Wyniki wyszukiwania - BazTech

1

Limit wear of working parts of subsoil shanks with regard to their design solutions

Stawicki T.

Journal of Research and Applications in Agricultural Engineering

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2018

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Vol. 63, nr 1

115--120

EN

The report presents results of a 3D study of the contour and angles of subsoil shanks changes which develop due to wear caused by the soil during the ground cultivation. The results of 3D imaging were subject to the analysis aimed at the identification of the limit wear of the parts concerned. Significant differences were found in changes in the contour and angles of blades with regard to the design variants. The results of the study can indicate a need of further operation research to verify the suitability of certain variants of the blades exhibiting differences in terms of material and design.

PL

Przedstawiono wyniki badań 3D stanu geometrii dłut głębosza, który konstytuował się w następstwie zużyciowego oddziaływania gleby w warunkach uprawy polowej. Wyniki obrazowania 3D poddano analizie ukierunkowanej na identyfikację granicznego stanu zużycia badanych elementów. Stwierdzono, że występują istotne różnice w wywoływanych zużyciem zmianach geometrii dłut w zależności od ich wariantu konstrukcyjnego. Uzyskane wyniki badań stanowią przesłankę do wnioskowania o potrzebie realizacji badań eksploatacyjnych, jako niezbędnych dla weryfikacji przydatności użytkowej wariantów dłut głębosza, wykazujących różnice materiałowo-konstrukcyjne.

2

Polish experience from the operation of helicopters under harsh conditions

Przysowa R., Gawron B., Kułaszka A., Placha-Hetman K.

Journal of KONBiN

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2018

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No. 48

263--299

EN

The result of operating the military helicopters in a dusty environment is a loss of performance and premature failures of gas paths of the engines. The efficient protection of the power plant against dust ingestion is tough, especially in the desert. The article summarises the experience accumulated while operating the military helicopters under harsh conditions in Poland and during foreign missions. There were characterised the types of conducted missions, operated helicopters, protection methods of engines and common failures. It was stated that the performance of TV3-117 engines and their particle separation systems was insufficient in the mountains and on the desert (Iraq and Afghanistan). The deterioration of gas paths resulted in the loss of helicopters’ performance and substantially contributed to the few aircraft incidents. The experience gained during foreign missions is used in training the crews and ground personnel and in the programmes of modernisation and renewal of the helicopter fleet.

PL

Wynikiem użytkowania śmigłowców wojskowych w warunkach zapylenia jest zmniejszenie osiągów i przedwczesne uszkodzenia traktów gazowych silników. Skuteczna ochrona zespołu napędowego przed pyłem jest bardzo trudna, szczególnie w terenie pustynnym. W artykule zebrano doświadczenia z użytkowania śmigłowców wojskowych w trudnych warunkach w kraju i na misjach zagranicznych. Scharakteryzowano rodzaje wykonywanych misji, stosowane typy śmigłowców, metody ochrony silników i typowe uszkodzenia. Stwierdzono, że osiągi stosowanych silników rodziny TV3-117 i ich systemów odpylania były niewystarczające w warunkach górskich i pustynnych (misje w Iraku i Afganistanie). Deterioracja traktów gazowych silników spowodowała zmniejszenie osiągów śmigłowców i istotnie przyczyniła się do kilku incydentów lotniczych. Doświadczenia zdobyte w trakcie misji zagranicznych są wykorzystywane przy szkoleniu załóg i personelu technicznego oraz w programach modernizacji i wymiany floty śmigłowców.

3

Validation of selected presented method measured of length fatigue gap on compressor blades forming during resonant tests

Kuźniar M., Bednarz A., Lichoń D., Witek L.

Journal of KONES

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2017

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Vol. 24, No. 3

151--158

EN

In this work, the validation of selected presented method measured of length fatigue gap was shown. The article describes three methods of determining fatigue gaps. The object of the study was the first stage compressor blade from aircraft engine. Blades have defects on the leading edge. This defect on the blade (as a result of the resonance vibration) was the origin point of the fatigue gap. Two of the methods, fluorescent and thermovision, were optical. The fluorescent method was a direct measurement, whereas direct-indirect thermography. The last of the presented methods was an analytical method, showing an algorithm based on amplitude-frequency characteristics. The advantages and disadvantages of these methods were compared. As a result of the analysis performed by the algorithm, there were specified patterns defining the dependence of change in crack length depending on the asymmetry of AF characteristics. The accuracy of the following methods and the results obtained for chord length were determined. Thanks to such use, these results have a utilitarian meaning. Such a compilation allowed us to evaluate the usefulness of particular measurement methods. Proposed methods of measuring the length of fatigue crack are used in experimental studies. It is also possible to implement them for research conducted during the operation of an aircraft engine.

