Research Papers

Effects of Downstream Vane Bowing and Asymmetry on Unsteadiness in a Transonic Turbine

[+] Author and Article Information
John P. Clark

Turbomachinery Branch,
Turbine Engine Division,
Aerospace Systems Directorate,
Air Force Research Laboratory,
1950 5th Street,
WPAFB, OH 45433
e-mail: john.clark.38@us.af.mil

Richard J. Anthony, Michael K. Ooten, John M. Finnegan

Wright-Patterson AFB, OH 45433

P. Dean Johnson

FTT America,
Jupiter, FL 33458
ASME Member

Ron-Ho Ni

AeroDynamic Solutions, Inc.,
Danville, CA 94526

1Corresponding author.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received July 16, 2018; final manuscript received July 20, 2018; published online September 28, 2018. Editor: Kenneth Hall. This work is in part a work of the U.S. Government. ASME disclaims all interest in the U.S. Government's contributions.

J. Turbomach 140(10), 101006 (Sep 28, 2018) (9 pages) Paper No: TURBO-18-1160; doi: 10.1115/1.4040998 History: Received July 16, 2018; Revised July 20, 2018

Accurate predictions of unsteady forcing on turbine blades are essential for the avoidance of high-cycle-fatigue issues during turbine engine development. Further, if one can demonstrate that predictions of unsteady interaction in a turbine are accurate, then it becomes possible to anticipate resonant-stress problems and mitigate them through aerodynamic design changes during the development cycle. A successful reduction in unsteady forcing for a transonic turbine with significant shock interactions due to downstream components is presented here. A pair of methods to reduce the unsteadiness was considered and rigorously analyzed using a three-dimensional (3D), time-resolved Reynolds-Averaged Navier-Stokes (RANS) solver. The first method relied on the physics of shock reflections itself and involved altering the stacking of downstream components to achieve a bowed airfoil. The second method considered was circumferentially asymmetric vane spacing which is well known to spread the unsteadiness due to vane-blade interaction over a range of frequencies. Both methods of forcing reduction were analyzed separately and predicted to reduce unsteady pressures on the blade as intended. Then, both design changes were implemented together in a transonic turbine experiment and successfully shown to manipulate the blade unsteadiness in keeping with the design-level predictions. This demonstration was accomplished through comparisons of measured time-resolved pressures on the turbine blade to others obtained in a baseline experiment that included neither asymmetric spacing nor bowing of the downstream vane. The measured data were further compared to rigorous post-test simulations of the complete turbine annulus including a bowed downstream vane of nonuniform pitch.

