Research Papers

Secondary Flows in Low-Pressure Turbines Cascades: Numerical and Experimental Investigation of the Impact of the Inner Part of the Boundary Layer

[+] Author and Article Information
Matteo Giovannini

Departimento di Ingegneria Industriale (DIEF),
Università degli Studi di Firenze,
Via di Santa Marta 3,
Firenze 50139, Italy
e-mail: Matteo.Giovannini@tgroup.unifi.it

Filippo Rubechini

Departimento di Ingegneria Industriale (DIEF),
Università degli Studi di Firenze,
Via di Santa Marta 3,
Firenze 50139, Italy
e-mail: Filippo.Rubechini@tgroup.unifi.it

Michele Marconcini

Departimento di Ingegneria Industriale (DIEF),
Università degli Studi di Firenze,
Via di Santa Marta 3,
Firenze 50139, Italy
e-mail: Michele.Marconcini@tgroup.unifi.it

Daniele Simoni

Dipartimento di Ingegneria meccanica,
energetica, gestionale e dei trasporti (DIME),
Università di Genova,
Via Montallegro, 1,
Genova 16145, Italy
e-mail: daniele.simoni@unige.it

Vianney Yepmo

Dipartimento di Ingegneria meccanica,
energetica, gestionale e dei trasporti (DIME),
Università di Genova,
Via Montallegro, 1,
Genova 16145, Italy
e-mail: vianney.yepmo.henang@edu.unige.it

Francesco Bertini

Avio Aero,
Via I Maggio 99,
Rivalta di Torino (TO) 10040, Italy
e-mail: Francesco.Bertini@avioaero.com

1Corresponding author.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received August 8, 2018; final manuscript received August 29, 2018; published online October 8, 2018. Editor: Kenneth Hall.

J. Turbomach 140(11), 111002 (Oct 08, 2018) (12 pages) Paper No: TURBO-18-1192; doi: 10.1115/1.4041378 History: Received August 08, 2018; Revised August 29, 2018

Due to the low level of profile losses reached in low-pressure turbines (LPT) for turbofan applications, a renewed interest is devoted to other sources of loss, e.g., secondary losses. At the same time, the adoption of high-lift profiles has reinforced the importance of these losses. A great attention, therefore, is dedicated to reliable prediction methods and to the understanding of the mechanisms that drive the secondary flows. In this context, a numerical and experimental campaign on a state-of-the-art LPT cascade was carried out focusing on the impact of different inlet boundary layer (BL) profiles. First of all, detailed Reynolds Averaged Navier-Stokes (RANS) analyzes were carried out in order to establish dependable guidelines for the computational setup. Such analyzes also underlined the importance of the shape of the inlet BL very close to the endwall, suggesting tight requirements for the characterization of the experimental environment. The impact of the inlet BL on the secondary flow was experimentally investigated by varying the inlet profile very close to the endwall as well as on the external part of the BL. The effects on the cascade performance were evaluated by measuring the span-wise distributions of flow angle and total pressure losses. For all the inlet conditions, comparisons between Computational Fluid Dynamics (CFD) and experimental results are discussed. Besides providing guidelines for a proper numerical and experimental setup, the present paper underlines the importance of a detailed characterization of the inlet BL for an accurate assessment of the secondary flows.

Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.


