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

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

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Numerical Study of Viscous Wave-Making Resistance of Ship Navigation in Still Water

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Journal of Marine Science and Application 2014年第2期13卷 158-166页

作者： Ruosi Zha Haixuan Ye Zhirong Shen Decheng Wan State Key laboratory of 0cean Engineering School of Naval Architecture 0cean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

The prediction of a ship＇s resistance especially the viscous wave-making resistance is an important issue in CFD applications. In this paper, the resistances of six ships from hull 1 to hull 6 with different hull forms advancing in still water are numerically studied using the solver naoe-FOAM-SJTU, which was developed based on the open source code package OpenFOAM. Different components of the resistances are computed and compared while considering two speed conditions （12 kn and 16 kn）. The resistance of hull 3 is the smallest while that of hull 5 is the largest at the same speed. The results show hull 3 is a good reference for the design of similar ships, which can provide some valuable guidelines for hull form optimization.

关键词： ship navigation CFD wave-making resistance viscous flow hull naoe-FOAM-SJTU solver OpenFOAM

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Containment control for heterogeneous multi-agent systems with time delay via an output regulation approach

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Journal of Measurement Science and Instrumentation 2022年第1期13卷 79-88页

作者： WEI Wenjun LÜJiahui Huang Julong GE Junde School of Automation and Electrical Engineering Lanzhou Jiaotong University Lanzhou 730070 China Key Lab of Opti-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Lanzhou 730070 China China Energy Engineering Group Gansu Electric Power design Institute Co. Ltd. Lanzhou 730050 China

This paper presents the containment analysis and design of heterogeneous linear multi-agent systems(MAS)with time-delay under the output *** leaders are treated as exosystems and an modified output regulation error is designed,which can deal with more than one leader in containment control,then the containment problem will be turned into an output regulation problem.A novel analysis framework of the output regulation is proposed to design a dynamic state feedback control law for containment error and distributed observer when the agents cannot receive external system signal,which guarantees the convergence of all follower agents to the dynamic convex hull spanned by the *** system stability for time-delay containment is proved by the output regulation method instead of the Lyapunov ***,a numerical example is given to illustrate the validity of the theoretical results.

关键词： heterogeneous multi-agent systems output regulation linear time-delay systems containment control

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Test Series Results of Varying Yaw and Roll Angles of Trimaran Amas

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Journal of Shipping and Ocean Engineering 2014年第3期4卷 53-62页

作者： Carmine G Biancardi John Kutcher Raju Datla Department of Sciences and Technology Parthenope University of Naples Naples 80143 Italy Department of Civil Environmental and Ocean Engineering Davidson Laboratory Stevens Institute of Technology (Castle Pointon Hudson) Hoboken NJ 07030-599 USA

This paper illustrates the reasons behind the research strategy that has led to a new generation of trimaran hulls by minimizing the hull＇s drag-design approach. The objective of this study was to search for the optimal side-hull yaw and roll angle to minimize induced drag of trimarans a^d so to investigate the differences in the performance results of a trimaran hull. Specifically, this research has been based on a critical analysis of the diversity of ama yaw and roll angles and outriggers positioning. Then, the paper will be comparing the results of the test series of the yaw and roll angles of trimaran areas. design and towing tank test of a scaled trimaran model will be illustrated and compared along with some key and relevant results. The term ＂ama＂ is a word in the Polynesian and Micronesian languages to describe the outrigger part of a canoe to provide stability.

关键词： Trimaran resistance stability naval architecture ship hydrodynamics.

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Effects of dietary fiber content and different fiber-rich ingredients on endogenous loss of fat and fatty acids in growing pigs

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Journal of Animal Science and Biotechnology 2019年第3期10卷 745-758页

作者： Yifan Chen Zhenyu Wang Jian Ding Dongxu Ming Wenhui Wang Zhaoning Jiang Ling Liu Fenglai Wang State Key laboratory of Animal Nutrition China Agricultural UniversityNo.2 Yuanmingyuan West RoadBeijing 100193China National Animal Husbandry Service Building No.20Maizidian streetChaoyang DistrictBeijing 100125China

