简介：Inthispaper,theaddedmassofplatesandbeamstiffenedplatesvibratinginwateraresummarizedforthepurposeofconvenienceinengineeringdesign.Theanalyticalformulae,calculateddatatables,calculatedcurvesandsomeexperimentalresultsarepresented.

简介：Biomimeticdesignemploystheprinciplesofnaturetosolveengineeringproblems.Suchdesignswhicharehopedtobequick,efficient,robust,andversatile,havetakenadvantageofoptimizationvianaturalselection.Inthepresentresearch,anenvironment-friendlypropulsionsystemmimickingundulatingfinsofstingraywasbuilt.Anon-conventionalmethodwasconsideredtomodeltheflexibilityofthefinsofstingray.Atwo-degree-of-freedommechanismcomprisedofseverallinkageswasdesignedandconstructedtomimictheactualflexiblefin.Thedrivinglinkageswereusedtoformamechanicalfincon-sistingofseveralfinsegments,whichareabletoproduceundulations,similartothoseproducedbytheactualfins.Owingtothemodularityofthedesignofthemechanicalfin,variousundulatingpatternscanberealized.Somequalitativeobservations,obtainedbyexperiments,predictedthatthethrustsproducedbythemechanicalfinaredifferentamongvariousundulatingpatterns.Tofullyunderstandthisexperimentalphenomenonisveryimportantforbetterperformanceandenergysavingforourbioroboticunderwaterpropulsionsystem.Here,fourbasicundulatingpatternsofthemechanicalfinwereperformedusingtwo-dimensionalunsteadycomputationalfluiddynamics(CFD)method.Anunstructured,grid-based,unsteadyNavier-Stokessolverwithautomaticadaptivere-meshingwasusedtocomputetheunsteadyflowaroundthefinthroughtwentycompletecycles.Thepressuredistributiononfinsurfacewascomputedandintegratedtoprovidefinforceswhichweredecomposedintoliftandthrust.Thepressureforceandfrictionforcewerealsocomputedthroughouttheswimmingcycle.Finally,vortexcontourmapsofthesefourbasicfinundulatingpatternsweredisplayedandcompared.

简介：［1］CHENGShangmu,1990.Heat-Transferring,TheHigherEducationPublishingHouse,21～23,60～69,126～138.(inChinese)［2］CHENGYushenandFENGLuping,1998.Heat-TransferAnalysisandNumericalModelingofUnderwaterConcreteOilTank,OilJournal,9(2):117～126.(inChinese)［3］DaqinFieldScienceandResearchDesignInstitute,1975.DesignManualofOilandGasCollectandTransport,422～426,497～501.(inChinese)［4］HOUFusheng.EngineeringManualofOilRefining,OilIndustryPublishingHouse.［5］LUPeiqiong,1997.ResearchonHeat-TransferringofEasyCurdlingOilStorageinUnderwater,StorageandTransportofOilandGas,16(8):4～9.(inChinese)［6］TAOWensuan,1986.NumericalCalculationofHeatTransferring,Xi′AnJiaotongUniversityPublishingHouse,23～27,83～87.(inChinese)［7］ZHANGFenglu,1982.FiniteDifferenceMethodforHeat-TransferCalculation,MetallurgicalIndustryPublishingHouse,86～100,151～160.(inChinese)

简介：在里面在水下目标察觉，底部回响有一些象目标回响的一样的性质，它在表演上有大影响。学习目标回响和回响之间的差别是必要的。在这份报纸，基于目标区别上的人的听能力的唯一的优点，Gammatone过滤器作为听觉的模型被拿。另外，时间频率感觉展示并且听觉光谱特征为活跃声纳目标回响和底部回响分离被提取。试验性的数据的特征在一样的类上有好集中特征并且有不同的类之间的大量差别，它证明这个方法罐头有效地在目标回响和回响之间区分。

