0
Research Papers

The Effect of Annulus Performance Parameters on Rotor-Stator Cavity Sealing Flow

[+] Author and Article Information
Alexander V. Mirzamoghadam

Fellow of ASME
Advanced Technology Development,
Honeywell International,
Phoenix, AZ 85034

G. Heitland, K. Molla-Hosseini

Advanced Technology Development,
Honeywell International,
Phoenix, AZ 85034

Manuscript received December 6, 2011; final manuscript received May 7, 2012; published online April 11, 2014. Assoc. Editor: Srinath V. Ekkad.

J. Thermal Sci. Eng. Appl 6(3), 031013 (Apr 11, 2014) (7 pages) Paper No: TSEA-11-1170; doi: 10.1115/1.4026963 History: Received December 06, 2011; Revised May 07, 2012

The amount of cooling air assigned to seal high pressure (HP) turbine rim cavities is critical for performance as well as component life. Insufficient air leads to excessive hot annulus gas ingestion and its penetration deep into the cavity compromising disk or cover plate life. Excessive purge air, on the other hand, adversely affects performance. This paper is a continuation of the authors' work on ingestion reported by Mirzamoghadam et al. (2008) (“3D CFD Ingestion Evaluation of a High Pressure Turbine Rim Seal Disk Cavity,” ASME Paper No. GT2008-50531), where the main focus of that investigation was to qualitatively describe ingestion driven by annulus circumferential pressure asymmetry under constant annulus conditions and rotational speed. In this paper, the research team investigated the variation of annulus circumferential pressure fluctuation and rotational speed on the double overlap platform rim seal cavity reported in part-1. The outcome from this study was to map out the resulting nondimensional minimum sealing flow (minimum value of Cw or Cw,min) as it relates to entrained ingestion in the absence of cavity cooling flow (Cw,ent). As was done in part-1, the runs were made with 3D computational fluid dynamics (CFD) in setup/run mode option using Fine/Turbo. At two rotational speeds, annulus conditions were varied by reducing turbine inlet pressure (i.e., mass flow) from the baseline operating condition, and the resulting pressure fluctuation was quantified. In addition, an investigation to assess the selected aft-located mixing plane steady state solution for this study as compared to the forward-located steady run was performed using unsteady (nonlinear Harmonics) CFD as the referee. The results yielded the linear decrease in Cw,ent at fixed rotational Reynolds number as annulus Reynolds number was decreased. Moreover, the rate of change in entrained flow sharply increases with increase in rotational Reynolds number. As annulus mass flow is reduced to a critical value defined by annulus-to-rotational Reynolds number ratio, the CFD prediction for Cw,ent converges to the turbulent boundary layer entrainment solution for the rotor, and Cw,min reverts to the rotational Reynolds number dominating region. The results from this study were compared to what has been observed by a previous study for a single overlap platform geometry. The resulting design curve allows insight in relating cavity purge flow requirements versus turbine cycle parameters which could lead to better efficiency.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Mirzamoghadam, A. V., Heitland, G., Morris, M. C., Smoke, J., Malak, M., and Howe, J., 2008, “3D CFD Ingestion Evaluation of a High Pressure Turbine Rim Seal Disk Cavity,” ASME Paper No. GT2008-50531.
Bayley, F. J., and Owen, J. M., 1970, “The Fluid Dynamics of a Shrouded Disk System With a Radial Outflow of Coolant,” ASME J. Eng. Power, 92, pp. 335–341. [CrossRef]
Phadke, U. P., and Owen, J. M., 1988, “Aerodynamic Aspects of the Sealing of Gas Turbine Rotor-Stator Systems, Part 1: The Behavior of Simple Shrouded Rotating Disk Systems in a Quiescent Environment,” Int. J. Heat Fluid Flow, 9, pp. 98–105. [CrossRef]
Phadke, U. P., and Owen, J. M., 1988, “Aerodynamic Aspects of the Sealing of Gas Turbine Rotor-Stator Systems, Part 2: The Performance of Simple Seals in a Quasi-Axisymmetric External Flow,” Int. J. Heat Fluid Flow, 9, pp. 106–112. [CrossRef]
