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Wyszukujesz frazę "turbine seals" wg kryterium: Temat


Wyświetlanie 1-9 z 9
Tytuł:
Research into flows in turbine blade seals. Part III: Numerical calculations versus experiment
Autorzy:
Kosowski, K.
Stępień, R.
Piwowarski, M.
Badur, J.
Powiązania:
https://bibliotekanauki.pl/articles/1955750.pdf
Data publikacji:
2003
Wydawca:
Politechnika Gdańska
Tematy:
turbine seals
CFD calculations
experimental investigations
Opis:
Experimental and theoretical investigations of the pressure field in the shroud clearance were performed on a one-stage air model turbine of the impulse type. Measurements of pressure distribution were carried out for various rotor speeds and turbine loads. 3D calculations of flows in this turbine were performed using the FLUENT CFD code. The calculations were carried out for variants which had been measured experimentally. The experimental data have been compared to theoretical results obtained with 3D codes for turbomachinery calculations. The Sliding Mesh and Multiple Reference methods have given very similar results of average values of pressure distribution and the velocity field in the shroud clearance. These results correspond to the experimental data. The pressure pulsations were determined only by the Sliding Mesh method, and these results have also been compared with the experiment. Stage flow calculations carried by the Sliding Mesh method with a structural shroud mesh and with a minimum number of 2-2.5 million cells have given a range of non-stationary pressure pulsations corresponding to the experimental data.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2003, 7, 3; 329-336
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research into flows in turbine blade seals. Part II: Numerical analysis
Autorzy:
Stępień, R.
Kosowski, K.
Badur, J.
Powiązania:
https://bibliotekanauki.pl/articles/1955751.pdf
Data publikacji:
2003
Wydawca:
Politechnika Gdańska
Tematy:
turbine seals
CFD calculations
experimental investigations
Opis:
3D calculations of an axial model turbine of the impulse type were performed using the FLUENT CFD code. The calculations were carried out for variants which had been measured experimentally. Special attention was paid to the pressure field in the rotor blade shroud clearance. The Multiple Reference Frame method, the Mixing Plane method and the Sliding Mesh method were applied, and meshes of different types and configurations were used for calculations. Only the Sliding Mesh technique appeared to describe non-stationary effects and pressure pulsations in the turbine flow channels and clearances. In this part of the paper, numerical analysis is described, while the comparison between the experimental and the calculated results is presented in part III.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2003, 7, 3; 319-327
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research into flows in turbine blade seals. Part I: research methods
Autorzy:
Badur, J.
Kosowski, K.
Stępień, R.
Piwowarski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1955758.pdf
Data publikacji:
2003
Wydawca:
Politechnika Gdańska
Tematy:
turbine seals
CFD calculations
experimental investigations
Opis:
Flows in the shroud clearance affect leakage losses and, thus, the turbine stage efficiency. However, at the same time, the distribution of pressure in the seal gaps plays an important role in the generation of the so-called "pressure forces", which may cause self-excited rotor vibrations of the aerodynamic type. Our investigations were carried out in order to show how a CFD code can cope with determining the pressure field in a rotor-blade shroud clearance. Experimental investigations of the pressure field in the shroud clearance were performed on a one-stage air model turbine of the impulse type. Measurements of pressure distribution were carried out for various rotor speeds and turbine loads. 3D calculations of flows in the model turbine were performed using the FLUENT CFD code. The calculations were carried out for the same variants which had been measured experimentally. In this part of the paper, the experimental stand and the numerical methods are described, while a detailed numerical analysis and a comparison between the experimental and the calculated results are presented in parts II and III, respectively.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2003, 7, 3; 309-317
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effects of variable operational parameters on an aero engine labyrinth seals performance
Autorzy:
Szymański, A.
Dykas, S.
Majkut, M.
Strozik, M.