4

The computer - aided analysis of images to assess condition of gas turbine blades

Pawlak W., Błachnio J.

Journal of KONES

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2013

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Vol. 20, No. 3

299--306

EN

In order to guarantee reliable and safe operation of avionic turbo engine their components and subassemblies are subjected to regular inspections and maintenance. The most frequent reasons for failures of the engines include overheating of materials, thermal fatigue of blades and vanes in the jet subassembly as well as the gas turbine rotor. Failures of that type lead to faulty operation of the engine and sometimes to accidents with disastrous consequences. The decision to have the engine repaired is taken by maintenance personnel that chiefly employ the method of visual inspection with use of a videoscope. However, such examination of turbine components is burdened by a subjective approach. To improve reliability and trustworthiness of the examinations results it is necessary to enable objective and unbiased evaluation of examination results. This paper outlines a non-destructive method that is suitable for evaluation of condition demonstrated by gas turbine blades and is based on digital processing of images acquired from the blade surface in visible light. To enable high clearness of these images the particular attention is paid to the problem of how to provide optimum conditions for investigations and mitigate geometrical distortions of images acquired from maintenance operations. The paper demonstrates that there are relationships between operation lifetime of blades and discoloration of their surfaces due to overheating of the blade material. These relationships are revealed by digital analysis of images acquired for the blade surfaces and expressed as statistical parameter of the first and second order. To improve unambiguity of the analysis results a low-pass filter was applied. It was demonstrated that these relationships are suitable for evaluation how much the status of the blade material microstructure is altered. Results from this study enable formulation of the conclusion that diagnostics of gas turbine blades through computer-aided analysis of images acquired from the blade surfaces may even be possible under field conditions with no downtime of the equipment under tests.

5

Investigation of the dynamic properties of engine fan titanium rotor blades in a high manoeuvrability aircraft in FOD aspect

Szczepanik R.

Journal of KONES

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2013

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Vol. 20, No. 2

371--376

EN

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.

6

Rozwiązanie konstrukcyjne uniwersalnego mieszadła turbinowego o zmiennej średnicy, liczbie i kącie pochylenia łopatek

Wesołowski P., Pawłowicz M., Alejski K.

Przemysł Chemiczny

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2011

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T. 90, nr 9

1698-1701

7

Teoretyczne i doświadczalne badania ruchu cząstek materiału na łopatkach wentylatora w rozdrabniaczu DZ-4P

Romaniuk W., Savinych P., Turubanov N.

Problemy Inżynierii Rolniczej

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2011

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R. 19, nr 2

117-124

PL

Przedstawiono wyniki teoretycznych i doświadczalnych badań pracy rozdrabniacza bijakowego wyposażonego w wentylator do zadawania i rozładunku paszy. Badano wentylatory wyposażone w łopatki o różnym kształcie i ustawieniu (proste ustawione promieniście i odchylone do tyłu oraz krzywoliniowe odchylone do przodu). Przedstawiono równania do wyznaczania miejsc kontaktu łopatek wentylatora z rozdrobnionymi cząstkami. Miejsca te podlegają zużyciu. Wykazano zgodność obliczeń teoretycznych i badań dotyczących miejsc zużycia łopatek o różnych kształtach i odchyleniu od promienia koła.

EN

Paper presents the results of theoretical and experimental studies on the work of hammer mill equipped with a fan for loading and unloading feedstuff material being ground. Fans with the blades of different shape and setting (the straight ones, set radially and inclined back, and the curvilinear, inclined forwards) were investigated. Equations were developed to determine contact places on the fan blades with particles of material being ground. Mentioned places are particularly liable to wear and tear. Compatibility of theoretical calculations with the results of experimental investigations was proved for wearing places on the fan blades of various shapes and deflection from circle radius.

8

Multistage coupling of eight mistuned bladed discs on a solid shaft with 1% mistuning

Maurin A., Rządkowski R., Drewczyński M.

Mechanics and Mechanical Engineering

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2011

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Vol. 15, nr 3

309-317

EN

Considered here was the effect of multistage coupling on the dynamics of a rotor consisting of eight mistuned bladed discs on a solid shaft. Free and forced vibrations were examined. In this study, the global rotating mode shapes of flexible mistuned bladed discs-shaft assemblies were calculated, taking into account rotational effects, such as centrifugal stiffening. The thus obtained natural frequencies of the blade, the shaft, the bladed disc, and the entire shaft with discs were carefully examined to discover resonance conditions and coupling effects.

