【7A文】航空飞机液压理论英文培训课件.ppt

《【7A文】航空飞机液压理论英文培训课件.ppt》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。

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