Search results for: SHIP CONTROL
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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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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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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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Synteza układu sterowania statkiem morskim dynamicznie pozycjonowanym w warunkach niepewności
PublicationNiniejsza monografia obejmuje zagadnienia związane z syntezą układu dynamicznego pozycjonowania statku w środowisku morskim z zastosowaniem wybranych nieliniowych metod sterowania. W ramach pracy autorka rozważała struktury sterowania z zastosowaniem wektorowej adaptacyjnej metody backstep oraz metod jej pokrewnych, takich jak regulatory MSS (ang. multiple surface sliding), DSC (ang. dynamic surface control), NB (ang. neural backstepping)....
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A methodology for ultimate strength assessment of ship hull girder accounting for enhanced corrosion degradation modelling
PublicationThe presented work shows a methodology for the ultimate strength assessment of a ship hull, considering enhanced corrosion modelling. The approach is based on the classical Smith method. However, the recent findings regarding the impact of corrosion degradation on ultimate strength are incorporated. To this end, the stress–strain relationships for particular elements composing ship hull cross-section are modified using a specially...
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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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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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A ship domain-based model of collision risk for near-miss detection and Collision Alert Systems
PublicationThe paper presents a new model of ship collision risk, which utilises a ship domain concept and the related domain-based collision risk parameters. An encounter is here described by five variables representing: degree of domain violation (DDV), relative speed of the two vessels, combination of the vessels’ courses, arena violations and encounter complexity. As for the first three variables, their values can be directly computed...
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Simplified approach to assess the dynamic response of a container ship subjected to bow slamming load
PublicationSimplified approach to assess the dynamic response of a container ship subjected to the bow slamming load, resulting in a transient vibratory response, typically called a 'whip-ping', is presented. The accurate numerical modelling is very complex and involves cou-pling of the hydrodynamic and structural solution at every time step, leading to huge com-putational and workload cost. Thus, the one-way coupling methodology is adopted,...
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Scale effect in the self-propulsion prediction for Ultra Large Container Ship with contra-rotating propellers
PublicationThis article addresses the problem of the scale effect for an Ultra Large Container Ship (ULCS) with a novel twin-crp-pod propulsion system. Twin-crp-pod steering-propulsion arrangement is an innovative solution that gains from three well-known systems: twin-propeller, contra-rotating propellers and pod propulsors. It is expected that applying the twin-crp-pod system to the analysed Ultra Large Container Ship will increase propulsion...
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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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Steam turbine as the main ship propulsion. More than a hundred years at sea.
PublicationPrzedstawiono rys historyczny rozwoju okrętowych turbin parowych. Omówiono główne rozwiązania konstrukcyjne podstawowych elementów parowych siłowni turbinowych i współczesne tendencje i perspektywy rozwoju tego napędu.
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Strength deterioration of 26H2MF and 34HNM steels used in ship engines: hydrogen factor
PublicationBadano podatność stali 26H2MF i 34HNM poddanych różnej obróbce cieplnej na niszczenie wodorowe. Badania wykonano metodą powolnego rozciągania z szybkością 10-6 s-1. Określano wytrzymałość, wydłużenie, przewężenie i energię zniszczenia. Stwierdzono znaczna degradację w 0,01 M kwasie siarkowym z dodatkiem arszeniku. Wykazano istnienie korelacji między obróbką cieplną i stopniem degradacji. Efekty przypisano pułapkowaniu wodoru.
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ADOPTED ISOCHRONE METHOD IMPROVING SHIP SAFETY IN WEATHER ROUTING WITH EVOLUTIONARY APPROACH
PublicationThe paper is focused on adaptation of an isochrone method necessary for application to a weather routing system with evolutionary approach. Authors propose an adaptation of the isochrone method with area partitioning assuring that the route found by the adopted method would not cross land. In result, when applied to a weather routing system with evolutionary approach, this proposal facilitates creation of initial population, resulting...
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Wieloźródłowy model pola elektrycznego okrętu = Multisource model of ship electric field
PublicationW pracy przedstawiono wieloźródłowy model pola elektrycznego okrętu. Wieloźródłowy model stanowi układ źródeł prądowych o określonych położeniach.