简介：Whentheshockwaveofunderwaterexplosionpropagatestothesurfacesofdifferentboundaries,itgetsreflected.Then,anegativepressureareaisformedbythesuperpositionoftheincidentwaveandreflectedwave.Cavitationoccurswhenthevalueofthenegativepressurefallsbelowthevaporpressureofwater.Animprovednumericalmodelbasedonthespectralelementmethodisappliedtoinvestigatethecavitationeffectofunderwatershockneardifferentboundaries,mainlyincludingthefeatureofcavitationeffectneardifferentboundariesandtheinfluenceofdifferentparametersoncavitationeffect.Intheimplementationoftheimprovednumericalmodel,thebilinearequationofstateisusedtodealwiththefluidfieldsubjectedtocavitation,andthefieldseparationtechniqueisemployedtoavoidthedistortionofincidentwavepropagatingthroughthemeshandthesecond-orderdoublyasymptoticapproximationisappliedtosimulatethenon-reflectingboundary.Themainresultsareasfollows.Asthepeakpressureanddecayconstantofshockwaveincreases,therangeofcavitationdomainincreases,andthedurationofcavitationincreases.Asthedepthofwaterincreases,theinfluenceofcavitationonthedynamicresponseofsphericalshelldecreases.

简介：Tostudytheinfluencelawsofweldingparametersonweldporosity,underwaterwetflux-coredarcwelding(FCAW)duplexstainlesssteelS32101wascarriedoutinahyperbaricchamber,andthesecond-ordermultipleregressionequationwasestablished.Theinteractiveeffectsofweldingparametersontheporositywereanalyzedbythethreedimensionalresponsesurfacesandthecontourplots.Theresultspresentthattheinteractioneffectbetweenwaterdepthandvoltageontheporosityisthemostsignificant.Theoretically,anon-poresweldbeadcanbegainedbyreasonablymatchingtheseparameterswithwaterdepthlessthan10m.Always,theweldporosityreachesitspeakvaluewitha7mm/sweldingspeed.

简介：察觉弱在水下信号是对海洋的工程的一般兴趣的一个区域。一个弱信号察觉计划被开发；它联合了非线性的动态重建技术，神经网络和扩大Kalman过滤的光线的基础功能(RBF)(EKF)。在这方法混乱，理论被用来为背景噪音建模。噪音被阶段空间重建技术和RBF神经网络以一种synergistic方式预言。当一个信号不在时，预言错误保持低并且当输入包含了一个信号时，变得相对大。EKF被用来改进RBF神经网络的集中率。甚至当signal-to-noise比率(SNR)是不到?40dB时，到不同试验性的数据集合的计划的申请证明算法能检测在强壮的噪音隐藏的信号。

简介：Inthispaper,anunderwaterstructureismodeledasacylindricalshellwithinternalbulkheads,andclosedbyatruncatedconicalshell,anditconsistsofmetalsubstrateandsoundabsorbingcoating,whoseFGMcoreisconsidered.Supposetheinnercavityandouterspaceofthestructurearefilledwithairandfluidmediums,themechanicalresponseoftheunderwaterstructureiscalculatedwithGalerkinmethodwhiletheacousticresponseisinvestigatedbymeansoftheHelmholtzintegral.Somenumericalexamplesaregivenandtheeffectofgeometricalsizeandmaterialparametersonmechanicalandacousticresponseisdiscussed.

简介：这篇文章讨论动态州的分析在水下拖引电缆线当拖引轮船在成为寓言的一个方向改变它的速度时，介绍路径。一个三维的模型在水下拖引的系统被学习。为系统的确定的管理方程用中央含蓄的有限差别的方法被解决了。获得的差别非线性的联合方程被牛顿鈥檚方法解决，令人满意的结果被完成。这个问题的答案在动态装载和运动的评价有实际重要性，并且因此它对安全的改进和有效性直接适用近海活动。

简介：Afiniteelement-Helmholtzintegralhybridmethodhasbeendevelopedtocalculatetheelectro-acousticperformanceofafinitelengthcylindricaltransducerimmersedinwater.Thenumericalstudyconcernedwithelectricalimpedancesandbeampatternsofthetransducerispresented.Experimentaldataareshowntosupportthenumericalstudy.

