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Combined experimental and numerical investigations on the roughness effects on the aerodynamic performances of LPT blades

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Abstract

The aerodynamic performance of a high-load low-pressure turbine blade cascade has been analyzed for three different distributed surface roughness levels (Ra) for steady and unsteady inflows. Results from CFD simulations and experiments are presented for two different Reynolds numbers (300000 and 70000 representative of take-off and cruise conditions, respectively) in order to evaluate the roughness effects for two typical operating conditions.

Computational fluid dynamics has been used to support and interpret experimental results, analyzing in detail the flow field on the blade surface and evaluating the non-dimensional local roughness parameters, further contributing to understand how and where roughness have some influence on the aerodynamic performance of the blade. The total pressure distributions in the wake region have been measured by means of a five-hole miniaturized pressure probe for the different flow conditions, allowing the evaluation of profile losses and of their dependence on the surface finish, as well as a direct comparison with the simulations.

Results reported in the paper clearly highlight that only at the highest Reynolds number tested (Re=300000) surface roughness have some influence on the blade performance, both for steady and unsteady incoming flows. In this flow condition profile losses grow as the surface roughness increases, while no appreciable variations have been found at the lowest Reynolds number. The boundary layer evolution and the wake structure have shown that this trend is due to a thickening of the suction side boundary layer associated to an anticipation of transition process. On the other side, no effects have been observed on the pressure side boundary layer.

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References

  1. J. Nikuradse. Laws of Flow in Rough Pipes. VDI-Forchungsheft 361, Series B, Vol. 4, 1933. (NACA TM 1292).

  2. K. A. Flack and M. P. Schultz. Review of Hydraulic Roughness Scales in the Fully Rough Regime. ASME J. Fluid Eng., 132(4): 041203, 2010.

    Google Scholar 

  3. A. L. Braslow. Review of the Effect of Distributed Surface Roughness on Boundary-Layer Transition. AGARDR-254, 1960.

    Google Scholar 

  4. H. P. Hodson, R. J. Howell. The Role of Transition in High-Lift Low-Pressure Turbines for Aeroengines. Prog. Aerosp. Sci., 41(6): 419–454, 2005.

    Article  Google Scholar 

  5. R. Vázquez and D. Torre, The Effect of Surface Roughness on Efficiency of Low Pressure Turbines. ASME Paper No.GT2013-94200, ASME Turbo Expo, June 3–7, San Antonio, TX, USA, 2013.

    Book  Google Scholar 

  6. M. Vera, X. F. Zhang, H. P. Hodson, N. Harvey. Separation and Transition Control on an Aft-Loaded Ultra-High-Lift LP Turbine Blade at Low Reynolds Numbers: High- Speed Validation. ASME J. Turbomach., 129(2): 340–347, 2007.

    Article  Google Scholar 

  7. R. J. Boyle and R. G. Senyitko, Measurements and Predictions of Surface Roughness Effects on Turbine Vane Aerodynamics. ASME Paper No.GT2003-38580, ASME Turbo Expo, June 16-19, Atlanta, GA, USA, 2003.

    Google Scholar 

  8. B. Aupoix, P. R. Spalart. Extensions of the Spalart–Allmaras Turbulence Model to Account for Wall Roughness. Int. J. Heat Fluid Flow, 24: 454–462, 2003.

    Article  Google Scholar 

  9. B. Aupoix. Roughness Corrections for the k-ω Shear Stress Transport Model: Status and Proposal. J. Fluid Eng., 137(2): 021202, 2015.

    Google Scholar 

  10. V. Nagabhushana Rao, R. Jefferson-Loveday, P. G. Tucker, S. Lardeau. Large Eddy Simulations in Turbines: Influence of Roughness and Free-Stream Turbulence. Flow Turbulence Combust., 92: 543–561, 2014.

    Article  Google Scholar 

  11. J. Bellucci, F. Rubechini, M. Marconcini, A. Arnone, L. Arcangeli, N. Maceli, V. Dossena, The Influence of Roughness on a High-Pressure Steam Turbine Stage: An Experimental and Numerical Study. ASME J. Eng. Gas Turb. Power, 137(1): 012602, 2015.

    Article  Google Scholar 

  12. J. P. Bons, A Review of Surface Roughness Effects in Gas Turbines. ASME J. Turbomach., 132(2): 021004, 2010.

    Article  Google Scholar 

  13. F. Satta, D. Simoni, M. Ubaldi, P. Zunino, F. Bertini. Experimental Investigation of Separation and Transition Processes on a High-Lift Low-Pressure Turbine Profile Under Steady and Unsteady Inflow at Low Reynolds Number. J. Therm. Sci., 19(1): 26–33, 2010.

