Autor: Zurek, J - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Analysis of the process of operating an aircraft from aspect of flight safety and effectiveness
Autorzy:: Żurek, J.
Powiązania:: https://bibliotekanauki.pl/articles/245779.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
air transport
durability
relibility
semi-Markov process
availability factor
Opis:: This paper presents the method of evaluation of a technical object as immersed in a logistic system with regard to its durability, the operational availability/readiness and the utilisation factor. These factors decide upon the object's effectiveness. For this evaluation probabilistic models from the theory of reliability and of the semi-Markov process were used. For the purpose of this paper as a technical object serves an aircraft. The process of operating an aircraft consists in using its resources to function accumulated during the process of its manufacture and resulting from a periodic regeneration of these resources in order to maintain its capability of being further operated. For the sake of better understanding our discussion we will refer to the sald 'flying craft' as an aircraft (including also other 'means of transport' into this notion). The paper in principle concerns on analysis of safe durability and aircraft availability/readiness analysis. The availability factor of an object in a logistic system expresses the prospective possibility of an effective action. The degree of utilisation of this „potential" for apassenger plane is represented by the occupancy factor. A product ctors of availability and occupancy can describe the overall effectiveness indicator, which characterises the availability and the market demand.
Źródło:: Journal of KONES; 2009, 16, 3; 527-536
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Experimental and numerical modelling of combustion process of liquid fuels under laminar conditions
Autorzy:: Żurek, J.
Jankowski, A.
Powiązania:: https://bibliotekanauki.pl/articles/950154.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engines
modelling of combustion processes
laser Doppler velocimetry
Phase Doppler
Laser Analyser
ANSYS Fluent
laminar bounduary layer
Opis:: The paper presents the results of experimental studies obtained in a special test stand, which was carried out with the addition of mass flow, summarizes the theoretical analysis of the phenomena occurring in the flow, and the calculations, which were performed using the modeling of flow in the channel. The two examples of model calculations for the two laminar Reynolds number values are shown. Paper presents: channel scheme for analyzing the flow arising as a result of adding mass, two-dimensional diagram of the computational domain with the mass addition, grid computing domain, two-component velocity field, the lines of current in the channel, the distribution of the vector field in the channel, the average velocity as a function of the distances, the speed and temperature distributions for each channel cross-sections for flow with various values of the Reynolds number. The increase in lateral velocity Vb , while maintaining constant lower speed Vd , decreases the thickness of the boundary layer, both the velocity and the thermal one, which was also referenced in experimental investigations, carried out on the special test rig, using LDV and PDPA laser techniques.
Źródło:: Journal of KONES; 2014, 21, 3; 309-316
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Analysis of the military vehicles operating process by means of Markov processes
Autorzy:: Żurek, J.
Borucka, A.
Ziółkowski, J.
Powiązania:: https://bibliotekanauki.pl/articles/245001.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: operation
Markov processes
military vehicles
Military Economic Units
Opis:: The article presents the method of analysing the operating process of Star military vehicles in their readiness aspect. The subject of research was the Military Economic Unit, recently created in the Polish Army. Markov processes were applied. A simple 5-state model was built, and the research was made in a discrete, as well as continuous time. The limit probabilities, both for the chain and the time, were estimated. Thanks to Chapman-Kołomogorov-Smoluchowski equations, the long-term projections could be estimated. To ensure of operating processes, correctly object’s permissible transitions from the previous state to the next one were chosen. It was defined based on technical documentation and owned operational knowledge on the considered operating process. The mathematical description of a set of permissible transitions includes a matrix of permissible Si → Sj transitions from the previous state Si (lines) to the next one. The five-state system has possible and forbidden transitions are presented. Graph of permissible transitions for the five-state operation model usage, standby, maintenance, repair, standstill in repair; correlogram for the average duration of the state; evolution of the probability of the Star cars’ staying in the state of usage, standby, maintenance, repair, standstill in repair are presented in the article.
Źródło:: Journal of KONES; 2016, 23, 2; 443-453
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: Dilatometric researches of novel alloy for combustion engine pistons
Autorzy:: Żurek, J.
Slawinski, Z.
Jankowski, A.
Powiązania:: https://bibliotekanauki.pl/articles/243032.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engine piston
composite alloy
piston sample elongation
hysteresis
piston clearance
Opis:: The article presents dilatometric research results of composite alloy (in-situ) for combustion engines piston. Researches were performed with a precise dilatometer. Alloy's research test stand and test results including relative elongation, course of derivative of dimension increasing versus time with phase transition and course of coefficient of linear thermal expansion α for composite alloy versus temperature are presented in the article. Novel composite alloy allows getting a minimum difference of the coefficient of linear thermal expansion α during heating and cooling. In particular, the chemical composition of the novel composite silumin alloys; ATD of standard alloy – silumin Ak12 and novel composite alloy; schema of research stand and view of the measuring-head of the extension; course of the coefficient of linear thermal expansion α versus temperature during heating and cooling for the standard alloy and novel composite alloy; course of the relative piston elongation ΔL/Lo versus temperature during heating and cooling for the standard alloy and novel composite alloy; course of the derived function of the extension in relation to time dL/dt versus temperature for the standard alloy on pistons and novel composite alloy; course of the relative elongation in function of time during ageing of composite alloy at the temperature of 200°C with two-stage ageing process; course of the relative elongation in function of time during ageing of composite alloy at the temperature of 200°C for the first stage and second stage are presented in the article.
Źródło:: Journal of KONES; 2016, 23, 3; 585-596
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: A method of estimating the risk of a catastrophic failure to engines rotating members as related to fatigue - an outline
Autorzy:: Tomaszek, H.
Żurek, J.
Jasztal, M.
Powiązania:: https://bibliotekanauki.pl/articles/243106.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: risk of failure
fatigue
load spectrum
probability density
stress intensity factor
Opis:: The paper has been intended to introduce a probabilistic method to estimate - from the standpoint of fatigue - the risk of a catastrophic failure to rotating (moving) members of an aircraft engine, i.e. to compressor blades. It has been assumed that there is a hidden defect in the material's structure, which initiates a small-size crack. Load-affected, the crack keeps growing. The crack propagation dynamics, when approached in a deterministic way, remains consistent with the Paris formula. The crack growth is effected by some random load characterised with the servicing load spectrum. While determining the load spectrum, all possible operational events are taken into account, excluding ones that could result in an immediate damage to the component. It has been assumed that random instances of load increase, which may result in an immediate damage, compose a separate set of events; hence, they have not been taken into account in this model. A partial differential equation of the Fokker-Planck type has been used to describe randomly approached dynamics of crack propagation. Having solved this equation enables a density function of the fatigue crack length to be found. This function, in turn, has been used to determine the risk of a catastrophic failure to a compressor blade. Furthermore, this function can also be used to find safe service life of the structure under consideration.
Źródło:: Journal of KONES; 2007, 14, 2; 505-511
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Informacja

Wyszukujesz frazę "Zurek, J" wg kryterium: Autor

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język