Research Papers

Experimental Investigation of Pressure Side Flow Separation on the T106C Airfoil at High Suction Side Incidence Flow

[+] Author and Article Information
Stephan Stotz

Institute of Jet Propulsion,
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: stephan.stotz@unibw.de

Yavuz Guendogdu

MTU Aero Engines AG,
München 80995, Germany
e-mail: yavuz.guendogdu@mtu.de

Reinhard Niehuis

Institute of Jet Propulsion,
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: reinhard.niehuis@unibw.de

1Corresponding author.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received September 16, 2016; final manuscript received September 28, 2016; published online January 24, 2017. Editor: Kenneth Hall.

J. Turbomach 139(5), 051007 (Jan 24, 2017) (11 pages) Paper No: TURBO-16-1242; doi: 10.1115/1.4035210 History: Received September 16, 2016; Revised September 28, 2016

The objective of this work is to study the influence of a pressure side separation bubble on the profile losses and the development of the bubble in the blade passage. For the experimental investigations, the T106 profile is used, with an increased loading due to an enlarged pitch to chord ratio from 0.799 to 0.95 (T106C). The experiments were performed at the high-speed cascade wind tunnel of the Institute of Jet Propulsion at the University of the Federal Armed Forces Munich. The main feature of the wind tunnel is to vary Reynolds and Mach number independently to achieve realistic turbomachinery conditions. The focus of this work is to determine the influence of a pressure side separation on the profile losses and hence the robustness to suction side incidence flow. The cascade is tested at four incidence angles from 0 deg to −22.7 deg to create separation bubbles of different sizes. The influence of the Reynolds number is investigated for a wide range at constant exit Mach number. Therefore, a typical exit Mach number for low pressure turbines in the range of 0.5–0.8 is chosen in order to consider compressible effects. Furthermore, two inlet turbulence levels of about 3% and 7.5% have been considered. The characteristics of the separation bubble are identified by using the profile pressure distributions, whereas wake traverses with a five hole probe are used to determine the influence of the pressure side separation on the profile losses. Further, time-resolved pressure measurements near the trailing edge as well as single hot wire measurements in the blade passage are conducted to investigate the unsteady behavior of the pressure side separation process itself and also its influence on the midspan passage flow.

