简介:Tbegoalofthispaperistoresearchonenewcharacteristicofcomplexsystem.Brittleness,whichisonenewcharacteriticofcomplexsystem,ispresentedinthispaper.Thelinguisticandqualitativedescriptionsofcomplexsystemarealsogiveninthispaper.Otherwise,thequalitativedescriptionofcomplexsystemispresentedatfirst.Onthebasisofanalyzingtheexistingbrittlenessproblems,linguisticdescriptionandmathematicdescriptionofbrittlenessaregivenaswell.Threekindsofphenomenatojudgebrittlenessofcomplexsystemarealsogiven,basedoncatastrophetheory.Basiccharacteristicsofbrittlenessaregivenonthebasisofitsmathematicdescription.Twocriticalpointsetsaredefinedbyusingcatastrophetheory.Thedefinitionofbrittlenessanditsrelatedtheorycanservethecontrolofcomplexsystem,andprovidetheoreticalbasisforthedesignandcontrolofcomplexsystem.
简介:对高速度的海洋的车辆(HSMV)的需求在商业、海军的用户之中高。提供减少的一个壳和推进系统是海洋的容器鈥檚设计者的责任拖,改进推进的效率,增加安全并且改进可操作性。从propulsor方面,表面穿透推进器(SPP)应该改进性能。不同于沉浸的推进器,SPP的行为被沉浸,威伯数字和柄倾斜角度的深度影响。这份报纸使用一个实际数字方法预言SPP的水动力学特征。批评进展速度比率在转变模式用威伯数字和沥青比率被导出,然后,潜在的基于的边界元素方法(BEM)在忙表面上被使用。三的二个模型和六片的SPP(SPP-1和SPP-2)被选择,一些结果被显示出。
简介:Anewgenerationconicalspraysystemforconventionaldieselenginesorpremixedcombustiondieselenginesisintroduced.Bymeansoforientedimpingementmethod,flexiblespraypenetrationindesignisrealized.High-speedphotographwasusedtoinvestigatethespatialdistributioncharacteristicsofthenewsprayforcasesofdifferentimpingementanglesandneedlevalveopeningpressures.Theresultsshowthat,byapplyingsprayimpingementorientation,fueljetsspreadalongtheconesurfaceasshapeofsectors,sothedispersionofjetsisincreasedobviously.Changingonimpingementangleleadstovariationofpenetration,whichiscriticalinhomogeneousmixturepreparation.Duetotheflexibilityofspraypenetrationindesign,thesprayimpingementonlinerisavoidedinagreatextent.Theresultsalsoindicatethathigherneedlevalveopeningpressureresultsinlongerpenetrationandlargersprayangleafterimpingement.Combustioncharacteristicsoftheimpingedconicalspraywerestudiedinthe1135typedieselengine.ThenewimpingedconicalspraysystemworksmoothlyinfullloadrangewithbetterfueleconomyandloweremissionsofNOxandsootthantheoriginaltestengine.
简介:Consideringthespecialresistancecharacteristicsoffluidsflowingthroughductswithsmallgaps,experimentsareperformedtoinvestigatetheresistancecharacteristicsofsingle-phasewater,whichisforcedtoflowthroughverticalannuli.Thegapsizesare0.9,1.4and2.4mm,respectively.Theexperimentsareconductedunderconditionof1atm.Thewaterintheannuliisheatedbyhightemperaturewaterreverselyflowingthroughtheinnertubeandtheouterannulus.TheresultsshowthattheflowpatternbegintochangefromlaminartoturbulentbeforeReynoldsnumberapproaches2000,theflowresistanceinannulushaslittlerelationswiththetemperaturedifferenceandwaysofbeingheated,butmainlydependsontheratioofmassfluxtothewidthofannulus.
简介:WaterramjetsusingouterwaterasanoxidizerhavebeendemonstratedasapotentialpropulsionmodeforunderwaterHighSpeedSupercavitatingVehicles(HSSVs)becauseoftheirhigherenergydensity,powerdensity,andspecificimpulse,butwaterfluxchangestheshapesofsupercavity.TouncoverthecavitatordragcharacteristicsandthesupercavityshapeofHSSVswithwaterinflowforramjets,supercavitationflowsaroundadiskcavitatorwithinletholearestudiedusingthehomogenousmodel.Bychangingthewaterinflowintherangeof0-10L/sthroughcavitatorshavingdifferentwaterinletareas,aseriesofnumericalsimulationsofsupercavitationflowswasperformed.Thewaterinflowfluxoframjetssignificantlyinfluencesthedragfeaturesofdiskcavitatorsandthesupercavityshape,butithaslittleinfluenceontheslenderratioofsupercavitaty.Furthermore,asthewaterinletareaincreases,thedragcoefficientofthecavitators'frontfacedecreases,butthisincreasedoesnotinfluencethediameterofthesupercavity'smaximumcrosssectionandthedragcoefficientoftheentirecavitatorsignificantly.Inaddition,withincreasingwaterfluxoftheramjet,boththedragcoefficientofcavitatorsandthemaximumdiameterofsupercavitiesdecreasestably.ThisresearchwillbehelpfulforlayoutoptimizationandsupercavitatyschemedesignofHSSVswithwaterinflowforramjets.
简介:Tofindthedifferenceindynamiccharacteristicsbetweenconventionalmonohullshipandwavepenetratingcatamaran(WPC),aWPCwastakenasanobject;itsdynamiccharacteristicswerecomputedbytransfermatrixmethodandfiniteelementmethodrespectively.Accordingtothecomparisonofthenaturefrequencyresultsandmodeshaperesults,thefactthatFEMmethodismoresuitabletodynamiccharacteristicsanalysisofaWPCwaspointedout,specialfeaturesondynamiccharacteristicsofWPCweregiven,andsomebeneficialsuggestionsareproposedtooptimizethestrengthofaWPCindesignperiod.
简介:Anewisolatorcomposedofasteelropespringandamagneto-rheological(MR)damperwasdesignedandastudyonlow-frequencymechanicalcharacteristicsofMRdampersinisolatorswascarriedout.ItusedthecharacteristicsoftheMRdamper,suchasfastresponse,controllabledamping,smallenergyconsumption,widedynamicscope,andgreatadaptation.TherelationshipsbetweenMRdampingforcesandinfluencingfactorswereanalyzedbasedonexperimentaldata.Theresultsshowthatdampingforceisnotonlyrelatedtostructuraldimensions,butalsocloselyrelatedtocontrollablecurrentandvibrationfrequency.Finally,theempiricalformulafordampingforceswascorrected,andtherelationshipbetweencorrectioncoefficientsandfactorsanalyzed.
简介:在这个工作,试验性的调查被追求了分析影响向下在在在冲积隧道的圆形的桥码头附近的旋涡结构的流动和相应变化的狂暴的特征上的渗出物。实验为没有渗出物,10%渗出物和20%渗出物盒子与不同尺寸的圆形的墩在沙床隧道被进行。象速度和雷纳兹压力那样的狂暴的流动统计的测量被发现在scour洞在以内否定墩在上游而申请向下,渗出物延迟在速度和雷纳兹引起减少的流动的颠倒强调。更高级的雷纳兹砍因为生产,应力在下游的方面占优势弄醒旋涡。到彻底的雷纳兹的所有爆炸事件的贡献砍压力生产被观察了增加与向下渗出物。不可分的规模的分析建议旋涡的那种尺寸与渗出物增加,它为粒子活动性的增加负责。开始搜索评价是消退逐渐地象与一样与膨胀预定的更多增加了向下渗出物。存在向下,渗出物向墩的下游的方面减少旋涡和移动的深度和长度。
简介:僵硬声学的散布由的部件的分离在水下目标在获得如此的目标的结构的特征是必要的。克服看起来有一样的僵硬结构的问题光谱在时间领域的结构,时间频率窗帘来源分离(BSS)能与图象形态学在联合被使用分开不同目标的僵硬散布部件。基于一个热点模型,有时间频率分发的目标的僵硬散布结构的分离被推出。用一个词法过滤器,在Wigner-Ville分布(WVD)的不同特征观察到术语能被简化移开任何跨术语的干扰单个汽车术语和十字。由选择术语表明的汽车的时间和频率点,BSS的精确性能被改进。试验性的模拟被使用了,与在播送信号,相对振幅和时间延期参数的脉搏宽度的变化,以便分析这个新方法的可行性。模拟结果证明新方法不仅能分开僵硬散布当有弹性的散布并且僵硬散布时,部件,而且罐头也分开部件同时存在。试验性的结果证实新方法能在分开僵硬散布结构被使用在水下目标。