A combustor-representative swirl simulator for a transonic turbine research facility

Abstract

Tighter aircraft emissions regulations have let to considerable improvement in gas turbine combustion in the past few decades. Modern combustors employ aggressive swirlers to increase mixing and to improve flame stability during the combustion process. The flow at combustor exit can therefore have high residual swirl. The impact of this swirl on the aerodynamic and heat transfer characteristics of the HP turbine stage has not yet received much attention.

In order to investigate the effects of swirl on the HP turbine stage, an inlet swirl simulator has been designed and commissioned in an engine scale, short duration, rotating transonic turbine facility. The test facility simulates engine representative Mach number, Reynolds number, non-dimensional speed and gas-to-wall temperature ratio at the turbine inlet. The target swirl profile at turbine stage inlet was based upon extreme exit swirl conditions for a modern low-NO_x combustor with peak yaw and pitch angles over ±40°. A number of candidate swirler designs were considered during a pilot study that was conducted in a subsonic wind tunnel to achieve suitable swirler design. The swirl simulator was developed based upon the pilot study results, which achieved a good match to the target profile after commissioning in the facility. This article mainly deals with the design and development of the swirl generator. It presents the experimental and computational results of the pilot study, followed by the description of the installation and commissioning of the swirl simulator on the test facility. Novel instrumentation was required to survey the swirl profile, which is also described. A comparison of the measured and computational aerodynamic results with and without swirl, at 10 per cent and 90 per cent span of HP nozzle guide vane is also presented. The comparison highlights significant impact of swirl on the vane incidence angle, and therefore a considerable affect on the loading distribution of the vane.

Keywords

transonic turbine gas turbine combustor swirl HP turbine

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References

Beer

J. M.

Chigier

N. A.

Combustion aerodynamics, 1974, Applied Science Publishers, London 100–113.

Lilley

D. G.

Swirl flows in combustion: a review. AIAA J., 1977, 15, 8–1063.

Gupta

A. K.

Lewis

M. J.

Daurer

Swirl effects on combustion characteristics of premixed flames. J. Eng. Gas Turbines Power, 2001, 123, 619–626.

Li, G. and Gutmark, E. J. Effects of swirler configurations on flow structures and combustion characteristics. ASME paper no. GT2004-53674, 2004.

Datta

Son

S. K.

Combustion and emission characteristics in a gas turbine combustor at different pressure and swirl conditions. Appl. Thermal. Engng., 1999, 19, 9–949.

Stone

Menon

Swirl control of combustion instabilities in a gas turbine combustor. Proc. Combust. Inst., 2002, 29, 155–160.

Yang

S. L.

Siow

Y. K.

Peschke

B. D.

Tacina

R. R.

Numerical study of nonreacting gas turbine combustor swirl flow using Reynolds stress model. Trans ASME, J. Eng. Gas Turbines Power, 2003, 125, 804–811.

Huang

Yang

Effects of swirl on combustion dynamics in a lean-premixed swirl-stabilized combustor. Proc. Combust. Inst., 2005, 30, 1775–1782.

Bicen

A. F.

Jones

W. P.

Velocity characteristics of isothermal and combusting flows in a model combustor. Combust. Sci. Technol., 1986, 49, 01–15.

10.

Koutmos

McGuirk

J. J.

Isothermal flow in a gas turbine combustor – a benchmark experimental study. Exp. Fluids, 1989, 7, 344–354.

11.

Wurm, B., Schulz, A., and Bauer, H. -J. A new test facility for investigating the interaction between swirl flow and wall cooling films in combustors. In Proceedings of ASME Turbo Expo: Power Land, Sea and Air, Orlando, Florida, USA, 8–12 June 2009, paper no. GT2009-59961.

12.

Barrigner

M. D.

Richard

O. T.

Walter

J. P.

Stitzel

S. M.

Thole

K. A.

Flow field simulations of a gas turbine combustor. Trans. ASME, J. Turbomachinery, 2002, 124, 508–516.

13.

Vakil

S. S.

Thole

K. A.

Flow and thermal field measurements in a combustor simulator relevant to a gas turbine aeroengine. J. Eng. Gas Turbines Power, 2005, 127, 257–267.

14.

