore, the expansion stroke is always greater than the compression stroke, the difference being greatest at part loads. This results in a cycle which approximates the Atkinson cycle for part-load operation. A simplified thermodynamic simulation of the cycle was formulated. Theoretical predictions were made based on this simulation.","abstract_has_math":false,"creators":["Van Binsbergen, Peter J"],"institution":"Department of Mechanical Engineering","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Yates, Andrew"],"committee_chairs":[],"committee_members":[],"year":1992,"date_issued":"1992","date_published":"1992","updated_at":"2026-07-22T22:23:23Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/17351","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Yates, Andrew"]},{"key":"dc:creator","label":"Author","values":["Van Binsbergen, Peter J"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-02-29T12:03:34Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-02-29T12:03:34Z"]},{"key":"dc:date.issued","label":"Date","values":["1992"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Mechanical Engineering"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc (Eng)"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/17351"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Bibliography: page 71."]},{"key":"dc:description.abstract","label":"Abstract","values":["This thesis is an investigation into the application of the hybrid Otto-Atkinson cycle, as a means of improving the part load fuel efficiency of spark-ignition engines. The primary objective of this thesis was to investigate the technical feasibility of the modified Atkinson cycle as a spark-ignition engine concept and thus to quantify the associated potential for greater fuel efficiency. The modified Atkinson cycle is a hybrid cycle which approximates the Otto cycle at full load but tends to emulate the Atkinson cycle at part load, and therefore it is referred to as the Otto-Atkinson cycle. In order to fulfil this objective, a single cylinder engine which operated on the Otto-Atkinson cycle, was designed and constructed. This unusual cycle was achieved by a crank linkage which allowed the power output to be controlled by varying the inlet and compression strokes rather than by the more conventional method of throttling the induced fuel-air mixture. Thus the pumping losses associated with throttled part-load operation are eliminated. Furthermore, the expansion stroke is always greater than the compression stroke, the difference being greatest at part loads. This results in a cycle which approximates the Atkinson cycle for part-load operation. A simplified thermodynamic simulation of the cycle was formulated. Theoretical predictions were made based on this simulation."]},{"key":"dc:title","label":"Title","values":["The design of a prototype Otto-Atkinson engine and evaluation of the part load fuel efficiency"]}]}],"canonical_facts":{"dc:contributor.advisor":["Yates, Andrew"],"dc:creator":["Van Binsbergen, Peter J"],"dc:date.accessioned":["2016-02-29T12:03:34Z"],"dc:date.available":["2016-02-29T12:03:34Z"],"dc:date.issued":["1992"],"dc:description":["Bibliography: page 71."],"dc:description.abstract":["This thesis is an investigation into the application of the hybrid Otto-Atkinson cycle, as a means of improving the part load fuel efficiency of spark-ignition engines. The primary objective of this thesis was to investigate the technical feasibility of the modified Atkinson cycle as a spark-ignition engine concept and thus to quantify the associated potential for greater fuel efficiency. The modified Atkinson cycle is a hybrid cycle which approximates the Otto cycle at full load but tends to emulate the Atkinson cycle at part load, and therefore it is referred to as the Otto-Atkinson cycle. In order to fulfil this objective, a single cylinder engine which operated on the Otto-Atkinson cycle, was designed and constructed. This unusual cycle was achieved by a crank linkage which allowed the power output to be controlled by varying the inlet and compression strokes rather than by the more conventional method of throttling the induced fuel-air mixture. Thus the pumping losses associated with throttled part-load operation are eliminated. Furthermore, the expansion stroke is always greater than the compression stroke, the difference being greatest at part loads. This results in a cycle which approximates the Atkinson cycle for part-load operation. A simplified thermodynamic simulation of the cycle was formulated. Theoretical predictions were made based on this simulation."],"dc:identifier.uri":["http://hdl.handle.net/11427/17351"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Mechanical Engineering"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["The design of a prototype Otto-Atkinson engine and evaluation of the part load fuel efficiency"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc (Eng)"]},"updated_at":"2026-07-22T22:23:23Z"}