简介：Lowweightandcompactnessarethemainrequirementsoncomponentsforexoskeletons.Fordrivesthismeansalsohighefficiencytokeepenergystorageandpowertransducingdevicessmall.Thedigitalhydrauliccylinderdriveisanexcellentcandidatetobecomeasuperiortechnologyforexoskeletonactuation.Itrequiresseveralvalvestocontrolpressureinitsmanychambers.Solenoidvalvessufferfromthehighweightandspaceofthesolenoids.Inthispaper,thehydraulicbinarycounterinaconfigurationwithonlypassiveelementsisstudiedmathematically,sinceitcancontroladigitalcylinderwithmuchsmallerspaceandweightthanmagneticallyactuatedvalves.Fromqualitativeconsiderationsofthesystemequationssupplementedbyanumericalstudy,itisshownthatsuchacounterworksproperly.Butitposesrequirementsonthecontrolpressurerangewhicharedifficulttofulfilfordigitalcylinderdriveswithmorethanfivechambers.

简介：Remainingusefullife(RUL)estimationisatopicthathasgainedmoreandmoreattentioninthefieldoffluidpowersystems,thankstothetremendouspotentialsshownforimprovingsafetyandreducedproductionlosses.However,manychallengesrelatedtoRULestimationarenotsolvedyet,mainlyconnectedtothedefinitionofthehealthstatusofeachcomponent.Aprognosticmethodbasedonadata-drivenmethodologyforhydraulicsystemsishereproposedtoestimatethepercentageoflifealreadyspentbythemonitoredcomponents.Thepotentialsofthemethodologyareshownconsideringthecaseofatruck-mountedhydrauliccrane,forwhichasimulationmodelwasavailable.

简介：

简介：

简介：ThispaperdescribestheNiiMiprocessdesignedtotreatlandscapewater.ThemainaimoftheresearchwastoinvestigatethefeasibilityofNiiMiforremovingorganicandnutrimentmaterialsfromlandscapewater.Duringthebatch-scaleNiiMioperation,theremovalratesofcolorrangedfrom66.7%-80%,ofturbidityfrom31.7%-89.3%,ofchemicaloxygendemand(COD)from7%-36.5%,oftotalphosphor(TP)from43%-84.2%,ofsolublephosphatefrom42.9%-100%,oftotalnitrogen(TN)from4.2%-46.7%,andofNH4+-Nfrom39.3%-100%atthehydraulicloadingof0.2m3/(m2·d).ResultsshowedthattheremovalefficienciesofCOD,TP,solublephosphateandTNdecreasedwiththedeclineinthetemperature.TheNiiMiprocesshadastrongshockloadingabilityfortheremovaloftheorganics,turbidity,TP,solublephosphate,TNandNH4+-N.Threesodiumchloridetracerstudieswereconducted,labeledasTS1,TS2,andTS3,respectively.Themeanhydraulicretentiontimes(meanHRTs)were31hand28hforTS1andTS2,respectively,indicatingtheoccurrenceofadeadzonevolumeof12%and20%forTS1andTS2,respectively.TS1andTS2displayedtheoccurrenceofshort-circuitingintheNiiMisystem.ThecomparisonresultsbetweenTS1andTS2werefurtherconfirmedinthevaluesobtainedforsomeindicators,suchasvolumetricefficiency(e),short-circuiting(S),hydraulicefficiency(λ)andnumberofcontinuouslystirredtankreactors(N).

简介：

简介：Thispaperpresentsananalysisofthepotentialforenginespeedreductioninhydraulicequipment,takingintoaccountnotonlytheminimumenginespeedrequiredtomeetthecurrentflowdemand,butalsotheminimumspeedcapableofacceleratingtheenginetomeetincreasedflowdemandinthenearfuture.Thisisapredictivetask,asitrequiresanestimateoftheoperator'sintentiontoincreaseflowdemand.Wepresentananalysisofthepotentialforenginespeedreductionusingaworkcyclefroma40tonexcavatorloadingatruck,whichresultsinapotential33%reductioninthemeanenginespeedwithnoreductioninusefulworkrate.Wealsopresenttwonewenginespeedcontrolalgorithmstoperformthispredictivetask.

简介：

简介：在氧化的缺氧的硫化物(ASO)的最佳的操作条件生物反应器被调查。最大的移动为硫化物评价；硝酸盐被发现是4.18kg/(m[3]·d)；1.73kg/(m[3]·d)分别地。装载在固定底层集中整个减少的水力的保留时间(HRT)观察的率(LR)的volumetricalvolumetri比由在固定HRT增加底层集中的那些高。在ASO反应堆的硫化物氧化部分正在生产两硫酸盐；硫；但是生产的硫酸盐的数量是约三分之一硫的。这个过程能高容忍硫化物集中，当流入的集中直到580mg/L时，硫化物移动百分比总是在99%附近留下了。它容忍了因为当流入的集中在110mg/L上面被增加时，移动百分比落下到85%，相对降低硝酸盐集中。这个过程能容忍更短的HRT但是小心的操作被需要。自从当HRT从3.12h被减少到2.88h时，进程性能突然地败坏了，硝酸盐变换比硫化物变换对HRT更敏感。以便在反应堆避免亚硝酸根累积，流入的硫化物；硝酸盐集中应该在280mg/L被保留；67.5mg/L分别地。现在的生物工学为把硫化物从下水道移开是有用的；原油。

