BazTech - Yadda

1

Methods for flow separation prevention on external contour at high expansion angles of steam turbine flow path

Zaryankin Arkadiy, Kindra Vladimir, Lisin Vladimir, Garanin lIvan

Journal of Power Technologies

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2019

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Vol. 99, nr 1

10--14

EN

Most thermal and nuclear power plants use a steam turbine to convert steam potential energy into mechanical work on the rotating rotor. To operate the steam turbine at high efficiency, the aerodynamic losses in the flow path must be decreased, especially in a low-pressure turbine (LPT). This study focuses on the problem of flow separation in the area of the external contour, occurring at high expansion angles of the flow path and constituting a principal cause of flow non-uniformity upstream of the nozzle assembly. Under specific flow conditions, the nozzle assembly peripheral area can be blocked by concentrated vortex, resulting in a sharp increase in losses. A numerical study and comparative analysis of two solutions to this problem were conducted. Quantitative evaluation of nozzle blade cascade energy loss reduction showed that the flow suction on the external surface of a wide-angle diffuser is the most effective in the case of removal of 2% of total flow, using holes located in the middle of an annular diffuser. In this case, the loss coefficient of nozzle blade cascade was reduced by 2.1%. Enhancement of LPT flow path, by mounting an aerodynamic deflector in a wide-angle diffuser, led to a 3% decrease in the loss coefficient. The research results lead to the conclusion that energy losses caused by high expansion angles of LPT flow path can be reduced by applying the considered methods to prevent flow separation on the external contour upstream of the nozzle assembly.

2

Performance of 3 Turbulence Models in 3D Flow Investigation for a 1.5-stage Turbine

Karczewski M., Błaszczak J.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2008

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Vol. 12, No 3-4

185-195

EN

The object of this study was to investigate the flow phenomena in a cold air turbine built at the Institute of Jet Propulsion and Turbomachinery at Aachen Technical University (IST RWTH Aachen, Germany). The said turbine had been studied previously both experimentally and numerically on an IST’s flow solver called Panta Rhei. Since that time certain improvements, computational-wise, have been implemented in the code. In order to test them, new simulation runs were conducted. The detailed studies of the measured and computed flow angles as well as a flow velocity analysis are the means for this evaluation.

3

Numeryczne badanie przepływu w 1.5 stopniowej turbinie z wykorzystaniem 3 modeli turbulencji

Karczewski M., Błaszczak J.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

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2007

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nr 131

79-88

PL

Celem pracy było trójwymiarowe numeryczne zobrazowanie zjawisk przepływowych w 1.5-stopniowej turbinie modelowej Instytutu Napędów Odrzutowych i Maszyn Przepływowych w Nadreńsko-Westfalskiej Wyższej Szkole Technicznej (IST RWTH Aachen) w Akwizgranie (Niemcy). Do badań wykorzystano udoskonaloną wersję kodu obliczeniowego Panta Rhei, stworzonego przez niemiecki Instytut, a uzyskane wyniki obliczeń porównano z pomiarami eksperymentalnymi.

EN

The object of this study was an investigation of flow phenomena in a cold air turbine built at the Institute of Jet Propulsion and Turbomachinery at Aachen Technical University (IST RWTH Aachen, Germany). The said turbine was studied previously both experimentally and numerically with the IST's flow solver called Panta Rhei. Since that time certain improvements, computational-wise, were implemented in the code. In order to test them, new simulation runs were conducted.