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Search results for: SHIP HYDRODYNAMICS
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NOx emission from a two-stroke ship engine: Part 2 – Laboratory test
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NOx emission from a two-stroke ship engine. Part 1: Modeling aspect
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Expert elicitation of a navigation service implementation effects on ship groundings and collisions in the Gulf of Finland
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Enhancing human performance in ship operations by modifying global design factors at the design stage
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Safety Qualification Process for an Autonomous Ship Prototype – a Goal-based Safety Case Approach
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Impact of the Time Window Length on the Ship Trajectory Reconstruction Based on AIS Data Clustering
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THE POSSIBILITIES OF ESTIMATING THE RELIABILITY OF SHIP PIPELINES’ ELEMENTS INCLUDING DESTRUCTIVE PHENOMENA ACTING ON THEM
PublicationIn the article an approach to the problem of estimating reliability data based on physical models is proposed. The possibility of reliability assessment for selected elements of ship pipelines, based on the recognition of the destructive physical phenomena taking place in them, is discussed. To do this, an overview of these phenomena has been made. In addition, a preliminary review of existing measures of destruction of materials...
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Problems of Determination of Welding Angular Distortions of T-fillet Joints in Ship Hull Structures
PublicationShip hull structure elements are in majority joined by welding. Welding distortions can cause a lot of problems during the manufacturing process. In the literature it is proposed wide spectrum of suggestions for a correct estimation of welding deformation in particular angular deformation in the fillet welded T joint. In the work verification of selected methods is proposed basing upon of the results of the laboratory measurements....
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The Conception of Decision-Making Support System for ComplexEnergetic System on Example of Ship Propulsion System
PublicationIn paper, the conception of decision-making support system for complex energetic system on example of ship propulsion system has been presented. Diversity of conditions, information overload and very often contradiction of decision-making criteria and time constraints result in difficulties in making right (rational) decision without using more or less expanded information processing systems (eg. database systems, expert systems,...
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A decision-making module for aiding ship system automation design; A knowledge-based approach
PublicationZastosowanie elementów sztucznej inteligencji, w tym systemów z bazą wiedzy staje się coraz bardziej powszechne przy komputerowo wspomaganym projektowaniu. Proces projektowy związany jest z wieloma problemami decyzyjnymi, jak: wybór struktury podsystemu, podzespołów czy też elementów składowych. Z tego względu zdecydowano się opracować system z bazą wiedzy z modułem wspirającym proces podejmowania decyzji.W artykule przedstawiono...
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Influence of main design parameters of ship propeller shaft water-lubricated bearings on their properties
PublicationW artykule omówiono wpływ głównych parametrów konstrukcyjnych i eksploatacyjnych takich jak wielkość luzu łożyskowego, własności materiału panwi, stanu powierzchni skojarzenia ślizgowego oraz temperatury i zasolenia wody na nośność hydrodynamiczną łożyska okrętowego wału śrubowego smarowanego wodą.
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Water-lubricated bearings of ship propeller shafts - problems, experimental tests and theoretical investigations
PublicationW pracy przedstawiono problemy związane z projektowaniem, montażem i ekspolatcją smarowanych wodą łożysk okrętowych wałów głównych.Przedstawiono wyniki prowadzonych prac badawczych ekperymntalnych i obliczeń.
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Computer graphics toos application for visualsation of measurements results of ship hull sections and blocks.
PublicationOpisano zakres minimalnych wymagań dla programu komputerowego, służącego do wizualizacji wyników pomiarów sekcji i bloków kadłuba okrętowego. Przedstawiono sposób przenoszenia danych z urządzenia pomiarowego do programu i pokazano przykłady pomiarów wykonanych na sekcjach zbudowanych w Stoczni Gdynia S.A.
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On a risk-based method for safety assessment of a ship in critical conditions at the preliminary design stage.
