Flow-inducedvibrationandfretting-wearpredictionsofsteamgeneratorhelicaltubesOriginalResearchArticle

Thispaperaddressesthepotentialflow-inducedvibrationsandfretting-wearofhelicallycoiledtubesoftheonce-throughsteamgeneratoremployedatanintegraltypenuclearreactor,wherethetubesaresubjectedtoliquidcross-flowexternallyandmulti-phaseflowinternally.Thethermal-hydraulicconditionsofbothtubesideandshellsideflowfieldsarepredictedusingageneralpurposecomputationalfluiddynamicscodeusingthefinitevolumeelementmodeling.Togetthenaturalfrequencyandcorrespondingmodeshapeofthehelicallycoiledtubeswithvariousconditions,afiniteelementanalysiscodeisused.Basedontheresultsofboththethermal-hydraulicanalysisofhelicallycoiledtubesteamgeneratorandthemodalanalysisofthetubes,predictionsofturbulence-inducedvibration,fluidelasticinstabilityandfretting-wearofthehelicallycoiledtubesareperformed.Inthepredictions,specialemphasisisplacedondeterminingtheeffectsofthenumberofsupports,coildiameterandhelixpitchonthenaturalvibrationmode,turbulencevibrationamplitude,fluidelasticinstabilityandfretting-wearcharacteristicsofthetubes.Theresultsprovidethetechnicalinformationandbasesneededbydesignersandregulatoryreviewersforevaluatingthedesign.