Phadke, U. P., and Owen, J. M., 1988, “Aerodynamic Aspects of the Sealing of Gas Turbine Rotor-Stator Systems, Part 3: The Effect of Nonaxisymmetric External Flow on Seal Performance,” Int. J. Heat Fluid Flow, 9, pp. 113–117. [CrossRef]
Green, T., and Turner, A. B., 1992, “Ingestion into the Wheel space of an Axial Turbine Stage,” ASME Paper No. 92-GT-203.
Ko, S. H., and Rhode, D. L., 1992, “Thermal Details in a Rotor-Stator Cavity at Engine Conditions with a Mainstream,” ASME J. Turbomachinery, 114, pp. 446–453. [CrossRef]
Bohn, D., Rudzinski, B., Suerken, N., and Gaertner, W., 1999, “Influence of Rim Seal Geometry on Hot Gas Ingestion into the Upstream Cavity of an Axial Turbine Stage,” ASME Paper No. 99-GT-248.
Bohn, D., Rudzinski, B., Suerken, N., and Gaertner, W., 2000, “Experimental and Numerical Investigation of the Influence of Rotor Blades on Hot Gas Ingestion into the Upstream Cavity of an Axial Turbine Stage,” ASME Paper No. 00-GT-284.
Bohn, D., and Wolff, M., 2003, “Improved Formulation to Determine Minimum Sealing Flow-Cw,min-for Different Sealing Configurations”, ASME Paper No. GT2003-38465.
Johnson, B. V., Wang, C. Z., and Roy, R. P., 2008, “A Rim Seal Orifice Model With Two Cds and Effects of Swirl in Seals,” ASME Paper No. GT2008-50650.
Roy, R. P., Feng, J., and Narzary, D., 2005, “Experiment on Gas Ingestion Through Axial-Flow Turbine Rim Seals,” ASME J. Eng. Gas Turbine Power, 127, pp. 573–582. [CrossRef]
Okita, Y., Nishiura, M., Yamawaki, S., and Hironaka, Y., 2005, “A Novel Method for Turbine Rotor-Stator Rim Cavities Affected by Mainstream Ingress,” ASME J. Eng. Gas Turbine Power, 127, pp. 798–806. [CrossRef]
Johnson, B. V., Bohn, D., Jakoby, R., and Cunat, D., 2006, “A Method for Estimating the Influence of Time-Dependent Vane and Blade Pressure Fields on Turbine Rim Seal Ingestion,” ASME Paper No. GT2006-90853.
He, L., 2008, “Efficient Computational Model for Non-Axisymmetric Flow and Heat Transfer in Rotating Cavity,” ASME Paper No. GT2008-51132.
Volkov, K. N., Hills, N. J., and Chew, J. W., 2008, “Simulation of Turbulent Flows in Turbine Blade Passages and Disc Cavities,” ASME Paper No. GT2008-50672.
Roy, R. P., Zhou, D. W., Ganesan, S., Wang, C. Z., and Paolillo, R. E., 2007, “The Flow Field and Main Gas Ingestion in a Rotor-Stator Cavity,” ASME Paper No. GT2007-27671.
Reid, K., Denton, J., Pullan, G., Curtis, E., and Longley, J., 2006, “The Effect of Stator-Rotor Hub Sealing Flow on the Mainstream Aerodynamics of a Turbine,” ASME Paper No. GT2006-90838.
Mirzamoghadam, A. V., Giebert, D., Molla-Hosseini, K., and Bedrosyan, L., 2012, “The Influence of HPT Forward Disc Cavity Platform Axial Overlap Geometry on Mainstream Ingestion,” ASME Paper No. GT2012-68429.
Owen, J. M., and Rogers, R. H., 1989, Flow and Heat Transfer in Rotating Disc Systems: Rotor-Stator Systems, Vol. 1, Research Studies Press, Taunton, UK, pp. 85–86.
Mirzamoghadam, A. V., and Xiao, Z., 2002, “Flow and Heat Transfer in an Industrial Rotor-Stator Rim Sealing Cavity,” ASME J. Eng. Gas Turbines Power, 124, pp. 125–132. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Configuration studied by Bohn and Wolff [10]

Grahic Jump Location
Fig. 2

Turbine stage and cavity

Grahic Jump Location
Fig. 3

(a) CFD model domain-sector view. (b) CFD model domain.

Grahic Jump Location
Fig. 5

CFD model boundary conditions [1] (figure not to scale)

Grahic Jump Location
Fig. 6

CFD solution convergence

Grahic Jump Location
Fig. 7

Total temperature contours of the tangential cutting plane. (a) Minimum pressure sectional view. (b) Maximum pressure sectional view.

Grahic Jump Location
Fig. 8

Cavity radial/axial cuts for results

Grahic Jump Location
Fig. 9

Sensitivity of annulus Reynolds number to rotor entrained flow at different rotational speeds

Grahic Jump Location
Fig. 10

Cw,ent and Cw,min versus annulus Re

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