Background: Determination of the endogenous loss of fat(ELF) is used to adjust for the estimation of true total tract digestibility(TTTD) of fat in diets and *** factor which affected ELF may further affect the digestibility of fat,including sources and concentrations of fat and fiber in the *** are some reports of determining the ELF using regression methods based on different levels of fat intake,while reports on effects of dietary fiber content and different fiber-rich ingredients in pig diets on ELF are very ***,the objective of this study was to determine the effects of dietary fiber content and different fiber-rich ingredients on endogenous losses of fat and fatty acids at the end of ileum and throughout the entire intestinal tract in growing ***: In Exp.1,the effect of fiber content on endogenous loss of fat was determined using six growing pigs(Duroc × Landrace × Yorkshire;27.6 ± 2.4 kg),fitted with a T-cannula at the end of *** experimental design was a 6 × 6 complete Latin square design with six periods of feeding and six *** six experimental fat-free diets were formulated to include graded levels of neutral detergent fiber(NDF)(0,40,80,120,160 and 200 g/kg) and soybean hull(SH) was the only fiber source,providing 0,75,150,225,300 and 375 g/kg,*** oxide was included at4 g/kg in all diets as an indigestible *** Exp.2,six crossbred growing barrows(27.6 ± 1.6 kg) were used and the experimental design was the same as for *** six fat-free diets were formulated to include six common fiber-rich ingredients and the concentration of NDF was 100 g/*** six fiber-rich ingredients were defatted rice bran(DRB),sugar beet pulp(SBP),rice hull(RH),corn germ meal(CGM),SH and wheat bran(WB) and they were fed at represented250,270,145,250,170 and 280 g/kg in the diet,***: In Exp.1,the endogenous loss of fatty acids profile did not change as dietary NDF increased in growing p

关键词： Endogenous loss Fat Fatty acids Fiber content Fiber-rich ingredients Growing pigs

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Study on Collision Between Two Ships Using Selected Parameters in Collision Simulation

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Journal of Marine Science and Application 2016年第1期15卷 63-72页

作者： Dong-Myung Bae Aditya Rio Prabowo Bo Cao Ahmad Fauzan Zakki Gunawan Dwi Haryadi Department of Naval Architecture and Marine Systems Engineering Pukyong National University Nam-gu Daeyon Busan 48513 Republic of Korea Interdisciplinary Program of Marine Convergence design Pulkyong National University Nam-gu Daeyon Busan 48513 Republic of Korea Department of Mechanical Engineering Diponegoro University Semarang Central Java 50275 Republic of Indonesia Department of Naval Architecture Diponegoro University Semarang Central Java 50275 Republic of Indonesia

In the present analysis, several parameters used in a numerical simulation are investigated in an integrated study to obtain their influence on the process and results of this simulation. The parameters studied are element formulation, friction coefficient, and material model. Numerical simulations using the non-linear finite element method are conducted to produce virtual experimental data for several collision scenarios. Pattern and size damages caused by collision in a real accident case are assumed as real experimental data, and these are used to validate the method. The element model study performed indicates that the Belytschko-Tsay element formulation should be recommended for use in virtual experiments. It is recommended that the real value of the friction coefficient for materials involved is applied in simulations. For the study of the material model, the application of materials with high yield strength is recommended for use in the side hull structure.

关键词： ship collision collision accident non-linear finite element collision parameter hull structure

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Analysis of structural behavior during collision event accounting for bow and side structure interaction

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Theoretical & Applied Mechanics Letters 2017年第1期7卷 6-12页

作者： Aditya Rio Prabowo Dong Myung Bae Jung Min Sohn Ahmad Fauzan Zakki Bo Cao Qing Wang Interdisciplinary Program of Marine Convergence design Pukyong National University Busan 48513 Republic of Korea Department of Naval Architecture Diponegoro University Tembalang Semarang 50268 Central Java Indonesia Department of Naval Architecture and Marine Systems Engineering Pukyong National University Busan 48513 Republic of Korea China Shipbuilding Industry Corporation Economic Research Center Beijing 100012 China College of Shipbuilding Engineering Harbin Engineering University Harbin 150000 China

The main goal of this study was to investigate the effects of selected ship collision parameter values on the characteristics of the absorbed energy in several ship collision scenarios. Non-linear simulations were performed using a finite element method （FEM） to obtain virtual experiment data. In the present research, the size of the side damage from a collision phenomenon were measured and used to verify the numerical configuration together with the calculation results using an empirical equation. Parameters in the external dynamics of a ship collision such as the location of the contact point and velocity of the striking ship were taken into consideration. The internal energy and deformation size on the side structure were discussed further in a comparative study. The effects of the selected parameters on several structural behaviors, namely energy, force, and damage extent were also observed and evaluated in this section. Stiffener on side hull was found to contribute significantly into resistance capability of the target ship against penetration of the striking bow. Remarkable force during penetration was observed to occur when inner shell was crushed as certain velocity was applied in the striking bow.

