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Wyszukujesz frazę "Girtler, J." wg kryterium: Autor


Tytuł:
A concept of determining the relation between load and wear of tribological systems of ship main selfignition engines by using probabilistic approach
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/258580.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
combustion engine load
probability
stochastic process
self-ignition engine
random variable
statistical relation
stochastic relation
Opis:
This paper presents a proposal of simultaneous consideration of load and wear associated with it , of tribological systems of ship main engines (intended for ship propulsion) . Based on results of investigations it was assumed that both the load Q (i.e. a cause of wear ) and the wear Z (i.e. an effect of load occurrence) considered in a given time t (0 ≤ t ≤ tn) are random variables Qt and Zt ,respectively. There was characterized operational principle of ship main engines in definite external conditions (WZ) as well as consequences of excessive load of engines. Three hypotheses highlighting relations existing between load and wear of the above mentioned systems, have been proposed. The first of them deals with explanation of stochastic relation between load and wear, the second highlights why it is possible to assume that the load Qt and the wear Zt are positively correlated , and the third – why it is possible to assume that coefficient of correlation between Qt and Zt may be taken close to one.
Źródło:
Polish Maritime Research; 2018, 4; 130-138
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physical aspects of application and usefulness of semi-Markovian processes for modelling the processes occurring in operational phase of technical objects
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/259227.pdf
Data publikacji:
2004
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
technical object
semi-Marcovian process
tribological unit
wear
Opis:
In the paper usefulness of semi-Markovian processes for modelling real processes which occur in the operational phase of various technical objects, is considered. The usefulness of this theory was proved by presenting specific features of the semi-Markovian processes and physical aspects of their use as models of the processes occurring in the operational phase of the objects in question. The specific features were described with taking into account the process of changing the technical states of such objects. The physical aspects of models in the form of semi-Markovian processes were justified by postulating a hypoŹthesis by which wear process of tribological units of crucial sub-assemblies of machines, can be explained. Also, the consequences logically resulting from the hypothesis and necessary to its verification, are discusŹsed. A method for its verification is also attached. It was proved possible to model the real processes in question by means of the continuous semi-Markovian processes of finite set of states.
Źródło:
Polish Maritime Research; 2004, 3; 25-30
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model of fuel combustion process in the marine reciprocating engine work space taking into account load and wear of crankshaft-piston assembly and the theory of semi-Markov processes
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/259557.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
engine load
marine internal combustion engine
probability
semi-Markov process
crankshaft-piston assembly
Opis:
The article analyses the operation of reciprocal internal combustion engines, with marine engines used as an example. The analysis takes into account types of energy conversion in the work spaces (cylinders) of these engines, loads of their crankshaft-piston assemblies, and types of fuel combustion which can take place in these spaces during engine operation. It is highlighted that the analysed time-dependent loads of marine internal combustion engine crankshaftpiston assemblies are random processes. It is also indicated that the wear of elements of those assemblies resulting from their load should also be considered a random process. A hypothesis is formulated which explains random nature of load and the absence of the theoretically expected detonation combustion in engines supplied with such fuels as Diesel Oil, Marine Diesel Oil, and Heavy Fuel Oil. A model is proposed for fuel combustion in an arbitrary work space of a marine Diesel engine, which has the form of a stochastic four-state process, discrete in states and continuous in time. The model is based on the theory of semi-Markov processes.
Źródło:
Polish Maritime Research; 2016, 3; 50-57
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Features of load and wear of main propulsion devices on sea-going ships with piston combustion engines and their impact on changes in technical states of the systems
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/259714.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
load
reciprocating internal combustion engine
seagoing ship
propulsion system of a ship
wear
Opis:
The paper presents the specificity of operation of propulsion systems of seagoing ships which causes the need to control the load on them, especially on their engines called main engines. The characteristics of the load on the propulsion systems, especially on the main engines as well as on the shaft lines and propellers driven by the engines, along with the process of wear in tribological joints (sliding tribological systems) of the machines have been described herein. Using examples of typical types of wear (both linear and volumetric) for the tribological systems of this sort, interpretation of states of their wear has been provided with regards to the wear levels defined as acceptable, unacceptable and catastrophic. The following hypotheses have been formulated: 1) hypothesis explaining necessity to consider the loads on the systems under operation as stochastic processes; 2) hypothesis explaining a possibility of considering the processes as stationary; and 3) hypothesis explaining why it can be assumed that a given technical state of any tribological system can be considered as dependent only on the directly preceding state and stochastically independent of the states that existed earlier. Accepting the hypotheses as true, a four-state continuous-time semi-Markov process has been proposed in the form of a model of changes in condition of a propulsion system (PS) of any ship. The model includes the most significant states affecting safety of a ship at sea, such as: s0 – PS ability state, s1 – PS disability state due to damage to the main engine (ME), s2 – PS disability state due to damage to the shaft line (SL) and s3 – PS disability state due to damage to the propeller (P). Probability of occurrence (changes) of the states has also been demonstrated.
