Abstract

Unsteady Reynolds-averaged Navier–Stokes modeling (URANS) is a valuable and cost-effective tool for computational fluid dynamics (CFD), including the investigation of mainstream–cavity interaction in turbines. Despite the gap in accuracy with higher order CFD methodologies, URANS is among the few simulation strategies of industrial interest suitable for predicting ingress/egress over a wide range of conditions. This paper presents a numerical study of the flow-field in the upstream double-radial seal of a 1.5 stage turbine. Various configurations are tested, including nonpurged and purged conditions. Rigor of the approach is ensured by a set of sensitivity analyses, allowing the delineation of a best practice on the use of URANS in rim seal simulations: this includes an assessment of the effects of sector size, cavity domain size, and blade count. Time-averaged and time-resolved flow predictions capture coherent structures in the rim gap. An association between the three-dimensional (3D) morphology of these structures and different ingress/egress mechanisms is proposed. Regions of enhanced radial activity are identified to correspond with the blade leading edges. A frequency analysis of unsteady pressure signals probed in the rim gap leads to a calculation of the structure number and speed. The structures are synchronous with the disk rotation for nonpurged cases but rotate at slower speed when purge is introduced. The relative number of blades and vanes directly influences the structure count and velocity. The configuration with no blades is characterized by the slowest structures. The calculations have been conducted at three different flow coefficients for the annulus flow. There is a reduction in radial activity and structure speed at lower flow coefficient, fundamentally related to the reduced pressure asymmetry and gradient of swirl across the rim seal.

References

1.
Scobie
,
J. A.
,
Sangan
,
C. M.
,
Michael Owen
,
J.
, and
Lock
,
G. D.
,
2016
, “
Review of Ingress in Gas Turbines
,”
ASME J. Eng. Gas Turbines Power
,
138
(
12
), p.
120801
.10.1115/1.4033938
2.
Chew
,
J. W.
,
Gao
,
F.
, and
Palermo
,
D. M.
,
2019
, “
Flow Mechanisms in Axial Turbine Rim Sealing
,”
Proc. Inst. Mech. Eng., Part C
,
233
, pp.
7637
7657
.10.1177/0954406218784612
3.
Bohn
,
D.
,
Rudzinski
,
B.
,
Sürken
,
N.
, and
Gärtner
,
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-248.10.1115/99-GT-248
4.
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. GT2008-50531.10.1115/GT2008-50531
5.
Da Soghe
,
R.
,
Bianchini
,
C.
,
Sangan
,
C. M.
,
Scobie
,
J. A.
, and
Lock
,
G. D.
,
2017
, “
Numerical Characterization of Hot-Gas Ingestion Through Turbine Rim Seals
,”
ASME J. Eng. Gas Turbines Power
,
139
(
3
), p.
032602
.10.1115/1.4034540
6.
Liu
,
J.
,
Weaver
,
A.
,
Shih
,
T. I.-P.
,
Sangan
,
C. M.
, and
Lock
,
G. D.
,
2015
, “
Modelling and Simulation of Ingress Into the Rim Seal and Wheelspace of a Gas-Turbine Rotor-Stator Configuration
,”
AIAA
Paper No. 2015-1445.10.2514/6.2015-1445
7.
Gao
,
F.
,
Chew
,
J. W.
,
Beard
,
P. F.
,
Amirante
,
D.
, and
Hills
,
N. J.
,
2017
, “
Numerical Studies of Turbine Rim Sealing Flows on a Chute Seal Configuration
,” 12th European Conference on Turbomachinery Fluid Dynamics and Thermodynamics (
ETC 2017
), Stockholm, Sweden, Apr. 3–7, Paper No. ETC2017-284.10.29008/ETC2017-284
8.
Da Soghe
,
R.
,
Bianchini
,
C.
,
Micio
,
M.
,
D'Errico
,
J.
, and
Bavassano
,
F.
,
2018
, “
Effect of Rim Seal Configuration on Gas Turbine Cavity Sealing in Both Design and Off-Design Conditions
,”
ASME
Paper No. GT2018-75712.10.1115/GT2018-75712
9.
