Author : Gregory Labelle
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (139 download)
Book Synopsis Phase-averaged PIV Measurements in the Draft Tube of a Francis Turbine at Speed No-load by : Gregory Labelle
Download or read book Phase-averaged PIV Measurements in the Draft Tube of a Francis Turbine at Speed No-load written by Gregory Labelle and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis aims to characterize the flow and identify flow phenomena in the draft tube of the Tr-Francis medium head model turbine operated at speed-no load and installed at the Heki laboratory at Laval University. With little research accomplished on the speed no-load regime and machines being operated increasingly in this regime, the thesis will help the industry understand by what mechanisms the machine is damaged by the no load regime. The experiments used stereoscopic particle image velocimetry in one radial-axial plane of the conical diffuser. The measurements were locked on the position of the turbine runner (phase-locked). This measurement method was applied at two heights in the conical diffuser to cover most of its height. The measured phases are equally spaced at an interval of 6° and cover 360°. For the upper measurement section, a finer resolution of 3° was used between phases 300° and 360°. The global flow structure discussed in the literature was found to be present in the studied model. A high velocity throughflow with a large tangential and axial velocity was measured near the diffuser's inner wall. A recirculation zone with much lower velocities was measured at the center of the diffuser. The shear layer mentioned by a few authors was characterised by calculating shear strain components. The flow was found not to be axisymmetric. Traces of inter-blade vortices in the draft tube were found in the phase-averaged measurements as was predicted by the numerical simulations.