000217563 001__ 217563
000217563 005__ 20190816052046.0
000217563 022__ $$a1814-2079
000217563 0247_ $$2doi$$a10.1080/00221686.2015.1131204
000217563 02470 $$2ISI$$a000378000000006
000217563 037__ $$aARTICLE
000217563 245__ $$aLocal wave speed and bulk flow viscosity in Francis turbines at part load operation
000217563 260__ $$bTaylor & Francis Ltd$$c2016$$aAbingdon
000217563 269__ $$a2016
000217563 300__ $$a12
000217563 336__ $$aJournal Articles
000217563 520__ $$aThe operation of Francis turbines at off-design conditions may cause the development of a cavitation vortex rope in the draft tube cone, acting as a pressure excitation source. The interactions between this excitation source and the hydraulic system at the natural frequency may result in resonance phenomena, causing serious hydro-mechanical oscillations. One-dimensional draft tube models for the simulation and prediction of part load resonances require an accurate modelling of the wave speed and the bulk viscosity for the draft tube flow. This paper introduces a new methodology for determining these two hydroacoustic parameters in the draft tube of a reduced scale physical model of a Francis turbine, based on experimental identification of the hydraulic natural frequency of the test rig. Finally, dimensionless numbers are derived to define both the wave speed and bulk viscosity for different operating points of the turbine.
000217563 6531_ $$aCavitation
000217563 6531_ $$adraft tube flow
000217563 6531_ $$aexperimental investigation
000217563 6531_ $$aFrancis turbine
000217563 6531_ $$ahydroacoustic modelling
000217563 700__ $$0245304$$g170545$$aLandry, Christian
000217563 700__ $$aFavrel, Arthur
000217563 700__ $$0244116$$g154802$$aMüller, Andres
000217563 700__ $$aNicolet, Christophe
000217563 700__ $$0241012$$g104417$$aAvellan, François
000217563 773__ $$tJournal of Hydraulic Research$$q185-196$$j54$$k2
000217563 909C0 $$xU10309$$0252135$$pLMH
000217563 909CO $$qGLOBAL_SET$$pSTI$$particle$$ooai:infoscience.tind.io:217563
000217563 917Z8 $$x104417
000217563 937__ $$aEPFL-ARTICLE-217563
000217563 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000217563 980__ $$aARTICLE