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Acoustic Emission Monitoring of Structural Elements of a Ship for Detection of Fatigue and Corrosion Damages
PublicationUszkodzenia korozyjne i pęknięcia zmęczeniowe są głównymi przyczynami defektów strukturalnych we wszystkich środkach transportu takich jak statki, cysterny drogowe i kolejowe. Oba typy degradacji tzn. degradacja materiału i konstrukcji są przedmiotem badań przeprowadzanych w projekcie badawczym VII Programu Ramowego Unii Europejskiej o nazwie ''Monitorowanie efektywnych kosztów korozji i zmęczenia w środkach transportu'' (akronim...
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Evolutionary Sets of Cooperating Trajectories in Multi-Ship Encounter Situations - use cases
PublicationPrzedstawiono tu zalety nowego, proponowanego przez autora podejścia do sytuacji spotkań wielu statków na morzu. Podejście to polega na zastąpieniu ewolucyjnej trajektorii własnej ewolucyjnym zbiorem trajektorii wszystkich obiektów. Umożliwia to predykcję manewrowania obiektów obcych przy jednoczesnym zachowaniu efektywności algorytmów ewolucyjnych. Zaprezentowano kilka sytuacji nawigacyjnych należących do różnych kategorii spotkań...
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Structures for parameterization, meshing and data exchange of topologically related surfaces of a ship hull
PublicationThis paper presents proposal of data structures for storage and processing of a parametric three-dimensional model of a midship hull sections. The model consists of coarse surfaces like: decks, frames, girders, stiffeners, brackets, partitions etc. bounded by topological relations. All workshop details are omitted as the model is intended for numeric calculations. Proposed data structures are prepared to facilitate changes in the...
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Loads of ship main diesel engine in the aspect of practical assessment of its operation
PublicationW artykule przedstawiono koncepcję metody pozwalającej na ocenę działania silnika pracującego na obciążeniu częściowym. Do określenia istniejącego zapasu parametrów użytkowych silnika oraz związanych z degradacją jego stanu technicznego dodatkowych kosztów ponoszonych przez użytkownika wykorzystane zostało wartościujące (ilościowe) ujęcie działania interpretowanego jako pewna wielkość fizyczna.
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Predicting Thrust Loss of Ship Propellers Due to Ventilation and Out-of-Water Effect
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A method for detecting possible near miss ship collisions from AIS data
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Modeling the risk of ship grounding—a literature review from a risk management perspective
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Sea Captains’ Views on Automated Ship Route Optimization in Ice-covered Waters
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Toward a hybrid model of ship performance in ice suitable for route planning purpose
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Comparative analysis of selected design variants of propulsion system for an inland waterways ship
PublicationW pracy zaprezentowano założenia projektowe i wstępną analizę porównawczą dwóch wariantów napędu śródlądowego statku pasażerskiego. Pierwsze rozwiązanie to wariant z przekładnią elektryczną, drugie natomiast, to wariant z przekładnią hydrostatyczną.
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Vortex cavitation as a source of high level acoustic pressure generated by ship propellers
PublicationPraca przedstawia wyniki badań teoretycznych i eksperymentalnych nad mechanizmami fizycznymi generowania wysokiego ciśnienia akustycznego przez kawitujące wiry wierzchołkowe powstające na śrubach okrętowych
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A new deterministic method of finding safe ship trajectory for any convex domain
PublicationW artykule wprowadzono nową deterministyczną metodę wyznaczania bezpiecznej trajektorii statku dla sytuacji spotkania z wieloma obiektami obcymi i dla dowolnej zadanej domeny. Jej prostota i fakt, że minimalizuje ona liczbę manewrów czynią ją dobrą alternatywą dla obecnie stosowanych metod. Metoda jest przedstawiona tak, aby mogła być bezpośrednio zastosowana w pokładowych systemach antykolizyjnych lub w systemach VTS.
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A method for selection of parameters of ship propulsion system fitted with compromise screw propeller
PublicationArtykuł dotyczy algorytmicznej metody wstępnego doboru parametrów układu napędowego okrętu wyposażonego w śrubę o skoku stałym, gdy eksploatacja okrętu związana jest z istotnymi zmianami: głębokości i szerokości drogi wodnej, oporu kadłuba i prędkości marszowej. Argumentami modelu matematycznego rozważanego zagadnienia projektowego są identyfikowane na etapie projektowania wstępnego główne parametry projektowe okrętu. Struktura...
