The draft tube of reaction hydraulic turbines is subject to numerous investigations since it accounts for a significant portion of the energy recovery. But even with up-to-date computational fluid dynamics methodologies, simulating the draft tube flow remains highly challenging since it is a diverging swirling flow that may undergo flow separations and become dominated by unsteady secondary flows. Within the framework of a collaborative research project on the flow dynamics of a propeller turbine model, the flow at the inlet region of the draft tube was studied using 2D-laser Doppler velocimetry (2D-LDV). Measurements were used to detect and characterize the flow structures at three operating conditions: partial discharge, near best efficiency, and full-load conditions. The paper presents analysis based on phased-averaged velocity fields to yield information on fluctuations and dominant frequencies according to runner positions. The main features detected are the flow nonuniformity at the runner exit and the secondary flow structures associated with the runner hub wake. Those results are part of a larger database aimed at providing test cases for the validation of numerical simulation strategies.

References

References
1.
Raabe
,
J.
, 1985,
Hydro Power: The Design, Use, and Function of Hydromechanical, Hydraulic, and Electrical Equipment
,
VDI Verlag
,
Düsseldorf, Germany
.
2.
Tridon
,
S.
,
Barre
,
S.
,
Ciocan
,
G.
,
Segoufin
,
C.
, and
Leroy
,
P.
, 2012, “
Discharge Imbalance Mitigation in Francis Turbine Draft-Tube Bays
,”
ASME J. Fluids Eng.
,
134
(
4
), p.
041102
.
3.
Houde
,
S.
, and
Giroux
,
A.-M.
, 2005, “
Recent Developments and New Challenges in the Use of Computational Fluid Dynamics at Hydro-Québec
,” Proceedings of the Hydro 2005 International Conference,
Villach
,
Austria
, Oct. 17–20.
4.
Gebart
,
B. R.
,
Gustavsson
,
L. H.
, and
Karlsson
,
R. I.
, 1999, “
Technical Report
,” Proceedings of Turbine-99—Workshop on Draft Tube Flow,
Lulea University of Technology, Department of Mechanical Engineering, Division of Fluid Mechanics
,
Porjus, Sweden
, June 20–23.
5.
Engström
,
T. F.
,
Gustavsson
,
L. H.
, and
Karlsson
,
R. I.
, 2001, “
Technical Report
,” Proceedings of Turbine-99—Workshop II on Draft-Tube Flow,
Lulea University of Technology, Department of Mechanical Engineering, Division of Fluid Mechanics
,
Porjus, Sweden
, April.
6.
Cervantes
,
M. J.
,
Engström
,
T. F.
, and
Gustavsson
,
L. H.
, 2005, “
Turbine-99 III
,” Proceedings of the 3rd IAHR/ERCOFTAC Workshop on Draft Tube Flows,
Lulea University of Technology, Department of Applied Physics and Mechanical Engineering, Division of Fluid Mechanics
,
Porjus, Sweden
, Dec. 8–9.
7.
Duprat
,
C.
,
Balarac
,
G.
,
Métais
,
O.
,
Tridon
,
S.
,
Barre
,
S.
,
Ciocan
,
G. D.
, and
Tomas
,
L.
, 2009, “
Large-Eddy Simulation of Draft Tube Flow Validation From Experimental Measurements
,” Proceedings of the 3rd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems,
Brno
,
Czech Republic
, Oct. 14–16.
8.
Petit
,
O.
,
Mulu
,
B.
,
Nilsson
,
H.
, and
Cervantes
,
M. J.
, 2010, “
Comparison of Numerical and Experimental Results of the Flow in the U9 Kaplan Turbine Model
,” Proceedings of the 25th IAHR Symposium on Hydraulic Machinery and Systems,
Timisoara
,
Romania
, Sept. 20–24.
9.
Avellan
,
F.
, 2000, “
Flow Investigation in a Francis Draft Tube: The FLINDT Project
,” Proceedings of the 20th IAHR Symposium,
Charlotte
,
NC
, Aug. 6–9.
10.
Ciocan
,
G. D.
,
Avellan
,
F.
, and
Kueny
,
J.-L.
, 2000, “
Optical Measurement Techniques for Experimental Analysis of Hydraulic Turbines Rotor-Stator Interaction
,” Proceedings of the ASME Fluids Engineering Division Summer Meeting,
Boston
,
MA
, June 11–15.
11.
Mauri
,
S.
,
Kueny
,
J.-L.
, and
Avellan
,
F.