关键词： Collision phenomenon Bow-side hull interaction Finite element analysisInternal energy Damage extent

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Experimental Study on the Configuration Hydrodynamics of Trimaran Ships

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Journal of Marine Science and Application 2022年第3期21卷 46-55页

作者： Jingbei Jia Zhi Zong School of Navigation and Naval Architecture Dalian Ocean UniversityDalian 16023China School of Naval Architecture Engineering Dalian University of TechnologyDalian 116024China State Key laboratory of Structural Analysis for Industrial Equipment Dalian 116024China

This paper presents experimental results on configuration *** models are used in the model tests,which are typical of hard,round,and soft *** specific values are different,the influence patterns are similar in the three ship models.A set of different outrigger positions is investigated in calm water and regular waves.A variety of interesting phenomena are observed,among which the splash resistance is the dominant component for a trimaran at high speeds(with Froude number Fr>0.6).If two small outriggers are placed inside Kelvin’s wave systems of the main hull,a strong splash appears,resulting in a significant resistance ***,short and long waves cannot be neglected,for they may excite the motions of much smaller *** condition leads to non-vanishing heaving at high-frequency and non-normalized pitches at low *** on the tests,three spectra of optimum configurations for resistance,longitudinal motions,and transverse motions are *** results reveal the optimum configurations of a trimaran hull in terms of hydrodynamic performance,thus providing a very powerful tool for optimum design of trimaran ships.

关键词： Trimaran ship Configuration Hydrodynamics Splash resistance Spectra of optimum configurations

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Numerical Simulation of Marine Vehicle Immersed in Water

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Journal of Marine Science and Application 2019年第3期18卷 282-294页

作者： Benamar Derrar Benameur Hamoudi Mohammed El-Amine Dris Fethi Saidi Aerohydrodynamic laboratory Department of Maritime EngineeringFaculty of Mechanical EngineeringUniversity of Sciences and Technology of Oran Mohamed BoudiafBir El DjirBP 150531000 El’MnaouerOranAlgeria Department of Hydraulics University Djillali Liabes of Sidi Bel-Abbes22000 Sidi Bel AbbèsAlgeria

This article presents a numerical study of the forces induced by hydrodynamic impact, that is, the impact of a part of the bottom of the hull on the water surface. The prediction of these efforts is often based on numerical simulations to determine the shock intensity of a structure on the surface of a weakly compressible fluid (for example, water). The short duration of the impact is also investigated in this work. This phenomenon occurs especially when a ship encounters a harsh and difficult sea conditions. Under such conditions, it is important to know how to predict the hydrodynamic forces applied to the structure to correctly optimize the ship elements during its design stage or to prevent possible damage. Indeed, various factors such as speed of the ship and height of the swell can cause the hull to partially emerge and then fall violently onto the water surface, which is referred to by naval personnel as tossing or slamming causing vibrations, stresses, and fatigue to the structural elements of the ship. In this work, we present an example of phenomenon modeling and then a numerical study of the different geometries (dihedron) that play a role in different sections of the bow. Then, we compare our present results with the theoretical and experimental results of other researchers in the field. The average interval impact time for a dihedral model corresponding to the section of the chosen ship and other experimental and theoretical data is in good agreement with the experimental and theoretical measurements.

关键词： Slamming Hydrodynamic impact Aero-hydro-elastic Dihedral Fluid/structure interaction Marine vehicle

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A case study of using an efficient CRISPR/Cas9 system to develop variegated lettuce

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Vegetable Research 2021年第1期1卷 26-35页

作者： Chi D Nguyen Juncheng Li Baiquan Mou Haijun Gong Heqiang Huo Mid-Florida Research and Education Center IFAS-University of Florida2725 South Binion RoadApopkaFL 32703United States Department of Environmental Horticulture IFAS-University of Florida2550 Hull RdGainesvilleFL 32611United States Fruit Tree Research Institute Guangdong Academy of Agricultural SciencesNo.80Dafeng Second StreetTianhe DistrictGuangzhou 510640China ARS/USDA 1636 E Alisal StSalinasCA 93905United States College of Horticultural Sciences Northwest Agriculture and Forestry University3 Taicheng RoadYangling 712100China

The clustered,regularly interspaced,short palindromic repeat associated endonuclease 9(CRISPR/Cas9)system has emerged as a powerful approach for precision breeding to create plants with desirable ***,the CRISPR/Cas9 system relies heavily on an efficient plant transformation system that is usually time-consuming and ***,we have constructed a CRISPR-Cas9 vector with neomycin phosphotransferase II and green fluorescent protein(eGFP-NPTII),where the high expression of GFP during plant regeneration allowed us to minimize the positional effect on T-DNA expression and facilitate screening T-DNA-free *** gene editing using CRISPR/Cas9 has been illustrated in different plant species,but an important aesthetic characteristic of leaf variegation remained *** the newly designed construct,we have targeted the variegation gene LsVAR2 in *** results indicated that LsVAR2 is closely related to both AtFtsH2 and AtFtsH8,in which homozygous mutations lead to an albino phenotype while a variegated phenotype was induced by CRISPR/Cas9 de novo gene *** conclusion,the unique design of our CRISPR/Cas9 construct could efficiently edit the target gene and ease the screening of non-TDNA mutants through detecting GFP signals during plant regeneration and progeny ***,the success of gene-editing of LsVAR2 in lettuce demonstrates proof in this method to develop novel plant breeding materials for valuable horticultural plant species.

关键词： system breeding consuming

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