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1

An approach to modelling of gasdynamic processes in turbocharging system of marine four-stroke diesel engine

100%
Korczewski Z.
Polish Maritime Research
|
2002
|
tom 09
|
nr 3
2

Identification of servic failures of cylinder valves of ship piston combustion engines

100%
Korczewski Z.
Polish Maritime Research
|
2007
|
tom 14
|
nr 2
This paper presents selected diagnostic problems of charge exchange system of ship piston combustion engines. Theoretical background of wear process of cylinder valves was highlighted in the aspect of identification and sources of known and identifiable states of unserviceability. The presented results of endoscopic examinations concern failures of cylinder valves of the engines installed on Polish Navy ships
3

Statistical analysis of sea accidents and breakdowns in the Polish Navy

100%
Korczewski Z.
Polish Maritime Research
|
2008
|
tom 15
|
nr 1
This paper presents the results of systematic, statistical approach to naval accidents and breakdowns which occurred in the Polish Navy between years 1985 – 2004. Additionally, the author of this work has made an initial assessment of the human factor. Human errors, which appeared on considered warships in the examined period of time, have been analyzed in the overall number of accidents and breakdowns
4

Preliminary identification of gasdynamic processes in exhaust gas channel of pulsatory supercharging system of a marine diesel engine

100%
Korczewski Z.
Polish Maritime Research
|
2002
|
tom 09
|
nr 4
5

An overview of the didactic and scientific activity at the faculty of machanical and electrical engineering of the Polish Naval Academy

100%
Korczewski Z.
Polish Maritime Research
|
2007
|
tom 14
|
nr 4
The article characterises the didactic and scientific activity at the Faculty of Mechanical andElectrical Engineering of the Polish Naval Academy. The current didactic offer and the areas of current research work are presented, along with main characteristics expected from the naval-specialisation graduate majoring in mechanics and machinery construction, in the context of the Polish Navy technical staff education system. Discussed are the subjects of research activities initiated in particular Faculty units, and leading scientificproblemswhichhavebeenstudied for years within the field of widely understood utilisation of naval technology
6

Analysing the potential for application of the phase shift method in endoscopic examination of marine engines

100%
Korczewski Z.
Polish Maritime Research
|
2013
|
tom 20
|
nr 1
The article presents theoretical principles of image processing in digital endoscopy which makes use of a miniaturised spectral scanner “PhaseProbe” designed by General Inspection Technologies LP, the producer of the measuring videoendoscope Everest XLG3. The technology of optoelectronic 3D mapping of the examined surface, which consists in measuring the phase shift between the emitted and reflected light waves, is briefly described. The efficiency of the “PhaseProbe” based method of endoscope measurements is compared with the earlier developed methods, such as “ShadowProbe” and “LaserDots”, which were used by the author in real conditions of diagnostic investigations of engines in operation in marine power plants. The processed results of the endoscope analysis of the broken gas turbine engine rotor blades which were earlier dimensioned using the inspection probes of “StereoProbe”, “ShadowProbe” and “LaserDots” type and now are examined by the author with the aid of the phase shift method make a valuable complement and synthesis of the discussion presented in the article
7

Contemporary diagnostic methods for ship engines: a report on scientific research activity of Polish Naval Academy in this field

100%
Korczewski Z.
Polish Maritime Research
|
2008
|
tom 15
|
nr 2
This paper devoted to ship combustion engine diagnostics, presents short characteristics of experimental test techniques applicable to state assessment of piston and gas turbine engines presently being in use in Polish Navy. Some metrological and organizational aspects of realization of necessary diagnostic tests as well as measurements of control parameters of engines of low susceptibility to control, were highlighted. Such engines are installed a.o. on board American origin frigates of Oliver Hazard Perry type as well as Norwegian origin submarines of Kobben type which have been recently incorporated into Polish Navy (i.e.General Electric turbine engines, Detroit Diesel and Mercedes Benz piston engines), as well as older engines of Russian production (Zorya turbine engines, Zvezda piston engines). Applicability of particular diagnostic methods was also assessed from the point of view of their effectiveness in identifying engine failures in conditions of its operation in ship power plant. Recently realized tests have made it possible to conduct operation of all piston and turbine engines used on board Polish Navy ships in accordance with their current technical state. On the average 120-130 diagnostic expertises are yearly issued, and the carried-out tests cover main functional systems of engines together with their control and safety subsystems
8

