检索结果-南通市图书馆

Propeller Torque Load and Propeller Shaft Torque Response Correlation During Ice-propeller Interaction

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Marine Science and Application 2017年第1期16卷 1-9页

作者： Drazen Polic Soren Ehlers Vilmar AEsoy Department of Marine Technology Norwegian University of Science and TechnologyTrondheim 7491Norway Institute for Ship Structural design and Analysis Hamburg University of TechnologyHamburg 21073Germany Department of Ocean Operations and Civil Engineering Norwegian University of Science and TechnologyAlesund 6025Norway

轮船使用推进机械系统创造方向性的戳。当轮船壳进展，航行在盖住冰的水里包含碎冰片和他们的 submergence。有时，沉没了冰片与推进器交往并且引起转矩负担的不规则的变化。作为结果，推进器和引擎动力学，变得的 imbalanced，和能量... 详细信息

轮船使用推进机械系统创造方向性的戳。当轮船壳进展，航行在盖住冰的水里包含碎冰片和他们的 submergence。有时，沉没了冰片与推进器交往并且引起转矩负担的不规则的变化。作为结果，推进器和引擎动力学，变得的 imbalanced，和能量通过推进机械系统宣传直到平衡被到达。处于如此的 imbalanced 状况，测量推进器柄转矩反应不等于推进器转矩。在这个工作，因此，全面系统反应用契约图模型在冰相关的转矩负担下面被模仿。推进器和推进器柄之间的能量差别被估计并且与他们的相应机械能量有关。另外，机械能量在模式之中被散布。基于分发，运动并且势能为在推进器转矩和推进器柄反应之间的关联是重要的。

关键词： propeller torque load propeller shaft torque response ice-propeller interaction load-response correlation

Bright spots for inland fish and fisheries to guide future hydropower development

在线全文

学校读者我要写书评

暂无评论

Water Biology and Security 2022年第1期1卷 81-99页

作者： William M.Twardek Ian G.Cowx Nicolas W.R.Lapointe Craig Paukert T.Douglas Beard Elena M.Bennett David Browne Andrew K.Carlson Keith D.Clarke Zeb Hogan Kai Lorenzen Abigail J.Lynch Peter B.McIntyre Paulo Pompeu Mark Rogers Alexis Sakas William W.Taylor Taylor D.Ward Zeenatul Basher Steven J.Cooke Fish Ecology and Conservation Physiology laboratory Department of Biology and Institute for Environmental StudiesCarleton University1125 Colonel By DrOttawaON K1S 5B6Canada Fisheries Institute at the University of hull Cottingham RdHullHU67RXUnited Kingdom Canadian Wildlife Federation 350 Michael Cowpland DrKanataONK2M 2W1Canada U.S.Geological Survey Missouri Cooperative Fish and Wildlife Research UnitUniversity of MissouriColumbiaMO65211United States U.S.Geological Survey National Climate Adaptation Science Center12201 Sunrise Valley DriveMS-516RestonVA20192United States McGill School of Environment McGill University845 Sherbrooke St WMontrealQuebec H3A 0G4Canada Princeton Environmental Institute and Department of Ecology and Evolutionary Biology Princeton UniversityM30 Guyot HallPrincetonNJ08544United States Ecological Sciences Section Science Branch Fisheries and Oceans CanadaCanadaPO Box/CP 5667St.John'sNewfoundland and LabradorA1C 5X1Canada University of Nevada Reno.4505 S Maryland PkwyLas VegasNV89154United States Fisheries and Aquatic Sciences School of Forest Resources and ConservationUniversity of Florida7922 NW 71st StreetGainesvilleFL32653United States Department of Natural Resources Cornell UniversityIthacaNY14853United States Departamento de Biologia Universidade Federal de LavrasAquenta SolLavrasState of Minas Gerais37200-900Brazil U.S.Geological Survey Tennessee Cooperative Fishery Research UnitTennessee tech UniversityCookevilleTN38505United States The Nature Conservancy 6375 Riverside DriveSuite 100DublinOH43017United States Michigan State University Department of Fisheries and WildlifeEast LansingMI48823United States

