This paper describes experiments in a subscale axial turbine stage equipped with an axially overlapping radial-clearance seal at the disk cavity rim and a labyrinth seal radially inboard which divides the disk cavity into a rim cavity and an inner cavity. An orifice model of the rim seal is presented; values of ingestion and egress discharge coefficients based on the model and experimental data are reported for a range of cavity purge flow rate. In the experiments, time-averaged pressure distribution was measured in the main gas annulus and in the disk cavity; also measured was the time-averaged ingestion into the cavity. The pressure and ingestion data were combined to obtain the discharge coefficients. Locations on the vane platform 1 mm upstream of its lip over two vane pitches circumferentially defined the main gas annulus pressure; in the rim cavity, locations at the stator surface in the radially inner part of the “seal region” over one vane pitch defined the cavity pressure. For the sealing effectiveness, two locations in the rim cavity at the stator surface, one in the “mixing region” and the other radially further inward at the beginning of the stator boundary layer were considered. Two corresponding sets of ingestion and egress discharge coefficients are reported. The ingestion discharge coefficient was found to decrease in magnitude as the purge flow rate increased; the egress discharge coefficient increased with purge flow rate. The discharge coefficients embody fluid-mechanical effects in the ingestion and egress flows. Additionally, the minimum purge flow rate required to prevent ingestion was estimated for each experiment set and is reported. It is suggested that the experiments were in the combined ingestion (CI) region with externally induced (EI) ingestion being the dominant contributor.

References

References
1.
Hills
,
N. J.
,
Chew
,
J. W.
, and
Turner
,
A. B.
,
2002
, “
Computational and Mathematical Modeling of Turbine Rim Seal Ingestion
,”
ASME J. Turbomach.
,
124
(
2
), pp.
306
315
.10.1115/1.1456461
2.
Roy
,
R. P.
,
Feng
,
J.
,
Narzary
,
D.
, and
Paolillo
,
R. E.
,
2005
, “
Experiment on Gas Ingestion Through Axial-Flow Turbine Rim Seals
,”
ASME J. Eng. Gas Turbines Power
,
127
(
3
), pp.
573
582
.10.1115/1.1850499
3.
Bunker
,
R. S.
,
Laskowski
,
G. M.
,
Bailey
,
J. C.
,
Palfox
,
P.
,
Kapetanovic
,
S.
,
Itzal
,
G. M.
,
Sullivan
,
M. A.
, and
Farell
,
T. R.
,
2010
, “
An Investigation of Turbine Wheelspace Cooling Flow Interactions With a Transonic Hot Gas Path—Part 1: Experimental Measurements
,”
ASME J. Turbomach.
,
138
(
2
), p.
021015
.10.1115/1.4001175
4.
Jakoby
,
R.
,
Zierer
,
T.
,
Lindblad
,
K.
,
Larsson
,
J.
,
deVito
,
L.
,
Bohn
,
D. E.
,
Funcke
,
J.
, and
Decker
,
A.
,
2004
, “
Numerical Simulation of the Unsteady Flow Field in an Axial Gas Turbine Rim Seal Configuration
,”
ASME
Paper No. GT2004-53829.10.1115/GT2004-53829
5.
Wang
,
C.-Z.
,
Mathiyalagan
,
S. P.
,
Johnson
,
B. V.
,
Glahn
,
J. A.
, and
Cloud
,
D. F.
,
2012
, “
Rim Seal Ingestion in a Turbine Stage From 360-Degree Time Dependent Numerical Simulations
,”
ASME
Paper No. GT2012-68193.10.1115/GT2012-68193
6.
Gentilhomme
,
O.
,
Hills
,
N. J.
,
Turner
,
A. B.
, and
Chew
,
J. W.
,
2003
, “
Measurement and Analysis of Ingestion Through a Turbine Rim Seal
,”
ASME J. Turbomach.
,
125
(
3
), pp.
505
512
.10.1115/1.1556411
7.
Phadke
,
U. P.
, and
Owen
,
J. M.
,
1988
, “
Aerodynamic Aspects of the Sealing of Gas Turbine Rotor–Stator System—Part 3: The Effect of Nonaxisymmetric External Flow on Seal Performance
,”
Int. J. Heat Fluid Flow
,
9
(
2
), pp.
113
117
.10.1016/0142-727X(88)90062-8
8.
Bayley
,
F. J.
, and
Childs
,
P. R. N.
,
1997
, “
Prediction of Ingress Rates to Turbine and Compressor Wheelspaces
,”
Int. J. Heat Fluid Flow
,
18
(
2
), pp.
218
228
.10.1016/S0142-727X(96)00090-2
9.
Scanlon
,
T.
,
Wilkes
,
J.
,
Bohn
,
D.
, and
Gentilhomme
,
O.
,
2004
, “
A Simple Method for Estimating Ingestion of Annulus Gas Into a Turbine Rotor–Stator Cavity in the Presence of External Pressure Variations
,”
ASME
Paper No. GT2004-53097.10.1115/GT2004-53097
10.
Johnson
,
B. V.
,
Wang
,
C.-Z.
, and
Roy
,
R. P.
,
2008
, “
A Rim Seal Orifice Model With 2 Cds and Effects of Swirl in Seals
,”
ASME
Paper No. GT2008-50650.10.1115/GT2008-50650
11.
Hüning
,
M.
,
2010
, “
Parametric Single Gap Turbine Rim Seal Model With Boundary Generation for Asymmetric External Flow
,”
ASME
Paper No. GT2010-22434.10.1115/GT2010-22434
12.
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
.10.1115/1.4006609
13.
Balasubramanian
,
J.
,
Junnarkar
,
N.
,
Roy
,
R. P.
, and
Glahn
,
J. A.
,
2012
, “
Disk Cavity Purge Air Outflow Into the Main Gas Path of a Model Turbine Stage
,”
Exp. Therm. Fluid Sci.
,
38
, pp.
266
269
.10.1016/j.expthermflusci.2011.11.010
14.
Owen
,
J. M.
,
Pountney
,
O.
, and
Lock
,
G.
,
2012
, “
Prediction of Ingress Through Turbine Rim Seals—Part II: Combined Ingress
,”
ASME J. Turbomach.
,
134
(
3
), p.
031013
.10.1115/1.4003071
You do not currently have access to this content.