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ID:32505429
大小:2.63 MB
页数:34页
时间:2019-02-09
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1、HydraulicsAirlineTransitionCourseLessonObjectivesDevelopabasicunderstandingofhydraulictheoryandthephysicsrelatedtohydraulicsFluidPowerLawofConservationofEnergyPascal’sLawHydrostaticParadoxMechanicaladvantageBernoulli’sprincipleTypesofFluidHydraulicSystemComponentsFluidPower
2、THEORYHydraulicsystemsoperateaccordingtoPascalslaw.ThelawofBlaisePascalsays:'Thepressure,inastatichydraulicfluidinaclosedsystemiseverywherethesame'.However,whenthevelocityoftheflowisconstantonemayapplyPascalsLawaswell.Animation:Whenthemanjumpsonthesmallpiston,heinducesapre
3、ssureinthesystem.Thispressurealsoworksonthelargepiston:becauseofthelargeareaofthispiston,theforceinducedbythepressureiscapabletoliftthecar.Thepressurecanbecalculatedwiththeformula:where:p=pressure(psi)F=force(pound)A=area(squareinch)FluidPowerForce=energyexerted(F=MA)Pressu
4、re=aforcethatisappliedoveragivenarea(usuallyinpsi)Pressure=Force/AreaWork=anytimeaforcecausesanobjecttomoveWork=ForcexDistancePower=theamountofpowerrequiredtoaccomplishagiveamountofworkinacertainperiodoftimePower=(ForcexDistance)/TimeLawofConservationofEnergyWeareabletotake
5、energyandchangeit’sform,conserveitforlater,andreleaseitatwill.Wegetthesameamountofenergyoutasweputin.Unfortunatelysomeenergyistransformedandlostintoanunusableform.Ex:Rubbingyouhandstogether,takesyourbodiesenergyandreleasesitasthermalenergy.(UnlessyourinNorthDakotainJan.doin
6、gthisisusuallyprettyuseless)ThislossofenergyisusuallyreferredtoasinefficiencyTwoFormsofEnergyPotential:ExistsinanobjectbecauseofitspositionEx:ArubberbandstretchedoutKinetic:ExistsinanobjectduetoitsmotionEx:ArubberbandafterIhaveletgoofit,asitfliestowardsyourfaceHydrostaticPa
7、radoxParadox:Atruestatementthatdoesnotreadilyappeartobetrue.HydrostaticParadox:Thepressureofafluidatthebottomofthecontainerwillbeeffectedbytheheightofthatcontainerbutnotitsshapeortheamountoffluid.Pascal’sLaw“Pressureinanenclosedcontaineristransmittedequallyandundiminishedto
8、allpartsofthecontainerandactsatrightanglestotheenclosingwalls.Pascal’sLawPressuree
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