As engine development continues to advance toward increased efficiency and reduced fuel consumption, efficient use of compressor bypass cooling flow becomes increasingly important. In particular, optimal use of compressor bypass flow yields an overall reduction of harmful emissions. Cooling flows used for cavity sealing between stages are critical to the engine and must be maintained to prevent damaging ingestion from the hot gas path. To assess cavity seals, the present study utilizes a one-stage turbine with true-scale engine hardware operated at engine-representative rotational Reynolds number and Mach number. Past experiments have made use of part-span (PS) rather than full-span (FS) blades to reduce flow rate requirements for the test rig; however, such decisions raise questions about potential influences of the blade span on sealing effectiveness measurements in the rim cavity. For this study, a tracer gas facilitates sealing effectiveness measurements in the rim cavity to compare data collected with FS engine airfoils and simplified, PS airfoils. The results from this study show sealing effectiveness does not scale as a function of relative purge flow with respect to main gas path flow rate when airfoil span is changed. However, scaling the sealing effectiveness for differing spans can be achieved if the fully purged flow rate is known. Results also suggest reductions of purge flow may have a relatively small loss of seal performance if the design is already near a fully purged condition. Rotor tip clearance is shown to have no effect on measured sealing effectiveness.

References

References
1.
Clark
,
K.
,
Barringer
,
M.
,
Johnson
,
D.
,
Thole
,
K.
,
Grover
,
E.
, and
Robak
,
C.
,
2018
, “
Effects of Purge Flow Configuration on Sealing Effectiveness in a Rotor-Stator Cavity
,”
ASME J. Eng. Gas Turbines Power
,
140
(
11
), p.
112502
.
2.
Scobie
,
J. A.
,
Sangan
,
C. M.
,
Owen
,
J. M.
, and
Lock
,
G. D.
,
2016
, “
Review of Ingress in Gas Turbines
,”
ASME J. Eng. Gas Turbines Power
,
138
(
12
), p.
120801
.
3.
Johnson
,
B. V.
,
Mack
,
G. J.
,
Paolillo
,
R. E.
, and
Daniels
,
W. A.
,
1994
, “
Turbine Rim Seal Gas Path Flow Ingestion Mechanisms
,”
AIAA
Paper No. 94-2703.
4.
Bayley
,
F. J.
, and
Owen
,
J. M.
,
1970
, “
The Fluid Dynamics of a Shrouded Disk System With a Radial Outflow of Coolant
,”
J. Eng. Power
,
92
(
3
), pp.
335
341
.
5.
Phadke
,
U. P.
, and
Owen
,
J. M.
,
1988
, “
Aerodynamic Aspects of the Sealing of Gas Turbine Rotor-Stator Systems—Part 1: The Behavior of a Simple Shrouded Rotating-Disk Systems in a Quiescent Environment
,”
Int. J. Heat Fluid Flow
,
9
(
2
), pp.
98
105
.
6.
Owen
,
J. M.
,
2011
, “
Prediction of Ingestion Through Turbine Rim Seals—Part I, Rotationally-Induced Ingress
,”
ASME J. Turbomach.
,
133
(
3
), p.
031005
.
7.
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
.
8.
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
.
9.
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 II: Rotationally-Induced Ingress
,”
ASME J. Turbomach.
,
135
(
2
), p.
021013
.
10.
Scobie
,
J. A.
,
Hualca
,
F. P.
,
Patinios
,
M.
,
Sangan
,
C. M.
,
Owen
,
J. M.
, and
Lock
,
G. D.
,
2018
, “
Re-Ingestion of Upstream Egress in a 1.5-Stage Gas Turbine Rig
,”
ASME J. Eng. Gas Turbines Power
,
140
(
7
), p.
072507
.
11.
Barringer
,
M.
,
Coward
,
A.
,
Clark
,
K.
,
Thole
,
K.
,
Schmitz
,
J.
,
Wagner
,
J.
,
Alvin
,
M. A.
,
Burke
,
P.
, and
Dennis
,
R.
,
2014
, “
Development of a Steady Thermal Aero Research Turbine (START) for Studying Secondary Flow Leakages and Airfoil Heat Transfer
,”
ASME
Paper No. GT2014-25570.
12.
Clark
,
K.
,
Barringer
,
M.
,
Thole
,
K.
,
Clum
,
C.
,
Hiester
,
P.
,
Memory
,
C.
, and
Robak
,
C.
,
2017
, “
Effects of Purge Jet Momentum on Sealing Effectiveness
,”
ASME J. Eng. Gas Turbines Power
,
139
(
3
), p.
031904
.
13.
Clark
,
K.
,
Barringer
,
M.
,
Thole
,
K.
,
Clum
,
C.
,
Hiester
,
P.
,
Memory
,
C.
, and
Robak
,
C.
,
2016
, “
Using a Tracer Gas to Quantify Sealing Effectiveness for Engine Realistic Rim Seals
,”
ASME
Paper No. GT2016-58095.
14.
Owen
,
J. M.
,
Zhou
,
K.
,
Pountney
,
O. J.
,
Wilson
,
M.
, and
Lock
,
G.
,
2012
, “
Prediction of Ingress Through Turbine Rim Seals—Part I: Externally Induced Ingress
,”
ASME J. Turbomach.
,
134
(
3
), p.
031012
.
You do not currently have access to this content.