Flow-induced vibrations (FIVs) of two tandem, rigid, circular cylinders with piecewise continuous restoring force are investigated for Reynolds number 24,000 ≤ Re ≤ 120,000 with damping, and restoring force function as parameters. Selective roughness is applied to enhance FIV and increase the hydrokinetic energy captured by the vortex-induced vibration for aquatic clean energy (VIVACE) converter. Experimental results for amplitude response, frequency response, interactions between cylinders, energy harvesting, and efficiency are presented and discussed. All experiments were conducted in the low-turbulence free-surface water (LTFSW) Channel of the MRELab of the University of Michigan. The main conclusions are as follows: (1) the nonlinear-spring converter can harness energy from flows as slow as 0.33 m/s with no upper limit; (2) the nonlinear-spring converter has better performance at initial galloping than its linear-spring counterpart; (3) the FIV response is predominantly periodic for all nonlinear spring functions used; (4) the influence from the upstream cylinder is becoming more dominant as damping increases; (5) optimal power harnessing is achieved by changing the linear viscous damping and tandem spacing L/D; (6) close spacing ratio L/D = 1.57 has a positive impact on the harnessed power in VIV to galloping transition; and (7) the interactions between two cylinders have a positive impact on the upstream cylinder regardless of the spacing and harness damping.

References

References
1.
Bearman
,
P. W.
,
1984
, “
Vortex Shedding From Oscillating Bluff Bodies
,”
Annu. Rev. Fluid Mech.
,
16
(
1
), pp.
195
222
.
2.
Bearman
,
P. W.
,
2011
, “
Circular Cylinder Wakes and Vortex-Induced Vibrations
,”
J. Fluids Struct.
,
27
(
5
), pp.
648
658
.
3.
Sarpkaya
,
T.
,
2004
, “
A Critical Review of the Intrinsic Nature of Vortex-Induced Vibrations
,”
J. Fluids Struct.
,
19
(
4
), pp.
389
447
.
4.
Williamson
,
C. H. K.
, and
Govardhan
,
R.
,
2004
, “
Vortex-Induced Vibrations
,”
Annu. Rev. Fluid Mech.
,
36
, pp.
413
455
.
5.
Blevins
,
R. D.
,
1990
,
Flow-Induced Vibration
,
2nd ed.
, Vol.
2
,
Van Nostrand Reinhold
,
New York
, pp.
50
65
.
6.
Bernitsas
,
M. M.
, and
Raghavan
,
K.
,
2009
, “Converter of Current, Tide, or Wave Energy,” U.S. Patent No. 7,493,759.
7.
Bernitsas
,
M. M.
, and
Raghavan
,
K.
,
2011
, “Enhancement of Vortex Induced Forces & Motion Through Surface Roughness Control,” The Regents of the University of Michigan, Flint, MI, U.S. Patent No.
8,047,232
.https://www.google.ch/patents/US20090250129
8.
Park
,
H.
,
Bernitsas
,
M. M.
, and
Chang
,
C. C.
,
2013
, “Map of Passive Turbulence Control to Flow-Induced Motions for a Circular Cylinder at 30,000< Re< 120,000: Sensitivity to Zone Covering,”
ASME
Paper No. OMAE2013-10123.
9.
Bernitsas
,
M. M.
,
2016
, “
Harvesting Energy by Flow Included Motions
,”
Springer Handbook of Ocean Engineering
,
M. R.
Dhanak
and
N. I.
Xiros
, eds.,
Springer-Verlag
,
Berlin
, Chap. 47.
10.
Liao
,
J. C.
,
2007
, “
A Review of Fish Swimming Mechanics and Behaviour in Altered Flows
,”
Philos. Trans. R. Soc. London B: Biol. Sci.
,
362
(
1487
), pp.
1973
1993
.
11.
Ma
,
C.
,
Sun
,
H.
,
Nowakowski
,
G.
,
Mauer
,
E.