Hydropower production is one of the greatest threats to fluvial ecosystems and freshwater *** that we have entered the Anthropocene,there is an opportunity to reflect on what might constitute a‘sustainable’Anthropocene in the context of hydropower and riverine fish *** elements of existing practices that promote favorable social-ecological outcomes(i.e.,‘bright spots’)is timely given that there are plans to expand hydropower capacity in previously undammed rivers,intensify dam development in some of the world's largest river systems,and re-license existing *** approach this from a pragmatic perspective:for the foreseeable future,hydropower will likely remain an important source of renewable *** offer support for moving toward a more‘sustainable’Anthropocene,we provide syntheses of best practices during the siting,design,construction,operation,and compensation phases of hydropower development to minimize impacts on inland *** each phase,we offer positive examples(or what might be considered‘bright spots’)pertaining to some of the approaches described within our syntheses,acknowledging that these projects may not be viewed as without ecological and(or)societal detriment by all *** findings underscore the importance of protecting critical habitat and free-flowing river reaches through careful site selection and basinscale planning,infrastructure designs that minimize reservoir effects and facilitate safe passage of fish,construction of hydropower plants using best practices that minimize long-term damage,operating guidelines that mimic natural flow conditions,and compensation that is lasting,effective,inclusive,and locally *** from these‘bright spots’may require engagement of diverse stakeholders,professionals,and governments at scales that extend well beyond a given site,river,or even ***,environmental planning that integrates hydropower development into broader discussions

关键词： Migration Dams Salmon Hydroelectric Flow Socioecological Fish passage Barriers Ecosystems

Vibration Reduction Performance of Damping-Enhanced Water-Lubricated Bearing Using Fluid-Saturated Perforated Slabs

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2020年第6期33卷 218-227页

作者： Yong Jin Jianjun Lu Wu Ouyang Zhenglin Liu Kunsheng Lao Ministry of Education Key Laboratory of High Performance Ship Technology(Wuhan University of Technology)Wuhan430063China School of Energy and Power Engineering Wuhan University of TechnologyWuhan430063China

As the first link element for the transmission of shaft vibration to the pedestal and even to the hull,water-lubricated bearing plays a key role in suppressing *** the porous structure is considered as one of the main methods for improving the wideband vibration and noise reduction performance of materials in many industrial fields,the studies in the field of water-lubricated bearing remain *** enhance vibration reduction performance,a fluid-saturated perforated slab is designed in this study,and via the establishment of a fluid-solid coupled vibration model,the influence law and impact levels were analyzed and verified by simulation and *** results obtained verified that the total vibration amplitude of damping-enhanced stern bearing in the vertical direction was smaller than that of the normal stern bearing,and the reduction amplitude of the characteristic frequency agreed with the optimal value at approximately 0.1 of the volume fraction of the liquid phase when the solid-fluid phase was rubber–***,the increase in fluid fraction did not enhance the damping effect,instead,it unexpectedly reduced the natural frequency of the raw material *** research indicates that the design of the fluid-saturated perforated slab is effective in reducing the transmission of the vibration amplitude from the shaft,and presents the best volume fraction of the liquid phase.

关键词： Water-lubricated stern bearing Fluid-saturated perforated slabs Fluid-salid coupled vibration model

THE OPTIMIZATION OF THE hull form WITH THE MINIMUM WAVE MAKING RESISTANCE BASED ON RANKINE SOURCE METHOD

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2009年第2期21卷 277-284页

作者： ZHANG Bao-ji MA Kun JI Zhuo-shang State Key laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian116024 China Ship CAD Engineering Center Dalian University of Technology Dalian 116024 China

The hull form optimization concerns one of the most important applications of wave making resistance theories. In order to obtain a hull form with the minimum wave making resistance, an optimization design method based on the CFD is proposed, which combines the Rankine source method with the nonlinear programming （NLP）. The bow-body shape is optimized with the minimum wave making resistance as the objective function. A hull form modification function is introduced to represent an improved hull surface, which can be used to generate a new smooth hull surface by multiplying it by the offset data of the original hull surface. The parameters of the hull form modification function are taken as the design variables. Other constraint conditions can also be considered, for example, in optimizing the lines of the bow, appropriate displacements can be taken as the basic constraints. S60 hull form is selected as the original hull. Three improved hulls are obtained by optimal design. Rankine source method proves to be an effective method in ship form optimization based on analysis of the resistance performance and lines of the improved hull.

