Abstract

In low-pressure turbines (LPTs), around 60–70% of losses are generated away from end-walls, while the remaining 30–40% is controlled by the interaction of the blade profile with the end-wall boundary layer. Experimental and numerical studies have shown how the strength and penetration of the secondary flow depends on the characteristics of the incoming end-wall boundary layer. Experimental techniques did shed light on the mechanism that controls the growth of the secondary vortices, and scale-resolving computational fluid dynamics (CFD) allowed to dive deep into the details of the vorticity generation. Along these lines, this paper discusses the end-wall flow characteristics of the T106 LPT profile at Re = 120 K and M = 0.59 by benchmarking with experiments and investigating the impact of the incoming boundary layer state. The simulations are carried out with proven Reynolds-averaged Navier–Stokes (RANS) and large-eddy simulation (LES) solvers to determine if Reynolds-averaged models can capture the relevant flow details with enough accuracy to drive the design of this flow region. Part I of the paper focuses on the critical grid needs to ensure accurate LES and on the analysis of the overall time-averaged flow field and comparison between RANS, LES, and measurements when available. In particular, the growth of secondary flow features, the trace and strength of the secondary vortex system, and its impact on the blade load variation along the span and end-wall flow visualizations are analyzed. The ability of LES and RANS to accurately predict the secondary flows is discussed together with the implications this has on design.