Powiązania:
https://bibliotekanauki.pl/articles/175364.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
labyrinth seals
experiment
turbomachinery
gas turbine
validation
Opis:
The paper presents the accurate assessment of the amount of gas flowing through three types of aero-engine expander sealing. Structures consisting of straight-through labyrinth seals – with one, two and three fins are considered. The study deploys two independent approaches. The first one focuses on the experimental research using high-precision test section with non-rotating labyrinth seals specimen connected to a high capacity vacuum installation. Experimentally tested seals are of actual size (model to engine scale is 1:1). High accuracy hot-wire anemometry probes, and orifice plate are deployed to evaluate the flow indicators accurately, allowing for comparison of different sealing structures. The second approach uses quasi-two-dimensional axissymmetric, steady-state Reynolds averaged Navier Stokes (RANS) computations to simulate the flow field. Various meshes and turbulence models were tested, presenting capabilities as well as limitations of specific computational approaches. The experimental and computational results were compared with literature data, showing a good agreement regarding overall trends, yet underlining some local discrepancies. This paper brings two significant findings. The 2D RANS methods tend to overestimate the leakage when compared with experimental results, and the difference is more significant for advanced arrangements. There is a notable difference between the performance of labyrinth seal with one fin and structure with two and three fins. In some operational areas, one-finned seal performs better than more advanced ones, reducing the leakage more effectively. This feature of one finned seal is not intuitive, as one would expect it to perform worse than a seal with two or three fins.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2018, 140; 83-104
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of leakage through labyrinth seals with analytical models
Autorzy:
Szymański, Artur
Dykas, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/1954459.pdf
Data publikacji:
2014
Wydawca:
Politechnika Gdańska
Tematy:
labyrinth seals
analytical methods
experiment
turbomachinery
gas turbine
validation
Opis:
Secondary flows in turbomachinery highly affect the overall efficiency and rotorstability. A prime example of such a phenomenon are leakage flows. Despite their complexity, they can often be estimated with simple semi-empirical formulae, solved with hand calculations.Such an approach is much more cost and time effective during the design process. The formula econsists of a carry-over coefficient and a discharge coefficient elements. To evaluate the leakage properly, an adequate model of the carry-over coefficient has to be developed. This paper presents how the flow conditions and the cavity geometry changes in a straight through labyrinth sea laffect the amount of leakage. The effect of the number of teeth, the gap size, the Reynolds number and the pressure ratio are considered. The data to validate the results was obtained from an in-house experiment, where a vast number of cases was tested. Additionally, the study was supported by a two-dimensional steady-state CFD study. Eleven analytical models, including both very simple as well as more sophisticated methods, were solved according to the experimental case and compared. Six different seal configurations were examined. They included straight through seals with two and three straight knives for various gap sizes.The comparison highlighted differences in the results for models – a certain group presented underestimated results. However, another group of models – presented an excellent agreement with the experimental data. Based on this study, a group of models representing the results within the 10% uncertainty band was selected.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2019, 23, 1; 61-73
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Remarks on aerodynamic forces in seals of turbine stages
Autorzy:
Stępień, R.
Kosowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/259359.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
rotor dynamics
self-excited vibrations
aerodynamic forces
blade seals
turbine shrouds
Opis:
This paper presents results of numerical examination of flow through over-shroud seals of turbine stages. Various labyrinth seals of different configurations and number of sealing teeth were considered. It was demonstrated that results of investigations of isolated seals cannot be directly used for analyzing turbine stage operation. Such approach may lead to relatively large errors in determining value of aerodynamic force and direction of its action.
Źródło:
Polish Maritime Research; 2009, S 1; 58-63
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the modelling of aerodynamic force coefficients for over-shroud seals of turbine stages
Autorzy:
Włodarski, W.
Kosowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/259389.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
rotor dynamics
self-excited vibrations
aerodynamic forces
blade seals
turbine shrouds
Opis:
This paper presents experimental investigations which made it possible to determine dynamic coefficients of labyrinth over-shroud seal of a model air turbine. The coefficients associate pressure forces with turbine rotor displacement, velocity and acceleration respective to turbine casing (linear model) and play important role in analyzing turbine-set dynamics. The obtained results indicated that involving serious errors can be expected in the case of application of the simplification consisting in neglecting inertia coefficients, proposed in the literature. It was simultaneously demonstrated that seals can be also met of weak damping qualities, for which to neglect damping coeffcients is allowable.