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Banieghbal, M. , Curtis, E. , Denton, J. , Hodson, H. , Huntsman, I. , Schulte, V. , Harvey, N. , and Steele, A. , 1995, “ Wake Passing in LP Turbine Blades,” Loss Mechanisms and Unsteady Flows in Turbomachines, Derby, UK, Paper No. AGARD-CP-571, pp. 23-1–23-12.
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]
Denton, J. D. , 1993, “ The 1993 IGTI Scholar Lecture: Loss Mechanisms in Turbomachines,” ASME J. Turbomach., 115(4), pp. 621–656. [CrossRef]
Lichtfuß, H. J. , 2004, “ Customized Profiles the Beginning of an Era: A Short History of Blade Design,” ASME Paper No. GT2004-53742.
Brear, M. J. , Hodson, H. P. , and Harvey, N. W. , 2002, “ Pressure Surface Separations in Low-Pressure Turbines—Part 1: Midspan Behavior,” ASME J. Turbomach., 124(3), pp. 393–401. [CrossRef]
Hodson, H. , 1986, “ The Off-Design Performance of a Low-Pressure Turbine Cascade,” ASME J. Turbomach., 109(2), pp. 201–209. [CrossRef]
González, P. , Ulizar, I. , Vázquez, R. , and Hodson, H. P. , 2002, “ Pressure and Suction Surfaces Redesign for High-Lift Low-Pressure Turbines,” ASME J. Turbomach., 124(2), pp. 161–166. [CrossRef]
Yamamoto, A. , and Nouse, H. , 1988, “ Effects of Incidence on Three-Dimensional Flows in a Linear Turbine Cascade,” ASME J. Turbomach., 110(4), pp. 486–496. [CrossRef]
Brear, M. J. , Hodson, H. P. , Gonzalez, P. , and Harvey, N. W. , 2002, “ Pressure Surface Separations in Low-Pressure Turbines—Part 2: Interactions With the Secondary Flow,” ASME J. Turbomach., 124(3), pp. 402–409. [CrossRef]
Gomes, R. A. , and Niehuis, R. , 2012, “ Film Cooling on Highly Loaded Blades With Main Flow Separation—Part I: Heat Transfer,” ASME J. Turbomach., 135(1), p. 011043. [CrossRef]
Ladisch, H. , Schulz, A. , and Bauer, H.-J. , 2009, “ Heat Transfer Measurements on a Turbine Airfoil With Pressure Side Separation,” ASME Paper No. GT2009-59904.
Walraevens, R. E. , and Cumpsty, N. A. , 1995, “ Leading Edge Separation Bubbles on Turbomachine Blades,” ASME J. Turbomach., 117(1), pp. 115–125. [CrossRef]
Hazarika, B. K. , and Hirsch, C. , 1997, “ Transition Over C4 Leading Edge and Measurement of Intermittency Factor Using PDF of Hot-Wire Signal,” ASME J. Turbomach., 119(3), pp. 412–425. [CrossRef]
Samson, A. , and Sarkar, S. , 2016, “ Effects of Free-Stream Turbulence on Transition of a Separated Boundary Layer Over the Leading-Edge of a Constant Thickness Airfoil,” ASME J. Fluids Eng., 138(2), p. 021202. [CrossRef]
Sturm, W. , and Fottner, L. , 1985, “ The High-Speed Cascade Wind Tunnel of the German Armed Forces University Munich,” 8th Symposium on Measuring Techniques for Transonic and Supersonic Flows in Cascades and Turbomachines, Genova, Italy.
Lichtfuß, H. J. , 1979, “ Awendung neuer Entwurfskonzepte auf Profile für Axiale Turbomaschinen, Teil II: Optimale Geschwindigkeitsverteilungen für die Auslegung von Verdichter- und Turbinengittern,” Technischer Bericht 78/054 B, MTU-München. ZTL-Abschlussbericht 1978.
Hoheisel, H. , Kiock, R. , Lichtfuss, H. J. , and Fottner, L. , 1987, “ Influence of Free-Stream Turbulence and Blade Pressure Gradient on Boundary Layer and Loss Behavior of Turbine Cascades,” ASME J. Turbomach., 109(2), pp. 210–219. [CrossRef]
Stieger, R. D. , Hollis, D. , and Hodson, H. P. , 2004, “ Unsteady Surface Pressures Due to Wake-Induced Transition in a Laminar Separation Bubble on a Low-Pressure Cascade,” ASME J. Turbomach., 126(4), pp. 544–550. [CrossRef]
Montis, M. , Fiala, A. , and Niehuis, R. , 2010, “ Effect of Surface Roughness on Loss Behaviour, Aerodynamic Loading and Boundary Layer Development of a Low-Pressure Gas Turbine Airfoil,” ASME Paper No. GT2010-23317.
Gier, J. , Franke, M. , Hübner, N. , and Schröder, T. , 2010, “ Designing Low Pressure Turbines for Optimized Airfoil Lift,” ASME J. Turbomach., 132(3), p. 031008. [CrossRef]
Marciniak, V. , Kügler, E. , and Franke, M. , 2010, “ Predicting Transition on Low-Pressure Turbine Profiles,” V European Conference on Computational Fluid Dynamics, ECCOMAS CFD 2010, Lisbon, Portugal, June 15–17. https://www.researchgate.net/profile/Vincent_Marciniak/publication/225006418_Predicting_Transition_on_Low-Pressure_Turbine_Profiles/links/5447a5460cf2d62c30508d36.pdf
Michàlek, J. , Monaldi, M. , and Arts, T. , 2012, “ Aerodynamic Performance of a Very High Lift Low Pressure Turbine Airfoil (T106C) at Low Reynolds and High Mach Number With Effect of Free Stream Turbulence Intensity,” ASME J. Turbomach., 134(6), p. 061009. [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), p. 091010. [CrossRef]
Hoheisel, H. , 1990, “ Test Cases for Computation of Internal Flows in Aero Engine Components: Test Case E/CA6, Subsonic Turbine Cascade T106,” Technical Report No. AGARD-AR-275.
Traupel, W. , 2001, Thermische Turbomaschinen, Springer-Verlag, Berlin, p. 271.
Amecke, J. , 1967, “ Auswertung von Nachlaufmessungen an Ebenen Schaufelgittern,” AVA Göttingen, Göttingen, Germany, Technical Report No. 67 A 49.
Ruck, G. , 1989, “ Ein Verfahren zur Instationären Geschwindigkeits- und Turbulenzmessung mit einer Pneumatischen Keilsonde,” Ph.D. thesis, Universität Stuttgart, Stuttgart, Germany.
Hänsel, H. , 1967, Grundzüge der Fehlerrechnung, Deutscher Verlag der Wissenschaften, Berlin.
Drela, M. , and Youngren, H. , 1998, A User's Guide to MISES 2.53, MIT Computational Aerospace Sciences Laboratory, Cambridge, MA.
Watmuff, J. H. , 1999, “ Evolution of a Wave Packet Into Vortex Loops in a Laminar Separation Bubble,” J. Fluid Mech., 397, pp. 119–169. [CrossRef]
Lou, W. , and Hourmouziadis, J. , 2000, “ Separation Bubbles Under Steady and Periodic-Unsteady Main Flow Conditions,” ASME J. Turbomach., 122(4), pp. 634–643. [CrossRef]
Satta, F. , Simoni, D. , Ubaldi, M. , Zunino, P. , and Bertini, F. , 2011, “ Separated-Flow Transition Process on a Lowpressure Turbine Blade Under Steady and Unsteady Inflows,” ETC 9, Paper No. 260.
Simoni, D. , Ubaldi, M. , Zunino, P. , Lengani, D. , and Bertini, F. , 2012, “ An Experimental Investigation of the Separated-Flow Transition Under High-Lift Turbine Blade Pressure Gradients,” Flow, Turbul. Combust., 88, pp. 45–62. [CrossRef]
Bradshaw, P. , 1971, An Introduction to Turbulence and Its Measurements, Pergamon Press, Oxford, UK.
Chandrasekhar, S. , 1981, Hydrodynamic and Hydromagnetic Stability, Dover Publications, New York.
Schmid, P. J. , and Henningson, D. S. , 2001, Stability and Transition in Shear Flows, Springer, New York.
Yang, Z. , and Voke, P. R. , 2001, “ Large-Eddy Simulation of Boundary-Layer Separation and Transition at a Change of Surface Curvature,” J. Fluid Mech., 439, pp. 305–333. [CrossRef]
Simoni, D. , Ubaldi, M. , and Zunino, P. , 2015, “ A Simplified Model Predicting the Kelvin–Helmholtz Instability Frequency for Laminar Separated Flows,” ASME J. Turbomach., 138(4), p. 044501. [CrossRef]
McAuliffe, B. R. , and Yaras, M. I. , 2010, “ Transition Mechanisms in Separation Bubbles Under Low- and Elevated-Freestream Turbulence,” ASME J. Turbomach., 132(1), p. 011004. [CrossRef]
Mayle, R. E. , 1991, “ The Role of Laminar-Turbulent Transition in Gas Turbine Engines,” ASME J. Turbomach., 113(4), pp. 509–536. [CrossRef]
Pope, S. B. , 2001, Turbulent Flows, Cambridge University Press, Cambridge, UK.


