Research Papers: Gas Turbines: Structures and Dynamics

Use of Pressure Measurements to Determine Effectiveness of Turbine Rim Seals

[+] Author and Article Information
J. Michael Owen, James A. Scobie, GeonHwan Cho, Gary D. Lock

Department of Mechanical Engineering,
University of Bath,
Bath BA2 7AY, UK

Kang Wu

Department of Thermal Engineering,
Tsinghua University,
Beijing 100084, China

Carl M. Sangan

Department of Mechanical Engineering,
University of Bath,
Bath BA2 7AY, UK
e-mail: c.m.sangan@bath.ac.uk

1Corresponding author.

Contributed by the Structures and Dynamics Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received July 21, 2014; final manuscript received July 28, 2014; published online October 7, 2014. Editor: David Wisler.

J. Eng. Gas Turbines Power 137(3), 032510 (Oct 07, 2014) (10 pages) Paper No: GTP-14-1417; doi: 10.1115/1.4028395 History: Received July 21, 2014; Revised July 28, 2014

The ingress of hot gas through the rim seal of a gas turbine depends on the pressure difference between the mainstream flow in the turbine annulus and that in the wheel-space radially inward of the rim seal. In this paper, a previously published orifice model is modified so that the sealing effectiveness εc determined from concentration measurements in a rig could be used to determine εp, the effectiveness determined from pressure measurements in an engine. It is assumed that there is a hypothetical “sweet spot” on the vane platform where the measured pressures would ensure that the calculated value of εp equals εc, the value determined from concentration measurements. Experimental measurements for a radial-clearance seal show that, as predicted, the hypothetical pressure difference at the sweet spot is linearly related to the pressure difference measured at an arbitrary location on the vane platform. There is good agreement between the values of εp determined using the theoretical model and values of εc determined from concentration measurements. Supporting computations, using a 3D steady computational fluid dynamics (CFD) code, show that the axial location of the sweet spot is very close to the upstream edge of the seal clearance. It is shown how parameters obtained from measurements of pressure and concentration in a rig could, in principle, be used to calculate the sealing effectiveness in an engine.

Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.