Źródło:
Polish Maritime Research; 2009, S 1; 71-74
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Checking the Correctness of the Process of Brazing of the Honeycomb Seal to the Base by Ultrasonic Method
Autorzy:
Świerek, Agata
Krysztofik, Józef
Matczak, Wojciech
Niepokólczycki, Antoni
Powiązania:
https://bibliotekanauki.pl/articles/24201175.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
turbine aircraft engines
honeycomb seals
hard soldering
non-destructive testing
soldering correctness control
Opis:
This work is focused on the checking of the correctness of the brazing process of honeycomb seals to stationary elements of aircraft turbine engines. It describes this process, paying attention to the aspects that have a fundamental impact on whether the seal will be brazed to the base as required, or whether unacceptable areas of non-brazing will appear. The aim of the study was to check the possibility of using the ultrasonic method to check the correctness of the brazing process of honeycomb seals and to compare the tests carried out using this method with the mostly used visual tests. The research carried out as part of the work showed very well that there are reasons to use the ultrasonic defectoscopy method to test the correctness of the brazing process of honeycomb seals in the elements of aircraft engines. This method also makes it possible to automate the checking process, fully document it and objectively assess the correctness of the connection. The results obtained in the study provide a very good starting point for further research, the aim of which will be to implement the ultrasonic defectoscopy method for testing the correctness of brazing honeycomb seals into practice in industrial conditions.
Źródło:
Fatigue of Aircraft Structures; 2022, 14; 47--68
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dystrybucja powietrza na potrzeby własne dwuprzepływowego silnika obrzutowego
Air system in a double spool engine
Autorzy:
Rowiński, A.
Powiązania:
https://bibliotekanauki.pl/articles/212480.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
lotniczy silnik turbinowy
uszczelnienia powietrzne
dystrybucja sprężonego powietrza w silniku
turbine engine
air seals
air distribution in a turbine engine
Opis:
W artykule przedstawiono problematykę dystrybucji sprężonego powietrza w silniku turbinowym. Sprężone powietrze pobierane jest z jednego lub więcej stopni sprężarki a i następnie rozprowadzane do komór powietrznych rozmieszczonych w różnych miejscach w silniku. Następnie jest wykorzystywane w celu kompensacji sił działających na wirnik, wymuszenia wymiany ciepła pomiędzy poszczególnymi z zespołami silnika w celu ochrony przed działaniem zbyt wysokiej temperatury na materiał konstrukcji oraz na sprężony i spieniony olej znajdujący się w instalacji. Ponadto umożliwia regulację luzów wierzchołkowego na łopatkach turbin poprzez kontrolowane chłodzenie elementów kadłuba i tym samym ich odkształcanie. System powietrzny zapewnia ogrzewanie elementów i zespołów silnika narażonych na obladzanie. Sprężone powietrze przepływa do komór powietrznych przez system kalibrowanych otworów. Ciśnienie i wydatek masowy przepływającego powietrza są kontrolowane poprzez uszczelnienia powietrzne umieszczone pomiędzy elementami wirnika a zespołami kadłuba. Przedstawiono metodykę obliczeń parametrów przepływów masowych powietrza w kanałach wewnętrznych silnika na przykładzie konstrukcji dwuprzepływowego silnika D-18 zaprojektowanego w Instytucie Lotnictwa.
The article presents the issue of compressed air distribution in a turbine engine. Compressed air flows from one or more stages of the compressor and then it its distributed to air chambers placed in many locations in the engine. Next, it is used to compensate the forces acting on the rotor and to impose the heat exchange in each assembly to protect the materials of which the assemblies are made as well as compressed oil and aerosol oil from high temperatures. Additionally, the air system regulates the top clearance of turbine blades by cooling the turbine case and protects the inlet case from icing. The compressed air is distributed to gas chambers by a system of calibrated holes. The pressure and mass flow of the air in the chambers is controlled by air seals. The methodology of the parameters of air mass flow in the engine internal ducts calculation is explained on the example of D-18 double-spool engine designed in the Institute of Aviation.
Źródło:
Prace Instytutu Lotnictwa; 2016, 3 (244); 393-402
0509-6669
2300-5408
Pojawia się w:
Prace Instytutu Lotnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

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