0
Research Papers

On the Periodically Unsteady Interaction of Wakes, Secondary Flow Development, and Boundary Layer Flow in An Annular Low-Pressure Turbine Cascade: An Experimental Investigation

[+] Author and Article Information
Martin Sinkwitz

Chair of Thermal Turbomachines and Aeroengines,
Department of Mechanical Engineering,
Ruhr-Universität Bochum,
44801 Bochum, Germany
e-mail: martin.sinkwitz@rub.de

Benjamin Winhart

Chair of Thermal Turbomachines and Aeroengines,
Department of Mechanical Engineering,
Ruhr-Universität Bochum,
44801 Bochum, Germany
e-mail: benjamin.winhart@rub.de

David Engelmann

Chair of Thermal Turbomachines and Aeroengines,
Department of Mechanical Engineering,
Ruhr-Universität Bochum,
44801 Bochum, Germany
e-mail: David.Engelmann@rub.de

Francesca di Mare

Chair of Thermal Turbomachines and Aeroengines,
Department of Mechanical Engineering,
Ruhr-Universität Bochum,
44801 Bochum, Germany
e-mail: francesca.dimare@rub.de

Ronald Mailach

Chair of Turbomachinery and Flight Propulsion,
Institute of Fluid Mechanics, Technische Universität Dresden,
01062 Dresden, Germany
e-mail: ronald.mailach@tu-dresden.de

1Corresponding author.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the Journal of Turbomachinery. Manuscript received January 18, 2019; final manuscript received April 18, 2019; published online May 23, 2019. Assoc. Editor: Kenneth Hall.

J. Turbomach 141(9), 091001 (May 23, 2019) (8 pages) Paper No: TURBO-19-1015; doi: 10.1115/1.4043577 History: Received January 18, 2019; Accepted April 18, 2019

The experimental results reported in this contribution address the time-dependent impact of periodically unsteady wakes on the development of profile and end wall boundary layers and consequently on the secondary flow system. Experimental investigations are conducted on an annular 1.5 stage axial turbine rig at Ruhr-Universität Bochum’s Chair of Thermal Turbomachines and Aeroengines. The object under investigation is a modified T106 profile low-pressure turbine (LPT) stator row at a representative exit flow Reynolds number of 200,000. By making use of an annular geometry instead of a linear cascade, the influence of curvilinear end walls, nonuniform, increasing pitch across the span and radial flow migration can be represented. Incoming wakes are generated by a variable-speed driven rotor equipped with cylindrical bars. Special emphasis is put on the wake-induced recurrent formation, suppression, weakening, and displacement of individual vortices and separated flow regimes. For this, based on a comprehensive set of time-resolved measurement data, the interaction of impinging bar wakes and boundary layer flow and thus separation and its periodic manipulation along the passage end walls and on the blade suction surface are studied within the frequency domain.

FIGURES IN THIS ARTICLE
<>
Copyright © 2019 by ASME
Your Session has timed out. Please sign back in to continue.

