Abstract

The energy market aims for high flexibility that allows guaranteed power to the consumers with minimum carbon footprint. Over the last three decades, hydropower has been a reliable and an efficient option to meet the fluctuating energy demand as it allows high-ramping rate and quick start-stop. However, such critical operations bring certain challenges for hydro turbines, i.e., high-amplitude stochastic loading and the fatigue. Credible investigation of unsteady pressure pulsations and their signature is important to understand the consequences. The present work aims to study pressure pulsations in a model Francis turbine, which is designed for the frequent start–stop operations. A total of 112 numerical simulations, across the hill diagram, are conducted. Pressure pulsations in the vaneless space, blade channels, and draft tube are investigated. The results show distinct patterns of rotor-stator interaction frequencies in the turbine. In the regions of high rotational speed and low flow rate, stochastic pulsations are predominant.

References

1.
Hell
,
J.
,
2017
, “
High Flexible Hydropower Generation Concepts for Future Grids
,”
J. Phy. Conf. Ser.
,
813
(
1
), p.
012007
. 10.1088/1742-6596/813/1/012007
2.
Yang
,
W.
,
Norrlund
,
P.
,
Saarinen
,
L.
,
Witt
,
A.
,
Smith
,
B.
,
Yang
,
J.
, and
Lundin
,
U.
,
2018
, “
Burden on Hydropower Units for Short-term Balancing of Renewable Power Systems
,”
Nat. Commun.
,
9
(
7
), pp.
1
12
. 10.1038/s41467-017-02088-w
3.
Trivedi
,
C.
,
Gogstad
,
P. J.
, and
Dahlhaug
,
O. G.
,
2017
, “
Investigation of Unsteady Pressure Pulsations in the Prototype Francis Turbines During Load Variation and Startup
,”
J. Renew. Sustainable Energy
,
9
(
6
), p.
064502
. 10.1063/1.4994884
4.
Presas
,
A.
,
Luo
,
Y.
,
Wang
,
Z.
, and
Guo
,
B.
,
2019
, “
Fatigue Life Estimation of Francis Turbines Based on Experimental Strain Measurements: Review of the Actual Data and Future Trends
,”
Renewable. Sustainable. Energy. Rev.
,
102
(
3
), pp.
96
110
. 10.1016/j.rser.2018.12.001
5.
Tengs
,
E.
,
Storli
,
P.-T.
, and
Holst
,
M.
,
2018
, “
Optimization Procedure for Variable Speed Turbine Design
,”
Eng. Appl. Comput. Fluid Mech.
,
12
(
1
), pp.
652
661
. 10.1080/19942060.2018.1507950
6.
Benigni
,
H.
,
Schiffer
,
J.
, and
Jaberg
,
H.
,
2019
, “
Refurbishment of Twin Francis Turbines - Maximizing the Annual Production
,”
IOP Conf. Ser. Earth Environ. Sci.
,
240
(
2
), p.
022036
. 10.1088/1755-1315/240/2/022036
7.
Kim
,
S.-J.
,
Choi
,
Y.-S.
,
Cho
,
Y.
,
Choi
,
J.-W.
, and
Kim
,
J.-H.
,
2019
, “
Effect of Blade Thickness on the Hydraulic Performance of a Francis Hydro Turbine Model
,”
Renew. Energy
,
134
(
4
), pp.
807
817
. 10.1016/j.renene.2018.11.066
8.
Monette
,
C.
,
Marmont
,
H.
,
Chamberland-Lauzon
,
J.
,
Skagerstrand
,
A.
,
Coutu
,
A.
, and
Carlevi
,
J.
,
2016
, “
Cost of Enlarged Operating Zone for An Existing Francis Runner
,”
IOP Conf. Ser. Earth Environ. Sci.
,
49
(
7
), p.
072018
. 10.1088/1755-1315/49/7/072018
9.
Seidel
,
U.
,
Mende
,
C.
,
Hubner
,
B.
,
Weber
,
W.
, and
Otto
,
A.
,
2014
, “
Dynamic Loads in Francis Runners and Their Impact on Fatigue Life
,”
IOP Conf. Ser. Earth Environ. Sci.
,
22
(
3
), p.
032054
. 10.1088/1755-1315/22/3/032054
10.
Nicolle
,
J.
,
Giroux
,
A. M.
, and
Morissette
,
J. F.
,
2014
, “
CFD Configurations for Hydraulic Turbine Startup
,”
IOP Conf. Ser. Earth Environ. Sci.
,
22
(
3
), p.
032021
. 10.1088/1755-1315/22/3/032021
11.
Gagnon
,
M.
,
Jobidon
,
N.