Horwood
,
T.
,
2019
, “
Computation of Flow Instabilities in Turbine Rim Seals
,” Ph.D. thesis,
University of Bath
, Bath, UK.
10.
Cao
,
C.
,
Chew
,
J. W.
,
Millington
,
P. R.
, and
Hogg
,
S. I.
,
2004
, “
Interaction of Rim Seal and Annulus Flows in an Axial Flow Turbine
,”
ASME J. Eng. Gas Turbines Power
,
126
(
4
), pp.
786
793
.10.1115/1.1772408
11.
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
12.
Schädler
,
R.
,
Kalfas
,
A. I.
,
Abhari
,
R. S.
,
Schmid
,
G.
, and
Voelker
,
S.
,
2017
, “
Modulation and Radial Migration of Turbine Hub Cavity Modes by the Rim Seal Purge Flow
,”
ASME J. Turbomach.
,
139
(
1
), p.
011011
.10.1115/1.4034416
13.
Gao
,
F.
,
Chew
,
J. W.
,
Beard
,
P. F.
,
Amirante
,
D.
, and
Hills
,
N. J.
,
2018
, “
Large-Eddy Simulation of Unsteady Turbine Rim Sealing Flows
,”
Int. J. Heat Fluid Flow
,
70
, pp.
160
170
.10.1016/j.ijheatfluidflow.2018.02.002
14.
Gao
,
F.
,
Chew
,
J. W.
, and
Marxen
,
O.
,
2020
, “
Inertial Waves in Turbine Rim Seal Flows
,”
Phys. Rev. Fluids
,
5
(
2
), p.
024802
.10.1103/PhysRevFluids.5.024802
15.
Graikos
,
D.
,
Carnevale
,
M.
,
Sangan
,
C. M.
,
Lock
,
G. D.
, and
Scobie
,
J. A.
,
2021
, “
Influence of Flow Coefficient on Ingress Through Turbine Rim Seals
,”
ASME J. Eng. Gas Turbines Power
,
143
(
11
), p.
111010
.10.1115/1.4051912
16.
Savov
,
S. S.
, and
Atkins
,
N. R.
,
2017
, “
A Rim Seal Ingress Model Based on Turbulent Transport
,”
ASME
Paper No. GT2017-63531.10.1115/GT2017-63531
17.
di Mare
,
L.
,
Kulkarni
,
D. Y.
,
Wang
,
F.
,
Romanov
,
A.
,
Ramar
,
P. R.
, and
Zachariadis
,
Z. I.
,
2011
, “
Virtual Gas Turbines: Geometry and Conceptual Description
,”
ASME
Paper No. GT2011-46437.10.1115/GT2011-46437
18.
Hadade
,
I.
,
Wang
,
F.
,
Carnevale
,
M.
, and
di Mare
,
L.
,
2019
, “
Some Useful Optimisations for Unstructured Computational Fluid Dynamics Codes on Multicore and Manycore Architectures
,”
Comput. Phys. Commun.
,
235
, pp.
305
323
. 0210.1016/j.cpc.2018.07.001
19.
Wang
,
F.
,
Carnevale
,
M.
,
Lu
,
G.
,
di Mare
,
L.
, and
Kulkarni
,
D.
,
2016
, “
Virtual Gas Turbine: Pre-Processing and Numerical Simulations
,”
ASME
Paper No. GT2016-56227.10.1115/GT2016-56227
20.
Carnevale
,
M.
,
Green
,
J. S.
, and
Di Mare
,
L.
,
2014
, “
Numerical Studies Into Intake Flow for Fan Forcing Assessment
,”
ASME
Paper No. GT2014-25772.10.1115/GT2014-25772
21.
Carnevale
,
M.
,
Wang
,
F.
, and
di Mare
,
L.
,
2016
, “
Low Frequency Distortion in Civil Aero-Engine Intake
,”
ASME
Paper No. GTP-16-1297.10.1115/GTP-16-1297
22.
Wang
,
F.
,
Carnevale
,
M.
