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Przegląd metod uszczelniania wirników turbin lotniczych

Przybyła B., Zapałowicz Z.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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2015

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z. 87 [291], nr 3

235--243

PL

W artykule przedstawiono najczęściej stosowane w praktyce sposoby przeciwdziałania przeciekom strumieni powietrza lub spalin pomiędzy wirnikiem a korpusem lotniczej turbiny gazowej, materiały stosowane do budowy uszczelnień oraz wady i zalety poszczególnych rozwiazań konstrukcyjnych. Szczegółowo opisano następujące rozwiązania konstrukcyjne: uszczelnienie przez wykonanie wgłębienia w materiale końcówki łopatki wirnikowej, uszczelnienie labiryntowe, wykorzystanie do uszczelniania materiałów odpornych na ścieranie (np. węglikowe płytki zabezpieczające) oraz materiałów tworzących tzw. „plaster miodu”.

EN

In this paper, the most frequently used in practice, the prevention of leakage of exhaust gas stream between the rotor and the housing aviation gas turbine, the materials used in the construction seals and the pros and cons of each design solutions have been presented. The following design solutions: the seal by making a recess in the material of the rotor blade tip, a labyrinth seal for sealing, the use of wear-resistant materials (e.g. Carbide protective plate) and the materials making up the so-called „Honeycomb” have been described in detail.

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Research into flows in turbine blade seals. Part III: Numerical calculations versus experiment

Kosowski K., Stępień R., Piwowarski M., Badur J.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2003

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Vol. 7, No 3

329-336

EN

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.

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Research into flows in turbine blade seals. Part II: Numerical analysis

Stępień R., Kosowski K., Badur J.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2003

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Vol. 7, No 3

319-327

EN

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.

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Research into flows in turbine blade seals. Part I: research methods

Badur J., Kosowski K., Stępień R., Piwowarski M.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2003

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Vol. 7, No 3

309-317

EN

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.