deventuallyreachtheregionsofhighpressurewithintheimpellerwheretheystartcollapsing.Thelifecycleofabubblehasbeenestimatedtobeintheorderof0.003seconds。StepThree,Collapseofbubbles,Asthevaporbubblesmovealongtheimpellervanes,thepressurearoundthebubblesbeginstoincreaseuntilapointisreachedwherethepressureontheoutsideofthebubbleisgreaterthanthepressureinsidethebubble.Thebubblecollapses.Theprocessisnotanexplosionbutratheranimplosion(inwardbursting).Hundredsofbubblescollapseatapproximatelythesamepointoneachimpellervane.Bubblescollapsenon-symmetricallysuchthatthesurroundingliquidrushestofillthevoidformingaliquidmicrojet.urs.Bubblecollapsepressuresgreaterthan1GPa(145x106psi)havebeenreported.Thehighlylocalizedhammeringeffectcanpitthepumpimpeller.Thepittingeffectisillustratedschematicallyinthisthefigure.
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