, and
Bernitsas
,
M. M.
,
2016
, “
Nonlinear Piecewise Restoring Force in Hydrokinetic Power Conversion Using Flow Induced Motions of Single Cylinder
,”
Ocean Eng.
,
128
, pp.
1
12
.
12.
Zdravkovich
,
M. M.
,
1997
,
Flow around Circular Cylinders
,
E.
Achenbach
, ed., Vol.
1
,
Oxford University Press
,
Oxford, UK
, pp.
121
162
.
13.
Sumner
,
D.
,
Heseltine
,
J. L.
, and
Dansereau
,
O. J. P.
,
2004
, “
Wake Structure of a Finite Circular Cylinder of Small Aspect Ratio
,”
Exp. Fluids
,
37
(
5
), pp.
720
730
.
14.
Chen
,
S. S.
,
1986
, “
A Review of Flow-Induced Vibration of Two Circular Cylinders in Crossflow
,”
ASME J. Pressure Vessel Technol.
,
108
(
4
), pp.
382
393
.
15.
King
,
R.
, and
Jones
,
R.
,
1980
, “
Flow-Induced Vibrations of an Anchor Agitator
,” Pract. Exper. Flow-Induced Vib.,
5
(
2
), pp.
323
332
.
16.
Ruscheweyh
,
H. P.
,
1983
, “
Aeroelastic Interference Effects Between Slender Structures
,”
J. Wind Eng. Ind. Aerodyn.
,
14
(
1–3
), pp.
129
140
.
17.
Bokaian
,
A.
, and
Geoola
,
F.
,
1984
, “
Wake-Induced Galloping of Two Interfering Circular Cylinders
,”
J. Fluid Mech.
,
146
, pp.
383
415
.
18.
Laneville
,
A.
, and
Brika
,
D.
,
1999
, “
The Fluid and Mechanical Coupling Between Two Circular Cylinders in Tandem Arrangement
,”
J. Fluids Struct.
,
13
(
7–8
), pp.
967
986
.
19.
Huera-Huarte
,
F. J.
, and
Gharib
,
M.
,
2011
, “
Flow-Induced Vibrations of a Side-by-Side Arrangement of Two Flexible Circular Cylinders
,”
J. Fluids Struct.
,
27
(
3
), pp.
354
366
.
20.
Sun
,
H.
,
Ma
,
C.
,
Kim
,
E. S.
,
Nowakowski
,
G.
,
Mauer
,
E.
, and
Bernitsas
,
M. M.
,
2017
, “
Hydrokinetic Energy Conversion by Two Rough Tandem-Cylinders in Flow Induced Vibrations: Effect of Spacing and Stiffness
,”
Renewable Energy
,
107
, pp.
61
80
.
21.
Sun
,
H.
,
Kim
,
E. S.
,
Bernitsas
,
P. M.
, and
Bernitsas
,
M. M.
,
2015
, “
Virtual Spring–Damping System for Flow-Induced Motion Experiments
,”
ASME J. Offshore Mech. Arct. Eng.
,
137
(
6
), p.
061801
.
22.
Kinaci
,
O. K.
,
Lakka
,
S.
,
Sun
,
H.
, and
Bernitsas
,
M. M.
,
2016
, “
Effect of Tip-Flow on Vortex Induced Vibration of Circular Cylinders for Re< 1.2 × 10 5
,”
Ocean Eng.
,
117
, pp.
130
142
.
23.
Chang
,
C. C. J.
,
Kumar
,
R. A.
, and
Bernitsas
,
M. M.
,
2011
, “
VIV and Galloping of Single Circular Cylinder With Surface Roughness at 3.0× 10 4≤ Re≤ 1.2× 10 5
,”
Ocean Eng.
,
38
(
16
), pp.
1713
1732
.
24.
Lee
,
J. H.
,
Xiros
,
N.
, and
Bernitsas
,
M. M.
,
2011
, “
Virtual Damper–Spring System for VIV Experiments and Hydrokinetic Energy Conversion
,”
Ocean Eng.
,
38
(
5
), pp.
732
747
.
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