9

Measurement of a Helicopter Main Rotor Composite Blade

Skalski P., Parafiniak M.

Machine Dynamics Research

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2011

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Vol. 35, No. 4

105-110

EN

The research presented in this paper focuses on a composite structure test. The object of the investigation is a blade from main rotor of the IS-2 helicopter. The basic methodology which is used is the Experimental Modal Analysis (EMA). The EMA technique is an established tool for the identification of dynamic properties of structure. Based on the experimental data collection, dynamic properties of a research object were estimated. The modal parameters have been estimated using PolyMAX - module of LMS Test.Lab software.

10

Testing of a Composite Blade

Skalski P.

Acta Mechanica et Automatica

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2011

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Vol. 5, no. 4

101-104

EN

The research presented in this paper focuses on the investigation of helicopter composite blade. The object of tests is a blade from main rotor of the IS-2 helicopter. The author describes briefly basic elements of composite blade manufactured at the Institute of Aviation in Warsaw. The composite blade was investigated by the Experimental Modal Analysis (EMA) to evaluate dynamic properties of tested structure. Based on the experimental data collection, dynamic properties of a research object were estimated. The modal parameters have been estimated using PolyMAX - module of LMS Test.Lab software.

11

Rapid prototyping process of monocrystal aircraft engine blades

Budzik G., Matysiak H., Cygan R., Bąk S., Cygnar M.

Journal of KONES

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2010

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Vol. 17, No. 1

81-86

EN

The article presents process application of the rapid prototyping (RP) for manufacturing of blades of aircraft turbine in mono- crystallization and also directional crystallization of casting process. It is describing the method of modelling of the chosen elements of casting model kit with the usage of RP and RT systems. The article presents the analysis of additive rapid prototyping methods (stereolithography) in an aspect of manufacturing of casting models. The possibilities of RP system usage to the ceramic form were the main criteria of the analysis. The ceramic form is a one of the parts of process casting of monocrystal blade of aircraft engine. In the article the possibilities making of models by means of rapid tooling system based on the Vacuum Casting (VC) technology were also analysed. The Vacuum Casting technology allows producing the silicone mold under decreasing pressure. Silicone tools allow creating wax casting models as a vacuum casting process, casting process and Iow pressure of injection. Rapid prototyping and rapid tooling technologies allow creating casting wax models of a blade and other parts of casting models. RP and RT methods allow creating connectors of the parts. These connectors allow connecting the parts of model kit in a fast and simple method. The stereolithography and Vacuum Casting allow accelerating process of manufacturing of monocrystal blades of aircraft engines.

12

Rapid prototyping process of monocrystal aircraft engine blades

Budzik G., Matysiak H., Cygan R., Bąk S., Cygnar M.

Journal of KONES

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2009

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Vol. 16, No. 4

23-28

EN

The article presents process application of the rapid prototyping (RP) for manufacturing of blades of aircraft turbine in mono- crystallization and also directional crystallization of casting process. It is describing the method of modeling of the chosen elements of casting model kit with the usage of RP and RT systems. The article presents the analysis of a additive rapid prototyping methods (stereolithography) in an aspect of manufacturing of casting models. The possibilities of RP system usage to the ceramic form were the main criteria of the analysis. The ceramic form is a one of the parts of process casting of monocrystal blade of aircraft engine. In the article the possibilities making of models by means of rapid tooling system based on the Vacuum Casting (VC) technology were also analysed. The Vacuum Casting technology allows producing the silicone mould under decreasing pressure. Silicone tools allow creating wax casting models as a vacuum casting process, casting process and low pressure of injection. Rapid prototyping and rapid tooling technologies allow creating casting wax models of a blade and other parts of casting models. RP and RT methods allow creating connectors of the parts. These connectors allow connecting the parts of model kit in a fast and simple method. The stereolithography and Vacuum Casting allow accelerating process of manufacturing of monocrystal blades of aircraft engines.

13

Aspekty metrologiczne bezdotykowego diagnozowania wirujących łopatek sprężarki

Witoś M., Kowalski M.

Biuletyn Wojskowej Akademii Technicznej

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2008

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Vol. 57, nr 2

289-299

PL

Przedstawiono podstawy teoretyczne stosowania elastycznego znacznika fazy - wirującej i drgającej łopatki sprężarki - do kompleksowego diagnozowania turbinowego silnika lotniczego (metoda tip timing). Wskazano na rolę numerycznych metod analizy w rozdzieleniu składowych sygnału pomiarowego (aperiodycznej i oscylacyjnej) oraz potrzebę weryfikacji istniejących algorytmów analizy danych, pochodzących z nierównomiernego próbkowania. Omówiono 15-letnie spostrzeżenia eksploatacyjne stosowania metody na samolotach TS-11 "Iskra".

