000218732 001__ 218732
000218732 005__ 20181203024238.0
000218732 0247_ $$2doi$$a10.1016/j.jfluidstructs.2016.05.009
000218732 022__ $$a0889-9746
000218732 02470 $$2ISI$$a000382411500005
000218732 037__ $$aARTICLE
000218732 245__ $$aSignal analysis of an actively generated cavitation bubble in pressurized pipes for detection of wall stiffness drops
000218732 269__ $$a2016
000218732 260__ $$bElsevier$$c2016$$aLondon
000218732 300__ $$a16
000218732 336__ $$aJournal Articles
000218732 500__ $$a[1070]
000218732 520__ $$aDue to the increasing production of volatile new renewable energies as solar and wind, storage hydropower plants have to operate under harsh operation conditions in order to stabilize the electricity grid. As a result, highly transient water pressures occur in pressure tunnels and shafts more frequently. Non-intrusive monitoring techniques are therefore of special interest for these critical infrastructures. The propagation of a pressure wave generated actively by a cavitation bubble was experimentally investigated in a steel test pipe divided in several reaches. A local wall stiffness drop was simulated by replacing steel pipe reaches with less stiff materials as aluminum and PVC. Through the analysis of the pressure wave reflections due to the cavitation bubble explosion, recorded by two hydrophones placed at the extremities of the test pipe, the location of the weak reaches could be detected. An underwater spark generator was developed to produce cavitation bubbles in the pipe resulting in very steep shock waves. This allowed identifying very precisely the wave front and correspondingly the wave speed and the weak reach location. Compared to the wave analysis from water-hammer signals, the active cavitation bubble generation in the pipe is an innovative method that significantly increased the effectiveness of the detection of wall stiffness drops. (C) 2016 Elsevier Ltd. All rights reserved.
000218732 6531_ $$aMonitoring
000218732 6531_ $$aSteel-lined pressure tunnels and shafts
000218732 6531_ $$aWave speed
000218732 6531_ $$aWave reflections
000218732 6531_ $$aShock wave
000218732 6531_ $$aCavitation bubble
000218732 700__ $$aMazzocchi, E.
000218732 700__ $$0246915$$g179222$$aPachoud, Alexandre Jean
000218732 700__ $$0240473$$g123870$$aFarhat, M.
000218732 700__ $$0242666$$g169461$$aHachem, F. E.
000218732 700__ $$aDe Cesare, Giovanni$$g101010$$0240404
000218732 700__ $$aSchleiss, Anton$$g112841$$0241228
000218732 773__ $$j65$$tJournal of Fluids and Structures$$kAugust$$q60-75
000218732 909C0 $$xU10263$$0252079$$pLCH
000218732 909C0 $$pLMH$$xU10309$$0252135
000218732 909C0 $$xU10263$$0255473$$pPL-LCH
000218732 909CO $$particle$$pSTI$$pENAC$$ooai:infoscience.tind.io:218732
000218732 917Z8 $$x246105
000218732 937__ $$aEPFL-ARTICLE-218732
000218732 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000218732 980__ $$aARTICLE