Autor: Szczepanik, R. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Early detection of fatigue cracks in turbine aero - engine rotor blades during flight
Autorzy:: Szczepanik, R.
Powiązania:: https://bibliotekanauki.pl/articles/245961.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: aero-engines
diagnostic of aircraft engine
non-contact blade-vibration measurement
damage to the aircraft
Opis:: The author shows results of research done in the Air Force Institute of Technology concerning design, development and implementation of modern diagnostic systems for aero-engines. The papers gives brief description of a project of a new advanced monitoring system basing on non-contact blade-vibration measurement. Recent monitoring systems for engines offer a great potential to reduce the high maintenance costs of aircraft while increasing reliability and safety. These systems check for abnormal engine responses to detect failures, saving lives and reducing secondary damage to the aircraft. A phenomenon of dynamic change of an aero-engine compressor blades natural frequency in course of fatigue cracks propagation in their roots on the example of a Polish turbojet engine is described. On the ground of this phenomenon main working principles of a device, which measures vibrations of turbine engine rotor blades with application of the noninterfering discrete method (MDPh), used for early detection of first stage compressor blade cracks are discussed. Typical representation of the first stage compressor blades vibration during engine acceleration, representation of the first stage blades vibration during engine acceleration and deceleration with steady-state stator distortions, crack initiation and propagation symptoms in blades, comparison of blade vibration spectra of the same blades for different conditions are presented in the paper.
Źródło:: Journal of KONES; 2013, 20, 1; 337-342
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Investigation of the dynamic properties of engine fan titanium rotor blades in a high manoeuvrability aircraft in FOD aspect
Autorzy:: Szczepanik, R.
Powiązania:: https://bibliotekanauki.pl/articles/244435.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: aircraft
combustion engines
turbine engines
engine diagnostic
blades
Opis:: A current problem concerning the use of military and civilian aircraft is the damage caused to turbine compressor blades by ‘foreign objects’. Here the term ‘foreign objects’ means small stones, pieces of metal, cement pitch, asphalt, etc., left on runways and taxiways. Foreign objects also include ice and iced lumps of snow as well as birds sucked into aircraft engine air ducts. All such objects pose a serious threat to proper engine operation. They are very harmful in two respects. One is the direct danger during flight when a bird or some other object is sucked into the engine. The other danger is in what might occur in later flights if the engine, especially the compressor and turbine blades, are not inspected for durability reassessment. This paper presents an analysis of how the size and distribution of defects on blade edges affect, the frequencies and fatigue strength of titanium blades in the first four stages of a high manoeuvrability jet engine fan (low pressure compressor). In particular, damaged high manoeuvrability aircraft fan stage rotor blades and measured natural vibration frequencies and logarithmic decrement of damping of high manoeuvrability aircraft fan titanium blades are presented in the paper.
Źródło:: Journal of KONES; 2013, 20, 2; 371-376
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Analysis of 1st stage compressor rotor blade stress and vibration amplitudes in one-pass jet engine
Autorzy:: Szczepanik, R.
Powiązania:: https://bibliotekanauki.pl/articles/244813.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: diagnostics of aircraft engines
compressor blade dynamics
Opis:: This paper considers 1st stage compressor blade dynamics in the one-pass jet engines of trainer aircraft. Research was carried out on an engine test bench using the SAD system and its results were compared with those obtained using the tensometric approach. In this paper presented basic dynamic properties of rotor blades, bench test of rotor blade dynamics, Bench tests of the dynamic behaviour of blades subjected to external impacts and then Comparison of strain gauge and SAD tip-timing results. Then discusses the results of tests assessing the accuracy of the 1987 ITWL device by comparing strain gauge signals with those recorded by SAD apparatus in a running engine. It also presented simultaneous vibration readings of all the rotor blades at selected rotation speeds. Also shows that increased stress in these blades may be due to repeated engine surges, normal and hot engine surges, entry into the engine of a foreign object. Among others selection and layout of rotor blades in the 1st stage of a one-pass engine compressor, stress amplitudes for rotor blade, stress in rotor blade, stress amplitudes, free inlet flow and smooth engine acceleration, vibration amplitudes, asynchronous vibrations are presented in the paper.