, 2000, “
Numerical Prediction of the Flow in a Turbine Draft Tube: Influence of the Boundary Conditions
,” Proceedings of the ASME Fluids Engineering Division Summer Meeting,
Boston
,
MA
, June 11–15.
12.
Mauri
,
S.
,
Kueny
,
J.-L.
, and
Avellan
,
F.
, 2002, “
Flow Simulation in an Elbow Diffuser: Verification and Validation
,” Proceedings of the 21st IAHR Symposium on Hydraulic Machinery and Systems,
Lausanne
,
Switzerland
, Sept. 9–12.
13.
Mauri
,
S.
,
Kueny
,
J.-L.
, and
Avellan
,
F.
, 2004, “
Werlé-Legendre Separation in a Hydraulic Machine Draft Tube
,”
ASME J. Fluids Eng.
,
126
, pp.
976
980
.
14.
Susan-Resiga
,
R.
,
Ciocan
,
G. D.
,
Anton
,
I.
, and
Avellan
,
F.
, 2006, “
Analysis of the Swirling Flow Downstream a Francis Turbine Runner
,”
ASME J. Fluids Eng.
,
128
, pp.
177
189
.
15.
Tridon
,
S.
,
Barre
,
S.
,
Ciocan
,
G. D.
, and
Thomas
,
L.
, 2010, “
Experimental Analysis of the Swirling Flow in a Francis Turbine Draft Tube: Focus on Radial Velocity Component Determination
,”
Eur. J. Mech. B/Fluids
,
29
(
4
), pp.
321
335
.
16.
Tridon
,
S.
,
Barre
,
S.
,
Ciocan
,
D. G.
,
Leroy
,
P.
, and
Ségoufin
,
C.
, 2010, “
Experimental Investigation of Draft Tube Flow Instability
,” Proceedings of the 25th IAHR Symposium on Hydraulic Machinery and Systems,
Timisoara
,
Romania
, Sept. 20–24.
17.
Payette
,
F. A.
,
De Hénau
,
V.
,
Dumas
,
G.
, and
Sabourin
,
M.
, 2008, “
Sensitivity of Draft Tube Flow Prediction to Boundary Conditions
,” Proceedings of the 24th IAHR Symposium on Hydraulic Machinery and Systems,
Foz do Iguassu
,
Brazil
, Oct. 27–31.
18.
Vincent
,
P. B.
,
Dumas
,
G.
, and
Houde
,
S.
, 2009, “
Comparison of URANS and DES Predictions for Hydroturbine Draft Tube
,” Proceedings of the 17th Annual Conference of the CFD Society of Canada,
Ottawa, ON, Canada
, May 3–5, Paper No. CFDSC2009-1A3.
19.
Stefan
,
D.
,
Rudolf
,
P.
,
Muntean
,
S.
, and
Susan-Resiga
,
R. F.
, 2012 “
Structure of Flow Fields Downstream of Two Different Swirl Generators
,” Proceedings of the 18th International Conference of Engineering Mechanics,
Svratka
,
Czech Republic
, May 14–17, pp.
1331
-
1342
.
20.
Muntean
,
S.
,
Nilsson
,
H.
, and
Susan-Resiga
,
R. F.
, 2009, “
3D Numerical Analysis of the Unsteady Turbulent Swirling Flow in a Conical Diffuser Using Fluent and Openfoam
,” Proceedings of the 3rd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems, Brno, Czech Republic, Oct. 14–16.
21.
Petit
,
O.
,
Bosioc
,
A. I.
,
Nilsson
,
H.
,
Muntean
,
S.
, and
Susan-Resiga
,
R. F.
, 2011, “
Unsteady Simulations of the Flow in a Swirl Generator, Using OpenFOAM
,”
Int. J. Fluid Mach, Syst.
,
4
(
1
), pp.
199
208
.
22.
Deschênes
,
C.
,
Ciocan
,
G. D.
,
De Henau
,
V.
,
Flemming
,
F.
,
Huang
,
J.
,
Koller
,
M.
,
Arzola Naime
,
F.
,
Page
,
M.
,
Qian
,
R.
, and
Vu
,
T.
, 2010, “
General Overview of the AxialT Project: A Partnership for Low Head Turbine Developments
,” Proceedings of the 25th IAHR Symposium on Hydraulic Machinery and Systems,
Timisoara
,
Romania
, Sept. 20–24.
23.
Gagnon
,
J -M.
,
Deschênes
,
C.
,
Ciocan
,
G. D.
, and
Iliescu
,
M.
