000186314 001__ 186314
000186314 005__ 20190522142438.0
000186314 0247_ $$2doi$$a10.1007/s00348-013-1514-6
000186314 022__ $$a0723-4864
000186314 02470 $$2ISI$$a000318158500019
000186314 037__ $$aARTICLE
000186314 245__ $$aDraft tube discharge fluctuation during self-sustained pressure surge: fluorescent particle image velocimetry in two-phase flow
000186314 260__ $$c2013$$bSpringer-Verlag$$aNew York
000186314 269__ $$a2013
000186314 300__ $$a11
000186314 336__ $$aJournal Articles
000186314 500__ $$aNational Licences
000186314 520__ $$aHydraulic machines play an increasingly important role in providing a secondary energy reserve for the integration of renewable energy sources in the existing power grid. This requires a significant extension of their usual operating range, involving the presence of cavitating flow regimes in the draft tube. At overload conditions, the self-sustained oscillation of a large cavity at the runner outlet, called vortex rope, generates violent periodic pressure pulsations. In an effort to better understand the nature of this unstable behavior and its interaction with the surrounding hydraulic and mechanical system, the flow leaving the runner is investigated by means of Particle Image Velocimetry. The measurements are performed in the draft tube cone of a reduced scale model of a Francis turbine. A cost-effective method for the in-house production of fluorescent seeding material is developed and described, based on off-the-shelf polyamide particles and Rhodamine-B dye. Velocity profiles are obtained at three streamwise positions in the draft tube cone and the corresponding discharge variation in presence of the vortex rope is calculated. The results suggest that 5-10% of the discharge in the draft tube cone is passing inside the vortex rope.
000186314 6531_ $$aFrancis turbines
000186314 6531_ $$acavitation
000186314 6531_ $$aPIV
000186314 6531_ $$afluid dynamics
000186314 6531_ $$avortex rope
000186314 6531_ $$apressure surge
000186314 6531_ $$aoverload
000186314 6531_ $$afluorescent particles
000186314 700__ $$0244116$$g154802$$aMüller, Andres
000186314 700__ $$0245367$$g170853$$aDreyer, Matthieu
000186314 700__ $$0242287$$g146461$$aAndreini, Nicolas
000186314 700__ $$0241012$$g104417$$aAvellan, François
000186314 773__ $$j54$$tExperiments in Fluids$$k4$$q1-11
000186314 8564_ $$uhttps://infoscience.epfl.ch/record/186314/files/348_2013_Article_1514.pdf$$zPUBLISHER'S VERSION$$s1423253
000186314 909C0 $$xU10309$$0252135$$pLMH
000186314 909C0 $$pLHE$$xU10257$$0252029
000186314 909CO $$particle$$pSTI$$pENAC$$ooai:infoscience.tind.io:186314
000186314 917Z8 $$x154802
000186314 917Z8 $$x154802
000186314 937__ $$aEPFL-ARTICLE-186314
000186314 973__ $$rNON-REVIEWED$$sPUBLISHED$$aEPFL
000186314 980__ $$aARTICLE