简介：Anexperimetalinvestigationwascarriedoutontheeffectofbladechordwiseleanonthelosseinhighlyloadedrectangularturbinecascades,Datailedmeasurementsinclude10traversesfromupstreamtodownstreamofthecascadeswithfive-holesphericalprobes.ComparedwiththeexperimentaldataofthecoventionalStraightandpitchwiseleanbladesunderthesameconditions,itisshownthattheeffectofchordwiseleanonthedevelopmentofthecascadelossesissimilartothatofpitchwiselean.However,thechordwiseleanproducessmallerstreamwiseadversepressuregradientsnearbothendwallsandasmallerspanwisenegativeonestartingfromtheactuteanglesideinthefirstpartofthepassagesinchordwiseleancascade,therebythesaddlepointseparationsandintensitiesofthepassagevorticesareweakenedandthesecondaryvortelossesarecutdownnotably.

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简介：上演注射者展出了大潜力完成低排出物并且正在成为许多民用的飞机的更好的选择。而且，它正在答应在军事引擎采用这个注射者图案，它要求大多数空气进入的燃烧通过到还原剂烟排放的注射者的燃烧室。然而，瘦上演注射者在低负担操作对燃烧不稳定性和扑灭敏感，因此为拓宽它的稳定的操作范围的技术为它在真实引擎的申请是关键的。

简介：Inthisstudy,aerodynamicbehaviorsofsweptandleanedbladeswereinvestigated.Axialandtangentialbladecurvaturesimpactsoncompressor'soperatingparameterswereanalyzedseparately.AcommercialCFDprogramwhichsolvestheReynolds-averagedNavier-Stokesequationswasusedtofindoutthementionedimpactandthecomplicatedflowfieldoftransoniccompressor-rotors.TheCFDmethodthatwasusedforsolvingflowfield'sequationwasvalidatedbyexperimentaldataofNASARotor67.Theresultsshowedthatthecompressorwithcurvedrotorshadhigherefficiency,rotorpressureratioandstableoperatingrangecomparedtothecompressorwithun-curvedrotors.Usingcurvedrotorsmostlyhadhigherimpactontheoverallstableoperatingrangecomparedtotheotheroperatingparameters.Operatingrangeinvolveschokingpointandstallpointthatwerechangedseparatelybyusingofbendedblade.Forfindingthedetailedimpactofsweepandleanangleontransonicblades,variousformsofleanandsweepangleswereexertedtobasicrotor.Itwasfoundthatsweepanglesincreasedoveralloperatingrangeupto30%,efficiencyupto2%andpressureratioupto1%.Leaningthebladesincreasedthesafeoperatingrange,thepressureratioandefficiencyby14%,4%and2%respectively.

简介：Improvementonextinctionandpollutionemissionhavebecomeoneofthemostprominentresearchtopicsingasturbine.Itiswidelyrecognizedthatthefuel/airmixturedistributionintherecirculationzoneisacriticalfactorinimprovingleanblow-out(LBO)andignition.Thispaperproposedanewlowemissionschemewithfuelstagedcentrallyandhybridinjectortoimproveflameoutandemission.Arelativesmallamountoffuelentersintocentralpilotairblastatomizerburnerandthenatomizedbyinnerswirlair.Theremainingmajorityoffuelisdirectlyinjectedintovanechannelsoftheprimaryswirlerthroughaseriesofholeslocatedonthesidewallofthemainstage.Onlypilotstageisfueledunderignitionandleanflameoutcondition.Theuniformityoffuel/airmixturedistributionintheprimaryzoneofthenewdesigndecreasesNOXemission,meanwhilethefuelairmixtureinpilotrecirculationzoneislocallyrichtoimproveflameoutandignition.Experimentalinvestigationwasconductedtocomparethenewschemewithbaselinedesignofdual-swirlerintermsofLBOandignitioncharacteristicsunderthesameconditioninamulti-sectorcombustor.Itisfoundthatthefuel-airratioofignitionlimitandLBOdecreasewiththereferencevelocityincreasing.Theexperimentalresultsalsoshowthatthenewschemesuccessfullyimproveleanblow-outandbroadentheoperationrangeofthecombustor.Theexperimentalresultsindicatedthatthecentrallystagedschemecanwidentheoperationboundaryofthecombustorandcanprovideguidancefordesignandoptimizationofcombustionchamber.

简介：PalladiumcatalystsaresupportedonTiO2,ZrO2,Al2O3,Zr0.5Al0.5O1.75andTiO2-Zr0.5Al0.5O1.75preparedbyco-precipitationmethod,respectively.CatalyticactivitiesformethaneandCOoxidationareevaluatedinagasmixturethatsimulatedtheexhaustfromlean-burnnaturalgasvehicles(NGVs).Pd/TiO2-Zr0.5Al0.5O1.75performsthebestcatalyticactivityamongthetestedfivecatalysts.ForCH4,thelight-offtemperature(T50)is254℃,andthecompleteconversiontemperature(T90)is280℃;forCO,T50is84℃,andT90was96℃.Varioustechniques,includingN2adsorption-desorption,X-raydiffraction(XRD),H2-temperature-programmedreduction(H2-TPR),X-rayphotoelectronspectroscopy(XPS),andscanningelectronmicroscopy(SEM)areemployedtocharacterizetheeffectofsupportsonthephysicochemicalpropertiesofpreparedcatalysts.N2adsorption-desorptionandSEMshowthatTiO2-Zr0.5Al0.5O1.75expressesuniformnano-particlesandlargemeso-porediametersof26nm.H2-TPRandXRDindicatethatPdOiswelldispersedonthesupportsandstronglyinteractedwitheachother.TheresultsofXPSshowthattheelectrondensityaroundPdOandtheproportionofactiveoxygenonTiO2-Zr0.5Al0.5O1.75aremaximaamongthefivesupports.