Abstract
Modern gas turbines have high efficiency. A further increase in their economic efficiency can be achieved, on the one hand, by enhancing the accuracy of the parameter prediction at the design stage and, on the other hand, by the possibility of improving the design for different components of the flow path based on the results of calculating the complicated viscous spatial structure of the flow. One of the tools for enhancing the efficiency of gas turbines is the minimization of the rotor-tip leakage, the rate of which is reduced by shrouding the rotor blades. In particular, using numerical methods and software tools based on the former, one can perform thorough computational analysis of the vortex structure of the flow in the vicinity of the tip shroud and sufficiently accurately determine the rotor-tip leakage rates and other parameters of the stage. Such an approach allows a more accurate assessment of the leakage than semiempirical approaches used in practice. In particular, the assessment by the correlation dependence showed that the leakage rate for the tip shroud design in question with a tip clearance of 5 mm exceeded the leakage rate calculated using the method that considers the specific features of the tip shroud design and the vortex structure of the flow in the vicinity of it by 8.65%. As exemplified by the last-stage rotor blade of a stationary gas turbine, the possibility of controlling the leakage of the main flow through the tip clearance is demonstrated based on results of a numerical experiment.
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REFERENCES
K. M. Popov, M. Kh. Mukhtarov, L. I. Kiselev, and I. V. Safron’ev, “Influence of radial clearance and banding of working blades on efficiency losses in highly loaded cooled turbines,” Tr. TsIAM, No. 911 (1980).
A. M. Wallis, J. D. Denton, and A. A. J. Demargne, “The control of shroud leakage flows to reduce aerodynamic losses in a low aspect ratio, shrouded axial flow turbine,” in Proc. ASME Turbo Expo 2000: Power for Land, Sea, and Air, Munich, Germany, May 8–11, 2000 (Am. Soc. Mech. Eng., 2000), paper id. ASME-2000-GT-475.
L. Porreca, T. Behr, J. Schlienger, A. I. Kalfas, R. S. Abhari, J. Ehrhard, and E. Janke, “Fluid dynamics and performance of partially and fully shrouded axial turbines,” ASME J. Turbomach. 127, 668–678 (2005).
K. Wolter, A. Giboni, P. Peters, J. R. Menter, and H. Pfost, “Experimental and numerical investigation of the unsteady leakage flow through the rotor tip labyrinth of a 1.5 stage axial turbine,” in Proc. ASME Turbo Expo 2005: Power for Land, Sea, and Air, Reno, NV, June 6–9, 2005 (Am. Soc. Mech. Eng., 2005), paper id. GT2005-68156.
A. G. Kostyuk, A. E. Bulkin, and A. D. Trukhnii, Steam Turbines and Gas Turbine Units for Power Plants (Mosk. Energ. Inst., Moscow, 2018) [in Russian].
K. G. Barmpalias, R. S. Abhari, A. I. Kalfas, N. Shibukawa, and T. Sasaki, “The impact of rotor inlet cavity volume and length scale on efficiency,” in Proc. ASME Turbo Expo 2012, June 11–15, 2012 (Am. Soc. Mech. Eng., 2012), paper id. GT2012-68076.
B. Rosic and J. D. Denton, “Control of shroud leakage loss by reducing circumferential mixing,” J. Turbomach. 130, 021010 (2008).
I. V. Afanas’ev and A. V. Granovskii, “Computational study on the effect of shroud shape on the efficiency of the gas turbine stage,” Therm. Eng. 65, 136–142 (2018). https://doi.org/10.1134/S0040601518030011
A. Granovskiy and I. Afanasiev, “The effect of tip shroud geometries on last turbine stage efficiency,” in Proc. ASME Turbo Expo 2018: Turbomachinery Technical Conf. and Expo., Oslo, Norway, June 11–15, 2018 (Am. Soc. Mech. Eng., 2018), paper id. GT2018-75416.
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Translated by O. Lotova
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Afanasiev, I.V., Granovskiy, A.V., Marchukov, E.Y. et al. Features of the Vortex Flow Structure around a One Fin Shroud. Therm. Eng. 66, 491–497 (2019). https://doi.org/10.1134/S0040601519070012
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DOI: https://doi.org/10.1134/S0040601519070012