Exhaust gas temperature measurements in diagnostics of turbocharged marine internal combustion engines. Part I. Standard measurements

100%
Korczewski Z.
Polish Maritime Research
|
2015
|
tom 22
|
nr 1
The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple. The first part of the article discusses possibilities to perform diagnostic inference about technical condition of a marine engine with pulse turbocharging system based on standard measurements of exhaust gas temperature in characteristic control cross-sections of its thermal and flow system. Selected metrological issues of online exhaust gas temperature measurements in those engines are discusses in detail, with special attention being focused on the observed disturbances and thermodynamic interpretation of the recorded measuring signal. Diagnostic informativeness of the exhaust gas temperature measurements performed in steady-state conditions of engine operation is analysed in the context of possible evaluations of technical condition of the engine workspaces, the injection system, and the fuel delivery process
9

Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines. Part II. Unsteady processes

100%
Korczewski Z.
Polish Maritime Research
|
2011
|
tom 18
|
nr 3
The second part of the article presents the results of operating diagnostic tests of a two- and three-shaft engine with a separate power turbine during the start-up and acceleration of the rotor units. Attention was paid to key importance of the correctness of operation of the automatic engine load control system, the input for which, among other signals, is the rate of increase of the exhaust gas flow temperature. The article presents sample damages of the engine flow section which resulted from disturbed functioning of this system. The unsteady operation of the compressor during engine acceleration was the source of excessive increase of the exhaust gas temperature behind the combustion chamber and partial burning of the turbine blade tips
10

Entropy function application in the selection process of diagnostic parameters of marine diesel and gas turbine engines

100%
Korczewski Z.
Polish Maritime Research
|
2010
|
tom 17
|
nr 2
The article presents the method of analysing the diagnostic informativeness of the parameters characterizing gas dynamic processes observed inside the working spaces of marine diesel and gas turbine engines. The entropy function was used as the measure of indeterminacy of the identified set of engine unserviceability states. Based on numerical simulation experiments of the analysed gasodynamic processes, the amount of introduced diagnostic information was assessed and the most adequate parameters for the technical state of the engine were selected. These parameters compose the minimised set of diagnostic parameters which make it possible to assess unmistakably the technical state of the examined working spaces
11

Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines. Part I. Steady-state processes

100%
Korczewski Z.
Polish Maritime Research
|
2011
|
tom 18
|
nr 2
The article presents a possible method of detecting failures in the flow section and supply system of a naval gas turbine engine based on the exhaust gas temperature measured behind the gas generator. This temperature is a basic diagnostic parameter use for evaluating the technical state of the turbine engine in operation, and is monitored during engine start-ups, accelerations and decelerations of rotor units, and steady-load states. The first part of the article is limited to the presentation of the results of diagnostic examination of a threeshaft engine with a separate power turbine, operating in steady-load states. The here presented diagnostic analyses and syntheses based on a simplified mathematical model of thermal and flow processes taking place in the combustion chamber, which was used for deriving the equation describing the average steadystate temperature of the exhaust gas flow at the outlet cross-section of the chamber
12

Application of expert systems in diagnostics, management and logistics

100%
Korczewski Z.
Polish Maritime Research
|
2008
|
tom 15
|
nr 3
There has been demonstrated base terms concerning expert systems and analysis of their organisation structure. Some possibilities of the expert knowledge codification worked out on the basis of different application of the object-attribute-value triplets have been presented as well.
13

Operational causes of fatigue failures within passages of gas turbine engines

100%
Korczewski Z.
Polish Maritime Research
|
2010
|
tom 17
|
nr 1
In this paper a short presentation of fatigue wear process of structural elements of gas turbine engines has been given. The primary causes of fatigue crack formation within engine mechanical system and flow passages have been highlighted. Special attention was paid to low-cycle fatigue associated with unsteady heat-and-gas-flow processes developed in the passages. The selected damages have been demonstrated of gas flow paths of the engines operating in aviation, navy and power industry, along with origins of their formation and growth
14

Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines. Part III. Diagnostic and operating tolerances

