Low-grade flow energy possesses large reserve and wide distribution in environment, but is far from fully exploited due to high cost when using traditional rotary convertors. Flapping foil can effectively extract flow energy with large span-chord ratio at the low Reynolds number and, thus, may find its application in low-grade flow energy conversion. The motion profiles are the key factors that determine its energy extraction performance. Although massive works have been devoted to optimize its motion parameters, the limit of its performance is still not clear. We developed a more flexible method to describe its motion profile to further approach its theoretical limiting performance. It is demonstrated that the spline motion profile is so flexible that it can cover sinusoidal and some non-sinusoidal motion profiles. This flexibility provides the possibility of much more complicated profile shape and, thus, better energy extraction performance. The spline motion profile obtains 11% and 7% performance improvement compared to sinusoidal and other non-sinusoidal motions, respectively. We achieved a maximum efficiency of 37.3% with a spline controlled motion profile at a low Reynolds number of 1100. Although this efficiency is, indeed, not the limiting performance at this Reynolds number, this work provides a new method approaching the theoretical limiting performance.

1.
P.
Moriarty
and
D.
Honnery
,
Energy Policy
93
,
3
7
(
2016
).
2.
O.
Ellabban
,
H.
Abu-Rub
, and
F.
Blaabjerg
,
Renewable Sustainable Energy Rev.
39
,
748
(
2014
).
3.
A.
Abdelkefi
,
Int. J. Eng. Sci.
100
,
112
(
2016
).
4.
W.
McKinney
and
J.
DeLaurier
,
J. Energy
5
,
109
(
1981
).
5.
T.
Kinseyand
and
G.
Dumas
,
AIAA J.
46
,
1318
(
2008
).
6.
Q.
Zhu
,
J. Fluid Mech.
675
,
495
(
2011
).
7.
T.
Kinsey
and
G.
Dumas
,
AIAA J.
52
,
1885
(
2014
).
8.
J.
Wu
,
Y. L.
Chen
,
N.
Zhao
, and
T. G.
Wang
,
Renewable Energy
94
,
440
(
2016
).
9.
B.
Wang
,
B.
Zhu
, and
W.
Zhang
,
Energy
189
,
116072
(
2019
).
10.
D.
Zhou
,
Y.
Cao
, and
X.
Sun
,
Ocean Eng.
224
,
108756
(
2021
).
11.
J.
Young
,
J. C.
Lai
, and
M. F.
Platzer
,
Prog. Aerosp. Sci.
67
,
2
28
(
2014
).
12.
Q.
Xiao
and
Q.
Zhu
,
J. Fluids Struct.
46
,
174
(
2014
).
13.
K. D.
Jones
,
S.
Davids
, and
M. F.
Platzer
, in
3rd ASME/JSME Joint Fluids Engineering Conference
, San Francisco,
1999
.
14.
K.
Jones
and
M.
Platzer
, in
35th Aerospace Sciences Meeting and Exhibit
,
1997
.
15.
M. S.
Campobasso
,
A.
Piskopakis
, and
M.
Yan
, in
ASME Turbo Expo 2013: Turbine Technical Conference and Exposition
, San Antonio,
2013
.
16.
J.
Young
,
F. B.
Tian
, and
J.
Lai
, in
JAXA Special Publication: Proceedings of the First International Symposium on Flutter and Its Application
,
2016
.
17.
W.
Jiang
,
Y.
Wang
,
D.
Zhang
, and
Y.
Xie
,
IET Renewable Power Gener.
14
,
3220
(
2020
).
18.
W.
Jiang
,
Y. L.
Wang
,
D.
Zhang
, and
Y. H.
Xie
,
Renewable Energy
117
,
12
21
(
2018
).
19.
M.
Platzer
,
M.
Ashraf
,
J.
Young
, and
J.
Lai
, in
Proceedings of the 47th AIAA Aerospace Sciences Meeting
, Orlando,
2009
).
20.
Q.
Xiao
,
W.
Liao
,
S.
Yang
, and
Y.
Peng
,
Renewable Energy
37
,
61
(
2012
).
21.
K.
Lu
,
Y. H.
Xie
, and
D.
Zhang
,
Renewable Energy
64
,
283
(
2014
).
22.
L.
Teng
,
J.
Deng
,
D.
Pan
, and
X.
Shao
,
Renewable Energy
85
,
810
(
2016
).
23.
W.
Wang
,
Y.
Yan
, and
F. B.
Tian
,
Ocean Eng.
147
,
606
(
2018
).
24.
A.
Boudis
,
H.
Oualli
,
A.
Benzaoui
,
O.
Guerri
,
A. C.
Bayeul-Lainé
, and
O.
Coutier-Delgosha
,
J. Appl. Fluid Mech.
14
,
485
(
2021
).
25.
Y.
Xie
,
W.
Jiang
,
K.
Lu
, and
D.
Zhang
,
Energy
109
,
694
(
2016
).
26.
W.
Jiang
,
D.
Zhang
, and
Y. H.
Xie
,
Energy
115
,
1010
(
2016
).
27.
F. M.
Bos
,
D.
Lentink
,
B. W.
Van Oudheusden
, and
H.
Bijl
,
J. Fluid Mech.
594
,
341
(
2008
).
28.
Q.
Zhu
and
Z.
Peng
,
Phys. Fluids
21
,
033601
(
2009
).
29.
M. S.
Campobasso
and
J.
Drofelnik
,
Comput. Fluids
67
,
26
(
2012
).
30.
Q.
Zhu
,
J. Fluids Struct.
34
,
157
(
2012
).
You do not currently have access to this content.