Źródło:
Polish Maritime Research; 2017, 4; 57-66
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of damages of tribological associations in crankshaft and piston systems of two-stroke internal combustion engines used as main propulsion in sea-going vessels and proposal of probabilistic description of loads as causes of these damages
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/259908.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
probability
friction associations
crankshaft and piston system
semi-Markov process
marine internal combustion engine
wear
Opis:
The article discusses damages of essential tribological associations in crankshaft and piston systems of large power two-stroke engines used as main engines, which take place during transport tasks performed by those ships. Difficulties are named which make preventing those damages impossible, despite the fact that the technical state of engines of this type is identified with the aid of complex diagnostic systems making use of advanced computer technology. It is demonstrated that one of causes of the damages is the lack of research activities oriented on recognising random properties of the loads leading to those damages. A proposal is made for the loads acting at a given time ton tribological associations in crankshaft and piston systems of internal combustion engines used as main engines to be considered as random variables Qt. At the same time the loads examined within a given time interval tr ≤ t ≤ tz would be considered stochastic processes {Q(t): t ≥ 0}. Essential properties of the loads of the abovementioned tribological associations are named and explained by formulating hypotheses which need empirical verification. Interval estimation is proposed for estimating the expected value E(Qt) of the load Qt acting at time t. A relation is indicated between the mechanical load and the thermal load acting on tribological associations in the ship main engine crankshaft and piston system. A suggestion is formulated that a stochastic form of the relation between these types of load is to be searched for, rather than statistic relation, and a proposal is made to measure the intensity (strength) of the stochastic relation using the Czuprow’s convergence coefficient.
Źródło:
Polish Maritime Research; 2015, 2; 44-54
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Probabilistic concept of defining the situations possible to occur during operation of floating docks
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/260295.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
floating dock
safety
model
reliability
technical object
semi-Markov process
technical state
Opis:
In this paper possibility to assess safety of floating docks as a result of application of the theory of semi-Markov processes both in the phase of their designing and operating, is outlined. Formal description of the situations which may occur during service of floating docks both those intended for building and repairing the ships, was presented. The following situations were distinguished : normal, complicated, hazardous, emergency and disastrous. A model of changing the distinguished situations was proposed in the form of a semi - Markov process with discrete set of states, and continuous with time. The mentioned situations are values of the process. An operational safety measure for dock was formulated in the form of the probability of the event consisting in occurrence of normal or complicated situation. It was proved that assessment of probability of occurrence of particular situations is possible.
Źródło:
Polish Maritime Research; 2005, S 1; 34-38
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A probabilistic concept of assessment of amount of noxious substances contained in exhaust gas emitted from self-ignition engines
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/260405.pdf
Data publikacji:
2006
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
engine start-up
self-ignition engine
noxious substance
Opis:
A probabilistic concept of toxicity assessment of exhaust gas emitted from self-ignition engines was presented. Without such assessment it is not possible to determine pro-ecological merits of various transport means driven by self-ignition engines, including inland waterways passenger ships. In the concept a model of starting-up process of self-ignition engines was taken into consideration. The model was presented in the form of a semi-Markovian process, discrete in states and continuous during service. The states of the process are : the cold engine state (s1 ), warm engine state (s2) and hot engine state (s3 ). It made it possible to determine probabilities of the starting-up of engines from its particular states. For determination of mass of noxious substances contained in exhaust gas it is necessary to know the probabilities. Usefulness of the model in assessing amount of the noxious substances results from that during the starting-up of such engines many noxious substances are produced.
Źródło:
Polish Maritime Research; 2006, S 2; 33-37
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model of occurrence of the situations endangering inland waterways passenger ships and the environment
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/260408.pdf
Data publikacji:
2006
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
inland waterways ship
prediction of failure probability
availability indices of ship devices
Opis:
In this paper a four-state semi-Markov model of occurrence of the situations endangering inland waterways passenger ships, is presented. The model was elaborated in the form of the semi - Markov process, values of which are kinds of the states interpreted as the following situations : normal, complicated, hazardous and emergency. An example of realization of the process of changing the situations possible to occur during trips of inland waterways passenger ships, is presented. Also, formulae are attached, which make it possible to determine probabilities of occurrence of the mentioned situations during ship trips. The formulae were interpreted as safety measures of operation of inland waterways ship. Possibility of performing statistical investigations which could provide data for determining the mentioned probabilities was also stated.
