Completed notes of the course Part2

Pagina 1

LOWER UPPERBOUNDFORTHE CHI LOWERBand Wefocuson aNonboilingcondition Singlephasesubcooledflowliquid 1Energybalance on a length 2 measuredfantheinlet I exchanged atthegenere coordinate TozTo n i Iff 9 T.z I.IT Fa Fa 7in 1 Eai.ae Ts . Fz q 5z T.in BOILINGCONTIATON Wehaveasubcooledliquid Inorderti getboilingweknowthatthewallmust ftp.t f ypI tothesaturation TOGETBOILING T z TSAT ΔTsurs in deopee ofsubcoolingoftheliquidattheinlet Sincewecannotget Effy b a 9 c Ig LowerBoundFORTHEONSETOFBOILING bailing T.inTo fthelandattheneletwhichin subcooled Thisvalueisidentifiedastheloverband fortheCHFSetually itas a lavaband fortheonsetofboiling Typically 2mi 10 pepe so unsmall andcan leneglected UPPERBOUND Completeevaporationcondition Energybalance I fantheinletfarasegitemthatundergoes aphasechange agenericdistance2 TIha hoa 9 HDZ Italeg Ge Atsuroin They x̅a Ge B i ftp.mepatteseaphasaareintoineomilibaum heho i Cpe TsAT Toin CheAtsubin Fate.FIa i II tF9i III 1 9 a III stsu.in III 7 CHI haia lineardependence onthedegree ofsubcooling attheinlet 9 µ CHE YWABLE RANGE UPPER BOUND µ III to Fie scorsoraversons DTsubin 9 IffSTB.int hfTlnianalymputinevidence sane notall oftherelevant LiTheupperbandhasthesameslopeofpanameteritocorrelatetheCHF Itsuggestes abasicstructure hatheCHEmodels thelowerboundbutitstraslated CHEcorrelations aregenerallyscouse noteasytoperformexperimentwithsystemsthatoneincriticalconditions LI Y EedIIpuatingonottean 1 PervelyempiricalmodelsIthecomplexityofthephenomenon issuchthatmechanisticmodelsarenotyetavailable Weneedacheckforthefeasibilityofthemodel isAFIRSTCHECK BASICSTRUCTURE FORANEMPIRICAL MODEL ai suggestedbytheupper andlancebounds CHEvanalinearlywithAserinlandencicaser 9 A BATsusmt Shsubin hehoin Inverselycorrelatedtothelenghtofthepipediatomeefantheinlet C DI A B C…