PublicationW pracy przedstawiono wybrane rezultaty badań na temat metody oceny bezpieczeństwa statków w warunkach krytycznych, na etapie projektu wstępnego. Podano główne założenia nowoczesnego podejścia do oceny bezpieczeństwa statków. Przedstawiono opis metody do projektowania statków dla bezpieczeństwa, w warunkach krytycznych. Opisano główne elementy modelu obliczeniowego. Podano wybrane wyniki obliczeń. Opisano propozycje dalszych badań.
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Semi-Markow Processes as Models of Devices´ Operating Process of Ship Pro-pulsion System
PublicationReferat zawiera formalny opis procesu eksploatacji urządzeń.
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Design and experimental evaluation of pod propulsor models for a large self-propelled ship model.
PublicationArtykuł przedstawia serię hydrodynamicznych badań swobodnych dwóch modeli pędnika podowego. Pędniki zostały zaprojektowane i zbudowane specjalnie dla dwóch wersji dużego modelu okrętu z własnym napędem, przeznaczonego do eksperymentów manewrowych. Jedna wersja jest napędzana pojedyńczym pędnikiem, druga jest wyposażona w dwa pędniki. Oba modele podów były badane w kanale obiegowym. Celem eksperymentu były pomiary sześciu składowych...
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Monitoring of Caged Bluefin Tuna Reactions to Ship and Offshore Wind Farm Operational Noises
PublicationUnderwater noise has been identified as a relevant pollution affecting marine ecosystems in different ways. Despite the numerous studies performed over the last few decades regarding the adverse effect of underwater noise on marine life, a lack of knowledge and methodological procedures still exists, and results are often tentative or qualitative. A monitoring methodology for the behavioral response of bluefin tuna (Thunnus thynnus)...
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Ship weather routing optimization with dynamic constraints based on reliable synchronous roll prediction
PublicationShip routing process taking into account weather conditions is a constrained multi-objective optimization problem and it should consider various optimization criteria and constraints. Formulation of a stability-related, dynamic route optimization constraint is presented in this paper. One of the key objectives of a cross ocean sailing is finding a compromise between ship safety and economics of operation. This compromise should...
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Weather Hazard Avoidance in Modeling Safety of Motor-Driven Ship for Multicriteria Weather Routing
PublicationWeather routing methods find the most suitable ocean?s route for a vessel, taking into account changeable weather conditions and navigational constraints. In the multicriteria approach based on the evolutionary SPEA algorithm one is able to consider a few constrained criteria simultaneously. The approach applied for a ship with hybrid propulsions has already been presented by one of the authors on previous TransNav?2009. This time...
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A design concept of main propulsion system with hydrostatic transmission gear for inland waterways ship
PublicationCelem analizy jest przedstawienie koncepcji napędu głównego statku oraz określenie jego sprawności całkowitej. Zrealizowanie zamierzenia przedstawionego powyżej wymaga spojrzenia na opis strat i sprawności energetycznej przekładni hydrostatycznej, uwzględniający jak najdalej idącą jego prostotę. Obraz wzajemnego wpływu strat we wszystkich elementach układu hydraulicznego okazuje się bardzo złożony. Przy założeniu koniecznych uproszczeń...
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Maritime traffic situation awareness analysis via high-fidelity ship imaging trajectory
PublicationSituation awareness provides crucial yet instant information to maritime traffic participants, and significant attentions are paid to implement traffic situation awareness task via various maritime data source (e.g., automatic identification system, maritime surveillance video, radar, etc.). The study aims to analyze traffic situation with the support of ship imaging trajectory. First, we employ the dark channel prior model to...
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Quantumness in Diagnostics of Marine Internal Combustion Engines and Other Ship Power Plant Machines
PublicationThe article provides proof that the diagnostics of marine internal combustion engines and other ship power plant machines should take into account the randomness and unpredictability of certain events, such as wear, damage, the variations of mechanical and thermal loads, etc., which take place during machine operation. In the article, the energy E, like the other forms (methods) that it can be converted into (heat and work), is...
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Influence of Added Water Mass on Ship Structure Vibration Parameters in Virtual and Real Conditions
PublicationModelling of ship structures in a virtual environment is now standard practice. Unfortunately, many engineers forget to consideri the influence of added water on the frequency values and the amplitude of natural vibrations. The article presents the effect of water damping on the frequency values of the individual natural vibration modes. The tests were carried out in two stages. First, the mentioned values were determined using...
