简介：

简介：Thispaperhadinvestigatedtheeffectsofsurfacewettabilityonthefrictionalresistanceofturbulenthorizontalflowfortapwaterinfivepipesmadeofvariousmaterialsandfourkindsofliquidsinapolytetrafluoroethylene(PTFE)pipe,withthesameinnerdiameterof14mm.Pressuredropsweremeasuredunderdifferentflowratesthroughanexperimentalflowloop.Thecontactanglesandadhesionworkofliquidsincontactwithpipesurfacesweredeterminedusingacontactanglemeter.Basedonthedimensionandregressionanalyses,twokindsofmodifiedrelationshipsbetweenthefrictionalcoefficientandthesurfacewettabilitywereestablishedaccordingtothemeasuredresultscorrespondingtotapwaterinfivepipesandfourliquidsinPTFEpipe.Theexperimentalresultsshowthatthesurfacewettabilityhassomeinfluenceonfrictionalcoefficientofthestudiedliquidsflowinginmacroscalepipes,andthefrictionalcoefficientdecreaseswiththeincreaseofthecontactangleatthesameReynoldsnumber.Meanwhiletheeffectofwettabilityonthehydrophobicsurfaceisgreaterthanthatonthehydrophilicone.Thefrictionalcoefficientspredictedbythemodifiedformulashaveverifiedtobeingoodagreementwiththeexperimentalvalues,therelativeerrorsofwhicharewithin±6%and±3%forthetapwaterflowinginfivedifferentpipesandfourkindsofliquidsflowinginPTFEpipe,respectively.