简介：

简介：

简介：Onthehypothesisthattheturbulentflowispracticallynotaffectedincharacterbypulsationoftheflow,theformulaforsoundpressurelevelofpulsedjetnoiseisobtainedin90°directionand1meterawayfromthenozzle.Thesteadyjetnoiseis,then,aspecialcasewhenthepulsatingfrequencyiszero.Theresultsagreewellwithexperiments.

简介：Numericalinvestigationofatransversesonicjetinjectedintoasupersoniccrossflowwascarriedoutusinglarge-eddysimulationforafree-streamMachnumberM=1.6andaReynoldsnumberRe=1.38×10~5basedonthejetdiameter.Effectsofthejet-to-crossflowmomentumratioonvariousfundamentalmechanismsdictatingtheintricateflowphenomena,includingflowstructures,turbulentcharactersandfrequencybehaviors,havebeenstudied.Thecomplexflowstructuresandtherelevantflowfeaturesaredisc...

简介：

简介：Inthisarticletheemphasiswasgiventothediscussionoftheeffectsofdiameterratioandswirlingoninstabilitycharacterforthegas/liquidcoaxialjetusedbyLiao,etal.[1].Theresultsindicatethatthefinitediameterratiomarkedlyincreasesthemaximumgrowthrate,themostunstablewavenumber,aswellasthecutoffwavenumber.Itimpliesthatthefinitediameterratiowillleadtotheliquidjetbreakuplengthshorterandtheliquiddropsizesmaller.Theeffectoftheswirlingjetsismuchmorecomplex:fortheaxisymmetricperturbationmode,theswirlingenhancestheflowstability,forhelicalperturbation,thedominantinstabilitymodeoccursatn<0.Anditisfoundthatinlongwaveregionthereexistsanewkindofinstabilitymodesatn=1thatwasnotmentionedinLiaoetal.'sarticle.Forthisnewmode,thereappearsadominatedswirlingratioatwhichtheflowhasthemaximumgrowthrate.

简介：Atypeofportwithamovablecoverisdesignedtoincreaseinitialdilutionandpreventseawaterandsedimentsfromintrudingintooutfallsystems.Horizontalradialjetspro-ducedbythistypeofportinacurrentareinvestigatedexperimentallyandtheoretically.TheanalysisbasedonReynolds’equationsandself-similarityhypothesisshowsthatthemaximumve-locityofradialjetsdecayswithr-1.5.Therelationshipsbetweenthewidth,thickness,averagedi-lutionofasubmergedwastefieldalongflow,andtheparametersoftheport,jetandambientareestablishedquantitativelyandverifiedbyexperiments.Itisdemonstratedthatthedilutionofhorizontalradialjetsismuchhigherthanthatofverticalroundjetsandthesurfaceboilpointoftheformerismuchmoredistantthanthatofthelatter.

简介：Anewroutewasdevelopedforthesynthesisofrenewabledecalinwithcyclopentanonewhichcanbederivedfromlignocellulose.Itwasfoundthat1,2,3,4,5,6,7,8-octahydronaphthalenecouldbeselectivelyproducedbythehydrogenation/dehydration/rearrangementof[1,1-bi(cyclopentylidene)]-2-one(i.e.theselfaldolcondensationproductofcyclopentanone)overadual-bedcatalystsystem.Amongtheinvestigatedcatalysts,theRu/CandAmberlyst-15resinexhibitedthehighestactivitiesforthehydrogenationof[1,1-bi(cyclopentylidene)]-2-oneto[1,1-bi(cyclopentan)]-2-olandthedehydration/rearrangementof[1,1-bi(cyclopentan)]-2-olto1,2,3,4,5,6,7,8-octahydronaphthalene,respectively.UsingRu/CandAmberlyst-15resinasthefirstbedandthesecondbedcatalysts,1,2,3,4,5,6,7,8-octahydronaphthalenewasdirectlyproducedinhighcarbonyield(83.7%)undermildconditions(393K,1MPa).Afterbeinghydrogenated,the1,2,3,4,5,6,7,8-octahydronaphthalenewasconvertedtodecalinwhichcanbeusedasadditivetoimprovethethermalstabilityandvolumetricheatvalueofjetfuel.