, 2008, “
Numerical Simulation and Experimental Investigation of the Flow in an Axial Turbine
,” Proceedings of the 24th IAHR Symposium on Hydraulic Machinery and Systems,
Foz Do Iguassu
,
Brazil
, Oct. 27–31.
24.
Duquesne
,
P.
,
Iliescu
,
M.
,
Fraser
,
R.
,
Deschênes
,
C.
, and
Ciocan
,
G. D.
, 2010, “
Monitoring of Velocity and Pressure Fields Within an Axial Turbine
,” Proceedings of the 25th IAHR Symposium on Hydraulic Machinery and Systems,
Timisoara
,
Romania
, Sept. 20–24.
25.
Gouin
,
P.
,
Deschênes
,
C.
,
Iliescu
,
M.
, and
Ciocan
,
G. D.
, 2009, “
Experimental Investigation of Draft Tube Flow of an Axial Turbine by Laser Doppler Velocimetry
,” Proceedings of the 3rd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems,
Brno
,
Czech Republic
, Oct. 14–16.
26.
Beaulieu
,
S.
,
Deschênes
,
C.
,
Iliescu
,
M.
, and
Ciocan
,
G. D.
, 2009, “
Study of the Flow Field Through the Runner of a Propeller Turbine Using Stereoscopic PIV
,” Proceedings of the 3rd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems,
Brno
,
Czech Republic
, Oct. 14–16.
27.
Houde
,
S.
,
Iliescu
,
M.
,
Fraser
,
R.
,
Lemay
,
S.
,
Ciocan
,
G. D.
, and
Deschênes
,
C.
, 2011, “
Experimental and Numerical Analysis of the Cavitating Part Load Vortex Dynamics of Low-Head Hydraulic Turbines
,” Proceedings of
ASME
-JSME-KSME 2011 Joint Fluids Engineering Conference (AJK2011-FED),
Hamamatsu
,
Japan
, July 24–29.
28.
Houde
,
S.
,
Lemay
,
S.
,
Fraser
,
R.
,
Iliescu
,
M.
,
Ciocan
,
G. D.
, and
Deschênes
,
C.
, 2011, “
Experimental Study of the Cavitating Part Load Vortex of a Propeller Turbine
,” Proceedings of IAHR Symposium on Hydraulic Machinery and Systems,
Belgrade
,
Serbia
, Oct. 26–28.
29.
Iliescu
,
M.
,
Houde
,
S.
,
Lemay
,
S.
,
Fraser
,
R.
, and
Deschênes
,
C.
, 2011, “
Investigation of the Cavitational Behavior of an Axial Hydraulic Turbine Operating at Partial Discharge by 3D-PIV
,” Proceedings of the 9th International Symposium on Particle Image Velocimetry,
Kobe
,
Japan
, July 21–23.
30.
Iliescu
,
M. S.
,
Ciocan
,
G. D.
, and
Avellan
,
F.
, 2004, “
Experimental Study of the Runner Blade-to-blade Shear Flow Turbulent Mixing in the Cone of Francis Turbine Scale Model
,” Proceedings of the 22nd IAHR Symposium on Hydraulic Machinery and Systems,
Stockholm
,
Sweden
, June 29-July 2.
31.
Mulu
,
B. G.
,
Jonsson
,
P. P.
, and
Cervantes
,
M. J.
, 2012, “
Experimental Investigation of a Kaplan Draft Tube—Part I: Best Efficiency
,”
J. Appl. Energy
,
93
, pp.
675
706
.
32.
Jonsson
,
P. P.
,
Mulu
,
B. G.
, and
Cervantes
,
M. J.
, 2012, “
Experimental Investigation of a Kaplan Draft Tube—Part II: Off-Design Conditions
,”
J. Appl. Energy
,
94
, pp.
71
83
.
33.
Castorph
,
D.
, and
Raabe
,
J.
, 1974, “
Measurement of Unsteady Pressure Unsteady Relative Velocity Field of a Kaplan Runner by Means of an Electronic Multi-Miniature Probe as a Basic Contribution to Research on Unsteady Runner Load
,” Proceedings of the 7th IAHR Symposium on Hydraulic Machinery and Cavitation,
Vienna
,
Austria
, Sept.
34.
Escudier
,
M.
, 1987, “
Confined Vortices in Flow Machinery
,”
Annu. Rev. Fluid Mech.
,
19
, pp.
27
52
.
35.
Jacob
,
T.
, 1993 “
Évaluation sur Modèle Réduit et Prédiction de la Stabilité de Fonctionnement des Turbines Francis
,” Ph.D. thesis, EPFL, Lausanne, Switzerland.
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