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


Magge, S. S. , Sharma, O. P. , Stetson, G. M. , and Wagner, J. H. , 2014, “ Overview of Turbine Design,” Turbine Aerodynamics, Heat Transfer, Materials, and Mechanics (Progress in Aerospace Sciences), Vol. 243, T. I.-P. Shih , and V. Yang , eds., AIAA, Reston, VA, pp. 1–37.
Adamczyk, J. J. , 2000, “ Aerodynamic Analysis of Multi-Stage Turbomachinery Flows in Support of Aerodynamic Design,” ASME J. Turbomach., 122(2), pp. 189–217. [CrossRef]
Dunn, M. G. , 2001, “ Convective Heat Transfer and Aerodynamics in Axial Flow Turbines,” ASME J. Turbomach., 123(4), pp. 637–686. [CrossRef]
Paniagua, G. , and Denos, R. , 2007, “ Unsteadiness in HP Turbines,” Advances in Turbomachinery Aero-Thermo-Mechanical Design Analysis (VKI Lecture Series), Rhode Saint Genèse, Belgium.
Seinturier, E. , Lombard, J.-P. , Dumas, M. , Dupont, C. , Sharma, V. , and Dupeux, J. , 2004, “ Forced-Response Methodology for the Design of HP Compressors Bladed Disks,” ASME Paper No. GT2004-53372.
Greitzer, E. M. , Tan, C. S. , Wisler, D. C. , Adamczyk, J. J. , and Strazisar, A. J. , 1994, “ Unsteady Flows in Turbomachines: Where's the Beef?,” ASME AD-Vol. 40, pp. 1–12.
Clark, J. P. , Koch, P. J. , Ooten, M. K. , Johnson, J. J. , Dagg, J. , McQuilling, M. W. , Huber, F. , and Johnson, P. D. , 2009, “ Design of Turbine Components to Answer Research Questions in Unsteady Aerodynamics and Heat Transfer,” Wright-Patterson Air Force Base, Dayton, OH, AFRL Report No. AFRL-RZ-WP-TR-2009-2180.
Davis, R. L. , Yao, J. , Clark, J. P. , Stetson, G. , Alonso, J. J. , Jameson, A. , Haldeman, C. W. , and Dunn, M. G. , 2004, “ Unsteady Interaction Between a Transonic Turbine Stage and Downstream Components,” Int. J. Rotating Mach., 10(6), pp. 495–506. [CrossRef]
Ooten, M. K. , Anthony, R. J. , Lethander, A. T. , and Clark, J. P. , 2015, “ Unsteady Aerodynamic Interaction in a Closely Coupled Turbine Consistent With Contrarotation,” ASME J. Turbomach., 138(6), pp. 1–13.
Clark, J. P. , Beck, J. A. , Kaszynski, A. A. , Still, A. , and Ni, R.-H. , 2018, “ The Effect of Manufacturing Variations on Unsteady Interaction in a Transonic Turbine,” J. Turbomach. 140(6), p. 061007.
Clark, J. P. , 2012, “ Design Strategies to Mitigate Unsteady Forcing,” Structural Design of Aircraft Engines: Key Objectives and Techniques (VKI Lecture Series), G. Paniagua , ed., NATO Research and Technology Office, Brussels, Belgium.
Joly, M. , Verstraete, T. , and Paniagua, G. , 2010, “ Attenuation of Vane Distortion in a Transonic Turbine Using Optimization Strategies—Part I: Methodology,” ASME Paper No. GT2010-22370.
Praisner, T. J. , Grover, E. A. , Knezevici, D. C. , Popovic, I. , Sjolander, S. A. , Clark, J. P. , and Sondergaard, R. , 2013, “ Toward the Expansion of Low-Pressure-Turbine Airfoil Design Space,” ASME J. Turbomach., 135(6), p. 061007. [CrossRef]
Kerrebrock, J. L. , Epstein, A. H. , Merchant, A. A. , Guennete, G. R. , Parker, D. , Onnee, J.-F. , Neumayer, F. , Adamczyk, J. J. , and Shabbir, A. , 2008, “ Design and Test of an Aspirated Counter-Rotating Fan,” ASME J. Turbomach., 130(2), p. 021004. [CrossRef]
Huber, F. , Johnson, P. D. , Sharma, O. P. , Staubach, J. B. , and Gaddis, S. W. , 1996, “ Performance Improvement Through Indexing of Turbine Airfoils—Part 1: Experimental Investigation,” ASME J. Turbomach., 118(4), pp. 630–635. [CrossRef]
Haldeman, C. W. , Dunn, M. G. , Barter, J. W. , Green, B. R. , and Bergholz, R. F. , 2005, “ Experimental Investigation of Vane Clocking in a One and 1/2 Stage High Pressure Turbine,” ASME J. Turbomach., 127(3), pp. 512–521. [CrossRef]
Kemp, R. H. , Hirschberg, M. H. , and Morgan, W. C. , 1958, “ Theoretical and Experimental Analysis of the Reduction of Rotor Blade Vibration in Turbomachinery Through the Use of Modified Stator Vane Spacing,” Washington, DC, Report No. NACA TN 4373.
Ni, R. H. , Humber, W. , Ni, M. , Capece, V. R. , Ooten, M. K. , and Clark, J. P. , “ Aerodynamic Damping Predictions for Oscillating Airfoils in Cascades Using Moving Meshes,” ASME Paper No. GT2016-57017.
Clark, J. P. , and Grover, E. A. , 2007, “ Assessing Convergence in Predictions of Periodic-Unsteady Flowfields,” ASME J. Turbomach., 129(4), pp. 740–749. [CrossRef]
Anthony, R. J. , and Clark, J. P. , 2013, “ A Review of the AFRL Turbine Research Facility,” ASME Paper No. GT2013-94741.
Graf, M. B. , and Sharma, O. P. , 1996, “ Effects of Downstream Stator Pressure Field on Upstream Rotor Performance,” ASME Paper No. 96-GT-507.
Fischer, A. , Riess, W. , and Seume, J. R. , 2003, “ Performance of Strongly Bowed Stators in a 4-Stage High Speed Compressor,” ASME Paper. No. GT2003-38392.
Smolny, A. , Blaszczak, J. R. , Krysinski, J. , and Borzecki, T. , 2007, “ Challenges and Opportunities for the Turbine Performance Improvement Through Stator Clocking and Vane Bowing,” ASME Paper No. GT2007-28008.
Poehler, T. , Niewoehner, J. , Jeschke, P. , and Guendogdu, Y. , 2015, “ Investigation of Nonaxisymmetric Endwall Contouring and Three-Dimensional Airfoil Design in a 1.5-Stage Axial Turbine – Part 1: Design and Novel Numerical Analysis Method,” ASME J. Turbomach., 137(8), p. 081009. [CrossRef]
Havakechian, S. , and Denton, J. , 2015, “ Three-Dimensional Blade Stacking Strategies and Understanding of Flow Physics in Low Pressure Steam Turbines—Part II: Stacking Equivalence and Differentiators,” J. Eng. Gas Turbines Power, 138(6), p. 062601.
Song, L. , Guo, Z. , Li, J. , and Feng, Z. , 2018, “ Optimization and Knowledge Discovery of a Three-Dimensional Parameterized Vane With Nonaxisymmetric Endwall,” AIAA J. Prop. Power, 34, pp. 234–246. [CrossRef]
Shapiro, A. H. , 1953, The Dynamics and Thermodynamics of Compressible Fluid Flow, Vol. I, Wiley, New York.
Hancock, B. J. , and Clark, J. P. , 2014, “ Reducing Shock Interactions in a Transonic Turbine Via Three-Dimensional Aerodynamic Shaping,” AIAA J. Prop. Power, 30(5), pp. 1248–1256. [CrossRef]
Clark, J. P. , Aggarwala, A. S. , Velonis, M. A. , Magge, S. S. , and Price, F. R. , 2002, “ Using CFD to Reduce Resonant Stresses on a Single-Stage, High-Pressure Turbine Blade,” ASME Paper No. GT2002-30320.
Kaneko, Y. , Mori, K. , and Okui, H. , 2004, “ Study on the Effect of Asymmetric Vane Spacing on Vibratory Stress of Blade,” ASME Paper No. GT2004-53023.
Miyakozawa, T. , Kielb, R. E. , and Hall, K. C. , 2009, “ The Effects of Aerodynamic Asymmetric Perturbations on Forced Response of Bladed Discs,” ASME J. Turbomach., 131(4), p. 041008. [CrossRef]
Ekici, K. , Kielb, R. E. , and Hall, K. C. , 2010, “ Aerodynamic Asymmetry Analysis of Unsteady Flows in Turbomachinery,” ASME J. Turbomach., 132(1), p. 011006. [CrossRef]
Monk, D. J. , Key, N. L. , and Fulayter, R. D. , 2016, “ Reduction of Aerodynamic Forcing Through Introduction of Stator Asymmetry in Axial Compressors,” AIAA J. Prop. Power, 32(1), pp. 134–141. [CrossRef]
Niu, Y. , Hou, A. , Zhang, M. , Sun, T. , Wang, R. , and Guo, H. , 2014, “ Investigation on the Effect of Asymmetric Vane Spacing on the Reduction of Rotor Blade Vibration,” ASME Paper No. GT2014-26710.
Sun, T. , Hou, A. , Zhang, M. , Niu, Y. , Gao, J. , and Guo, H. , 2015, “ Analysis on the Reduction of Rotor Blade Vibration Using Asymmetric Vane Spacing,” ASME Paper No. GT2015-42778.
Ifeachor, E. C. , and Jervis, B. W. , 1996, Digital Signal Processing, Addison-Wesley, New York.
Dunn, M. G. , and Haldeman, C. W., Jr. , 1995, “ Phase-Resolved Surface Pressure and Heat Transfer Measurements on the Blade of a Two-Stage Turbine,” ASME J. Fluids Eng., 117(4), pp. 653–658. [CrossRef]