简介：水力的断裂是过去常从水库刺激uid生产的一种强大的技术。充分3-D水力的断裂进程的数字模拟对这种技术的effcient应用程序很重要，但是因为，也是大挑战强壮的非线性的联合在之间粘滞uid和破裂繁殖的ow。由利用一个连贯的地区方法模仿破裂过程，一个有限元素模型基于存在毛孔压力，连贯的有限元素被建立了在无限的有弹性的媒介调查塑造便士的水力的破裂的繁殖。水力的破裂行为上的连贯的材料参数和uid粘性的效果被调查了。在破裂过程被岩石破裂坚韧统治的限制案例的有限元素结果和分析答案之间的优秀同意表明连贯的地区的能力在为这个案例模仿水力的破裂生长的有限元素模型。

简介：

简介：Atheoreticalstudywasconductedtocharacterizehydraulicjumpoflaminarcircularliquidjets.Theobjectiveofthisresearchwastodeterminethejumplocationinasimpleexplicitform,Theeffectsofmanyfactorswereinvestigatedincludingnozzlediameter,jetexitpressure,nozzle-to-platespacing,jetvelocityandReynoldsnumber,ItwasfoundthatthetheoreticaldatacollapsedwellovertherangeofjetReynoldsnumber500≤Re≤1800withpreviousdata.

简介：Tortuosityisoneofthekeyparameterstocharacterizethetransportpropertiesofporousmedia.Therearemanymodelsfortortuosityestimationbasedonsomedefinitions:geometric,hydraulic,electric,anddiffusivedefinitions.However,relationshipsamongthosetortuositiesremainunclearduetothelackofdirectcomparisononthesameporousmedia.HerewefocusonhydraulicandelectrictortuositiesandhaveconductedaseriesoffiniteelementsimulationswiththeNavier–Stokesequationandtheequationforelectriccurrenttodirectlycomparetortuosities.Theresultsrevealedthat:(1)onaverage,hydraulictortuosityis15%greaterthanthatoftheelectricone;(2)theproposedmodelbasedonthevanGenuchten-typefunctionsuccessfullyapproximatesbothhydraulicandelectrictortuosities;(3)tortuositiesobtainedfromtheporousmediapackedwithcircularparticlesandsquareparticlesshowquantitativelysimilartrends.

简介：Hardwareintheloopsimulation(HILS)hasbeeninvestigatedinthefieldofthemultibodydynamics(MBD),whichcombinedtheMBDsimulationwiththeactualmechanicalsystem.ThefastsimulationisnecessaryfortheHILSsysteminordertorequiretherealtimesimulation.Thispaperpresentsafastsimulationtechniqueusingthedomaindecompositionmethodwiththeiterationintheflexiblemultibodysysteminwhichflexiblelinkagesystemandelectro-hydraulicdrivesystemarecoupledwitheachother.

简介：Electro-hydraulicservovalveisatypicalcomplicatedmulti-domainsystemconstitutedbymechanical,electric,hydraulicandmagneticcomponents,whichiswidelyusedinelectro-hydraulicservosystemssuchasconstructionmachinery,heavyequipment,weaponandsoforth.Thetraditionalmethodofmodelingandsimulationofservovalveisbasedonblockdiagramorsignalflow,whichcannotdescribetheservovalvesystemfromcomponentslevelnorbeusedinmodelingandsimulationofoverallservosystems.Intheprocedureoftraditionalmethod,computationalcausalitymustbeinvolvedinmodelingofservovalve,whichisinconvenienttoexecutemodificationoncomponentsorparameters.Modelicaisanobject-orientedmodelinglanguagewhichissuitedforlarge,complex,heterogeneousandmulti-domainsystems.ThekeyfeaturesofModelicaaremulti-domain,object-orientedandnon-causal,whicharesuitableformodelingofservovalveandmakethemodelreadable,reusable,andeasytomodify.Thesimulationresultsshowsimilarcurveswithtraditionalmethod.Thisnewservovalvemodelingandsimulationmethodcanprovidetheengineersamoreefficientwaytodesignandoptimizeaservovalveandanoverallservosystem.

简介：

简介：Formulatedaresimplemodelsfortheflowinliquidfilm,formedbyimpingingjet,andatwo-phasedownwardflowinpipe.Themodelsarebasedonsimplifiedequationsofmass,momentumandenergy.thesolutionofsuchconservationequationsmayhaveregularpointsbelongingtooneintegralcurveonlyaswellasturningpointscanbefoundamongstthem.Whichrefertoextremevaluesintheappropriateco-ordinatesystem.Thesolutionscanalsohavesingularpointsbelongingtononeormorethanoneintegralcurve,Boththeturningandsingularpointshaveaclearphysicalmeaning.Theycouldbelinkedtocriticalflowconditionsinthepipeflowortotheso-calledhydraulicjump.Analogyexistingbetweencriticalconditionsinthepipeandtheflowofliquidfilmsformedbytheliquidjethavebeenshowninthepaper.