000231248 001__ 231248
000231248 005__ 20190812210002.0
000231248 0247_ $$2doi$$a10.1088/1742-6596/813/1/012023
000231248 037__ $$aCONF
000231248 245__ $$aDynamics of the precessing vortex rope and its interaction with the system at Francis turbines part load operating conditions
000231248 269__ $$a2017
000231248 260__ $$c2017
000231248 336__ $$aConference Papers
000231248 520__ $$aAt part load conditions, Francis turbines experience the formation of a cavitation vortex rope at the runner outlet whose precession acts as a pressure excitation source for the hydraulic circuit. This can lead to hydro-acoustic resonances characterized by high pressure pulsations, as well as torque and output power fluctuations. This study highlights the influence of the discharge factor on both the vortex parameters and the pressure excitation source by performing Particle Image Velocimetry (PIV) and pressure measurements. Moreover, it is shown that the occurrence of hydro-acoustic resonances in cavitation conditions mainly depend on the swirl degree of the flow independently of the speed factor. Empirical laws linking both natural and precession frequencies with the operating parameters of the machine are, then, derived, enabling the prediction of resonance conditions on the complete part load operating range of the turbine.
000231248 700__ $$aFavrel, A
000231248 700__ $$aMüller, A
000231248 700__ $$aLandry, C
000231248 700__ $$aGomes, J
000231248 700__ $$aYamamoto, K
000231248 700__ $$aAvellan, F
000231248 7112_ $$dFebruary 2-3, 2017$$cPorto, Portugal$$aHYPERBOLE Conference
000231248 773__ $$j813$$tJournal of Physics: Conference Series$$k1$$q012023
000231248 909C0 $$xU10309$$pLMH$$0252135
000231248 909CO $$pconf$$pSTI$$ooai:infoscience.tind.io:231248
000231248 917Z8 $$x104417
000231248 937__ $$aEPFL-CONF-231248
000231248 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000231248 980__ $$aCONF