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CFD analysis of steady state flow reaction forces in a rim spool valve

dc.contributor.advisorBurton, Richard T.en_US
dc.contributor.advisorBergstrom, Donald J.en_US
dc.contributor.committeeMemberSchoenau, Greg J.en_US
dc.contributor.committeeMemberEvitts, Richard W.en_US
dc.contributor.committeeMemberBugg, James D.en_US
dc.contributor.committeeMemberWu, Fang-Xiangen_US
dc.creatorOkungbowa, Norense Stanleyen_US
dc.date.accessioned2006-02-20T10:45:00Zen_US
dc.date.accessioned2013-01-04T04:25:41Z
dc.date.available2006-02-20T08:00:00Zen_US
dc.date.available2013-01-04T04:25:41Z
dc.date.created2006-01en_US
dc.date.issued2006-01-27en_US
dc.date.submittedJanuary 2006en_US
dc.description.abstractHydraulic spool valves are found in most hydraulic circuits in which flow is to be modulated. Therefore their dynamic performance is critical to the overall performance of the circuit. Fundamental to this performance is the presence of flow reaction forces which act on the spool. These forces can result in the necessity of using two stage devices to drive the spool and in some cases have been directly linked to valve and circuit instabilities. As such, a great deal of research and design has concentrated on ways to reduce or compensate for flow forces. In one particular series of studies conducted on flow divider valves, it was established that a rim machined into the land of the spool reduced the flow dividing error by approximately 70-80%, and it was deduced that the main contribution to this error was flow forces. Direct verification of the claim regarding flow force reduction was not achieved and hence was the motivation for this particular study. This thesis will consider the reaction (flow) force associated with a conventional spool land and one with a rim machined into it, and a modified form of the rimmed land referred to as a “sharp edge tapered rim spool land”. The rim and the sharp edge tapered rim were specially designed geometrical changes to the lands of the standard spool in order to reduce the large steady state flow forces (SSFF) inherent in the standard spool valve. In order to analyze the flow field inside the interior passages of the valve, three configurations of the spool were considered for orifice openings of 0.375, 0.5, 0.75 and 1.05 mm. Computational Fluid Dynamics (CFD) analysis was used to describe the fluid mechanics associated with the steady state flow forces as it provided a detailed structure of the flow through the valve, and to identify the flow mechanism whereby flow forces are reduced by the machining of a rim and tapered rim on the land of the spool. For all openings of the spool, the sharp tapered rim valve provides the largest reduction in SSFF. It was also observed that for all cases studied, the inflow SSFF’s were smaller than for the outflow conditions. The prediction of the steady state flow force on the rim spool was investigated in a flow divider valve configuration, and the results from the CFD analysis indicated a reduction by approximately 70%.en_US
dc.identifier.urihttp://hdl.handle.net/10388/etd-02202006-104500en_US
dc.language.isoen_USen_US
dc.subjectFlow Reaction Forcesen_US
dc.subjectCFDen_US
dc.subjectmeasuring fluid jet angle in spool valveen_US
dc.subjectspool valveen_US
dc.subjectSteady State Flow Forcesen_US
dc.subjectRim spoolen_US
dc.titleCFD analysis of steady state flow reaction forces in a rim spool valveen_US
dc.type.genreThesisen_US
dc.type.materialtexten_US
thesis.degree.departmentMechanical Engineeringen_US
thesis.degree.disciplineMechanical Engineeringen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Science (M.Sc.)en_US

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