Owen, J. M., 2011, “Prediction of Ingestion Through Turbine Rim Seals—Part I: Rotationally Induced Ingress,” ASME J. Turbomach., 133(3), p. 031005. [CrossRef]
Owen, J. M., 2011, “Prediction of Ingestion Through Turbine Rim Seals—Part II: Externally Induced and Combined Ingress,” ASME J. Turbomach., 133(3), p. 031006. [CrossRef]
Wang, C. Z., Johnson, B. V., Cloud, D. F., Paolillo, R. E., Vashist, T. K., and Roy, R. P., 2006, “Rim Seal Ingestion Characteristics for Axial Gap Rim Seals in a Closely-Spaced Turbine Stage From a Numerical Simulation,” ASME Paper No. GT2006-90965. [CrossRef]
Palafox, P., Ding, Z., Bailey, J., Vanduser, T., Kirtley, K., Moore, K., and Chupp, R., 2013, “A New 1.5-Stage Turbine Wheelspace Hot Gas Ingestion Rig (HGIR)—Part I: Experimental Test Vehicle, Measurement Capability and Baseline Results,” ASME Paper No. GT2013-96020. [CrossRef]
Ding, Z., Palafox, P., Moore, K., Chupp, R., and Kirtley, K., 2013, “A New 1.5-Stage Wheelspace Hot Gas Ingestion Rig (HGIR)—Part II: CFD Modeling and Validation,” ASME Paper No. GT2013-96021. [CrossRef]
Gentilhomme, O., Hills, N. J., and Turner, A. B., 2003, “Measurement and Analysis of Ingestion Through a Turbine Rim Seal,” ASME J. Turbomach., 125(3), pp. 505–512. [CrossRef]
Sangan, C. M., Pountney, O. J., Scobie, J. A., Wilson, M., Owen, J. M., and Lock, G. D., 2013, “Experimental Measurements of Ingestion Through Turbine Rim Seals—Part 3: Single and Double Seals,” ASME J. Turbomach., 135(5), p. 051011. [CrossRef]
Zhou, D. W., Roy, R. P., Wang, C. Z., and Glahn, J. A., 2011, “Main Gas Ingestion in a Turbine Stage for Three Rim Cavity Configurations,” ASME J. Turbomach., 133(3), p. 031023. [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 Non-Axisymmetric External Flow on Seal Performance,” Int. J. Heat Fluid Flow, 9(2), pp. 113–117. [CrossRef]
Green, T., and Turner, A. B., 1994, “Ingestion Into the Upstream Wheelspace of an Axial Turbine Stage,” ASME J. Turbomach., 116(2), pp. 327–332. [CrossRef]
Bohn, D., Rudzinski, B., Sürken, N., and Gärtner, 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. 2000-GT-0284. [CrossRef]
Scobie, J. A., Sangan, C. M., Teuber, R., Pountney, O. J., Owen, J. M., Wilson, M., and Lock, G. D., 2013, “Experimental Measurements of Ingestion Through Turbine Rim Seals: Part 4—Off-Design Conditions,” ASME Paper No. GT2013-94147. [CrossRef]
Johnson, B. V., Jakoby, R., Bohn, D. E., 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. [CrossRef]
Johnson, B. V., Wang, C.-Z., and Roy, P. R., 2008, “A Rim Seal Orifice Model With Two Cds and Effect of Swirl in Seals,” ASME Paper No. GT2008-50650. [CrossRef]
Roy, R. P., Zhou, D. W., Ganesan, S., Wang, C.-Z., Paolillo, R. E., and Johnson, B. V., 2007, “The Flow Field and Main Gas Ingestion in a Rotor-Stator Cavity,” ASME Paper No. GT2007-27671. [CrossRef]
Chew, J. W., Green, T., and Turner, A. B., 1994, “Rim Sealing of Rotor-Stator Wheelspaces in the Presence of External Flow,” ASME Paper No. 94-GT-126.
Sangan, C. M., Pountney, O. J., Zhou, K., Wilson, M., Owen, J. M., and Lock, G. D., 2013, “Experimental Measurements of Ingestion Through Turbine Rim Seals—Part I: Externally-Induced Ingress,” ASME J. Turbomach., 135(2), p. 021012. [CrossRef]
Zhou, K., Wood, S. N., and Owen, J. M., 2013, “Statistical and Theoretical Models of Ingestion Through Turbine Rim Seals,” ASME J. Turbomach., 135(2), p. 021014. [CrossRef]
Owen, J. M., Zhou, K., Pountney, O. J., Wilson, M., and Lock, G. D., 2012, “Prediction of Ingress Through Turbine Rim Seals—Part 1: Externally-Induced Ingress,” ASME J. Turbomach., 134(3), p. 031012. [CrossRef]
Childs, P. R. N., 2010, Rotating Flow, Butterworth-Heinemann, Oxford, UK.
Bohn, D., Johann, E., and Kruger, U., 1995, “Experimental and Numerical Investigations of Aerodynamic Aspects of Hot Gas Ingestion in Rotor-Stator Systems With Superposed Cooling Mass Flow,” ASME Paper No. 95-GT-143.
Sangan, C. M., Lalwani, Y., Owen, J. M., and Lock, G. D., 2013, “Experimental Measurements of Ingestion Through Turbine Rim Seals: Part 5—Fluid Dynamics of Wheel-Space,” ASME Paper No. GT2013-94148. [CrossRef]
Teuber, R., Wilson, M., Lock, G. D., Owen, J. M., Li, Y. S., and Maltson, J. D., 2012, “Computational Extrapolation of Turbine Sealing Effectiveness From Test Rig to Engine Conditions,” ASME Paper No. GT2012-68490. [CrossRef]


Grahic Jump Location
Fig. 2

Rig test section with inset highlighting the static pressure taps in the vane hub (location A) and typical pressure asymmetry in the annulus. (Red indicates the stationary disk and blue indicates the rotating disk.)

Grahic Jump Location
Fig. 3

Typical circumferential variation of pressure coefficient at location A in the annulus. CF = 0.538, Reϕ = 8.17 × 105, and Φ0 = 0. (Symbols denote experimental measurements and curve shows computed variation.)

Grahic Jump Location
Fig. 5

Comparison between theoretical and measured values of εc for radial-clearance seal

Grahic Jump Location
Fig. 4

Schematic of radial-clearance seal and annulus showing location A. Static dimensions in mm: h = 10; S = 20; sc,ax = 2.00; sc,rad = 1.28; and soverlap = 1.86.

Grahic Jump Location
Fig. 6

Effect of Φomin on computed variation of g∧ and g with x showing location of sweet spot. (Horizontal broken lines show values of g∧; solid curve shows computed variation of g(x); and solid vertical line shows mean value of computed x∧.)

Grahic Jump Location
Fig. 7

Computed variation of x∧ with Φomin. (Solid line shows mean value of x∧, with its geometric position shown in relation to the seal clearance (inset).)

Grahic Jump Location
Fig. 8

Effect of r1/b on measured variation of g(xA) with Φo/Φmin

Grahic Jump Location
Fig. 9

Variation of g∧ with measured values of g(xA). (Solid line shows linear regression of data.)

Grahic Jump Location
Fig. 10

Variation of g∧ and g (xA) with Φomin

Grahic Jump Location
Fig. 11

Variation of sealing effectiveness with Φomin. (Solid symbols denote values of εp from pressure measurements; open symbols denote values of εc from concentration measurements; and solid curve is based on effectiveness equation.)

Grahic Jump Location
Fig. 1

(a) Typical high-pressure gas-turbine stage and (b) detail of rim seal



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