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000139211 0247_ $$2doi$$a10.5293/IJFMS.2009.2.4.286
000139211 037__ $$aARTICLE
000139211 245__ $$aInfluence of the Francis turbine location under vortex rope excitation on the hydraulic system stability
000139211 269__ $$a2009
000139211 260__ $$c2009
000139211 336__ $$aJournal Articles
000139211 520__ $$aHydroelectric power plants are known for their ability to cover variations of the consumption in electrical power networks. In order to follow this changing demand, hydraulic machines are subject to off-design operation. In that case, the swirling flow leaving the runner of a Francis turbine may act under given conditions as an excitation source for the whole hydraulic system. In high load operating conditions, vortex rope behaves as an internal energy source which leads to the self excitation of the system. The aim of this paper is to identify the influence of the full load excitation source location with respect to the eigenmodes shapes on the system stability. For this, a new eigenanalysis tool, based on eigenvalues and eigenvectors computation of the nonlinear set of differential equations in SIMSEN, has been developed. First the modal analysis method and linearization of the set of the nonlinear differential equations are fully described. Then, nonlinear hydro-acoustic models of hydraulic components based on electrical equivalent schemes are presented and linearized. Finally, a hydro-acoustic SIMSEN model of a simple hydraulic power plant, is used to apply the modal analysis and to show the influence of the turbine location on system stability. Through this case study, it brings out that modeling of the pipe viscoelastic damping is decisive to find out stability limits and unstable eigenfrequencies.
000139211 6531_ $$aInstability
000139211 6531_ $$aVortex rope
000139211 6531_ $$aEigenvalues
000139211 6531_ $$aViscoelastic damping
000139211 6531_ $$aFrancis Turbine
000139211 700__ $$0243097$$g178059$$aAlligné, Sébastien
000139211 700__ $$aNicolet, Christophe
000139211 700__ $$0242127$$g107264$$aAllenbach, Philippe
000139211 700__ $$0241012$$g104417$$aAvellan, François
000139211 700__ $$aKawkabani, B.$$0240495$$g105539
000139211 700__ $$0240024$$g106434$$aSimond, J.J.
000139211 773__ $$j2$$tInternational Journal of Fluid Machinery and Systems$$k4$$q286-294
000139211 8564_ $$uhttps://infoscience.epfl.ch/record/139211/files/IJFMS_v2.pdf$$zn/a$$s1049145
000139211 909C0 $$xU10313$$0252015$$pLME
000139211 909C0 $$pLMH$$xU10309$$0252135
000139211 909CO $$qGLOBAL_SET$$pSTI$$particle$$ooai:infoscience.tind.io:139211
000139211 917Z8 $$x148230
000139211 937__ $$aLMH-ARTICLE-2009-009
000139211 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000139211 980__ $$aARTICLE