Show simple item record

dc.contributor.authorThapa, Biraj Singh
dc.contributor.authorDahlhaug, Ole Gunnar
dc.contributor.authorThapa, Bhola
dc.identifier.citationIOP Conference Series: Earth and Environment. 2016, 49 .nb_NO
dc.description.abstractIn Francis turbine, a small clearance gap between the guide vanes and the cover plates is usually required to pivot guide vanes as a part of governing system. Deflection of cover plates and erosion of mating surfaces causes this gap to increase from its design value. The clearance gap induces the secondary flow in the distributor system. This effects the main flow at the runner inlet, which causes losses in efficiency and instability. A guide vane cascade of a low specific speed Francis turbine has been developed for experimental investigations. The test setup is able to produce similar velocity distributions at the runner inlet as that of a reference prototype turbine. The setup is designed for particle image velocimetry (PIV) measurements from the position of stay vane outlet to the position of runner inlet. In this study, velocity and pressure measurements are conducted with 2 mm clearance gap on one side of guide vane. Leakage flow is observed and measured together with pressure measurements. It is concluded that the leakage flow behaves as a jet and mixes with the main flow in cross-wise direction and forms a vortex filament. This causes non-uniform inlet flow conditions at runner blades.nb_NO
dc.publisherIOP Publishingnb_NO
dc.titleVelocity and pressure measurements in guide vane clearance gap of a low specific speed Francis turbinenb_NO
dc.typeJournal articlenb_NO
dc.typePeer reviewednb_NO
dc.source.journalIOP Conference Series: Earth and Environmentnb_NO
dc.description.localcodeContent from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.nb_NO
cristin.unitnameInstitutt for energi- og prosessteknikk

Files in this item


This item appears in the following Collection(s)

Show simple item record
Except where otherwise noted, this item's license is described as