,
Lawrence
,
M.
, and
Larouche
,
D.
,
2014
, “
Optimization of Turbine Startup: Some Experimental Results From a Propeller Runner
,”
IOP Conf. Ser. Earth Environ. Sci.
,
22
(
3
), p.
032022
. 10.1088/1755-1315/22/3/032022
12.
Gagnon
,
M.
,
Tahan
,
A.
,
Bocher
,
P.
, and
Thibault
,
D.
,
2014
, “
Influence of Load Spectrum Assumptions on the Expected Reliability of Hydroelectric Turbines: A Case Study
,”
Struct. Saf.
,
50
(
9
), pp.
1
8
. 10.1016/j.strusafe.2014.03.008
13.
Gagnon
,
M.
,
Nicolle
,
J.
,
Morissette
,
J.-F.
, and
Lawrence
,
M.
,
2016
, “
A Look At Francis Runner Blades Response During Transients
,”
IOP Conf. Ser. Earth Environ. Sci.
,
49
(
5
), p.
052005
. 10.1088/1755-1315/49/5/052005
14.
Morissette
,
J.-F.
, and
Nicolle
,
J.
,
2019
, “
Fluid-structure Simulations of the Stochastic Behaviour of a Medium Head Francis Turbine During Startup
,”
IOP Conf. Ser. Earth Environ. Sci.
,
240
(
2
), p.
022026
. 10.1088/1755-1315/240/2/022026
15.
Wang
,
W.
,
Pavesi
,
G.
,
Pei
,
J.
, and
Yuan
,
S.
,
2020
, “
Transient Simulation on Closure of Wicket Gates in a High-head Francis-type Reversible Turbine Operating in Pump Mode
,”
Renew. Energy
,
145
(
1
), pp.
1817
1830
. 10.1016/j.renene.2019.07.052
16.
Li
,
Z.
,
Bi
,
H.
,
Karney
,
B.
,
Wang
,
Z.
, and
Yao
,
Z.
,
2017
, “
Three-dimensional Transient Simulation of a Prototype Pump-turbine During Normal Turbine Shutdown
,”
J. Hydraulic Res.
,
55
(
4
), pp.
520
537
. 10.1080/00221686.2016.1276105
17.
Chen
,
H.
,
Zhou
,
D.
,
Zheng
,
Y.
,
Jiang
,
S.
,
Yu
,
A.
, and
Guo
,
Y.
,
2018
, “
Load Rejection Transient Process Simulation of a Kaplan Turbine Model by Co-adjusting Guide Vanes and Runner Blades
,”
Energies
,
11
(
12
), pp.
3354
18
. 10.3390/en11123354
18.
Xiuli
,
M.
,
Giorgio
,
P.
, and
Yuan
,
Z.
,
2018
, “
Francis-Type Reversible Turbine Field Investigation During Fast Closure of Wicket Gates
,”
ASME J. Fluid. Eng.
,
140
(
6
), p.
061103
. 10.1115/1.4039089
19.
Fu
,
X.
,
Li
,
D.
,
Wang
,
H.
,
Zhang
,
G.
,
Li
,
Z.
, and
Wei
,
X.
,
2018
, “
Influence of the Clearance Flow on the Load Rejection Process in a Pump-Turbine
,”
Renew. Energy
,
127
(
11
), pp.
310
321
. 10.1016/j.renene.2018.04.054
20.
Seidel
,
U.
,
Hubner
,
B.
,
Lofflad
,
J.
, and
Faigle
,
P.
,
2012
, “
Evaluation of RSI-Induced Stresses in Francis Runners
,”
IOP Conf. Seri.: Earth Environ. Sci.
,
15
(
5
), p.
052010
. 10.1088/1755-1315/15/5/052010
21.
Pasche
,
S.
,
Avellan
,
F.
, and
Gallaire
,
F.
,
2019
, “
Optimal Control of Part Load Vortex Rope in Francis Turbines
,”
ASME J. Fluid. Eng.
,
141
(
8
), p.
081203
. 10.1115/1.4042560
22.
Trivedi
,
C.
,
Gogstad
,
P. J.
, and
Dahlhaug
,
O. G.
,
2018
, “
Investigation of the Unsteady Pressure Pulsations in the Prototype Francis Turbines–Part 1: Steady State Operating Conditions
,”
Mech. Syst. Signal. Process.
,
108
(
8
), pp.
188
202
. 10.1016/j.ymssp.2018.02.007
23.
Yamamoto
,
K.
,
Muller
,
A.
,
Favrel
,
A.
, and
Avellan
,
F.
