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dc.contributor.supervisor Bibeau, Eric (Mechanical Engineering) Chatoorgoon, Vijay (Mechanical Engineering) en_US
dc.contributor.author Shahsavarifard, Mohammad
dc.date.accessioned 2015-10-05T22:34:17Z
dc.date.available 2015-10-05T22:34:17Z
dc.date.issued 2015
dc.identifier.uri http://hdl.handle.net/1993/30868
dc.description.abstract To investigate the effect of shroud on the performance of hydrokinetic turbines in inline and off-axis flows, a horizontal axis model turbine and two shrouds were designed and fabricated. Consistent power, torque, and thrust coefficients for the shrouded and unshrouded turbines were obtained for a complete range of performance curve in water tunnel experiments. A maximum power enhancement of 91% over the unshrouded turbine is obtained with the straight wall diffuser design. Power coefficients of the model turbine with the diffuser calculated based on the diffuser exit area, in agreement with the van Bussel momentum theory, is found comparable to the performance coefficients of the unshrouded turbine with the size of the diffuser exit diameter. In off-axis flows the output power of a hydrokinetic turbine is observed to decrease. The reduction is negligible up to 10° yaw angle but increases as the yaw angle increases beyond 10°. The model turbine with the convergent–divergent wall shroud design experiences negligible performance loss in yaw operations compared to the unshrouded turbine. Using the experimental results and in an analogy to the cosine rules of the linear momentum theory, similar cosine relations for the shrouded turbines are proposed for the first time. The optimum power of the model turbine with the shroud is experimentally observed to decrease with cosine of yaw angle. Based on this, the turbine with the shroud in a 45° yaw angle would generate 29% less power than in an inline flow. The unshrouded turbine, based on the cosine cubed rule of the momentum theory, would generate 65% less power in the same flow. This study addresses the fact why the reported augmentation factors for diffuser augmented wind turbines in the literature has a broad range from -36% to 760% which shows disagreements between researchers. en_US
dc.rights info:eu-repo/semantics/openAccess
dc.subject Hydrokinetic turbine, horizontal turbine, shroud, performance, yaw angle en_US
dc.title Effect of shroud on the performance of horizontal axis hydrokinetic turbines en_US
dc.type info:eu-repo/semantics/doctoralThesis
dc.type doctoral thesis en_US
dc.degree.discipline Mechanical Engineering en_US
dc.contributor.examiningcommittee Tachie, Mark (Mechanical Engineering) Dick, Kristopher (Biosystems Engineering) Wood, David (University of Calgary) en_US
dc.degree.level Doctor of Philosophy (Ph.D.) en_US
dc.description.note February 2016 en_US


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