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Wyszukujesz frazę "labyrinth seals" wg kryterium: Temat


Wyświetlanie 1-10 z 10
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:
The assessment of the calculation method for determining characteristics of one straight fin labyrinth sea
Autorzy:
Szymański, A.
Dykas, S.
Majkut, M.
Strozik, M.
Powiązania:
https://bibliotekanauki.pl/articles/175271.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
labyrinth seals
Computational Flow Dynamics (CFD)
seal
smooth
turbomachinery
leakage flow rate
Opis:
The method for the selection of a calculation scheme for the evaluation of the flow behaviour of labyrinth seal with one straight fin, against smooth wall, was presented. Experimental results were obtained from measurement data carried out on the in house, vacuum test section. The advantage of the test rig is a circular shape of the labyrinth specimen, providing similar shape to configuration operated in practise. In computational fluid dynamics study different types of mesh resolution were tested, with variable volume discretization in the area of a labyrinth fin tip. Moreover, a wide range of turbulence models basing on k-ε and k-ω, exploiting the (Reynolds Average Navier Stokes) scheme, for the flow pattern evaluation, were examined. All obtained results were compared with literature data, covering research conducted on similar configurations. The presented study shows challenges as well as the possibilities of calculation simplification and compares results obtained by means of simulations and experiment. The proposed method is characterised by excellent agreement of computational results with experiment data.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 134; 89-107
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of the calculation process related to labyrinth sealing with extraction
Autorzy:
Joachimiak, D.
Joachimiak, M.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/955282.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
maszyna wirnikowa
maszyna przepływowa
uszczelnienie
labyrinth seals
turbomachines
fluid-flow machines
method of calculation labyrinth seals
Opis:
The work presents a calculation process enabling one-dimensional numerical calculations of labyrinth sealing. A DSV program determines the thermodynamic parameters of gas in the sealing chambers with extraction. The influence of the sealing length upon the stability of a matrix solution of the system of equations with the use of Cond(C) parameter is analysed. Next, the operation of the software extended with a module that enables determination of the initial pressure p0, to which the assumed mass flow for a set geometry and sealing length would correspond is discussed. The work analyzes Cond(C) and initial pressure values for various sealing lengths with an assumed leak value. The work also compares the values of static pressures on the extraction plane, as obtained from the measurements, to theoretically calculated values. The calculations and comparisons were made for various heights of incomplete sealing fissures.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 4; 1057-1066
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research and CFD calculations based investigations into gas flow in a short segment of a heavily worn straight through labyrinth seal
Autorzy:
Joachimiak, D.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/258744.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth seals
turbomachines
fluid-flow machines
experiment
CFD
gas velocity
Opis:
Steam turbines are used as propulsion components in not only power plants but also on merchant and naval ships. The geometry of the steam turbine seals changes throughout the machine life cycle. The rate of deterioration of these seals, in turn, affects heavily the efficiency of the thermal machine. However, the literature overview does not provide any research reports on flow phenomena occurring in heavily deteriorated seals. The paper describes the course and results of investigations into a model straight through labyrinth seal composed of 4 discs, each with the slot height of 2 mm. The investigations have been conducted with air as the working medium. Changes of gas flow parameters due to wear were analysed. Based on the experimental data, more intensive leakage was observed as the result of the increased slot height. The static pressure distribution along the examined segment was measured. The experimentally recorded distribution differed remarkably from the theoretical assumptions. Another part of the experimental research focused on comparing the gas velocities at points situated upstream of the first and second seal disc. The velocity measurements were carried out using a constant temperature wire probe. This part of the investigations provided opportunities for analysing the influence of seal wear on gas flow conditions in the seal segment. The paper compares the results of the experimental research with those obtained using the CFX software. The presented results of velocity distributions provide a clear picture of the nature of the gas flow in the seal, which enables its analysis.
Źródło:
Polish Maritime Research; 2017, 2; 83-88
1233-2585
Pojawia się w:
Polish Maritime Research
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:
Comparison of results of experimental research with numerical calculations of a model one-sided seal
Autorzy:
Joachimiak, D.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/239985.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
labyrinth seals
turbomachines
fluid-flow machines
uszczelnienia labiryntowe
maszyny wirnikowe
maszyny przepływowe
Opis:
Paper presents the results of experimental and numerical research of a model segment of a labyrinth seal for a different wear level. The analysis covers the extent of leakage and distribution of static pressure in the seal chambers and the planes upstream and downstream of the segment. The measurement data have been compared with the results of numerical calculations obtained using commercial software. Based on the flow conditions occurring in the area subjected to calculations, the size of the mesh defined by parameter y+ has been analyzed and the selection of the turbulence model has been described. The numerical calculations were based on the measurable thermodynamic parameters in the seal segments of steam turbines. The work contains a comparison of the mass flow and distribution of static pressure in the seal chambers obtained during the measurement and calculated numerically in a model segment of the seal of different level of wear.