简介：Thecharacteristicsofalaminarwalljetsubmittedtodifferentconfigurationshavebeenexperimentallyexploredinordertoobtainabetterknowledgeoftransitionmodifications,Infactdifferentparameterscanaccelerateordelaythetransitionusingasmoothorroughsurface,heatedornot,submittedtovibrationsornot.Inthisstudy,significanteffectscanbenoticed.Ithasbeenpossibletomeasurethebeginningofgrowthratesofdisturbanceamplitudeusingawindtunnelandcomparingtheresultswiththelinearstabilitytheory.

简介：这份报纸涉及一口跳入的液体喷气的三维的数字模拟。在喷气附近形成一个空气洞的短暂过程，捕获这个大塑造toroidal的水泡的一个开始大的空气水泡，和分散进更小的水泡被分析。一个稳定的有限元素方法(女性)基于适应、未组织的格子在平行数字模拟下面被采用并且结合了一个水平集合方法追踪在空气和液体之间的接口。这些模拟证明液体喷气的惯性开始压抑水池的表面，形成包围液体喷气的一个环形的空气洞。随后在液体水池被形成的一个toroidal液体旋涡导致空气洞倒塌，并且接着乘火车空气进从在液体喷气附近的不稳定的环形的空气差距区域的液体水池。

简介：

简介：

简介：AdeuteriumclusterjetproducedinthesupersonicexpansionintovacuumofdeuteriumgasatliquidnitrogentemperatureandmoderatebackingpressuresarestudiedbyRayleighscatteringtechniques.Theexperimentalresultsshowthatdeuteriumclusterscanbecreatedatmoderategasbackingpressuresrangingfrom8to23bar,andamaximumaverageclustersizeof350atomsperclusterisestimated.Thetemporalevolutionoftheclusterjetgeneratedatthebackingpressureof20bardemonstratesatwo-plateaustructure.Thepossiblemechanismresponsibleforthisstructureisdiscussed.Theformerplateauwithhigheraverageatomandclusterdensitiesismoresuitableforthegenerallaser-clusterinteractionexperiments.

简介：实验的完整的因素的设计被开发以便调查喷气压力的效果，粗糙的混合率，切喂，并且在三个反应变量之上的板厚度，表面切完成穿地区，有条纹或刻痕之状态的百分比比例免费区域，和最大的宽度切。十六个实验的集合在每下列二可锻的材料上被执行：AISI4340(高力量低合金钢，变硬到49HRc)并且铝2219。变化(ANOVA)的分析在试验性的数据上被执行以便在性能措施上决定不同参数的效果的意义。它被发现那切喂并且厚度是高度有影响的参数，当粗糙的混合时，率仅仅在表面粗糙之上是有影响的。强壮的相互作用在喷气压力和细工品材料之间被发现。多标准数字优化被执行以便同时最大化/最小化表演措施的不同联合。

简介：作为无梭的织布机之一，空气喷气织布机用一口空气喷气的粘性和动能搬运一支纱进经纱。这个拣的系统的性能取决于即时inhalation/exhaust的能力，嘴的配置，一个检查阀门的操作特征，等等。在最近的过去，许多研究在从一个嘴出口解除的空气喷气上被报导了，但是为理解流动的研究回答与联系的特征砍在嘴的层和冲击波层相互作用没足够被进行。在这份报纸，计算研究被执行与一个加速试管在空气喷气嘴解释流动领域并且与可得到的以前的试验性的数据验证了。从计算学习获得的结果证明在超声的流动政体，流动领域显著地取决于加速试管的长度。作为嘴压力比率增加，拖也对绳起作用的力量增加。为一个更长的加速试管，全部的压力损失大，由于摩擦损失。