Grahic Jump Location
Fig. 1

Unsteady interaction between a transonic turbine blade and a downstream vane that is consistent with a counter-rotating LPT. Colorization by instantaneous static pressure highlights the shocks, whereas contours of entropy rise indicate shear layers.

Grahic Jump Location
Fig. 2

Downstream vane stacking configurations ((a)–(d)) assessed in this study. The view is nominally aft-looking-forward, and the colorization is the DFT magnitude of the fundamental upstream passing frequency: (a) baseline, (b) initial bowed, (c) reverse bowed, and (d) final bowed.

Grahic Jump Location
Fig. 3

DFT magnitudes on the blade suction side at the first harmonic of the downstream vane passing frequency for the vane stacking configurations (a-d) assessed: (a) baseline, (b) initial bowed, (c) reverse bowed, and (d) final bowed

Grahic Jump Location
Fig. 4

DFT phase angles on the blade suction side at the first harmonic of the downstream vane passing frequency for the (a) baseline and (b) final bowed vane configurations

Grahic Jump Location
Fig. 5

Overall unsteadiness on the blade suction side for (a) baseline and (b) asymmetric vanes as indicated by the local mean-square of unsteady pressure fluctuations

Grahic Jump Location
Fig. 6

Percentage of the overall mean-square unsteadiness due to frequencies associated with shock reflections for (a) baseline and (b) asymmetric vanes

Grahic Jump Location
Fig. 7

DFT magnitudes on the blade suction side at the first harmonic of the downstream passing frequencies for the baseline symmetric (a) and asymmetric vane configurations ((b)–(d)): (a) baseline 46E, (b) asymmetric 46E, (c) 44E, and (d) 48E

Grahic Jump Location
Fig. 8

The downstream vane ring used for experimental verification of design changes including both bowing and asymmetric spacing, presented as (a) an engineering drawing and (b) a view of the instrumented hardware

Grahic Jump Location
Fig. 9

DFT magnitudes on the blade suction side at the first harmonic of the downstream passing frequencies for the baseline (a) and bowed, asymmetric vane configurations ((b)–(d)) at experimental conditions: (a) baseline 46E, (b) bowed asymmetric 46E, (c) bowed asymmetric 44E, and (d) bowed asymmetric 48E

Grahic Jump Location
Fig. 10

A comparison of measured and simulated DFT magnitudes on the blade suction side at frequencies around the first harmonic of the downstream passing frequencies for the Baseline and Bowed, Asymmetric vane configurations



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