References

References
1.
Sieverding
,
C.
,
1985
, “
Recent Progress in the Understanding of Basic Aspects of Secondary Flows in Turbine Blade Passages
,”
J. Eng. Gas Turb. Power
,
107
(
2
), pp.
248
257
. 10.1115/1.3239704
2.
Langston
,
L.
,
2001
, “
Secondary Flows in Axial Turbines—A Review
,”
Ann. N. Y. Acad. Sci.
,
934
(
1
), pp.
11
26
. 10.1111/j.1749-6632.2001.tb05839.x
3.
Langston
,
L.
,
1980
, “
Crossflows in a Turbine Cascade Passage
,”
J. Eng. Power
,
102
(
4
), pp.
866
874
. 10.1115/1.3230352
4.
Goldstein
,
R.
, and
Spores
,
R.
,
1988
, “
Turbulent Transport on the Endwall in the Region Between Adjacent Turbine Blades
,”
ASME J. Heat Transfer
,
110
(
4a
), pp.
862
869
. 10.1115/1.3250586
5.
Sieverding
,
C.
, and
Van Den Bosche
,
P.
,
1983
, “
The Use of Coloured Smoke to Visualize Secondary Flows in a Turbine-Blade Cascade
,”
J. Fluid Mech.
,
134
, pp.
85
89
. 10.1017/S0022112083003237
6.
Wang
,
H.
,
Olson
,
S.
,
Goldstein
,
R.
, and
Eckert
,
E.
,
1997
, “
Flow Visualization in a Linear Turbine Cascade of High Performance Turbine Blades
,”
ASME J. Turbomach.
,
119
(
1
), pp.
1
8
. 10.1115/1.2841006
7.
Hodson
,
H.
, and
Dominy
,
R.
,
1987
, “
Three-Dimensional Flow in a Low-Pressure Turbine Cascade at Its Design Condition
,”
ASME J. Turbomach.
,
109
(
2
), pp.
177
185
. 10.1115/1.3262083
8.
Hermanson
,
K. S.
, and
Thole
,
K. A.
,
2000
, “
Effect of Inlet Conditions on Endwall Secondary Flows
,”
J. Propuls. Power
,
16
(
2
), pp.
286
296
. 10.2514/2.5567
9.
Vera
,
M.
,
de la Rosa Blanco
,
E.
,
Hodson
,
H.
, and
Vazquez
,
R.
,
2009
, “
Endwall Boundary Layer Development in an Engine Representative Four-Stage Low Pressure Turbine Rig
,”
ASME Conf. Proc.
,
131
(
1
), p.
011017
. 10.1115/1.2952382
10.
de la Rosa Blanco
,
E.
,
Hodson
,
H. P.
,
Vazquez
,
R.
, and
Torre
,
D.
,
2003
, “
Influence of the State of the Inlet Endwall Boundary Layer on the Interaction Between Pressure Surface Separation and Endwall Flows
,”
P. I. Mech. Eng. A-J. Pow.
,
217
(
4
), pp.
433
442
. 10.1243/095765003322315496
11.
Koschichow
,
D.
,
Fröhlich
,
J.
,
Kirik
,
I.
, and
Niehuis
,
R.
,
2014
, “
DNS of the Flow Near the Endwall in a Linear Low Pressure Turbine Cascade With Periodically Passing Wakes
,”
ASME Turbo Expo 2014: Turbine Technical Conference and Exposition
, Paper No. GT2014-25071.
12.
Cui
,
J.
,
Nagabhushana Rao
,
V.
, and
Tucker
,
P.
,
2015
, “
Numerical Investigation of Contrasting Flow Physics in Different Zones of a High-Lift Low-Pressure Turbine Blade
,”
ASME J. Turbomach.
,
138
(
1
), p.
011003
. 10.1115/1.4031561
13.
Cui
,
J.
,
Rao
,
V. N.
, and
Tucker
,
P. G.
,
2017
, “
Numerical Investigation of Secondary Flows in a High-Lift Low Pressure Turbine
,”
Int. J. Heat Fluid Flow
,
63
, pp.
149
157
. 10.1016/j.ijheatfluidflow.2016.05.018
14.
Duden
,
A.
, and
Fottner
,
L.
,
1997
, “
Influence of Taper, Reynolds Number and Mach Number on the Secondary Flow Field of a Highly Loaded Turbine Cascade
,”
P. I. Mech. Eng. A-J. Pow.
,
211
(
4
), pp.
309
320
. 10.1177/095765099721100401
15.
Sandberg
,
R.
,
Michelassi
,
V.
,
Pichler
,
R.
,
Chen
,
L.
, and
Johnstone
,
R.
,
2015
, “
Compressible Direct Numerical Simulation of Low-Pressure Turbines—Part I: Methodology
,”
ASME J. Turbomach.
,
137
(
5
), p.
051011
. 10.1115/1.4028731
16.
Michelassi
,
V.
,
Chen
,
L.-W.
,
Pichler
,
R.
, and
Sandberg
,
R.
,
2015
, “
Compressible Direct Numerical Simulation of Low-Pressure Turbines—Part II: Effect of Inflow Disturbances
,”
ASME J. Turbomach.
,
137
(
7
), p.
071005
. 10.1115/1.4029126
17.
Carpenter
,
M. H.
,
Nordström
,
J.
, and
Gottlieb
,
D.
,
1999
, “
A Stable and Conservative Interface Treatment of Arbitrary Spatial Accuracy
,”
J. Comp. Phys.
,
148
(
2
), pp.
341
365
. 10.1006/jcph.1998.6114
18.
Sandberg
,
R. D.
, and
Sandham
,
N. D.
,
2006
, “
Nonreflecting Zonal Characteristic Boundary Condition for Direct Numerical Simulation of Aerodynamic Sound
,”
AIAA Journal
,
44
(
2
), pp.
402
405
.
19.
Klein
,
M.
,
Sadiki
,
A.
, and
Janicka
,
J.
,
2003
, “
A Digital Filter Based Generation of Inflow Data for Spatially Developing Direct Numerical or Large Eddy Simulations
,”
J. Comp. Phys.
,
186
(
2
), pp.
652
665
. 10.1016/S0021-9991(03)00090-1
20.
Xie
,
Z. T.
, and
Castro
,
I. P.
,
2008
, “
Efficient Generation of Inflow Conditions for Large-Eddy Simulation of Street-Scale Flows
,”
Flow, Turbul. Combust.
,
81
(
3
), pp.
449
470
. 10.1007/s10494-008-9151-5
21.
Pichler
,
R.
,
Sandberg
,
R. D.
,
Laskowski
,
G.
, and
Michelassi
,
V.
,
2017
, “
High-Fidelity Simulations of a Linear HPT Vane Cascade Subject to Varying Inlet turbulence
,”
ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition
, Paper No. GT2017-63079.
22.
Wilcox
,
D. C.
,
1998
,
Turbulence Modeling for CFD
, 2nd ed.,
DCW Industries
,
CA
.
23.
Pichler
,
R.
,
Sandberg
,
R. D.
, and
Michelassi
,
V.
,
2016
, “
Assessment of Grid Resolution Requirements for Accurate Simulation of Disparate Scales of Turbulent Flow in Low-Pressure Turbines
,”
Procedings of ASME Turbo Expo 2016
, Paper No. GT2016-56858.
24.
Arnone
,
A.
,
1994
, “
Viscous Analysis of Three-Dimensional Rotor Flow Using a Multigrid Method
,”
ASME J. Turbomach.
,
116
(
3
), pp.
435
445
. 10.1115/1.2929430
25.
Langtry
,
R. B.
, and
Menter
,
F. R.
,
2009
, “
Correlation-Based Transition Modeling for Unstructured Parallelized Computational Fluid Dynamics Codes
,”
AIAA J.
,
47
(
12
), pp.
2894
2906
. 10.2514/1.42362
26.
Pacciani
,
R.
,
Marconcini
,
M.
,
Arnone
,
A.
, and
Bertini
,
F.
,
2014
, “
Predicting High-Lift Low-Pressure Turbine Cascades Flow Using Transition-Sensitive Turbulence Closures
,”
ASME J. Turbomach.
,
136
(
5
), p.
051007
. 10.1115/1.4025224
27.
Ciorciari
,
R.
,
Kirik
,
I.
, and
Niehuis
,
R.
,
2013
, “
Effects of Unsteady Wakes on the Secondary Flows in the Linear T106 Turbine Cascade
,”
Proceedings of ASME Turbo Expo 2013
, Paper No. GT2013-94768.
28.
Eitel-Amor
,
G.
,
Örlü
,
R.
, and
Schlatter
,
P.
,
2014
, “
Simulation and Validation of a Spatially Evolving Turbulent Boundary Layer Up to Reθ=8300
,”
Int. J. Heat Fluid Flow
,
47
, pp.
57
69
. 10.1016/j.ijheatfluidflow.2014.02.006
29.
Marconcini
,
M.
,
Pacciani
,
R.
,
Arnone
,
A.
,
Michelassi
,
V.
,
Pichler
,
R.
,
Zhao
,
Y.
, and
Sandberg
,
R.
,
2019
, “
Large Eddy Simulation and RANS Analysis of the End-Wall Flow in a Linear Low-Pressure-Turbine Cascade—Part II: Loss Generation
,”
ASME J. Turbomach.
,
141
(
5
), p.
051004
. 10.1115/1.4042208
30.
Contini
,
D.
,
Manfrida
,
G.
,
Michelassi
,
V.
, and
Riccio
,
G.
,
2000
, “
Measurements of Vortex Shedding and Wake Decay Downstream of a Turbine Inlet Guide Vane
,”
Flow, Turbul. Combust.
,
64
(
4
), pp.
253
278
. 10.1023/A:1026535810140
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