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Multi-layered mineral glass units used as viewport elements of underwater ship structures
PublicationIn the paper, Authors deals with viewport elements of underwater marine constructions. If a single-plate viewport constructions are considered, big thicknesses of the glass plate are required to resist the pressure. To build the viewports from the commercially accessible glass panes, multi-layered glass units are proposed in the paper. Numerical calculations are presented, summarized and compared with experimental tests. Focusing...
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The Impact of Material Selection on Durability of Exhaust Valve Faces of a Ship Engine – A Case Study
Publicationwo alloys were used in order to extend the service life of marine engine exhaust valve head. Layers of cobalt base alloys were made of the powders with with chemical composition as follow: the layer marked L12; C-1,55%; Si-1,21%; Cr-29,7%; W-9%; Ni-2%; Mo<0,01%; Fe-1,7%; Co-54,83% and the layer marked N; C-1,45%; Co-38,9%; Cr-24,13%; Ni-10,43%; W-8,75%; Fe-7,64%; Mo-7,56%; Si-2,59%. Base metal was valve steel after heat treatment....
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On reliability assessment of ship machinery system in different autonomy degree; A Bayesian-based approach
PublicationAnalyzing the reliability of autonomous ships has recently attracted attention mainly due to epistemic uncertainty (lack of knowledge) integrated with automatic operations in the maritime sector. The advent of new random failures with unrecognized failure patterns in autonomous ship operations requires a comprehensive reliability assessment specifically aiming at estimating the time in which the ship can be trusted to be left unattended....
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Experimental investigation of Steel–Concrete–Polymer composite barrier for the ship internal tank construction
PublicationTransportation of dangerous cargo by ships demands ensuring an appropriate protection level in case of an accident. Two of the most dangerous accident types resulting in an oil spill are grounding and ship to ship collision. The article presents results of research on a new composite construction for a ship hull that increases structural safety during collision. The concept of semi-elastic Steel–Concrete–Polymer structure is presented....
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Damage tests of the single shell ship fuel tank with additional elastic protective coating
PublicationWejście na mieliznę lub kolizja średniej wielkości np. kontenerowca może doprowadzić do zanieczyszczenia środowiska Morza Bałtyckiego paliwem uwolnionym z rozszczelnionych, jednoposzyciowych zbiorników dennych, a ilość tego paliwa może być znaczna. W związku z tym podjęto prace badawcze zmierzające do opracowania sposobu obniżenia ryzyka rozlewu paliwa w wypadku kolizji poprzez wprowadzenie drugiej bariery ochronnej. Idea pomysłu...
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Structural Reliability Assessment Of Corroded Tanker Ship Based On Experimentally Estimated Ultimate Strength
PublicationThis work deals with the reliability assessment of a tanker ship hull structure subjected to a vertical bending moment and corrosion degradation. The progressive collapse and ultimate load carrying capacity are estimated based on experimentally tested scaled box-shaped-specimens. The translation of the strength estimate of the scaled specimen to the real tanker ship hull structure is performed based on the dimensional theory developing...
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Dynamically positioned ship steering making use of backstepping method and artificial neural networks
PublicationThe article discusses the issue of designing a dynamic ship positioning system making use of the adaptive vectorial backstepping method and RBF type arti cial neural networks. In the article, the backstepping controller is used to determine control laws and neural network weight adaptation laws. e arti cial neural network is applied at each time instant to approximate nonlinear functions containing parametric uncertainties....
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Ship domain applied to determining distances for collision avoidance manoeuvres in give-way situations
PublicationShip domain is often used in marine navigation and marine traffic engineering as a safety condition. The basic idea behind those applications is that an encounter of two or more ships can be considered safe if neither of ship domains is intruded by other ships. Research utilising this approach has been documented in numerous works, including publications on optimising collision avoidance manoeuvres performed to fulfil domain-based...