Colban

W. F.

Thole

K. A.

Combustor turbine interface studies – part 1: end wall effectiveness measurements. J. Turbomachinery, 2003, 125, 193–202.

15.

Colban

W. F.

Lethander

A. T.

Thole

K. A.

Zess

Combustor turbine interface studies – part 2: flow and thermal field measurements. J. Turbomachinery, 2003, 125, 203–209.

16.

Van Fossen

G. J.

Bunker

R. S.

Augmentation of stagnation region heat transfer due to turbulence from a DLN can combustor. Trans ASME, J. Turbomachinery, 2001, 123, 140–146.

17.

Shih

T. I.-P.

Lin

Y.-L.

Controlling secondary-flow structure by leading-edge airfoil fillet and inlet swirl to reduce aerodynamic loss and surface heat transfer. Trans. ASME, J. Turbomachinery, 2003, 125, 48–56.

18.

Jones, T. V., Schultz, D. L., and Hendley, A. D. On the flow in an isentropic light piston tunnel. Report no. 3731, Department of Engineering Science, University of Oxford, MoD (Proc Exec), Aeronautical Research Council, January 1973.

19.

Goodisman

M. I.

Oldfield

M. L. G.

Kingcombe

R. C.

Jones

T. V.

Ainsworth

R. W.

Brooks

A. J.

An Axial Turbobrake. ASME J. Turbomachinery, 1992, 114, 419–425.

20.

Hilditch, M. A., Fowler, A., Jones, T. V., Chana, K. S., Oldfield, M. L. G., Ainsworth, R. W., Hogg, S. I., Anderson, S. J., and Smith, G. C. Installation of a turbine stage in the pyestock isentropic light piston facility. ASME paper no. 94-GT-277, 1994.

21.

Povey

Chana

K. S.

Jones

T. V.

Oldfield

M. L. G.

The design and performance of a transonic flow deswirling system: an application of current CFD design techniques tested against model and full-scale experiments. In Advances of CFD in fluid machinery design (Eds Elder

R. L.

Tourlidakis

Yates

M. K.

, 2003, IMechE Professional Engineering, Bury St Edmunds and London 65–94.

22.

Povey

Qureshi

A hot-streak (combustor) simulator suited to aerodynamic performance measurements. Proc. IMechE, Part G: J. Aerospace Engineering, 2008, 222(G6), 705–720.

23.

Povey

Qureshi

Developments in hot-streak simulators for turbine testing. J. Turbomachinery, 2009, 131(3), 031009-1–031009-15 .

24.

Qureshi, I., Beretta, A., and Povey, T. Effect of simulated combustor temperature non-uniformity on HP vane and endwall heat transfer: an experimental and computational investigation. In Proceedings of ASME Turbo Expo 2010, Power for Land, Sea, Air, Glasgow, UK, 13–18 June 2010.

25.

Qureshi, I., Smith, A., Chana, K. S., and Povey, T. Effect of temperature non-uniformity on heat transfer in an unshrouded transonic HO turbine: an experimental and computational investigation. In Proceedings of ASME Turbo Expo 2010, Power for Land, Sea, Air, Glasgow, UK, 13–18 June 2010.

26.

Beard, P. F. On ransient turbine efficiency measurements with engine representative inlet flows. PhD Thesis, Department of Engineering Science, University of Oxford, 2010.

27.

Beard

P. F.

Povey

Chana

K. S.

Turbine efficiency measurement system for the qinetiQ turbine test facility. ASME J. Turbomachinery, 2008, 132(1), 011002–011002.

28.

Shepherd

I. C.

A four hole pressure probe for fluid flow in three dimensions. ASME Fluids Eng., 1981, 103, 590–594.

29.

Main

A. J.

Day

C. R. B.

Lock

G. D.

Oldfield

M. L. G.

Calibration of a four-hole pyramid probe and area traverse measurements in a short-duration transonic turbine cascade tunnel. Exp. Fluids, 1996, 21, 302–311.

30.

Calvin, L. P. T. High blockage turbulators in gas turbine cooling passages. PhD Thesis, University of Oxford, UK, 2002.

31.

Pisasale

A. J.

Ahmed

N. A.

A novel method for extending the calibration range of five-hole probe for highly three-dimensional flows. Flow Meas. Instrum., 2002, 13, 23–30.