简介：在现在的学习，一个计算液体动力学方法被使用了在下面膨胀的声音的喷气结构上以水库状况调查过度饱和的起始的度的效果，例如马赫磁盘地点和直径，桶冲击波和喷气边界。调查的axisymmetric嘴几何学是有直部分的一张收敛的嘴。作为结果，过压由于冷凝作用产生，这被发现，没有冷凝作用，有过压的产生的流动的特征与那些由于在喷气的冷凝作用不同。

简介：Experimentswerecarriedouttoeliminatethescreechtonegeneratedfromasupersonicjet.Compressedairwaspassedthroughacircularconvergentnozzleprecededbyastraighttubeofsamediameter.Inordertoreducethejetscreechasphericalreflectorwasusedandplacedatthenozzleexit.Theplacementofthesphericalreflectoratthenozzleexitcontrolledthelocationoftheimagesourceaswellasminimizedthesoundpressureatthenozzleexit.Theweaksoundpressuredidnotexcitetheunstabledisturbanceattheexit.Thustheloopofthefeedbackmechanismcouldnotbeaccomplishedandthejetscreechwaseliminated.Thetechniqueofscreechreductionwithaflatplatewasalsoexaminedandcomparedwiththepresentmethod.Agoodandeffectiveperformanceincancelingthescreechcomponentbythenewmethodwasfoundbytheinvestigation.Experimentalresultsindicatethatthenewsystemsuppressesnotonlythescreechtonesbutalsothebroadbandnoisecomponentsandreducestheoverallnoiseofthejetflow.Thesphericalreflectorwasfoundveryeffectiveinreducingoverallsoundpressurelevelintheupstreamregionofthenozziecomparedtoaflatplate.Thepropsedsphericalreflectorcan.accordingly,protecttheupstreamnoisepropagation.

简介：Thevolumeexpansionofthestuff(e.g.tobaccostem)isofgreatimportancetoanincreaseintheproductqualityandadecreaseintheproductioncost.Thispaterputsforwardthebasicconfigurationandtheexpansionmechanismofanewtypeofjetpressurizationevaporationexpansionapparatur.Bythethermodynamiccalculationoftheapparatus,wegivevariationsinsteampressureonvariouscrosssectionsoftheflowsystemfortheapparatus,manufactureasamplemachine,andfinishruntestsofthemachine.Thetestresultsshowthattheapparatusmaymaketherelativeincreaseinfillvalueoftobaccostemhigherthan75%,andmaycausethesteamconsumptionrequiredintheexpansionprocessofeachkilogramstemtoreducedabout40%comparedwithconventionalexpansionapparatus.Additionally,theconfigurationoftheapparatusissimpleandsmall,itscostofmanufactureisverylow,andbothitsoperationandmaintenanceareextremelyconvenient.

简介：介绍了光突发交换(OBS)中JET协议的基本概念以及JET协议实现时需要考虑的因素,用排队论模型求得了JET协议下OBS网络的突发包丢失率,并分析了OXC配置时间和突发包平均长度对突发包丢失率的影响.

简介：TheeffectsofReynoldsnumberonbothlarge-scaleandsmall-scaleturbulencepropertiesareinvestigatedinasquarejetissuingfromasquarepipe.ThedetailedvelocityfieldsweremeasuredatfivedifferentexitReynoldsnumbersof8×103190,thevalueofA=εL/〈u2)3/2inthepresentsquarejetconvergesto0.5,whichisconsistentwiththeobservationindirectnumericalsimulationsofboxturbulence,butlowerthanthatincircularjet,platewakeflows,andgridturbulence.ThediscrepanciesincriticalReynoldsnumberandA=εL/〈u2〉3/2amongdifferentturbulentflowsmostlikelyresultfromtheflowtypeandinitialconditions.