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简介：一个信号处理方法为高速度在水下图象的声学的传播被介绍。它有二部分。第1部分介绍信号处理为在水下声学的协调通讯。第1部分包括3个技术的点。(1)Doppler移动compensation.Chirp信号在数据包裹之间被插入。在二个拷贝关联函数之间的关联进程给吝啬的Doppler移动的更多的精确评价。然后，它能被采样补偿数据。在适应决定反馈均衡器(DFE)一个适应阶段赔偿者与快，自我优化的最不吝啬的广场(FOLMS)改编算法被利用与第二顺序阶段锁环算法比赔偿者导致更好的运动忍耐。吝啬的Doppler移动赔偿和适应阶段赔偿者的联合的表演相当好。(2)差异combiner(DC)在均衡器之前使用了。combiner和适应DFE基于FOLMS改编算法。这导致减少的计算复杂性和更好的性能。(3)串联了均衡器，涡轮架子编码了调整(TCM)解码器和重复算法。一个新bitsymbol变换器基于软产量Viterbi算法(SOVA)被学习。与传统的决定作比较，编码并且印射算法，在将近2的新变换器罐头还原剂小点错误率(BER)订。第2部分主要在一个柔韧的图象压缩算法附近。基于分离小浪变换并且修理了长度编码，为声学的图象的一个柔韧的压缩算法被学习。算法包括4个技术的点。(1)利用小浪基于转变图象的CDF9/7。(2)分析subband系数的精力分发。合适的转变层数字是3。(3)根据他们的精力分发把不同量子化步用于不同subbands。(4)使用修理了长度编码阻止错误繁殖。结果证明算法在图象质量，压缩率，和大多数之中完成平衡重要，坚韧性到BER。灰色的规模的压缩的位率声学的图象是0.85小点/象素。当BER比10-3低时，图象质量仍然保持好。当BER起床到10-2时，在那里削减一些小脏点。基于提及的上面的信号处理技术，一在水下声学的通讯系统是运作的频率乐队是的

简介：这篇论文在一种控制体系结构上研究为自治在水下车辆(AUV)。在描述AUV控制系统的混合性质以后，我们在场层次AUV控制体系结构。建筑学在三层被组织：使命层，任务层和实行层。声明监督人和任务协调人是处理分离事件的二个关键模块，因此我们详细描述这二个模块。最后，我们执行了一系列测试验证这体系结构。测试结果证明AUV能有效地并且安全地执行自治使命。我们能断定控制建筑学有效、实际。

简介：

简介：Underwatervehicleplaysanimportantroleinoceanengineering.Depthcontrolbyfinisoneofthedifficultiesforunderwatervehicleinmotioncontrol.Depthcontrolisindirectduetothefreedomcouplingbetweentrimandaxialmotion.Itincludesthemethodofdynamicanalysisandlift-resistance-coefficientexperimentandtheoryalgorithm.Byconsideringthecurrentspeedanddepthdeviation,comprehensiveinterpretationisusedinobject-planninginstruction.Expecteddepthistransformedintoexpectedtrim.Dynamicoutputfluctuationcanbeavoided,whichiscausedbylinearmappingofdeviation.Itissteadyandaccurateforthemotionofcontrolledunderwatervehicles.Thefeasibilityandefficiencyofthecontrolmethodaretestifiedinthepoolandnaturalareaforexperiments.

简介：Thepresentsimulationinvestigatesthemultiphasecavitatingflowaroundanunderwaterprojectile.BasedontheHomogeneousEquilibriumFlowassumption,amixturemodelisappliedtosimulatethemultiphasecavitatingflowincludingventilatedcavitationcausedbyairinjectionaswellasnaturalcavitationthatformsinaregionwherethepressureofliquidfallsbelowitsvaporpressure.Thetransportequationcavitatingmodelisapplied.ThecalculationsareexecutedbasedonasuiteofCFDcode.Thehyd...