,
2019
, “
Physical Mechanism of Interblade Vortex Development At Deep Part Load Operation of a Francis Turbine
,”
ASME J. Fluid. Eng.
,
141
(
11
), p.
111113
. 10.1115/1.4043989
24.
Wang
,
W.
,
Chen
,
Q.
, and
Yan
,
D.
,
2018
, “
Hydraulic Stability Analysis of a Large Prototype Francis Turbine Based on Field Test
,”
ASME J. Fluid. Eng.
,
140
(
11
), p.
114501
. 10.1115/1.4040973
25.
Agnalt
,
E.
,
Ostby
,
P.
,
Solemslie
,
B. W.
, and
Dahlhaug
,
O. G.
,
2019
, “
Experimental Study of a Low-Specific Speed Francis Model Runner During Resonance
,”
Int. J. Rot. Mach.
,
2019
(
1
), pp.
1
11
. 10.1155/2019/5375149
26.
Nennemann
,
B.
,
Morissette
,
J.-F.
,
Chamberland-Lauzon
,
J.
,
Monette
,
C.
,
Braun
,
O.
,
Melot
,
M.
, et al
,
2014
, “
Challenges in Dynamic Pressure and Stress Predictions At No-load Operation in Hydraulic Turbines
,”
IOP Conf. Ser. Earth Environ. Sci.
,
22
(
3
), p.
032055
. 10.1088/1755-1315/22/3/032055
27.
Hosseinimanesh
,
H.
,
Devals
,
C.
,
Nennemann
,
B.
,
Reggio
,
M.
, and
Guibault
,
F.
,
2017
, “
A Numerical Study of Francis Turbine Operation at No-load Condition
,”
ASME J. Fluids Eng.
,
139
(
1
), p.
011104
. 10.1115/1.4034422
28.
Trivedi
,
C.
,
2018
, “
Compressible Large Eddy Simulation of a Francis Turbine During Speed-No-Load: Rotor Stator Interaction and Inception of a Vortical Flow
,”
ASME J. Eng. Gas. Turbines. Power.
,
140
(
11
), p.
112601
. 10.1115/1.4039423
29.
Trivedi
,
C.
, and
Dahlhaug
,
O. G.
,
2018
, “
Interaction Between Trailing Edge Wake and Vortex Rings in a Francis Turbine At Runaway Condition: Compressible Large Eddy Simulation
,”
Phys. Fluids.
,
30
(
7
), p.
075101
. 10.1063/1.5030867
30.
Foroutan
,
H.
, and
Yavuzkurt
,
S.
,
2014
, “
Flow in the Simplified Draft Tube of a Francis Turbine Operating At Partial Load–Part II: Control of the Vortex Rope
,”
ASME J. Appl. Mech.
,
81
(
6
), p.
061011
. 10.1115/1.4026818
31.
Xia
,
L.-S.
,
Cheng
,
Y.-G.
,
Yang
,
J.-D.
, and
Cai
,
F.
,
2019
, “
Evolution of Flow Structures and Pressure Fluctuations in the S-Shaped Region of a Pump-Turbine
,”
J. Hydraulic Res.
,
57
(
1
), pp.
1
15
. 10.1080/00221686.2018.1444676
32.
Rajan
,
G. K.
, and
Cimbala
,
J. M.
,
2017
, “
Computational and Theoretical Tnalyses of the Trecessing Tortex Rope in a Simplified Draft Tube of a Scaled Model of a Francis Turbine
,”
ASME J. Fluid. Eng.
,
139
(
2
), p.
021102
. 10.1115/1.4034693
33.
Spalart
,
P. R.
,
2009
, “
Detached-eddy Simulation
,”
Annu. Rev. Fluid. Mech.
,
41
(
1
), pp.
181
202
. 10.1146/annurev.fluid.010908.165130
34.
Wilhelm
,
S.
,
Balarac
,
G.
,
Metais
,
O.
, and
Segoufin
,
C.
,
2016
, “
Analysis of Head Losses in a Turbine Draft Tube by Means of 3d Unsteady Simulations
,”
Flow, Turbulence Combust.
,
97
(
4
), pp.
1255
1280
. 10.1007/s10494-016-9767-9
35.
Choi
,
H.
, and
Moin
,
P.
,
2012
, “
Grid-Point Requirements for Large Eddy Simulation: Chapman’s Estimates Revisited
,”
Phys. Fluids.
,
24
(
1
), p.
011702
. 10.1063/1.3676783
36.
Javadi
,
A.
, and
Nilsson
,
H.
,
2015
, “
Time-Accurate Numerical Simulations of Swirling Flow with Rotor Stator Interaction
,”
Flow, Turbul. Combust.
,
95
(
4
), pp.
