Experimental studies have been conducted on a modified T106 low pressure turbine (LPT) profile in an annular 1.5 stage axial turbine rig at the Chair of Thermal Turbomachines and Aeroengines, Ruhr-Universität Bochum. The rig setup allows the highly resolved measurement of unsteady wake–stator flow interaction in both space and time. Incoming wakes are generated by a variable-speed driven rotor equipped with cylindrical bars. In the present paper, an experimental approach to the investigation of unsteady phenomena is proposed. Time-averaged and instantaneous measurement data from 2D flow field traverses at the stator exit are provided for the analysis of the periodically unsteady vortex formation, displacement, and suppression. Additional time-accurate blade pressure data are used to study the relationship between the flow structures downstream of the stator row and the immediate intermittent wake impact on the blades. Bar wake kinematics is also discussed in relation to the observations.

References

References
1.
Denton
,
J. D.
,
1993
, “
The 1993 IGTI Scholar Lecture: Loss Mechanisms in Turbomachines
,”
ASME J. Turbomach.
,
115
(
4
), pp.
621
656
.
2.
Langston
,
L. S.
,
2001
, “
Secondary Flows in Axial Turbines—A Review
,”
Ann. N. Y. Acad. Sci.
,
934
(
1
), pp.
11
26
.
3.
Puddu
,
P.
,
Palomba
,
C.
, and
Nurzia
,
F.
,
2006
, “
Time-Space Evolution of Secondary Flow Structures in a Two-Stage Low-Speed Turbine
,”
ASME
Paper No. GT2006-90787.
4.
Kang
,
S.
, and
Hirsch
,
C.
,
1991
, “
Three Dimensional Flow in a Linear Compressor Cascade at Design Conditions
,”
ASME
Paper No. 91-GT-114.
5.
Goldstein
,
R. J.
, and
Spores
,
R. A.
,
1988
, “
Turbulent Transport on the Endwall in the Region Between Adjacent Turbine Blades
,”
ASME J. Heat Transfer
,
110
(
4a
), pp.
862
869
.
6.
Hawthorne
,
W. R.
,
1955
, “
Rotational Flow Through Cascades—Part 1: The Components of Vorticity
,”
Q. J. Mech. Appl. Math.
,
8
(
3
), pp.
266
279
.
7.
Ciorciari
,
R.
,
Kirik
,
I.
, and
Niehuis
,
R.
,
2014
, “
Effects of Unsteady Wakes on the Secondary Flows in the Linear T106 Turbine Cascade
,”
ASME J. Turbomach.
,
136
(
9
), p.
091010
.
8.
Krug
,
A.
,
Busse
,
P.
, and
Vogeler
,
K.
,
2015
, “
Experimental Investigation Into the Effects of the Steady Wake-Tip Clearance Vortex Interaction in a Compressor Cascade
,”
ASME J. Turbomach.
,
137
(
6
), p.
061006
.
9.
Volino
,
R. J.
,
2011
, “
Effect of Unsteady Wakes on Boundary Layer Separation on a Very High Lift Low Pressure Turbine Airfoil
,”
ASME J. Turbomach.
,
134
(
1
), p. 011011.
10.
Lengani
,
D.
,
Simoni
,
D.
,
Ubaldi
,
M.
,
Zunino
,
P.
, and
Bertini
,
F.
,
2017
, “
Time Resolved PIV Measurements of the Unsteady Wake Migration in a LPT Blade Passage: Effect of the Wake Passing Frequency
,”
12th European Conference on Turbomachinery, Fluid Dynamics and Thermodynamics
(
ETC
), Apr. 3–7, Stockholm, Sweden, Paper No. ETC2017-324.https://www.euroturbo.eu/publications/proceedings-papers/etc2017-324/
11.
Lampart
,
P.
,
2009
, “
Investigation of Endwall Flows and Losses in Axial Turbines—Part I: Formation of Endwall Flows and Losses
,”
J. Theor. Appl. Mech.
,
47
(
2
), pp.
321
342
.http://www.ptmts.org.pl/jtam/index.php/jtam/article/view/v47n2p321
12.
Hodson
,
H. P.
, and
Howell
,
R. J.
,
2005
, “
The Role of Transition in High-Lift Low-pressure Turbines for Aeroengines
,”
Prog. Aerosp. Sci.
,
41
(
6
), pp.
419
454
.
13.
Sinkwitz
,
M.
,
Engelmann
,
D.
, and
Mailach
,
R.
,
2017
, “
Experimental Investigation of Periodically Unsteady Wake Impact on Secondary Flow in a 1.5 Stage Full Annular LPT Cascade With Modified T106 Blading
,”
ASME
Paper No. GT2017-64390.
14.
Berrino
,
M.
,
Lengani
,
D.
,
Simoni
,
D.
,
Ubaldi
,
M.
,
Zunino
,
P.
, and
Bertini
,
F.
,
2015
, “
Dynamics and Turbulence Characteristics of Wake-Boundary Layer Interaction in a Low Pressure Turbine Blade
,”
ASME
Paper No. GT2015-42626.
15.
Stieger
,
R. D.
, and
Hodson
,
H. P.
,
2004
, “
The Transition Mechanism of Highly Loaded Low-Pressure Turbine Blades
,”
ASME J. Turbomach.
,
126(
4)
, pp.
536
543
.
16.
Winhart
,
B.
,
Sinkwitz
,
M.
,
Schramm
,
A.
,
Engelmann
,
D.
,
di Mare
,
F.
, and
Mailach
,
R.
,
2017
, “
Experimental and Numerical Investigation of Secondary Flow Structures in an Annular LPT Cascade Under Periodical Wake Impact—Part 2: Numerical Results
,”
ASME J. Turbomach.
(accepted).
You do not currently have access to this content.