Curtis, E. M. , Hodson, H. P. , Banieghbal, M. R. , Denton, J. D. , Howell, R. J. , and Harvey, N. W. , 1997, “ Development of Blade Profiles for Low-Pressure Turbine Applications,” ASME J. Turbomach, 119(3), pp. 531–538. [CrossRef]
Hodson, H. P. , and Howell, R. J. , 2005, “ Bladerow Interactions, Transition, and High-Lift Aerofoils in Low-Pressure Turbines,” Annu. Rev. Fluid Mech., 37(1), pp. 71–98. [CrossRef]
Denton, J. D. , 1993, “ The 1993 Igti Scholar Lecture—Loss Mechanisms in Turbomachines,” ASME J. Turbomach., 115(4), pp. 621–656. [CrossRef]
Langston, L. S. , 2001, “ Secondary Flows in Axial Turbines—A Review,” Ann. New York Acad. Sci., 934(1), pp. 11–26. [CrossRef]
Sieverding, C. H. , 1985, “ Recent Progress in the Understanding of Basic Aspects of Secondary Flows in Turbine Blade Passages,” ASME J. Turbomach., 107(2), pp. 248–257.
De La Rosa Blanco, E. , Hodson, H. P. , Vazquez, R. , and Torre, D. , 2003, “ Influence of the State of the Inlet Endwall Boundary Layer on the Interaction Between Pressure Surface Separation and Endwall Flows,” Proc. Inst. Mech. Eng., Part A: J. Power Energy , 217(4), pp. 433–441. [CrossRef]
Coull, J. D. , 2017, “ Endwall Loss in Turbine Cascades,” ASME J. Turbomach., 139(8), p. 081004. [CrossRef]
Gregory-Smith, D. G. , Graves, C. P. , and Walsh, J. A. , 1988, “ Growth of Secondary Losses and Vorticity in an Axial Turbine Cascade,” ASME J. Turbomach., 110(1), pp. 1–8. [CrossRef]
Perdichizzi, A. , and Dossena, V. , 1993, “ Incidence Angle and Pitch–Chord Effects on Secondary Flows Downstream of a Turbine Cascade,” ASME J. Turbomach., 115(3), pp. 383–391. [CrossRef]
Ligrani, P. , Potts, G. , and Fatemi, A. , 2017, “ Endwall Aerodynamic Losses From Turbine Components Within Gas Turbine Engines,” Propulsion Power Res., 6(1), pp. 1–14. [CrossRef]
Denton, J. , and Pullan, G. , 2012, “ A Numerical Investigation Into the Sources of Endwall Loss in Axial Flow Turbines,” ASME Paper No. GT2012-69173.
Coull, J. D. , Clark, C. , and Vazquez, R. , 2017, “ Turbine Cascade Endwall Loss: Inlet Conditions and Vorticity Amplification,” GPPS Paper No. N.72.
Marconcini, M. , Pacciani, R. , Arnone, A. , and Bertini, F. , 2015, “ Low-Pressure Turbine Cascade Performance Calculations With Incidence Variation and Periodic Unsteady Inflow Conditions,” ASME Paper No. GT2015-42276.
Simoni, D. , Berrino, M. , Ubaldi, M. , Pietro, Z. , and Francesco, B. , 2015, “ Off-Design Performance of A Highly Loaded LP Turbine Cascade Under Steady and Unsteady Incoming Flow Conditions,” ASME J. Turbomach., 137(7), p. 071009. [CrossRef]
Lengani, D. , Simoni, D. , Ubaldi, M. , Zunino, P. , Bertini, F. , and Michelassi, V. , 2017, “ Accurate Estimation of Profile Losses and Analysis of Loss Generation Mechanisms in a Turbine Cascade,” ASME J. Turbomach., 139(12), p. 121007. [CrossRef]
Arnone, A. , 1994, “ Viscous Analysis of Three–Dimensional Rotor Flow Using a Multigrid Method,” ASME J. Turbomach., 116(3), pp. 435–445. [CrossRef]
Arnone, A. , and Pacciani, R. , 1996, “ Rotor-Stator Interaction Analysis Using the Navier-Stokes Equations and a Multigrid Method,” ASME J. Turbomach., 118(4), pp. 679–689. [CrossRef]
Cozzi, L. , Rubechini, F. , Marconcini, M. , Arnone, A. , Astrua, P. , Schneider, A. , and Silingardi, A. , 2017, “ Facing the Challanges in Cfd Modelling of Multistage Axial Compressors,” ASME Paper No. GT2017-63240.
Chorin, A. J. , 1967, “ A Numerical Method for Solving Incompressible Viscous Flow Problems,” J. Comput. Phys., 2(1), pp. 12–26. [CrossRef]
Wilcox, D. C. , 1998, Turbulence Modeling for CFD, 2nd ed., DCW Ind., LA Cañada, CA.
Langtry, R. B. , and Menter, F. R. , 2009, “ Correlation-Based Transition Modeling for Unstructured Parallelized Computational Fluid Dynamics Codes,” AIAA J., 47(12), pp. 2894–2906. [CrossRef]
Pacciani, R. , Marconcini, M. , Arnone, A. , and Bertini, F. , 2014, “ Predicting High-Lift Low-Pressure Turbine Cascades Flow Using Transition-Sensitive Turbulence Closures,” ASME J. Turbomach., 136(5), p. 051007. [CrossRef]
Greitzer, E. M. , Tan, C. S. , and Graf, M. , 2004, Internal Flow: Concepts and Applications, Cambridge University Press, Cambridge, UK.


Grahic Jump Location
Fig. 1

Blade loading at cascade mid span

Grahic Jump Location
Fig. 2

Blade loading near endwall and at midspan (fully turbulent calculation with inviscid endwall)

Grahic Jump Location
Fig. 3

Sketch of the test rig

Grahic Jump Location
Fig. 4

Cell clustering in span-wise direction

Grahic Jump Location
Fig. 5

Mesh details near hub endwall

Grahic Jump Location
Fig. 6

Grid dependence analysis: distributions of blade-to-blade angle and total pressure loss along the span

Grahic Jump Location
Fig. 7

Grid dependence analysis: contour plots of losses at cascade exit

Grahic Jump Location
Fig. 8

Analytical total pressure distribution. Different locations of the first point above the wall.

Grahic Jump Location
Fig. 9

Impact of the inlet BL sampling on secondary flows

Grahic Jump Location
Fig. 10

Experimental inlet total pressure distribution. Different near-wall shapes below the first measured point.

Grahic Jump Location
Fig. 11

Impact of the inlet near-wall BL on secondary flows

Grahic Jump Location
Fig. 12

Experimental distributions of inlet total pressure. Original and wall-refined measurements.

Grahic Jump Location
Fig. 13

Comparison between measured and computed span-wise distributions at cascade exit. Impact of the inlet near-wall characterization.

Grahic Jump Location
Fig. 14

Measurements versus CDF. Fully turbulent and transitional results.

Grahic Jump Location
Fig. 15

Sketch of the test-rig upstream of the blade leading edge. Closed and opened slot for BL suction.

Grahic Jump Location
Fig. 16

Span-wise profile of the three inlet BLs

Grahic Jump Location
Fig. 17

Contour plots of total pressure loss coefficient at cascade exit. Comparison between measurements and calculations.

Grahic Jump Location
Fig. 18

Measured and computed span-wise distributions of blade-to-blade angle and total pressure loss at cascade exit

Grahic Jump Location
Fig. 19

Contour plots of total pressure loss and SWV over a plane normal to the exit flow direction

Grahic Jump Location
Fig. 20

Secondary losses at varying inlet BL

Grahic Jump Location
Fig. 21

Span-wise distribution of the normal-like component of vorticity at cascade inlet



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In