EN

The paper presents theoretical background of using elastic key phasor-rotating and vibrating compressor blade - for complex jet engine diagnosis (tip timing method). The role of numerical methods of measurement signal decomposition onto parts (aperiodic and oscillation) is pointed. It also shows the need of existing algorithms (from irregular sampling) verification. Fifteen years' service knowledge of using mentioned method aboard T-11 "Iskra" is presented.

14

Analiza modalna łopatek jako metoda badań nieniszczących

Witoś M., Zalewski J.

Biuletyn Wojskowej Akademii Technicznej

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2008

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Vol. 57, nr 2

327-338

PL

Omówiono wpływ komputeryzacji stanowiska prób zmęczeniowych na nowe możliwości badawcze i niezawodność remontowanych silników. Przedstawiono wybrane wyniki z laserowego badania właściwości modalnych stalowych i tytanowych łopatek sprężarki osiowej. Omówiono możliwość eksperckiej oceny stanu technicznego łopatek, obejmującej nie tylko detekcję otwartego pęknięcia, ale również identyfikację fazy umocnienia i osłabienia materiału pióra.

EN

The influence of digitalization of fatigue testing stand on experimental possibilities and reliability of overhauled engines has been discussed. Chosen data from laser determination of axial compressor blades modal characteristics (steel and titanium alloys) have been showed. The expert blade health diagnostics method has been described. It includes not only open-crack detection but also material strengthening and weakening phase

15

Kształtowanie fragmentów łopatek turbin parowych za pomocą wycinania elektroerozyjnego

Poroś D., Zaborski S.

Inżynieria Maszyn

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2007

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R. 12, z. 1

103-112

PL

W przedstawionym artykule badania realizowano na nowoczesnej, obrabiarce wyposażonej w napędy liniowe tj. wycinarce elektroerozyjnej firmy Sodick model AQ 327L. Opisany proces odnosi się do obróbki zamków łopatek turbin parowych, służących do mocowania łopatek do wirnika. Problemem przy zastosowaniu WEDM (Wire electrical discharge machining) do obróbki łopatek turbin parowych jest ograniczenie głębokości warstwy zmienionej termicznie (HAZ Heat affected zone). Ograniczenie takie ma na celu wyeliminowanie mikropęknięć powierzchni mających inicjujący wpływ na powstawanie uszkodzeń zamków łopatek podczas eksploatacji turbiny. Praca stanowi propozycję zastąpienia tradycyjnych metod obróbki zamków łopatek przez WEDM, a przez to eliminację problemów takich jak np. konieczność nadzorowania zużycia narzędzia.

EN

This paper presents method for the unconventional machining of the blades of steam turbines. Blade material as steel X12Cr13 was chosen into the investigation, which provides an enhanced understanding on the effect of material machining to reduce the corrosion fatigue damage of blades. Blade failures in gas turbine engines often lead to loss of all downstream stages and can have a dramatic effect on the availability of the turbine engines. Conventional machining of the locks of steam turbine blades causes high temperature and rapid wear of tool which makes machining expensive. The presented experimental study was carried out on a modern wire EDM Sodick AQ327L. Brass CuZn37 type of the wire was used. Investigated were: the effects of WEDM of steel X12Cr13 as the Heat Affected Zone, the micro-fractures and surface roughness parameters

16

Finite element computational dynamics of rotating systems, an addendum (A bibliography (1998-2004))

Mackerle J.

Computer Assisted Mechanics and Engineering Sciences

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2006

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Vol. 13, No. 2

323-349

EN

Gives a bibliographical review of the finite element analyses of rotating systems from the theoretical as well as practical points of view. The bibliography lists references to papers, conference proceedings and theses/dissertations that were published between 1998-2004. It is a continuation of the author's earlier bibliography with the same title published in Shock Vibration 6 (1999) 209-222 where papers published between 1994-1998 are listed. At the end of this paper 479 references are listed.

17

Species macroelements' content and distribution in selected grass

Radkowski A., Grygierzec B.