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Possibility of defining of the average loads of main propulsion on the basis of ship design parameters.
PublicationZaprezentowano możliwość określania zależności między mocą holowania wybranych typów statków a średnim obciążeniem napędu głównego podczas pływania swobodnego. Przedstawione badania umożliwiają wyznaczenie średnich obciążeń napędu głównego podczas pływania swobodnego przy wykorzystaniu parametrów projektowych statku zawartych w założeniach armatorskich.
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Relation ship between electron scattering grand total and ionization totalcross section.
PublicationZaproponowano funkcję wiążącą całkowity przekrój czynny i jonizacyjny przekrój czynny na rozpraszanie elektronów na prostych drobinach węglowodorowych i perfluorowanych. Posługując się znalezioną relacją wyznaczono przekroje czynne dla kilku związków fluoru i wodoru.
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Selected problems of planning machinery and devices location in a ship´s engine room.
PublicationPrzedstawiono podstawowe zasady rozplanowania maszyn i urządzeń w przedziale maszynowym na statku. Podano warunki i kryteria wpływające na proces projektowania rozmieszczenia maszyn i urządzeń w siłowni. Przedstawiono główne warunki i zasady dotyczące rozplanowania głównego układu napędowego, elektrowni, kotłowni pomocniczych oraz innych instalacji siłownianych.
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A new method of ship routing on raster grids, with turn penalties and collision avoidance
PublicationArtykuł przedstawia nowy algorytm znajdowania optymalnych tras na siatkach rastrowych. Szczegółowo opisano zastosowane struktury danych, dzięki którym algorytm ma liniową złożoność obliczeniową. Na podstawie algorytmu opracowano metodę wyznaczania tras dla statków, uwzględniającą kwestie unikania kolizji z innymi statkami i przeszkodami nawigacyjnymi.Przedstawiono dwa warianty metody, dedykowane odpowiednio systemom pokładowym...
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Evaluation of Response Amplitude Operator of Ship Roll Motions Based on the Experiments in White Noise Waves
PublicationEvaluation of the response amplitude operator (RAO) function for ship wave frequency motions by means of scale model tests in regular waves is a standard procedure conducted by hydrodynamic model testing institutions. The resulting RAO function allows for evaluating sufficiently reliable seakeeping predictions for low to moderate sea states. However, for standard hull forms, correct prediction of roll motion in irregular wave (and...
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Magnetic signature reproduction of ferromagnetic ships at arbitrary geographical position, direction and depth using a multi-dipole model
PublicationThe reproduction of magnetic signatures is an important issue concerning the safety of ship traffic, as well as the identification and classification of vessels. Moreover, military applications of magnetic signatures and their reproduction refer to the activation or protection against activation of magnetic naval mines. Previous works on this subject focused on recording and replicating the signatures under the same conditions...
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The sensitivity of bacteria to heavy metals in presence of mineral ship motor oil in coastal marine sediments and waters.
PublicationThe sensitivity of bacteria, isolated from coastal marine sediments and waters of Sopot beach, Gdańsk Bay (Poland), to heavy metals in the presence of mineral ship motor oil were studied. All isolated heterotrophic bacteria were resistant to the 0.1 mM lead concentration occurring in the environment. Metal resistance of bacteria isolated from coastal water was strongly related to mineral ship motor oil concentration. At 0.1% mineral...
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A multiparameter simulation-driven analysis of ship turning trajectory concerning a required number of irregular wave realizations
PublicationIn times of progressive automation of the marine industry, accurate modeling of ship maneuvers is of utmost importance to all parties involved in maritime transportation. Despite the existence of modern collisionavoidance algorithms using 6DOF motion models to predict ship trajectories in waves, the impact of stochastic realization of irregular waves is usually neglected and remains under-investigated. Therefore, herein, this phenomenon...
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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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Data fusion of GPS sensors using Particle Kalman Filter for ship dynamic positioning system
PublicationDepending on standards and class, dynamically positioned ships make use of different numbers of redundant sensors to determine current ship position. The paper presents a multi-sensor data fusion algorithm for the dynamic positioning system which allows it to record the proper signal from a number of sensors (GPS receivers). In the research, the Particle Kalman Filter with data fusion was used to estimate the position of the vessel....