    Article  ADS  Google Scholar 

  14. F. Montomoli, H. P. Hodson, F. Haselbach. Effect of Roughness and Unsteadiness on the Performance of a New Low Pressure Turbine Blade at Low Reynolds Numbers. ASME J. Turbomach., 132(3): 031018, 2010.

    Article  Google Scholar 

  15. M. Marconcini, F. Rubechini, R. Pacciani, A. Arnone, F. Bertini. Redesign of High-Lift Low Pressure Turbine Airfoils For Low Speed Testing. ASME J. Turbomach., 134(5): 051017, 2012.

    Article  Google Scholar 

  16. F. Satta, D. Simoni, M. Ubaldi, P. Zunino, F. Bertini. Loading Distribution Effects on Separated Flow Transition of Ultra-High-Lift Turbine Blades. J. Propul. Power, 30(3): 845: 856, 2014.

    Article  Google Scholar 

  17. D. Simoni, M. Berrino, M. Ubaldi, P. Zunino, F. Bertini. Off-Design Performance of a Highly Loaded LP Turbine Cascade Under Steady and Unsteady Incoming Flow Conditions. ASME J. Turbomach., 137 (7): 071009, 2015.

    Article  Google Scholar 

  18. A. Arnone. Viscous Analysis of Three–Dimensional Rotor Flow Using a Multigrid Method. ASME J. Turbomach., 116(3): 435–445, 1994.

    Article  Google Scholar 

  19. A. J. Chorin. A Numerical Method for Solving Incompressible Viscous Flow Problems. J. Comput. Phys., 2: 12–26, 1967.

    Article  ADS  MATH  Google Scholar 

  20. D. C. Wilcox. Turbulence Modeling for CFD. 2nd ed., DCW Industries, Inc., La Cañada, ISBN 1-928729-10-X, 1998.

    Google Scholar 

  21. R. E. Mayle and A. Schultz. The Path to Predicting Bypass Transition. ASME J. Turbomach., 119(3): 405–411, 1997.

    Article  Google Scholar 

  22. D. C. Wilcox. Formulation of the k-ω Turbulence Model Revisited. AIAA J., 46(11): 2823–2838, 2008.

    Article  ADS  Google Scholar 

  23. R. Pacciani, M. Marconcini, A. Fadai-Ghotbi, S. Lardeau, M. A. Leschziner. Calculation of High-Lift Cascades in Low Pressure Turbine Conditions Using a Three-Equation Model. ASME J. Turbomach., 133(3): 031016, 2011.

    Article  Google Scholar 

  24. H. Schlichting. Boundary-Layer Theory, 7th ed., Mc-Graw-Hill Inc., New York, ISBN 0-07-055334-3, 1979.

    MATH  Google Scholar 

  25. A. Schäffler, Experimental and Analytical Investigation of the Effects of Reynolds Number and Blade Surface Roughness on Multistage Axial Flow Compressors. ASME J. Eng. Power, 102(1): 5–13, 1980.

    Article  Google Scholar 

  26. T. Adams, C. Grant, H. Watson. A Simple Algorithm to Relate Measured Surface Roughness to Equivalent Sand-Grain Roughness. Int. J. Mech. Eng. and Mechatronics, 1(1): 008, 2012.

    Google Scholar 

  27. D. Lengani, D. Simoni. Recognition of Coherent Structures in the Boundary Layer of a Low-Pressure-Turbine Blade for Different Free-Stream Turbulence Intensity Levels. Int. J. Heat Fluid Flow, 54: 1–13, 2015.

    Article  Google Scholar 

  28. Q. Zhang and P. M. Ligrani. Aerodynamic Losses of a Cambered Turbine Vane: Influences of Surface Roughness and Freestream Turbulence Intensity. ASME J. Turbomach., 128(3): 536–546, 2006.

    Article  Google Scholar 

  29. E. G. Feindt. Untersuchungen über die Abhängigkeit des Umshclages laminar-turbulent von der Oberflächenrauhigkeit und der Druckverteilung, Springer-Verlag, Berlin, 1956.

    Google Scholar 

  30. M. Marconcini, R. Pacciani, A. Arnone, F. Bertini. Low-Pressure Turbine Cascade Performance Calculations with Incidence Variation and Periodic Unsteady Inflow Conditions. ASME paper No. GT2015-42276, ASME Turbo Expo, June 15–19, Montréal, Canada, 2015.

    Book  Google Scholar 

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Berrino, M., Bigoni, F., Simoni, D. et al. Combined experimental and numerical investigations on the roughness effects on the aerodynamic performances of LPT blades. J. Therm. Sci. 25, 32–42 (2016). https://doi.org/10.1007/s11630-016-0831-5

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