Chemia i Inżynieria Ekologiczna

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2005

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Vol. 12, nr 8

865-869

EN

Distribution of macroelements' content in certain parts of plants was presented. Three grass species were studied: Poa pratensis Eska 40, Festuca pratensis Skawa, Festuca rubra Brudzyńska, in which average content of total-N, P, K, Ca, Mg and Na in inflorescences, leaves and stems were compared. The investigations were conducted in 2001-2003 on degraded mould made from loess. The aim of this study was to determine which species of grass is the reachest in nutrients and where is the highest content of the particular macroelement. Usually leaves have bad the highest maeroelements' content but that tendency bas not been observed for all compounds. Inflorescences were the richest in phosphorus. Summarizing the leaves contained on average 40%, inflorescences - 31 % and stems - 29% of mineral compounds.

PL

Przedstawiono zróżnicowanie zawartości składników mineralnych w poszczególnych organach roślin. W doświadczeniu użyto trzy gatunki traw: Paa pratensis Skrzeszowicka (ESKA 40), Festuca pratensis Skawa i Festuca rubra Brudzyńska, w których porównano średnie zawartości N-ogólnego, P, K, Ca, Mg i Na w kwiatostanach, liściach i łodygach. Badania przeprowadzono w latach 2001-2003 na czarnoziemie zdegradowanym wytworzonym z lessu. Celem podjętych badań było określenie, który gatunek jest najzasobniejszy i gdzie jest największa zawartość poszczególnych makroelementów. Z reguły liście cechowały się największą zawartością składników, ale nie we wszystkich składnikach ta tendencja się utrzymywała. Fosforu najwięcej odnotowano w kwiatostanach. Reasumując liście zawierały średnio 40%, kwiatostany 31 %, a łodygi 29% składników mineralnych.

18

Numerical analysis of turbine blading vibrations

Vorobyev Yu. S., Tyshkovets O. V., Janecki S.

Transactions of the Institute of Fluid-Flow Machinery

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2003

|

nr 114

229-236

EN

Turbomachine blading vibrations are one of the most important problems. They are the reason for turbine damages. Numerical methods of vibration analysis are useful in prediction of the frequencies, the distribution and localisation of stress in blades. Accordingly, in this work numerical methods and results of computations are performed for various types of blading.

19

Influence of the blade length on natural frequencies and modes shapes of two bladed rigid discs on the shaft

Sokołowski J., Rządkowski R., Kwapisz L.

Transactions of the Institute of Fluid-Flow Machinery

|

2003

|

nr 114

177-190

EN

The dynamic behaviour of a rotor consisting of two bladed discs on a solid shaft is considered. The effect of shaft flexibility on the dynamic characteristics of the bladed discs and the coupling effects between the shaft and bladed disc modes are investigated. Results presented for various cases with differing blades flexibility show cleary the coupling effects in a bladed disc-shaft system. Calculated natural frequencies obtained from blade, shaft, bladed disc and shaft with two discs are checked to discover resonance conditions and the coupling effects. The calculations show the influence of the shaft on the natural frequencies of the bladed discs up to one nodal diameter frequencies. The torsional frequency of the shaft with two discs is coupled with the zero nodal diameters modes of the single bladed discs. The bending modes of the shaft are coupled with one nodal diameter modes of the bladed discs. It is shown that including the shaft in the bladed discs model is important from the designer's point of view and can change the spectrum of frequencies considerably.

20

High and low frequency excitations of the last stage rotor blades and shaft of the steam turbine 13K215

Rządkowski R., Gnesin V., Soliński M.

Transactions of the Institute of Fluid-Flow Machinery

|

2003

|

nr 114

123-132

EN

A three-dimensional numerical analysis for aerodynamic unsteady forces of the last stage steam turbine 13K215 rotor blades and total unsteady forces acting on the shaft from considered stage, have been presented. The numerical calculations were performed for different pressure distribution behind the rotor blades in circumferential direction (p2=6000, 7500, 9000, 7500 Pa). The analysis of the 3D transonic flow of an ideal gas through turbomachinery blade rows moving relatively one to another without takong into account the blades oscillations is presented. An ideal gas flow through the mutually moving stator and rotor blades with periodicity on the whole annulus is describrd by the unsteady Euler conservation equations, which are integrated using the explicit monotonous finite-volume difference scheme of Godunov-Kolgan and moving hybrid H-H grid. The algorithm proposed allows to calculate turbine stages with an arbitrary pitch ration of stator and rotor blades. The unsteady forces acting on the rotor blades in axial, tangential and radial directions were found. Due to non-uniform pressure distribution the low frequency excitation appeared. Values of the low frequency excitations are greater than the high frequency excitation caused by the stator blades. Next, the total unsteady forces acting on the shaft from all rotor blades in considered stage were calculated. Values of unsteady forces are very small in comparison to the single blade. The low frequency excitation disappeared. The high frequency excitation is depended on the number of rotor blades.