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Evolutionary sets of safe ship trajectories with speed reduction manoeuvres within traffic separation schemes
PublicationIn the previous paper the author presented the evolutionary ship trajectory planning method designed to support Traffic Separation Schemes (TSS). This time the extensions of this method are described which allow to combine evolutionary trajectory planning with speed reduction manoeuvres. On TSS regions with higher than usual density of traffic and smaller distances between ships, the course alterations alone are not always sufficient...
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TIME-DOMAIN NUMERICAL EVALUATION OF SHIP RESISTANCE AND MOTION IN REGULAR WAVES BY USING THE CFD URANS METHOD
PublicationTaking into account the International Maritime Organisation’s (IMO) strategy to radically reduce the GHG emitted by the shipping industry towards zero emission operation, today's assessment of ship behaviour in waves, its seakeeping characteristics and resistance and their interrelation with fuel consumption and emissions are one of the most attended research subject. There are three methods to conduct this analysis, which are...
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Methods of determination of C coefficient for period of rolling vessel in calm water for example of pax cargo ship
PublicationThis article presents a different approach to calculate the C coefficient needed to determine the period of own rolling vessel in calm water. The C coefficient is usually adopted as the approximate value from the available literature, usually depending on the type of vessel, and less dependent on the loading condition. In experimental studies of marine properties (seakeeping) often have a problem with the selection of the correct...
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An attempt to create a digital reconstruction of the Copper Ship = Próba cyfrowej rekonstrukcji kadłuba wraku Miedziowca
PublicationThis study presents an attempt to create a digital reconstruction of the W-5 shipwreck (the Copper Ship) based on data acquired by 3D scanning of structural components held at the National Maritime Museum in Gdańsk and on a physical reconstruction model of the ship’s hull. A digital reconstruction would facilitate analysis of various possible options for the structural design of the hull, and would enable the preparation of a model for...
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Full-scale CFD simulations for the determination of ship resistance as a rational, alternative method to towing tank experiments
PublicationResults of ship resistance predictions obtained from towing tank experiments are affected by the method used to extrapolate from a model scale to a ship scale. Selection of method to determine a form factor is subjective and the extrapolation method is accurate for typical hull forms. For innovative hull forms the proper method for calculating the form factor is questionable. Moreover, the influence of the extrapolation method...
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Comparison of selected parametric methods for prediction of inland waterways ship hull resistance in towing tank test
PublicationIn the paper selected approximate methods for calculation of inland waterways ship resistance and their verification by towing tests, compared on the example of a small urban ferry, are presented. The test results are made for both the bare hull and the hull with appendages (skeg, azimuthal propeller). Significant differences between results of the theoretical methods and experimental ones, especially in the case of the model with...
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The influence of the geographic positioning system error on the quality of ship magnetic signature reproduction based on measurements in sea conditions
PublicationIn previous studies, the authors performed the magnetic signature reconstruction of the marine ship Zodiak as part of the measurement campaign focused on recording magnetic data and the relative position of a ship during its passage over a magnetometer immersed on the testing ground. A high degree of representation of the magnetic signature was obtained. However, the recorded measurement data revealed new patterns of the multidipole model...
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PREDICTION OF SHIP MOTIONS IN IRREGULAR WAVES BASED ON RESPONSE AMPLITUDE OPERATORS EVALUATED EXPERIMENTALLY IN NOISE WAVES
PublicationThe most common methods for predicting ship roll motions in a specified sea state are direct measurements of motions in a representative irregular wave realisation (time domain) or calculations of motions from response amplitude operators (RAOs) in the frequency domain. The result of the first method is valid only for the tested sea state, whilst the second method is more flexible but less accurate. RAO-based predictions are calculated...
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Experimental Comparison of Straight Lines and Polynomial Interpolation Modeling Methods in Ship Evolutionary Trajectory Planning Problem
PublicationPaper presents the application of evolutionary algorithms and polynomial interpolation in ship evolutionary trajectory planning method and its comparison to classic approach, where trajectory is modeled by straight lines. Evolutionary algorithms are group of methods that allows\ to find a collision free trajectory in real time, while polynomial interpolation allows to model smooth trajectory, which keeps continuity of velocity...
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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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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....