简介:Inordertostudytheeffectsofwetcompressiononatransoniccompressor,afull3-Dsteadynumericalsimulationwascarriedoutundervaryingconditions.Differentinjectedwaterflowratesanddropletdiameterswereconsidered.Theeffectofwetcompressionontheshock,separatedflow,pressureratio,andefficiencywasinvestigated.Additionally,theeffectofwetcompressiononthetipclearancewhenthecompressorrunsinthenear-stallandstallsituationswasemphasized.Analysisoftheresultsshowsthattherangeofstableoperationisextended,andthatthepressureratioandinletairflowratearealsoincreasedatthenear-stallpoint.Inaddition,itseemsthatthereisanoptimumsizeofthedropletdiameter.
简介:Rigidblockingmassesarelocatedinthetypicalbasestructureofapowercabinbasedontheimpedancemismatchprinciple.Bycombiningtheacoustic-structuralcouplingmethodandstatisticalenergyanalysis,thefull-bandvibrationandsoundradiationreductioneffectofvibrationisolationmasseslocatedinabasestructurewasresearched.Theinfluenceoftheblockingmass’cross-sectionsizeandshapeparametersandthelayoutlocationofthebaseisolationperformancewasdiscussed.Furthermore,theeffectivenessofrigidvibrationisolationdesignofthebasestructurewasvalidated.Theresultsshowthatthemediumandhighfrequencyvibrationandsoundradiationofapowercabinareeffectivelyreducedbyablockingmass.Concerningweightincrementandsectionrequirement,suitablyincreasingtheblockingmasssizeandsectionheightandreducingsectionwidthcanresultinanefficiency-costratio.
简介:CorrosionbehaviourandbiofoulingcharacteristicsofmildsteelinthreedifferentcoastallocationsintheGulfofMannar,Indiahavebeenstudiedoveraperiodof24months.OysterfoulingwaspredominantatOpensea-Tuticorin,whilebarnaclefoulingwasdominantatbothMandapamandHarbour-Tuticorin.Therateofcorrosionfor24monthsexposureperiodwashighestatMandapam,wherefoulingwasminimal.Thesurfaceofthemildsteelwascharacterizedbyetchings&crevicesbeneaththehardfoulersattachedonit,atallthetestlocations.ThedepthofcrevicecausedbyhardfoulerswashigheratOpensea-TuticorinfollowedbyHarbour-TuticorinandMandapam.ThelossinultimatetensilestrengthwasmoreinOpensea-Tuticorinthantheothertwolocations.Corrosionbehaviourofmildsteelisdiscussedbasedonthevariationinthebiofoulingassemblageatthethreetestlocations.
简介:文章针对"STCW78/10修正案"对海员有效沟通和交际能力提出的新标准,剖析了新标准对我国航海英语教育的影响,在对比分析新旧标准的基础上,探讨了新标准下航海英语教育的对策,以提高我国航海英语教育整体质量。
简介:文中介绍高级值班水手和高级值班机工的产生背景,分析高级值班水手和高级值班机工发展现状及趋势,针对部分船旗国对高级值班水手和高级机工配员要求的变化,阐述对海员外派机构所产生的影响,并提出应对措施的建议。
简介:研究了烧结温度和保温时间对电流活化烧结Fe-2Cu-1.5Ni-0.5Mo-0.8C混合粉末的影响.结果表明,当位移变化量几乎为零时,延长保温时间或增加烧结温度,烧结体密度仍有增长,且有明显的强化烧结.增加烧结温度比延长保温时间更能有效提高烧结体的密度、硬度和抗弯强度.