Numerical Prediction of Fluid Flow and Heat Transfer in a Wavy Pipe

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摘要 Hydrodynamicandthermalcharacteristicsinapipewithsinusoidalwavysurfaceforsteadylaminarflowareinvestigatednumericallyinthepresentstudy.TheintegralformsofgoverningequationsarediscretizedusingcontrolvolumebasedFinitevolumemethodwithcollocatedvariablearrangement.SIMPLEalgorithmisusedandTDMAsolverisappliedforsolutionofsystemofequations.Apipeoflengthequalto4λisconsidered.Effectofsurfacewaviness,determinedbywavelength-amplituderatioλ/a(=L^*),onflowandthermalfieldispresented.ThesimulationworkhasbeencarriedoutforL^*=11.0-30.0foraReynoldsnumberrange50to2000.Resultsarepresentedintheformofstreamfunction,isothermallines,velocityandvorticityprofiles,changeofmeanfrictionfactor,variationinskinfriction,localandaverageNusseltnumberwithReynoldsnumber,wavenumber(n)andL^*.Foraparticulargeometry,lengthofcirculationzoneincreaseswithreynoldsnumberandapproachesalimitingvalueforhigherReynoldsnumber.Wallshearstressinthebulgepartofthechannelshowssmallervaluesthataffectlargely.therateofheattransferandNusseltnumbershowsminimumvaluesinthisregion.Thiscirculationzonedrasticallyincreaseswiththeincreaseofsurfacewavinessshowinghighmeanfrictionfactorperwavelength.MeanfrictionfactorinverselyvarieswithReynoldsnumber.Acorrelationisproposedforcalculatingfrictionfactorintheformf=C/(Re)^m,where‘C’and‘m’representstwopolynomialsofdegree4and2respectivelyandarefunctionofL^*.Higherwavinessofthesurfaceshowsthehigherheattransferratethanlowerwaviness.Heattransferratefallsalmostexponentiallyalongtheaxialdirectionwiththeincreaseofwavenumber.
机构地区 不详
出版日期 2001年02月12日(中国期刊网平台首次上网日期,不代表论文的发表时间)
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