关键词： Rankine source method CFD NLP optimization method,wave making resistance

舰船刚性阻振质量复合托板隔振特性优化设计(英文)

在线全文

学校读者我要写书评

暂无评论

Journal of Marine Science and Application 2011年第2期10卷 215-219页

作者：王强勇姚熊亮于丹竹庞福振 Wuhan Second Ship design and Research Institute College of Shipbuilding Engineering Harbin Engineering University

In considering the theory of structural dynamic optimization design, a design method of the structural style of ship composite brace with rigid vibration isolation mass was studied. Two kinds of structural dynamic optimization formulations minimizing the vibration acceleration of the non-pressure hull on the restraining condition of the gross weight of the ship cabin were established: 1) dynamic optimization of the sectional dimensions of the rigid vibration isolation mass in the composite brace; 2) dynamic optimization of the arranging position of the rigid vibration isolation mass. Through the optimization results, sectional dimensions and the arranging position of the rigid vibration isolation mass with better performance in reducing vibration were gained, and some reference was provided for practical engineering designs as well as enrichment of the design method of a novel ship vibration-isolation brace.

关键词：优化设计质量隔振刚性振动特性船舶支撑动态优化

Effects of intermittent loading time and stress ratio on dwell fatigue behavior of titanium alloy Ti-6Al-4V ELI used in deep-sea submersibles

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第18期77卷 223-236页

作者： Chengqi Sun Yanqing Li Kuilong Xu Baotong Xu State Key laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Engineering Sciences University of Chinese Academy of SciencesBeijing 100049China State Key laboratory of Deep-sea Manned Vehicles(China Ship Scientific Research Center) Wuxi 214082China LuoyangShip Material Research Institute Luoyang471023China Aero Engine Corporation of China Beijing Institute of Aeronautical Materials Beijing 100095China

Different components of deep-sea submersibles,such as the pressure hull,are usually subjected to intermittent loading,dwell loading,and unloading during ***,for the design and reliability assessment of structural parts under dwell fatigue loading,understanding the effects of intermittent loading time on dwell fatigue behavior of the alloys is *** this study,the effects of the intermittent loading time and stress ratio on dwell fatigue behavior of the titanium alloy Ti-6 Al-4 V ELI were *** suggest that the dwell fatigue failure modes of Ti-6 Al-4 V ELI can be classified into three types,i.e.,fatigue failure mode,ductile failure mode,and mixed failure *** intermittent loading time does not affect the dwell fatigue behavior,whereas the stress ratio significantly affects the dwell fatigue life and dwell fatigue *** dwell fatigue life increases with an increase in the stress ratio for the same maximum stress,and specimens with a negative stress ratio tend to undergo ductile *** mechanism of dwell fatigue of titanium alloys is attribute to an increase in the plastic strain caused by the part of the dwell loading,thereby resulting in an increase in the actual stress of the specimens during the subsequent loading cycles and aiding the growth of the formed crack or damage,along with the local plastic strain or damage induced by the part of the fatigue load promoting the cumulative plastic strain during the dwell fatigue *** interaction between dwell loading and fatigue loading accelerates specimen failure,in contrast to the case for individual creep or fatigue loading *** dwell fatigue life and cumulative maximum strain during the first loading cycle could be correlated by a linear relationship on the log–log *** relationship can be used to evaluate the dwell fatigue life of Ti alloys with the maximum stress dwell.