755
774
. 10.1007/s10494-015-9632-2
37.
Pacot
,
O.
,
Kato
,
C.
,
Guo
,
Y.
,
Yamade
,
Y.
, and
Avellan
,
F.
,
2016
, “
Large Eddy Simulation of the Rotating Stall in a Pump-Turbine Operated in Pumping Mode At a Part-load Condition
,”
ASME J. Fluid. Eng.
,
138
(
11
), p.
111102
. 10.1115/1.4033423
38.
Menter
,
F. R.
, and
Egorov
,
Y.
,
2010
, “
The Scale-Adaptive Simulation Method for Unsteady Turbulent Flow Predictions. Part 1: Theory and Model Description
,”
Flow, Turbul. Combust.
,
85
(
1
), pp.
113
138
. 10.1007/s10494-010-9264-5
39.
Egorov
,
Y.
,
Menter
,
F. R.
,
Lechner
,
R.
, and
Cokljat
,
D.
,
2010
, “
The Scale-adaptive Simulation Method for Unsteady Turbulent Flow Predictions. Part 2: Application to Complex Flows
,”
Flow, Turbul. Combust.
,
85
(
1
), pp.
139
165
. 10.1007/s10494-010-9265-4
40.
Trivedi
,
C.
,
Agnalt
,
E.
, and
Dahlhaug
,
O. G.
,
2017
, “
Investigations of Unsteady Pressure Loading in a Francis Turbine During Variable-Speed Operation
,”
Renew. Energy
,
113
(
12
), pp.
397
410
. 10.1016/j.renene.2017.06.005
41.
Trivedi
,
C.
,
Agnalt
,
E.
, and
Dahlhaug
,
O. G.
,
2018
, “
Experimental Study of a Francis Turbine Under Variable-speed and Discharge Conditions
,”
Renew. Energy
,
119
(
4
), pp.
447
458
. 10.1016/j.renene.2017.12.040
42.
Iliev
,
I.
,
Trivedi
,
C.
, and
Dahlhaug
,
O. G.
,
2019
, “
Variable-Speed Operation of Francis Turbines: A Review of the Perspectives and Challenges
,”
Renew. Sustain. Energy Rev.
,
103
(
4
), pp.
109
121
. 10.1016/j.rser.2018.12.033
43.
Iliev
,
I.
,
Tengs
,
E.
,
Trivedi
,
C.
, and
Dahlhaug
,
O. G.
,
2020
, “
Optimization of Francis Turbines for Variable Speed Operation Using Surrogate Modeling Approach
,”
ASME J. Fluids Eng.
,
142
(
10
), p.
101214
. 10.1115/1.4047675
44.
Trivedi
,
C.
,
Iliev
,
I.
, and
Dahlhaug
,
O. G.
,
2020
, “
Numerical Study of a Francis Turbine Over Wide Operating Range: Some Practical Aspects of Verification
,”
Sustainability
,
12
(
10
), pp.
4301
10
. 10.3390/su12104301
45.
Trivedi
,
C.
,
Cervantes
,
M. J.
,
Gandhi
,
B. K.
, and
Dahlhaug
,
O. G.
,
2014
, “
Transient Pressure Measurements on a High Head Model Francis Turbine During Emergency Shutdown, Total Load Rejection, and Runaway
,”
ASME J. Fluid. Eng.
,
136
(
12
), p.
121107
. 10.1115/1.4027794
46.
Trivedi
,
C.
,
Cervantes
,
M. J.
,
Gandhi
,
B. K.
, and
Dahlhaug
,
O. G.
,
2014
, “
Pressure Measurements on a High-head Francis Turbine During Load Acceptance and Rejection
,”
J. Hydraulic Res.
,
52
(
2
), pp.
283
297
. 10.1080/00221686.2013.854846
47.
Trivedi
,
C.
,
Cervantes
,
M. J.
,
Gandhi
,
B. K.
, and
Dahlhaug
,
O. G.
,
2014
, “
Experimental Investigations of Transient Pressure Variations in a High Head Model Francis Turbine During Start-up and Shutdown
,”
J. Hydrodynamics
,
26
(
2
), pp.
277
290
. 10.1016/S1001-6058(14)60031-7
48.
Trivedi
,
C.
,
Iliev
,
I.
,
Dahlhaug
,
O. G.
,
Markov
,
Z.
,
Engstrom
,
F.
, and
Lysaker
,
H.
,
2020
, “
Investigation of a Francis Turbine During Speed Variation: Inception of Cavitation
,”
Renew. Energy
,
166
(
4
), pp.
147
162
. 10.1016/j.renene.2020.11.108
You do not currently have access to this content.