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1、WORP文档下载可编辑1.1Whatwillbethe(a)thegaugepressureand(b)theabsolutepressureofwateratdepth12mbelowthesurface?ρwater=1000kg/m3,andPatmosphere=101kN/m2.Solution:Rearrangingtheequation1.1-4Setthepressureofatmospheretobezero,thenthegaugepressureatdepth12mbelowthesurfaceisA
2、bsolutepressureofwateratdepth12m1.3AdifferentialmanometerasshowninFig.issometimesusedtomeasuresmallpressuredifference.Whenthereadingiszero,thelevelsintworeservoirsareequal.AssumethatfluidBismethane(甲烷),thatliquidCinthereservoirsiskerosene(specificgravity=0.815),an
3、dthatliquidAintheUtubeiswater.TheinsidediametersofthereservoirsandUtubeare51mmand6.5mm,respectively.Ifthereadingofthemanometeris145mm.,whatisthepressuredifferenceovertheinstrumentInmetersofwater,(a)whenthechangeinthelevelinthereservoirsisneglected,(b)whenthechange
4、inthelevelsinthereservoirsistakenintoaccount?Whatisthepercenterrorintheanswertothepart(a)?Solution:pa=1000kg/m3pc=815kg/m3pb=0.77kg/m3D/d=8R=0.145mWhenthepressuredifferencebetweentworeservoirsisincreased,thevolumetricchangesinthereservoirsandUtubes(1)so(2)andhydro
5、staticequilibriumgivesfollowingrelationship(3)so(4)substitutingtheequation(2)forxintoequation(4)gives(5)(a)whenthechangeinthelevelinthereservoirsisneglected,专业技术资料WORP文档下载可编辑(b)whenthechangeinthelevelsinthereservoirsistakenintoaccounterror=1.4TherearetwoU-tubemano
6、metersfixedonthefluidbedreactor,asshowninthefigure.ThereadingsoftwoU-tubemanometersareR1=400mm,R2=50mm,respectively.Theindicatingliquidismercury.Thetopofthemanometerisfilledwiththewatertopreventfromthemercuryvapordiffusingintotheair,andtheheightR3=50mm.Trytocalcul
7、atethepressureatpointAandB.Figureforproblem1.4Solution:ThereisagaseousmixtureintheU-tubemanometermeter.Thedensitiesoffluidsaredenotedby,respectively.ThepressureatpointAisgivenbyhydrostaticequilibrium专业技术资料WORP文档下载可编辑issmallandnegligibleincomparisonwithandρH2O,equa
8、tionabovecanbesimplified==1000×9.81×0.05+13600×9.81×0.05=7161N/m²=7161+13600×9.81×0.4=60527N/mDdpapaHhAFigureforproblem1.51.5Waterdischargesfromthereser