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Fig. 1

The high-speed cascade wind tunnel

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Fig. 2

Profile, investigated inlet angles and measurement planes

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Fig. 5

Mach number distribution at different incidence angles, comparison with predictions

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Fig. 4

Mach number distribution at different incidence angles for Re2th=200,000 and Low Tu

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Fig. 9

Influence of incidence angle on the integral total pressure losses for low and high Tu

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Fig. 10

Influence of Reynolds number on the pressure side separation: (a) low Tu, i=−11.7 deg, (b) low Tu, i=−17.7 deg, (c) low Tu, i=−22.7 deg, (d) high Tu, i=−11.7 deg, (e) high Tu, i=−17.7 deg, and (f) high Tu, i=−22.7 deg

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Fig. 11

Mach number distribution at different turbulence levels for i=−22.7 deg (β1=105 deg)

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Fig. 12

Wake traverses at different turbulence levels for i=−22.7 deg (β1=105 deg)

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Fig. 3

T106A [24] and T106C Mach number distributions at design inlet angle β1=127.7 deg (i=0 deg)

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Fig. 6

Wake traverses at different incidence angles for Re2th=200,000 and low Tu

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Fig. 16

Acceleration parameter along the pressure surface

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Fig. 14

Contour plots from hot wire measurements at i=−22.7 deg (β1=105 deg), Re2th=200,000, low Tu: (a) time-mean streamwise velocity, (b) velocity fluctuations and skewness, and (c) turbulence intensity

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Fig. 15

Power spectral density of velocity

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Fig. 7

Integral total pressure losses at different incidence angles: (a) low Tu and (b) high Tu

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Fig. 8

Wake traverses at different incidence angles for Re2th=200,000 and high Tu

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Fig. 13

Pitot tube traverses for i=−22.7 deg (β1=105 deg) and low Tu at xax/lax=0.96: (a) total pressure loss (mean ζ and variation ζ1%,99%) and (b) turbulence intensity of dynamic pressure




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