Numericalpredictionofaddedmassanddampingforacylinderoscillatinginconfinedincompressiblegas–liquidtwo-phasemixtureOriginalResearchArticle

Thispaperisconcernedwiththenumericalanalysisoftheaddedmassanddampingofacircularcylinder,whichoscillatesinanair–waterbubblymixtureenclosedbyaconcentricshell.Themixtureisassumedtobeincompressible.Thisisbecausetheoscillationfrequencyofthecylinderislowinthisstudy,andaccordinglythepressurechangearoundthecylinderisnotsolarge.Anincompressibletwo-fluidmodelissolvedbythefiniteelementmethod,proposedbytheauthorinapriorpaper,tocalculatethebubblyflowaroundtheoscillatingcylinder.Theanalysisrevealstheeffectsofthediameterratioofthecylindertotheshell,theairvolumetricfractionandthebubblediameter.Italsoclarifiesthattheincreaseofdampingratiointhebubblymixtureisattributabletothephaselagofthedragforceactingonthecylinderbehindthecylinderdisplacement.