000167360 001__ 167360
000167360 005__ 20190812205530.0
000167360 037__ $$aCONF
000167360 245__ $$aDetermination of Hydroacoustic Draft Tube Parameters by High Speed Visualization during Model Testing of a Francis Turbine
000167360 269__ $$a2011
000167360 260__ $$c2011$$aBelgrade
000167360 336__ $$aConference Papers
000167360 520__ $$aFrancis turbines can experience critical instabilities at high load operating points, limiting their maximum power output. The swirling flow developed in the draft tube produces a cavitating axisymmetric volume, acting as an internal energy source leading to a self-excited surge phenomenon. The pulsation of the vortex rope corresponds to one of the eigenfrequencies of the hydraulic system. Efforts to accurately characterize, simulate and predict this phenomenon have been undertaken by several researchers, using a 1-D hydroacoustic model of the full load vortex rope. The key physical parameters are the mass flow gain factor, standing for the excitation mass source of the hydraulic system, the cavitation compliance factor, representing the wave speed and the thermodynamic damping, modeling the energy dissipation between the liquid and the gas. These parameters need to be determined either numerically or experimentally. The aim of the present investigation is to determine the mass flow gain factor and the cavitation compliance using experimental data obtained during a measurement campaign on a reduced scale Francis turbine model and to compare the results to existing CFD data.
000167360 6531_ $$ainstability, cavitation, vortex rope, experimental measurements, hydroacoustic, full load
000167360 700__ $$0244116$$g154802$$aMüller, Andres
000167360 700__ $$0243097$$g178059$$aAlligné, Sébastien
000167360 700__ $$aParaz, Florine
000167360 700__ $$g170545$$aLandry, Christian$$0245304
000167360 700__ $$aAvellan, François$$g104417$$0241012
000167360 7112_ $$dOctober 26-28, 2011$$cBelgrade, Serbia$$a4th International Meeting on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems
000167360 773__ $$tProceedings of the 4th International Meeting on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems$$q125-131
000167360 8564_ $$zn/a$$yn/a$$uhttps://infoscience.epfl.ch/record/167360/files/IAHR-WG2011-Mueller-EPFL-LMH_20110701.pdf$$s469184
000167360 909C0 $$xU10309$$pLMH$$0252135
000167360 909CO $$ooai:infoscience.tind.io:167360$$qGLOBAL_SET$$pconf$$pSTI
000167360 917Z8 $$x154802
000167360 917Z8 $$x154802
000167360 937__ $$aEPFL-CONF-167360
000167360 973__ $$rNON-REVIEWED$$sPUBLISHED$$aEPFL
000167360 980__ $$aCONF