Źródło:
Polish Maritime Research; 2006, S 2; 38-42
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method for evaluating theoretical and real operation of diesel engines in energy conversion formulation taking into account their operating indices
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/260600.pdf
Data publikacji:
2011
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
operation
energy
diesel engine
ship’s main engine
Opis:
The article proposes valuating the operation of an arbitrary diesel engine, based on the sample case of a ship’s main engine in which energy conversion processes take place in a given time. The above operation is understood as the energy transfer to the screw propeller in the given time in which the energy conversion into work and/or heat and its further transmission take place. The here proposed method for evaluating the operation of the main engines installed in marine power plants consists in comparing the operation of these engines to a physical quantity the measuring unit of which is the joule-second (joule×second). A new term is introduced which bears the name of the theoretical engine operation and is the standard (ideal) operation which can be compared to the operation of real engines revealing different levels of wear. It was shown that the calculations of the theoretical operation defined in the above way cannot make direct use of commonly known theoretical Diesel and Sabathe cycles. Instead they should use the cycles modified by heat abstraction taking place in accordance with the isobaric, or isothermal process. Other new terms introduced in the article are: the degree of excellence of energy conversion to work, considered as the measure of excellence of engine operation, and the degree of engine operation dissipation, being the measure of its real operation. It is shown that if in time t of engine operation the case takes place that: Li = idem and Le = idem, then the engine operation dissipation is equal to its mechanical efficiency.
Źródło:
Polish Maritime Research; 2011, 3; 31-36
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of theory of semi-Markov processes to determining distribution of probabilistic process of marine accidents resulting from collision of ships
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/260618.pdf
Data publikacji:
2014
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
critical manoeuvre
port
probability
semi-Markov process
sea-going ship
Opis:
In this paper is presented possible application of the theory of semi-Markov processes to elaborating an eight-state model of the process of occurrence of serviceability state and unserviceability states of sea-going ships making critical manoeuvres during their entering and leaving the ports. In the analysis it was taken into account that sea-going ships are in service for a very long time t (t → ∞). The model was elaborated to determine the probability (P0) of correct execution of critical manoeuvres during ship’s entering and leaving the port as well as the probabilities Pj(j = 1, 2, 3, …, 7) of incorrect execution of critical manoeuvres by a ship, that leads to marine accidents. It was assumed that such accidents result from: ship’s grounding on port approaching fairway, collision with a ship on port approching fairway, collision with a pierhead during passing through port entrance, collision with a hydrotechnical structure during ship’s passing through port channels, collision with a port quay during coming alongside it and collision with a ship already moored to the quay. The probability (P0) was assumed a measure of safe execution of a critical manoeuvre. The probability characterizes possibility of avoiding any collision during ship’s entering and leaving the port. The probability Pa = 1 – P0 was assumed a measure of occurrence of a collsion and - consequently - marine accident. The probability Pa was interpreted as a sum of the probabilities Pj(j = 1, 2, 3, …, 7) of occurrence of all the selected events. In summing up the paper, attention was drawn to its merits which - in opinion of this author - are crucial for research on real process of accidents during entering the port and leaving it by sea-going ship in difficult navigation conditions.
Źródło:
Polish Maritime Research; 2014, 1; 9-13
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A semi-Markov model of fuel combustion process in a diesel engine
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/963463.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Opis:
A four-state model of the combustion process in working spaces (cylinders) of a diesel engine is presented in the form of a semi-Markov process, discrete in states and continuous in time. The values in this process are the states : s1, s2, s3, s4 corresponding to commonly accepted types of combustion in those engines, namely : s1 - the process state which corresponds to total (complete and perfect) combustion, s2 - the process state which corresponds to incomplete combustion, s3 - the process state which corresponds to imperfect combustion, and s4 - the process state which corresponds to both incomplete and imperfect combustion. It is also mentioned that proper use of diesel engines can secure a correct course of the combustion process, if it is properly attended and shaped. During this course the state s4 does not take place. Formulas are given which make it possible to determine the probability of staying of the combustion process in the above named states, along with the interpretation of the probability P1 = P(s1) as the probability of correct (reliable) engine operation.