简介：在水下圆柱的壳结构被发现了一许多设计领域里的申请宽例如水兵的元素，给平台上油，等等。联合颤动分析是为这些的一个热问题在水下结构。颤动特征在水下结构不仅被水动力学压力而且由相应于不同的水深度的静水力学的压力影响。在这研究，一个声学的有限元素方法被用来评估在水下结构。以起始的压力僵硬考虑静水力学的压力，听觉的液体结构联合了分析在水下圆柱的壳被做了在自然频率和健全放射上学习水动力学压力的效果。由与频率基于Bessel功能由声学的有限元素方法并且由增加的集体方法获得了作比较，现在的分析的有效性被检查。最后，使硬的圆柱的壳的健全放射的测试样品被泛音获得声学的分析。结果证明静水力学的压力在与水深度决定健全放射变化的一个大沉没身体运动，和特征起一个重要作用。而且，分析方法和结果具有为另外的复杂海底的结构的研究的重要参考价值。

简介：穿孔面板结构有一个宽潜力在在水下应用程序。然而，直到现在，几乎没有很少相关研究。声学的阻抗一在水下穿孔面板为空气基于理论被获得穿孔面板声音absorption.In这个论文声音传播特征在水下穿孔面板结构被转移矩阵方法理论上分析。为正常发生声音传播系数的一个公式被给。在声学的传播系数上有效果的主要因素被数字模拟分析。自己做的穿孔面板结构被四传感器的转移功能method.The在一个看台波浪试管测试试验性的结果被数字方法很好与结果一致获得，它证明理论分析是正确的。这篇论文为设计提供了理论、试验性的底在水下穿孔面板结构。

简介：Themodeloflinearfrequencymodulationcontinuouswave(LFMCW)appliedinunderwaterdetectionandthemethodforthedetectionofechosignalandtheestimationoftargetparameterswerestudied.Byanalyzingtheheterodynesignal,analgorithmwiththestructureofheterodyne-FractionalFourierTransform(FRFT)wasproposed.Toreducethecomputationofsearchingtargetsinatwo-dimensionalFRFTresult.theheterodynesignalwouldbeprocessedbyFRFTataspecificorder,afterRadon-AmbiguityTransform(RAT)wasappliedtoccstimatethesweeprateofthesignal.SimulationsprovedthatthealgorithmcaneliminatethecouplingphenomenonofdistanceandvelocityofLFMCW,andestimatetargets’parametersaccurately.ThelaketrialresultsshowedthattheprocessinggainofLFMCWprocessedbythealgorithminthispaperwas13dBbetterthanthatoftheLFMprocessedbymatchedfilter.TheresearchresultsindicatedthatthealgorithmappliedinLFMCWunderwaterdetectionwasfeasibleandeffective,anditcouldestimatetargets’parametersaccuratelyandobtainagooddetectionperformance.

简介：S-surfacecontrolhasproventobeaneffectivemeansformotioncontrolofunderwaterautonomousvehicles(AUV).Howevertherearestillproblemsmaintainingsteadyprecisionofcourseduetotheconstantneedtoadjustparameters,especiallywheretherearedisturbingcurrents.Thusanintelligentintegralwasintroducedtoimproveprecision.AnexpertS-surfacecontrolwasdevelopedtotunetheparameterson-line,basedontheexpertsystem,itprovidesS-surfacecontrolaccordingtopracticalexperienceandcontrolknowledge.Topreventcontroloutputover-compensation,afuzzyneuralnetworkwasincludedtoadjusttheproductionrulestotheknowledgebase.ExperimentswereconductedonanAUVsimulationplatform,andtheresultsshowthattheexpertS-surfacecontrollerperformsbetterthananS-surfacecontrollerinenvironmentswithcurrents,producinggoodsteadyprecisionofcourseinarobustway.