关键词： Ti-6Al-4V ELI Dwell fatigue Intermittent loading time Stress ratio Creep fatigue interaction

Receding horizon H_∞ control for constrained time-delay systems

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2009年第2期20卷 363-370页

作者： Lu Mei Jin Chengbo Shao Huihe Inst. of Automation Shanghai Jiaotong Univ. Shanghai 200240 P. R. China Dept. of Fieldbus Shanghai Automation Instrument Co. Ltd. Shanghai 200233 P. R. China Dept. of Product design Shanghai Gaoke Valve Manufactory Co. Ltd. Shanghai 200092 P. R. China

A receding horizon Hoo control algorithm is presented for linear discrete time-delay system in the presence of constrained input and disturbances. Disturbance attenuation level is optimized at each time instant, and the receding optimization problem includes several linear matrix inequality constraints. When the convex hull is applied to denote the saturating input, the algorithm has better performance. The numerical example can verify this result.

关键词： receding horizon control Hoo control time-delay constrained input

Light weight optimization of stratospheric airship envelope based on reliability analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2020年第10期33卷 2670-2678页

作者： Yunce ZHANG Yafei WANG Changguo WANG National Key laboratory of Science and Technology for National Defence on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150001China Center for Composite Materials Harbin Institute of TechnologyHarbin 150001China

A stratospheric airship is an essential flight vehicle in the aviation *** this paper,optimal design approach of stratospheric airships is developed to optimize envelope shape considering three failure modes and multidisciplinary analysis models,and could also reduce the mass of a stratospheric airship to be deployed at a specific *** on a theoretical analysis,three failure modes of airships including bending wrinkling failure,hoop tearing failure and bending kink failure,are given to describe and illustrate the failure mechanism of stratospheric *** results show that the location,length and size of the local uniform load and the large fineness ratio are easier to lead to bending wrinkling failure and bending kink *** small fineness ratio and the increasing differential pressure are more prone to cause hoop tearing failure for an airship *** failure probability is sensitive to the wind *** an optimization design,the reliability analysis is essential to be carried out based on the safety of the *** solution in this study can provide economical design recommendations.

关键词： Failure modes Mass optimization Optimal design Reliability analysis Stratospheric airship

Minimizing Buoyancy Factor of Metallic Pressure-hull Subjected to Hydrostatic Pressure

在线全文

学校读者我要写书评

暂无评论

Intelligent Automation & Soft Computing 2023年第1期35卷 769-793页

作者： Mahmoud Helal Elsayed Fathallah Abdulaziz H Alghtani Hussein Shawki Osman Jong Wan Hu Hasan Eleashy Department of Mechanical Engineering Faculty of EngineeringTaif UniversityTaif 21944Saudi Arabia Production and Mechanical design Department Faculty of EngineeringMansoura UniversityMansoura 35516Egypt Civil Engineering Department M.T.C.Kobry ElkobbaCairo 11865Egypt Ships and Submarines Engineering Department Military Technical CollegeCairo 11865Egypt Civil Engineering Department Sohag UniversitySohag 82524Egypt Department of Civil and Environmental Engineering Incheon National UniversityIncheon 22012Korea Incheon Disaster Prevention Research Center Incheon National UniversityIncheon 22012Korea Mechanical Engineering Department Faculty of Engineering&TechnologyFuture University in EgyptCairo 11835Egypt

To increase the payload,reduce energy consumption,improve work efficiency and therefore must accordingly reduce the total hull weight of the *** paper introduces a design optimization process for the pressurehull of submarines under uniform external hydrostatic pressure using bothfinite element analysis(FEA)and optimization tools.A comprehensive study about the optimum design of the pressure hull,to minimize the weight and increase the volume,to reach minimum buoyancy factor and maximum operating depth minimizing the buoyancy factor(B.F)is taken as an objective function with constraints of plate and frame yielding,general instability and *** optimization process contains many design variables such as pressure-hull plate thickness,unsupported spacing,dimensions of long and ring beams andfinally the elliptical submersible pressure-hull *** optimization process was conducted using ANSYS parametric design language(APDL)and *** Multi-Island Genetic Algorithm(G.A)is considered to conduct the optimization ***,parametric analysis is done on the pressure hull to examine the effect of different design variables on the pressure-hull *** a result,the B.F of the proposed optimal model is reduced by an average of 31.78%compared with Reference Model(RM).Maximum von Mises stress is reduced by 27%as *** results can be helpful for submarine pressure-hull designers.

关键词： Buoyancy factor pressure-hull material failure ANSYS ISIGHT general instability