, and
di Mare
,
L.
,
2018
, “
Numerical Study of Deterministic Fluxes in Compressor Passages
,”
ASME J. Turbomach.
,
140
(
10
), p.
101005
.10.1115/1.4041450
23.
Wang
,
F.
,
Carnevale
,
M.
,
di Mare
,
L.
, and
Gallimore
,
S.
,
2018
, “
Simulation of Multistage Compressor at Off-Design Conditions
,”
ASME J. Turbomach.
,
140
(
2
), p.
021011
.10.1115/1.4038317
24.
Wilcox
,
D. C.
,
2008
, “
Formulation of the kω Turbulence Model Revisited
,”
AIAA J.
,
46
(
11
), pp.
2823
2838
.10.2514/1.36541
25.
Patinios
,
M.
,
Scobie
,
J. A.
,
Sangan
,
C. M.
,
Michael Owen
,
J.
, and
Lock
,
G. D.
,
2017
, “
Measurements and Modeling of Ingress in a New 1.5-Stage Turbine Research Facility
,”
ASME J. Eng. Gas Turbines Power
,
139
(
1
), p.
012603
.10.1115/1.4034240
26.
Hualca
,
F. P.
,
Horwood
,
J. T. M.
,
Sangan
,
C. M.
,
Lock
,
G. D.
, and
Scobie
,
J. A.
,
2020
, “
The Effect of Vanes and Blades on Ingress in Gas Turbines
,”
ASME J. Eng. Gas Turbines Power
,
142
(
2
), p.
021020
.10.1115/1.4045149
27.
Schreiner
,
B. D. J.
,
Wilson
,
M.
,
Li
,
Y. S.
, and
Sangan
,
C. M.
,
2020
, “
Effect of Purge on the Secondary Flow-Field of a Gas Turbine Blade-Row
,”
ASME J. Turbomach.
,
142
(
10
), p.
101006
.10.1115/1.4047185
28.
Horwood
,
J. T. M.
,
Hualca
,
F. P.
,
Wilson
,
M.
,
Scobie
,
J. A.
,
Sangan
,
C. M.
,
Lock
,
G. D.
,
Dahlqvist
,
J.
, and
Fridh
,
J.
,
2020
, “
Flow Instabilities in Gas Turbine Chute Seals
,”
ASME J. Eng. Gas Turbines Power
,
142
(
2
), p.
021019
.10.1115/1.4045148
29.
Savov
,
S. S.
,
Atkins
,
N. R.
, and
Uchida
,
S.
,
2016
, “
Comparison of Single and Double Lip Rim Seal Geometry
,”
ASME
Paper No. GT2016-56317.10.1115/GT2016-56317
30.
Beard
,
P. F.
,
Gao
,
F.
,
Chana
,
K. S.
, and
Chew
,
J.
,
2017
, “
Unsteady Flow Phenomena in Turbine Rim Seals
,”
ASME J. Eng. Gas Turbines Power
,
139
(
3
), p.
032501
.10.1115/1.4034452
31.
Zerobin
,
S.
,
Bauinger
,
S.
,
Marn
,
A.
,
Peters
,
A.
,
Heitmeir
,
F.
, and
Göttlich
,
E.
,
2017
, “
The Unsteady Flow Field of a Purged High Pressure Turbine Based on Mode Detection
,”
ASME
Paper No. GT2017-63619.10.1115/GT2017-63619
32.
Zerobin
,
S.
,
Peters
,
A.
,
Marn
,
A.
,
Peters
,
A.
,
Heitmeir
,
F.
, and
Göttlich
,
E.
,
2018
, “
Impact of Purge Flows on the Unsteady HPT Stator-Rotor Interaction
,” Proceedings of GPPS Forum 18, Zurich, Switzerland, Jan. 10–12, Paper No.
GPPS2018-0026
.https://www.semanticscholar.org/paper/Impact-of-Purge-Flows-on-the-Unsteady-HPT-Zerobin-Peters/1a8b6a052d2eff8ab4cdda230270cf7a3a49c2c9
You do not currently have access to this content.