简介：A3-DnonlinearproblemofsupercavitatingflowpastanaxisymmetricbodyatasmallangleofattackisinvestigatedbymeansoftheperturbationmethodandFourier-cosine-expansionmethod.Thefirstthreeorderperturbationequationsarederivedindetailandsolvednumericallyusingtheboundaryintegralequationmethodanditerativetechniques.Computationalresultsofthehydrodynamiccharacteristicsandcavityshapesofeachorderarepresentedfornonaxisymmetricsupercavitatingflowpastconeswithvariousapex-anglesatdiffer-entcavitationnumbers.Thenumericalresultsarefoundingoodagreementwithexperimentaldata.

简介：TheIsodynetechniquebasedonthescatteredlightscanningfromathinlaserbeamcanbeusedtoobtaintheinformationinsidetheloadedobjectintheroomtemperaturenondestructively,soitisaverypowerfultechniquein3Dstressanalysis.Theproblemsarehowtointerprettheinformationandhowtogetsufficientinformationfromthefewinterferencefringe.Birefringencephaseshifttechniquecandistinguishthefringeordersautomaticallyandenrichtheinformationin256graylevelsbetweenmaximandminimlightintensity.InthepapertheIsodynebirefringencephaseshiftmethodwithanobliqueincidenceandequilibriumequationispresented,bywhichthe3DstressesinthemiddleplaneofaplatewithUshapenotchareseparatedsuccessfully.

简介：Basedonthegeneralconservationlawsincontinuummechanics,theEulerianandLagrangiandescriptionsofthejumpconditionsofshockwavesin3-dimensionalsolidswerepresentedrespectively.Theimplicationofthejumpconditionsandtheirrelationsbetweeneachother,particularlytherelationbetweenthemassconservationandthedisplacementcontinuity,werediscussed.Meanwhiletheshockwaveresponsecurvesin3-dimensionalsolids,i.e.theHugoniotcurveswereanalysed,whichprovidethefoundationforstudyingthecouplingeffectsofshockwavesin3-dimensionalsolids.

简介：The1/3subharmonicsolutionfortheDuffing'sequationisinvestigatedbyusingthemethodsofharmonicbalanceandnumericalintegration.Thesensitivityofparametervariationforthetransientprocessandthetransientprocessfortheperturbanceinitialconditionsarestudied.Overandabove,theprecisionofnumericalintegrationmethodisdiscussedandthenumericalintegrationmethodiscomparedwiththeharmonicbalancemethod.Finally,asymptoticalstabilityofthepuresubharmonicoscillationselementisinspected.

简介：Inthepresentpaper,amultifluidmodeloftwo-phaseflowswithpulverized-coalcombustion,basedonacontinuum-trajectorymodelwithreactingparticlephase,isdevelopedandemployedtosimulatethe3-Dturbulenttwo-phaseflowsandcombustioninanewtypeofpulverized-coalcombustorwithoneprimary-airjetplacedalongthewallofthecombustor.Theresultsshowthat:(1)thiscontinuum-trajectorymodelwithreactingparticlephasecanbeusedinpracticalengineeringtoqualitativelypredicttheflamestability,concentrationsofgasspecies,possibilitiesofslagformationandsootdeposition,etc.;(2)largerecirculationzonescanbecreatedinthecombustor,whichisfavorabletotheignitionandflamestabilization.

简介：AlaminarpremixedPropane/Airflamewithafuelequivalenceratioof2.1wasemployedforanalysisofsootparticles.Zeroth-orderIognormaldistributions(ZOLD)wereusedintheanalysisofexperimentaldistributionphenomenaatdifferentresidencetimesduringsootformationintheflame.Rayleigh'stheoryandMie'sscatteringtheorywerecombinedwithagglomerateanalysisusingscatteringandextinctiondatatodeterminethefollowingsootcharacteristics:agglomerateparameters,volumetricfractions,massflowratesandsurfacegrowthrate.Sootdensitymeasurementswerecarriedouttodeterminedensityvariationsatdifferentstagesofgrowth.Themeasuredresultsshowthatmetricfractionandmassflowrateindicatethatthesurfacegrowthrateofsootparticlesexceedstheoxidationratesintheflamestudied.Thedataobtainedinthisworkwouldbeusedtostudysootoxidationrateunderflamingcondition.