Źródło:
Archives of Thermodynamics; 2015, 36, 2; 61-74
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of fluid flow through the labyrinth seal
Autorzy:
Kaszowski, P.
Dzida, M.
Powiązania:
https://bibliotekanauki.pl/articles/175521.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
labyrinth seals
k-ǫ model
CFD calculations
fliud-flow machines
modeling
Opis:
Steam and gas turbines are essential to produce electricity. Since the launch of the first turbine in the world, there become a tendency to constantly achieve higher efficiency. There are many solutions to overcome losses in the working steam turbine. One of such methods is the use of seals. To determine thermodynamic parameters of steam, which prevail in the seal, we could use experimental methods or numerical calculations. Experimental researchs are too expensive and time consuming. Therefore, computational fluid dynamics (CFD) is increasingly used in the analysis of fluid flow through the labyrinth seal. The paper describes the results using CFD simulation software with the help of contained a computational k-ε model.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2015, 130; 57-69
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculations of labyrinth seals with and without diagnostic extraction in fluid-flow machines
Autorzy:
Kaszowski, P.
Dzida, M.
Krzyślak, P.
Powiązania:
https://bibliotekanauki.pl/articles/259462.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth seals
Fanno curve
diagnostic extraction
Opis:
Labyrinth seals are essential components of steam turbine unit constructions. Two types of labyrinth seals can be named, the first of which is the seal without diagnostic steam extraction, and the second – with extraction. The distribution of flow parameters along the packing is affected remarkably by the average seal clearance. The presence of diagnostic extraction leads to the equation system which is determinable and can be inversed to calculate the average seal clearance Si. Analysing the obtained results leads to the conclusion that the information about this parameter provides opportunities to monitor the current state of the packing in real time. The applied calculation procedure bases on the de Saint - Venant equation. The article also includes a brief description of both types of seals.
Źródło:
Polish Maritime Research; 2013, 4; 34-38
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the impact of mass flow extraction on the change of parameters in a labytinth seal using the Stodola method
Autorzy:
Kaszowski, P.
Dzida, M.
Powiązania:
https://bibliotekanauki.pl/articles/2073619.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth seals
Fanno curve
diagnostic extraction
Stodola
uszczelnienie labiryntowe
krzywa Fanno
ekstrakcja diagnostyczna
Opis:
Labyrinth seals are an important element of a steam turbine set design. The use of diagnostic extraction makes it possible to control the operation of a seal by providing information on the thermodynamic parameters along the length of the seal. Diagnostic extraction has a considerable impact on the change of the parameters, the amount of the extracted mass. This article describes the dependence of pressure in the clearance downstream of the extraction and in the chamber in which the extraction point is located, on the amount of the extracted steam. Relation between pressure and nominal seal clearance is discussed, which enables the control of the seal operation. The calculations of the seal operation parameters were performed using a method proposed by Stodola.
Źródło:
Journal of Polish CIMEEAC; 2016, 11, 1; 55--67
1231-3998
Pojawia się w:
Journal of Polish CIMEEAC
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza krytyczna metod obliczania uszczelnień labiryntowych w maszynach cieplnych wirnikowych
Autorzy:
Kaszowski, Paweł
Dzida, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2073538.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
labyrinth seals
fanno curve
zasada de Saint-Venanta
maszyny przepływowe
metody obliczeniowe
Opis:
Uszczelnienia labiryntowe są ważnym elementem budowy maszyn cieplnych wirnikowych. Istnieje wiele metod obliczeniowych, pozwalających określić parametry termodynamicznych gazu na długości dławnicy labiryntowej. W niniejszej pracy przedstawiona zostanie krytyczna analiza metod obliczania uszczelnień labiryntowych dostępnych w literaturze oraz przykładowe wyniki obliczeń wykonanych metodą wyznaczania linii Fanno i zasady De Saint–Venanta.
Źródło:
Journal of Polish CIMEEAC; 2019, 14, 1; 97--110
1231-3998
Pojawia się w:
Journal of Polish CIMEEAC
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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