简介:灵活圆形的柱体的导致流动的颤动(FIV)上的集体比率的效果试验性地在一辆拖引的坦克被调查。分别地,有7.9公里和4.8公里的外部、内部的直径的一个Tygon试管为学习被采用。试管被连接到一辆马车并且从休息拖引到一稳定在慢下来在1.6m的距离上再休息在前加快m/s到1.6仍然流水。雷纳兹数字基于柱体,外部直径是80013,000,并且减少的速度(柱体天赋频率使正常化的速度和外部直径)从2~25跨越了。当连接时,柱体在11N的轴的虚荣下面从420公里被伸长到460公里。把伸长的长度基于柱体,方面比率(到外部直径的柱体长度的比率)作为58被计算。三集体比率(柱体的比率结构的质量到代替的液体质量,m*)被分别地用空气,水,和合金粉末(nickel-chromium-boron矩阵合金)填满柱体内部0.7,1.0,和3.4决定。一个光方法为反应大小被采用。多频率颤动在两个被观察同轴(IL)并且跨流动(CF)回答;在高级雷纳兹数字,颤动模式直到3rd在CF反应被识别。模式转变被发现为最高测试的集体比率在更低的减少的速度发生。颤动振幅和频率关于减少的速度被确定并且表示。一个重要减少的颤动振幅与增加集体比率在IL反应被发现,并且仅仅起始、上面的分支在IL和CF反应振幅存在。规范的反应频率被揭示线性地关于减少的速度增加,并且为线性关系的斜坡被发现为测试的三格相同。
简介:Asanoveltypeoffoundationinbeachandshallowsea,thebucketstructureisespeciallysuitableforcomplexconditionssuchassoftclaygroundandtheworsetypesofseaenvironments.Inthispaper,thebearingcapacityofamulti-bucketstructureisstudiedbyexperimentswithasinglebucketandfour-bucketfoundationinasaturatedsandlayer.Basedontheexperimentaldataandnumericalanalysisresults,thebearingcapacitybehaviorandthebucketgroupeffectarecomparedandanalyzed.Furthermore,someinfluentialfactors,suchasthesoiltype,theratiooflengthtodiameterL/D,theratioofthebucketspacingtothebucketdiameterS/D,andthebucketnumberareintroducedandtheireffectsonthemulti-bucketstructuralcapacityareinvestigatedTheverticalstaticcapacityadjustmentfactorisintroducedtoevaluatethebucketgroupeffectsofthemulti-bucketfoundation.
简介:Inthispaper,theeffectofplasticconstraintontheinitiationofductiletearsinfourdifferentshipbuildingstructuralsteelshasbeenexperimentallystudiedbymeasuringtheJ-integralandcrackopeningdisplacementCODatinitiationinthree-pointbendspecimenswithdeepandshallownotches.ExperimentalresultsofsevengroupsofdifferentstrengthalloysteelsshowthatbothδìandJìvaluesofductiletearfromtheshallowcrackspecimenswhichhavelessconstraintflowfieldaresignificantlyhigherthanthoseofdeeplynotchedspecimens.Slip-line-fieldanalysisshowsthat,forshallowcrack,thehydrostaticstressislowerthanthatfromstandarddeeplycrackedbendspecimen,whichdevelopsahighlevelofcracktipconstraint,providesalowerboundestimateoftoughness,andwillensureanundulyconservativeapproachwhenappliedtostructuraldefects,especiallyifinitiationvaluesofCODandJ-integralareused.
简介:Usingthesupercavitationphenomenonisnecessarytoreachhighvelocitiesunderwater.Supercavitationcanbeachievedintwoways:naturalandartificial.Inthisarticle,thesimulationofflowsaroundatorpedowasstudiednaturallyandartificially.Thevalidityofsimulationusingtheoreticalandpracticaldatainthenaturalandartificialphaseswasevaluated.Resultsshowedthatthesimulationswereconsistentwiththelaboratoryresults.Theresultsindifferentinjectioncoefficientrates,injectionangles,andcavitationnumberswerestudied.Theobtainedresultsshowedtheimportanceofcavitationnumber,injectionratecoefficient,andinjectionangleincavityshape.Atthefinallevel,determiningtheperformanceconditionsusingtheDesignofExperiment(DOE)methodwasemphasized,andtheperformanceofcavitationnumber,injectionratecoefficient,andinjectionangleindragandliftcoefficientwasstudied.Theincreaseininjectionangleinthelowinjectionratecoefficientresultedinadiminisheddragcoefficientandthatinthehighinjectionratecoefficientresultedinanenhanceddragcoefficient.
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:Throughanalyzingtherollmodeloftheintegratedsystemoffinandanti-rollingtank,thispaperusesbinomialequationtosimplifythemoduleandcheckhowtheapproximateparameterssimulatetheoriginalfunction.Basedonthesimplifiedmodule,theinfluenceoffinandanti-rollingtankonthecoefficientitemsoftherollmoduleisdiscussed,andtheinfluencingfactorsbetweenfinandanti-rollingtankareanalysed.Andthroughsimulation,theinfluenceofactionbetweenfinandanti-rollingtankonthestaticcharacteristics,andtheintegratedstabilizationeffect,areanalyzed.
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简介:在这研究,为海洋的申请目的,我们评估了在微观结构,机械加强和经由电极淀积生产的Zn-TiO2-WO3nanocomposite的腐蚀抵抗性质上装载的过程参数和粒子的效果。我们与与一个精力散分光计(版本)装备的一台扫描电子显微镜(SEM)描绘了合成涂层的词法性质。我们用一个Dura扫描坚硬测试者和一件必然发生的事情执行了机械检查UMT-2多功能的tribological测试者。我们在3.5%NaCl由线性极化评估了腐蚀性质。结果证明涂层展出了好稳定性,极大地装载的量的粒子提高了结构、词法的性质,坚硬行为和涂层的腐蚀抵抗。我们观察到钢上的这合金的降水被合成特征极大地影响。