NumericaltreatmentofpebblecontactintheflowandheattransferanalysisofapebblebedreactorcoreOriginalResearchArticle

Thispaperstudiesthenumericaltreatmentoftheinter-pebbleregionsinthemodelingofapackedbedgeometryforthecomputationalfluiddynamics(CFD)analysisofapebblebedreactor(PBR)core,wherethepebblesarephysicallyincontactwitheachother.Insomestudies,theinter-pebbleregionshavebeenapproximatedwithgaps,inconsiderationoftheproblemsonmeshqualityoreconomyoftheCFDcalculation.Toexaminesuchamethodology,asensitivityanalysisforthegapsizewasconductedwithtwosphericalpebbles,wheretheinter-pebbleregionwasmodeledbymeansoftwokindsofinter-pebblegapandtwokindsofdirectcontact.Thecasesofdirectcontactshowednumerousdifferencesintheresultsoftheflowregimearoundthepebblesaswellasinthewake,comparedtothecasesoftheinter-pebblegap.Nolargedifferenceswerefoundbetweenthetwocasesofdirectcontact.Basedontheresultofthesensitivityanalysis,thetwocasesofinter-pebblemodeling,i.e.,the1-mmgapandarea-contact,wereappliedtothePBRsimulation.Itwasconcludedthattheflowregimesandtheirrelevantflow-inducedlocalheattransferweresignificantlydependentonthemodelingoftheinter-pebbleregion.