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Path planning algorithm for ship collisions avoidance in environment with changing strategy of dynamic obstacles
PublicationIn this paper a path planning algorithm for the ship collision avoidance is presented. Tested algorithm is used to determine close to optimal ship paths taking into account changing strategy of dynamic obstacles. For this purpose a path planning problem is defined. A specific structure of the individual path and fitness function is presented. Principle of operation of evolutionary algorithm and based on it dedicated application...
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A Ship Domain-Based Method of Determining Action Distances for Evasive Manoeuvres in Stand-On Situations
PublicationA ship encounter can be considered safe if neither of ships’ domains (defined areas around ships) is intruded by other ships. Published research on this includes optimising collision avoidancemanoeuvres fulfilling domain-based safety conditions.However, until recently there was no method, using ship’s domain to determine exact moment when a particular collision avoidance manoeuvre can still be successfully performed. The authors...
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Changing the Ship Propulsion System Performances Induced by Variation in Reaction Degree of Turbocharger Turbine
PublicationArtykuł przedstawia szczegółowy model matematyczny układu napędu statku obejmującego: wolnoobrotowy silnik spalinowy okrętowy, śruba okrętowa oraz regulator prędkości kątowej. Model ten, następnie jest wykorzystany do badania symulacyjnego zachowania układu zarówno w stanach ustalonych jak i nieustalonych. Model jest zweryfikowany z wynikami eksperymentalnymi. Przedstawienie oryginalnej metody oceny wrażliwości układu względem...
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Evolutionary Sets of Safe Ship Trajectories: improving the method by adjusting evolutionary techniques and parameters
PublicationThe paper presents some of the evolutionary techniques used by the evolutionary sets of safe ship trajectories method. In general, this method utilizes a customized evolutionary algorithm to solve a constrained optimization problem. This problem is defined as finding a set of cooperating trajectories (here the set is an evolutionary individual) of all the ships involved in the encounter situation. The resulting trajectories are...
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Impact of steel grade on a ship colliding with an offshore wind turbine monopile supporting structure
PublicationOffshore wind power is experiencing rapid development around the world. The number of installations and their size is growing. Thousands of monopile support structures with diameters of 10 m and weights of 2000 tons will be installed in the coming years. Offshore wind power installations, often located close to the shore and shipping routes, pose a new challenge to ship safety. The study analyses the damages from an accidental...
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Circular saws with closed chip grooves
PublicationW pracy przedstawiono analizę wpływu kształtu rowków wiórowych ostrzy piły tarczowej na sposób odprowadzania wiórów ze strefy skrawania. Zaprezentowano rozwiązanie konstrukcyjne piły tarczowej z domkniętymi rowkami wiórowymi
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Chromatic scheduling in a cyclic open shop
PublicationPraca jest poświęcona złożoności obliczeniowej problemu cyklicznego szeregowania w systemie otwartym. Autorzy analizując wykazują, że problem jest NP-trudny dla 3 procesorów i konstruują algorytm dokładny dla przypadku dwóch procesorów.Ponadto analizowany jest zwarty wariant cyklicznego systemu otwartego. W tym przypadku autorzy pokazują, że już szeregowanie na dwóch procesorach prowadzi do problemu NP-trudnego.
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Hull strength assessment of the designed ships
PublicationPrzedstawiono metody i wyniki analizy wytrzymałości konstrukcji kadłubów czterech statków zaprojektowanych w ramach EUREKA Project E!2772: zbiornikowca, kontenerowca, Ro-Ro i statku rzeka-morze. Obliczenia wykonano według zaleceń i wymagań przepisów Det Norske Veritas.
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Environment friendly ships for Baltic area
PublicationPrzedstawiono końcowy efekt projektu europejskiego grupy Eureka E!2772. Scharakteryzowano zagrożenia stwarzane przez żeglugę oraz ekologiczne wymagania stawiane statkom. Przedstawiono plany generalne jednostek.