References

Sinkwitz, M., Winhart, B., Engelmann, D., di Mare, F., and Mailach, R., 2019, “Experimental and Numerical Investigation of Secondary Flow Structures in an Annular LPT Cascade Under Periodic Wake Impact—Part 1: Experimental Results,” ASME J. Turbomach., 141(2), pp. 021008. [CrossRef]
Stotz, S., Guendogdu, Y., and Niehuis, R., 2017, “Experimental Investigation of Pressure Side Flow Separation on the T106C Airfoil at High Suction Side Incidence Flow,” ASME J. Turbomach., 139(5), pp. 051007. [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. N. Y. Acad. Sci., 934(1), pp. 11–26. [CrossRef] [PubMed]
Puddu, P., Palomba, C., and Nurzia, F., 2006, “Time–Space Evolution of Secondary Flow Structures in a Two–Stage Low–Speed Turbine,” Proceedings of ASME Turbo Expo 2006: Power for Land, Sea, and Air, Barcelona, Spain, May 8–11, Paper No. GT2006-90787.
Kang, S., and Hirsch, C., 1991, “Three Dimensional Flow in a Linear Compressor Cascade at Design Conditions,” Proceedings of ASME 1991 International Gas Turbine and Aeroengine Congress and Exposition, Orlando, FL, June 3–6, Paper No. 91-GT-114.
Hodson, H. P., and Dawes, W. N., 1998, “On the Interpretation of Measured Profile Losses in Unsteady Wake–Turbine Blade Interaction Studies,” ASME J. Turbomach., 120(2), pp. 276–284. [CrossRef]
Volino, R. J., 2011, “Effect of Unsteady Wakes on Boundary Layer Separation on a Very High Lift Low Pressure Turbine Airfoil,” ASME J. Turbomach., 134(1), p. 011011. [CrossRef]
Ciorciari, R., Kirik, I., and Niehuis, R., 2014, “Effects of Unsteady Wakes on the Secondary Flows in the Linear T106 Turbine Cascade,” ASME J. Turbomach., 136(9), pp. 091010. [CrossRef]
Krug, A., Busse, P., and Vogeler, K., 2015, “Experimental Investigation into the Effects of the Steady Wake-Tip Clearance Vortex Interaction in a Compressor Cascade,” ASME J. Turbomach., 137(6), p. 061006. [CrossRef]
Berrino, M., Lengani, D., Simoni, D., Ubaldi, M., Zunino, P., and Bertini, F., 2015, “Dynamics and Turbulence Characteristics of Wake-Boundary Layer Interaction in a Low Pressure Turbine Blade,” Proceedings of ASME Turbo Expo 2015, Montreal, Canada, June 15–19, Paper No. GT2015-42626.
Infantino, D., Satta, F., Simoni, D., Ubaldi, M., Zunino, P., and Bertini, F., 2015, “Phase-Locked Investigation of Secondary Flows Perturbed by Passing Wakes in a High-Lift LPT Turbine Cascade,” Proceedings of ASME Turbo Expo, Montreal, Quebec, Canada, June 15–19, Paper No. GT2015-42480.
Lengani, D., Simoni, D., Ubaldi, M., Zunino, P., and Bertini, F., 2017, “Time Resolved PIV Measurements of the Unsteady Wake Migration in a LPT Blade Passage: Effect of the Wake Passing Frequency,” Proceedings of 12th European Conference on Turbomachinery, Fluid Dynamics and Thermodynamics, ETC12, Stockholm, Sweden, Apr. 3–7, Paper No. ETC2017-324.
Hodson, H. P., and Howell, R. J., 2005, “The Role of Transition in High-Lift Low-Pressure Turbines for Aeroengines,” Progr. Aerosp. Sci., 41(6), pp. 419–454. [CrossRef]
Sinkwitz, M., Engelmann, D., and Mailach, R., 2017, “Experimental Investigation of Periodically Unsteady Wake Impact on Secondary Flow in a 1.5 Stage Full Annular LPT Cascade With Modified T106 Blading,” Proceedings of ASME Turbo Expo 2017, Charlotte, NC, June 26–30, Paper No. GT2017-64390.
Winhart, B., Sinkwitz, M., Schramm, A., Engelmann, D., di Mare, F., and Mailach, R., 2019, “Experimental and Numerical Investigation of Secondary Flow Structures in an Annular LPT Cascade Under Periodic Wake Impact—Part 2: Numerical Results,” ASME J. Turbomach., 141(2), pp. 021009. [CrossRef]
Winhart, B., Sinkwitz, M., Engelmann, D., di Mare, F., and Mailach, R., 2018, “On the Periodically Unsteady Interaction of Wakes, Secondary Flow Development and Boundary Layer Flow in an Annular LPT Cascade: Part 2—Numerical Investigation,” Proceedings of ASME Turbo Expo 2018, Oslo, Norway, June 11–15, Paper No. GT2018-76873.
Lampart, P., 2009, “Investigation of Endwall Flows and Losses in Axial Turbines. Part I. Formation of Endwall Flows and Losses,” J. Theor. Appl. Mech., 47(2), pp. 321–342.
Vera, M., de la Rosa Blanco, E., Hodson, H., and Vazquez, R., 2008, “Endwall Boundary Layer Development in an Engine Representative Four-Stage Low Pressure Turbine Rig,” ASME J. Turbomach., 131(1), p. 011017. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Test facility: (a) sectional view of the test section, (b) 3D illustration, and (c) view onto T106RUB stator row

Grahic Jump Location
Fig. 2

Measurement setup for the acquisition of time-resolved profile and end wall pressures. T106RUB blade: (a) suction side prepared for Kulite LQ-125 instrumentation, (b) arrangement of sensors along the profile, (c) screw-in Kulite XT-190 sensor, and (d) casing element for end wall pressure sensor access.

Grahic Jump Location
Fig. 3

Flow field 0.15C downstream of T106RUB TE (Sr = 1.33, ϕ = 0.97): (a) distributions of time-averaged, normalized velocity and (b) axial vorticity

Grahic Jump Location
Fig. 4

Flow field 0.15C downstream of T106RUB TE for one representative position within the stator wake (θ = –6 deg, R/H = 60%): (a) time-resolved velocity signal and (b) corresponding amplitude spectrum (Sr = 1.33, ϕ = 0.97)

Grahic Jump Location
Fig. 5

Spectral analysis: flow field 0.15C downstream of T106RUB TE (Sr = 0.45, ϕ = 2.84 (left), Sr = 1.33, ϕ = 0.97 (right)). Amplitudes of the (a) main flow direction c1, (b) perpendicular direction c2, and (c) radial direction c3 excited by BPF.

Grahic Jump Location
Fig. 6

Spectral analysis: blade pressure distribution at midspan for four operating points (BPF), excitation by particular BPF

Grahic Jump Location
Fig. 7

Spectral analysis of time-resolved end wall pressures for three operating points (BPF). Excitation by particular BPF.

Tables

Errata

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