{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/42936"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/42936","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Reduction of energy losses: a key to improved rock drilling?","abstract":"The viscous power losses of a rotary-vibratory drilling system are estimated in this study. Rotational and pure vibratory losses are considered separately. This analysis indicates that considerable power is dissipated into the drilling fluid. Pure vibratory power losses of over 3,728 W (5 hp) are expected at frequencies equal to the first mode maximum response point for a drill column that is 152.4 m (500 ft) long. This is a frequency slightly less than the first undamped natural frequency of the drill column. For the same column, viscous rotational power losses of over 74.56 W ( 0.1 hp) are expected at rotational speeds of 10.47 rad/s (100 rpm). Rotational and vibratory losses increase with increases in the length of the column, fluid viscosity, and operating frequency.","abstract_html":"The viscous power losses of a rotary-vibratory drilling system are estimated in this study. Rotational and pure vibratory losses are considered separately. This analysis indicates that considerable power is dissipated into the drilling fluid. Pure vibratory power losses of over 3,728 W (5 hp) are expected at frequencies equal to the first mode maximum response point for a drill column that is 152.4 m (500 ft) long. This is a frequency slightly less than the first undamped natural frequency of the drill column. For the same column, viscous rotational power losses of over 74.56 W ( 0.1 hp) are expected at rotational speeds of 10.47 rad/s (100 rpm). Rotational and vibratory losses increase with increases in the length of the column, fluid viscosity, and operating frequency.","abstract_has_math":false,"creators":["Ohanehi, Donatus Chukwubueze"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Mechanical Engineering","degree_department":"Mechanical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1975,"date_issued":"1975","date_published":"1975","updated_at":"2026-07-22T22:19:24Z","subjects":[],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-06082010-020314"],"render_values":[{"text":"etd-06082010-020314","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/42936","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Mechanical Engineering"]},{"key":"dc:creator","label":"Author","values":["Ohanehi, Donatus Chukwubueze"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:37:15Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:37:15Z","2010-06-08"]},{"key":"dc:date.issued","label":"Date","values":["1975"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-06082010-020314"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/42936"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The viscous power losses of a rotary-vibratory drilling system are estimated in this study. Rotational and pure vibratory losses are considered separately. This analysis indicates that considerable power is dissipated into the drilling fluid. Pure vibratory power losses of over 3,728 W (5 hp) are expected at frequencies equal to the first mode maximum response point for a drill column that is 152.4 m (500 ft) long. This is a frequency slightly less than the first undamped natural frequency of the drill column. For the same column, viscous rotational power losses of over 74.56 W ( 0.1 hp) are expected at rotational speeds of 10.47 rad/s (100 rpm). Rotational and vibratory losses increase with increases in the length of the column, fluid viscosity, and operating frequency."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Reduction of energy losses: a key to improved rock drilling?"]}]}],"canonical_facts":{"dc:contributor.department":["Mechanical Engineering"],"dc:creator":["Ohanehi, Donatus Chukwubueze"],"dc:date.accessioned":["2014-03-14T21:37:15Z"],"dc:date.available":["2014-03-14T21:37:15Z","2010-06-08"],"dc:date.issued":["1975"],"dc:description.abstract":["The viscous power losses of a rotary-vibratory drilling system are estimated in this study. Rotational and pure vibratory losses are considered separately. This analysis indicates that considerable power is dissipated into the drilling fluid. Pure vibratory power losses of over 3,728 W (5 hp) are expected at frequencies equal to the first mode maximum response point for a drill column that is 152.4 m (500 ft) long. This is a frequency slightly less than the first undamped natural frequency of the drill column. For the same column, viscous rotational power losses of over 74.56 W ( 0.1 hp) are expected at rotational speeds of 10.47 rad/s (100 rpm). 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