Źródło:: Journal of KONES; 2013, 20, 4; 441-450
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Examination of the dynamic properties of 1st stage rotor blades in one - pass engine compressors under operating conditions
Autorzy:: Szczepanik, R
Powiązania:: https://bibliotekanauki.pl/articles/242705.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: diagnostics of aircraft engines
compressor blade dynamics
Opis:: This article includes studies of vibration and stress amplitudes in the Is' stage rotor blades of jet trainer one-pass engine compressors before and after refurbishment in operating conditions. The presented results were obtained using SAD-2 blade vibration amplitude registering and measuring apparatus. The same tests were carried on the same one-pass engine after modernisation. Example oscillograms from the vibration tests of the 16 blades are shown in this article, where show the vibrations of three randomly selected one-pass engines after refurbishment (marked 1, 2 and 3) out of a total of 50 engines. The engine vibration spectra cover the full rotation speed range. The difference between the vibration amplitudes of 1st stage rotor blades, in one-pass engine compressors before and after the refurbishment, is results from the difference in how the blades were attached to the disc. Before modernisation the hammer-type root was used, whereas after refurbishment dovetail-type fittings were applied. Furthermore, it was confirmed that there is nocoupling via the blade disc occurred when the blades were arranged on the disc according to the sinusoidal order of their free vibration frequencies. In such cases recorded vibration amplitudes remain within the average range (from 100 to 120 MPa in terms of stress).
Źródło:: Journal of KONES; 2013, 20, 3; 395-404
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Studies on unsteady operation of a turbojet engine and an intake channel of a supersonic aircraft
Autorzy:: Kowalski, M.
Szczepanik, R.
Powiązania:: https://bibliotekanauki.pl/articles/244953.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: stall in the intake channel
Opis:: The paper explains how to analyse possible disturbances in the intake air stream and their impact on engine operation. The introduction outlines possible reasons that induce disorders in the intake air stream. Then the substantial differences in operational characteristics between a centrifugal and an axial compressor are enlightened. The phenomenon of an unsteady compressor, referred to as the compressor stall, is explained through presentation of the process phases when air stream detaches from the surfaces of the compressor blades. Then the paper presents how disturbances in the air stream propagate down subsequent stages of the engine compressor with the emphasis on the fact that the air stream is not able to affect the full height of blades but usually only a portion of them. In addition, the mechanism of the unsteady operation of the engine (compressor) is presented on the graph that shows fuel consumption Q as a function of the engine rpm n. Attention is drawn to the fact that the phenomenon of the engine unsteady operation is associated with the so called rotating areas of air detachments that revolute in the same direction as the engine rotor itself but their rotation speed is lower than the rotor rpm. Consequently, flame downstream the area of detachment may go out for a moment and then quickly reappear, since air is kept supplied at quite high rates. If the foregoing process fails to go in phase with the rotating areas of air detachment, it may even lead to a total flameout of the engine. Then the unsteady operation of the intake channel is discussed in details, as it is frequently mismatched with the compressor stall. The mechanism of the phenomenon origination and the consequences it entails is presented with adequate details by means of appropriated graphs. In addition, the paper explains the phenomenon of beats in the intake channel, which is a result of detachment of the wall-adjacent layer of air flow just downstream the perpendicular shock wave in the intake channel. The effect of beats frequency often leads to the engine stall. The paper ends up with conclusions, in which it is emphasized that studies on the phenomenon and familiarity with the process are extremely important for the safety of flights.
Źródło:: Journal of KONES; 2014, 21, 2; 143-151
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: The rate of decohesion of a gas turbine blade as assessed with the X-ray computed tomography (CT)
Autorzy:: Chalimoniuk, M.
Szczepanik, R
Błachnio, J.
Powiązania:: https://bibliotekanauki.pl/articles/242103.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: gas turbine
blade
maintenance status
diagnosing
X-Ray computer tomography (CT)
composite materials
Opis:: The overheating of the material is among major reasons for failures/damages to gas turbine blades throughout the entire process of operating aircraft turbine engines. The essential method of diagnosing condition of the blades is metallographic examination being however a destructive technique. The paper has been intended to discuss one of non-destructive testing (NDT) methods, i.e. the X-ray computed tomography (CT), and capabilities of applying it to diagnose changes in condition of gas turbine blades. ‘Tomography’ is a comprehensive term to define a set of diagnostic techniques to produce three-dimensional images that present cross-sections through detail items under scrutiny. The CT is a transmission diagnostic technique that allows layered models (images) of details to be acquired. Most commonly, it is used in research laboratories and throughout the process of the product quality inspection. The paper delivers findings of the preliminary investigation into the assessment of health/maintenance status of gas turbine blades by means of the X-ray computed tomography. The results gained have been successfully verified using the metallographic examination techniques. It has been found that the radiographic imaging method enables recognition of types, sizes, and locations of internal faults in the blades while generating three-dimensional images thereof. Presented are capabilities of the high-resolution X-ray inspection machine with computed tomography (CT), V/tome/x, furnished with a 300 kV tube, and the CT data processing capabilities of the VG Studio Max software solution, high-performance CT reconstruction included (using an optional module). At the same time work is under way with the X-ray tube for nanotomography with the 0.5 m resolution to examine, in particular, modern composite materials.
Źródło:: Journal of KONES; 2013, 20, 3; 89-96
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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