100%
Korczewski Z.
Polish Maritime Research
|
2011
|
tom 18
|
nr 4
The third part of the article presents a method for detecting failures of the automatic engine control system with the aid of an exhaust gas temperature setter, specially designed and machined for this purpose. It also presents a procedure of identifying the operating tolerances and determining the diagnostic tolerances for the exhaust gas temperature recorded in the naval turbine engine during the start-up and acceleration processes. The diagnostic tolerances were determined using the statistic inference, based on the hypothesis about the normal distribution of the starting exhaust gas temperature dispersion at the initial time of engine operation. The above hypothesis was verified using the non-parametric statistic test χ2 for examining the consistency of the empirical distribution with the assumed normal distribution. As a result of the examination, satisfactory convergence of the compared distributions was obtained which made the basis for assuming the three-sigma limits of the diagnostic tolerance for the analysed engine control parameter
15

Exhaust gas temperature measurements in diagnostics of turbocharged marine internal combustion engines. Part II. Dynamic measurements

100%
Korczewski Z.
Polish Maritime Research
|
2016
|
tom 23
|
nr 1
The second part of the article describes the technology of marine engine diagnostics making use of dynamic measurements of the exhaust gas temperature. Little-known achievements of Prof. S. Rutkowski of the Naval College in Gdynia (now: Polish Naval Academy) in this area are presented. A novel approach is proposed which consists in the use of the measured exhaust gas temperature dynamics for qualitative and quantitative assessment of the enthalpy flux of successive pressure pulses of the exhaust gas supplying the marine engine turbocompressor. General design assumptions are presented for the measuring and diagnostic system which makes use of a sheathed thermocouple installed in the engine exhaust gas manifold. The corrected thermal inertia of the thermocouple enables to reproduce a real timehistory of exhaust gas temperature changes
16

A method to assess transverse vibration energy of ship propeller shaft for diagnostic purposes

100%
Korczewski Z.
Polish Maritime Research
|
2017
|
tom 24
|
nr 4
The article discusses a key problem of ship propulsion system vibration diagnostics, which concerns assessing this part of mechanical energy transmitted from the main engine to the ship propeller which is dissipated due to propeller shaft vibration. A simplified calculation model is proposed which allows the total energy of the generated torsional vibration to be assessed from the shaft deflection amplitude measured at the mind-span point between the supports. To verify the developed model, pilot tests were performed on the laboratory rotational mechanical system test rig. In those tests, cyclic bending moment was applied to a unified (cylindrical) material sample, which modelled, at an appropriate scale, structural and functional properties of a real propeller shaft
17

Examination of the fuel supply system of a naval gas turbine in operation

100%
Korczewski Z.
Polish Maritime Research
|
1999
|
tom 06
|
nr 2
18

Energy analysis of propulsion shaft fatigue process in rotating mechanical system. Part I. Testing significance of influence of shaft material fatigue excitation parameters

63%
Korczewski Z., Marszalkowski K.
Polish Maritime Research
|
2018
|
tom 25
|
nr Special Issue S1
The article discusses the problem of mathematical modelling of energy conversion processes in a rotating mechanical system for the purpose of identifying fatigue states of propulsion shafts in this system. A simplified physical model of the analysed system, constructed in an appropriate scale, has made the basis for the experimental research. The research programme took into consideration mechanical fatigue excitation of the model propulsion shaft to find the correlation between the dynamic system load generated by a bending moment and the energy state of a specified shaft segment. A physical model of the analysed process was proposed, for which the plan of static randomised block experiment was worked out. The recorded experimental results were used for statistical analysis of the significance of influence of the quantities exciting the propeller shaft fatigue process and the adequacy of the developed mathematical model describing shaft’s durability. The analysis made use of the F-Snedecor test. The article describes the general concept of the research, the constructed laboratory test rig, and the methodology of statistical inference concerning the significance of influence of input (exciting) parameters of the physical model on the recorded output parameters. The results of the performed statistical tests confirm the absence of the significance of influence of the rotational speed of the propulsion shaft on the selected types of rotating operation of the mechanical system. As a consequence, only one exciting parameter, which is the loading mass, is going to be taken into account in the functional description of fatigue life of the propulsion shaft
19

Energy analysis of the propulsion shaft fatigue process in a rotating mechanical system. Part II. Identification studies – developing the fatigue durability model of a drive shaft

63%
Korczewski Z., Marszalkowski K.
Polish Maritime Research
|
2020
|
tom 27
|
nr 2
20

Approximation method of determining the analytical model of naval gas turbine axial compressor

63%
Korczewski Z., Olejniczak K.
Polish Maritime Research
|
1999
|
tom 06
|
nr 3
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