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Hydrodynamic cavitation based advanced oxidation processes: Studies on specific effects of inorganic acids on the degradation effectiveness of organic pollutants
PublicationThe use of cavitation in advanced oxidation processes (AOPs) to treat acidic effluents and process water has become a promising trend in the area of environmental protection. The pH value of effluents – often acidified using an inorganic acid, is one of the key parameters of optimization process. However, in the majority of cases the effect of kind of inorganic acid on the effectiveness of degradation is not studied. The present...
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The experimental identification of the dynamic coefficients of two hydrodynamic journal bearings operating at constant rotational speed and under nonlinear conditions.
PublicationHydrodynamic bearings are commonly used in ship propulsion systems. Typically, they are calculated using numerical or experimental methods. This paper presents an experimental study through which it has been possible to estimate 24 dynamic coefficients of two hydrodynamic slide bearings operating under nonlinear conditions. During the investigation, bearing mass coefficients are identified by means of a newly developed algorithm....
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A hybrid model of flooding of the ro-ro ships in damaged conditions
PublicationThe paper presents some results on investigations concerning development of a hybrid model for assessment of performance of the ro‐ro ships in damaged conditions. The model is devoted towards assessing the performance of the damaged ro‐ro ships at the preliminary stage of design. The key problems associated with preparing of such the model are associated with working out a method of assessment of the damaged roro ships performance,...
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Assessment of under power ed propulsion machinery in electrically driven small inland waterway passenger ships from classification society point of view
PublicationPaper presents short operat ional a nd engineering analysis of underpowered propulsion in small electrically propelled small inland passenger ships. There is evidence that in certain weather conditions the phenomena of added aerodynamic resistance of small water crafts may have seriou s influence on their speed and manoeuvrability. Existing regulations like class societies rules for ship classification and construction or EU Directive 2006/87/EC do...
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ASSESSMENT OF UNDERPOWER ED PROPULSION MACHINERY IN ELECTRICALLY DRIVEN SMALL INLAND WATERWAY PASSENGER SHIPS FROM CLASSIFICATION SOCIETY POINT OF View
PublicationPaper presents short operat ional a nd engineering analysis of underpowered propulsion in small electrically propelled small inland passenger ships. There is evidence that in certain weather conditions the phenomena of added aerodynamic resistance of small water crafts may have serious influence on their speed and manoeuvrability. Existing regulations like class societies rules for ship classification and construction or EU Directive 2006/87/EC do...
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Assesment of operation of ship main diesel engine using the theory of semi-markovian and markov processes.
PublicationTo precisely determine the task it is necessary to specify also its duration time, apart from conditions in which it will be realized. When considering propulsion engine, i.e. the main element of ship propulsion system, especially important becomes not only the problem which amount of energy could be at one's disposal but also within which time interval it could be delivered. Therefore apart from applying the commonly used reliability...
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Analysis and Experimental Verification of Improving the EEDI of a Ship using a Thruster Supplied by a Hybrid Power System
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Influence of cathodic-protection-induced hydrogenation on mechanical properties of two ship hull plate steels
PublicationPrzedstawiono wyniki próby rozciągania i udarowej Charpy V dla stali zwykłej wytrzymałości (kategorii A) i podwyższonej wytrzymałości (kat. AH32) zarówno w stanie dostawy jak i po nawodorowaniu (protektor Zn w słonej wodzie). Nawodorowanie obydwu stali zwiększyło nieco granicę plastyczności (Re) i wydłużenie (A), nie zmieniając (atal A) lub nieco zmniejszając przewężenie (Z). Wpływ nawodorowania na udarność był ewidentnie pozytywny...
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Assessment of operation of energy system of serial reliability structure on the example of ship main propulsion system
PublicationW artykule przedstawiono rozwinięcie znanej metody oceny działania systemu energetycznego, zastosowanej w odniesieniu do głównego układu napędowego statku. Według tej interpretacji działanie może być przedstawiane jako wielkość fizyczna. W tym aspekcie, na podstawie wybranego podsystemów funkcjonalnego statku, oceniono jej przydatność do opisu własności niezawodnościowych tego systemu. W analizie zastosowano teorię procesów Poissona,...
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A Fuzzy Event Tree Model for Accident Scenario Analysis of Ship Stuck in Ice in Arctic Waters
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