Źródło:
Polish Maritime Research; 2007, S 1; 58-61
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Designing engine rooms of new generation ships realized within the framework of European research projects EUREKA - chosen questions
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/962810.pdf
Data publikacji:
2004
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship power plant
sea-going ship
reliability and safety
design
semi-Markovian process
Opis:
Importance of reliability and safety in the operation phase of engine rooms has been proven. A concept of designing engine rooms taking into consideration their reliability, safety i of functioning as well as ecological features has been proposed. The need for as well as the main principles of carrying out empirical research in particular ship design stages have been introduced. Possibilities of the use of the semi-Markov theory in designing engine rooms have been justified. Possibilities of formulation and importance of hypothesis in scientific research related to engine rooms of sea going and inland ships depending on their particular specific features have been introduced. Examples of such hypothesis and their verification methods have been given. Possibilities of the use of semi-Markov processes in optimization of the ship operation have been signalled.
Źródło:
Polish Maritime Research; 2004, S 1; 57-61
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A probabilistic concept of load assessmentof self-ignition engines
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/258922.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
hypothesis
load
self-ignition engine
stochastic process
Opis:
A proposal of probabilistic interpretation of loading process of self-ignition combustion engines, was presented. Probabilistic description of loading the engines was proposed with taking into account known parameters (indices) of their operation. It was demonstrated that instantaneous load of such engines can be considered a random variable. Attention was paid to the fact that the load can be taken as a multi-dimensional random variable. Engine load changes during its operation were considered as the loading process and presented in the form of a multi-dimensional stochastic process whose states are loads considered to be random variables. It was demonstrated that the loading process can be taken as the stochastic one of asymptotically independent incements, stationary and ergodic. Justification of the above mentioned features of the loading process is contained in the presented hypotheses. It was also demonstrated that in testing the load process of self-ignition engines stochastic relation between thermal and mechanical loading should be taken into account.
Źródło:
Polish Maritime Research; 2008, 2; 65-70
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The semi-Markov model of the process of appearance of sea-going ship propupsion system ability and inability states in application to determining the reliablity of these systems
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/259071.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
reliability
semi-Markov process
state of ability
state of inability
sea-going ship
ship propulsion system
Opis:
The article presents possible application of the theory of semi-Markov processes in creating the eight-state model of the process of appearance of the propulsion systems ability and inability states on sea-going vessels performing transportation tasks in a relatively long operating time t (t → ∞). The model has been proved to be able to be successfully used for determining the reliability of the abovementioned systems. The probability of faultless operation in time t was assumed the measure of system reliability. Operating situations of sea-going vessels were characterised, with special attention being paid to the fact that the loads of propulsion system components of these vessels are of random nature. These loads lead to damages which for this reason were also considered random events. It was also assumed that the damages provoke the appearance of states of inability of particular ship propulsion system components which means that these states are random events as well. The states of ability of a given ship propulsion system have been assumed to exist when all components of this system are in the state of ability. In case when at least one component is in the state of inability, the entire system is in the state of inability. Conditions were formulated for the reliability model of an arbitrary system to be able to be worked out in the form of the semi-Markov process. The need for the use of technical diagnostics in reliability examination of sea-going ship propulsion systems was indicated. In conclusions, certain qualities of the article were highlighted which are, in author’s opinion, of highest importance in reliability examination of sea-going ship propulsion systems.
Źródło:
Polish Maritime Research; 2013, 4; 18-24
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-Markovian models of the process of technical state changes of technical objects
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/259191.pdf
Data publikacji:
2004
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
model
technical object
semi-Marcovian process
technical state
Opis:
The most important problem of operation of all technical objects (devices) is the problem of rational (optimum) decision control of the process of technical state changes of the objects. Such control can be realized when a model of the process of technical stale chanŹges is applied. In view of this, a formal description of the operational process of technical objects was presented in this paper, as well as it was justified that the model of the process may be a semi-Markovian process of finite set of states. Examples of 4-and 3-state semiŹ-Markovian process were given as a model of the above mentioned process of state chanŹges of any device. Difficulties associated with forming such model, which arise from application of the theory of semi-Markovian processes, were indicated. Therefore the proposed model is the semi-Markovian process whose values are technical states occurring in the phase of operation of many technical objects of practical importance (e.g. combustion piston engines, turbines, displacement and rotary compressors, impeller pumps etc).
Źródło:
Polish Maritime Research; 2004, 4; 3-7
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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