The interaction of surface gravity waves with horizontal pitching plate for actively control waves is investigated based on the linearized theory of water waves. The three-dimensional (3D) problem is formulated for the submerged plate pitching about its middle point and the other plate is considered to be floating above the submerged plate. The submerged plate's thickness is considered negligible in comparison with the water depth and wavelength of the incident wave. The study is carried out using the matched eigenfunction expansion method and the analytical solution is developed for the interaction of the surface gravity waves with horizontal submerged structure. The performance is analyzed for both impermeable and porous submerged pitching plate. The numerical results for the reflection coefficient, transmission coefficient, and free-surface deflection are computed and analyzed. The study is carried to find the optimal value of the length and depth of the submerged plate at which the dissipation of the incident wave energy is observed. The reduction the wave transformation due to the pitching of the plate with the change in angle of incidence is also analyzed. The present study will be helpful in the analysis of proper functioning of submerged pitching plate to control wave motion for the protection of offshore structures.

References

1.
Milgram
,
J. H.
,
1970
, “
Active Water-Wave Absorbers
,”
J. Fluid Mech.
,
42
(
4
), pp.
845
859
.
2.
Yip
,
T. L.
, and
Chwang
,
A. T.
,
1997
, “
Water Wave Control by a Pitching Plate
,”
J. Eng. Mech.
,
123
(
8
), pp.
800
807
.
3.
Yip
,
T. L.
, and
Chwang
,
A. T.
,
1998
, “
Water Wave Control by a Submerged Pitching Porous Plate
,”
J. Eng. Mech.
,
124
(
4
), pp.
428
434
.
4.
Williams
,
A. N.
, and
Abul-Ajm
,
A. G.
,
1997
, “
Dual Pontoon Floating Breakwater
,”
Ocean Eng.
,
24
(
5
), pp.
465
478
.
5.
Williams
,
A. N.
,
Lee
,
H. S.
, and
Huang
,
Z.
,
2000
, “
Floating Pontoon Breakwater
,”
Ocean Eng.
,
27
(3), pp.
221
240
.
6.
Wang
,
K. H.
, and
Shen
,
Q.
,
1999
, “
Wave Motion Over a Group of Submerged Horizontal Plates
,”
Int. J. Eng. Sci.
,
37
(6), pp.
703
715
.
7.
Hsu
,
H. H.
, and
Wu
,
Y. C.
,
1998
, “
Scattering of Water Wave by a Submerged Horizontal Plate and a Submerged Permeable Breakwater
,”
Ocean Eng.
,
26
(
4
), pp.
325
341
.
8.
Liang
,
N. K.
,
Huang
,
J. S.
, and
Li
,
C. F.
,
2004
, “
A Study of Spar Buoy Floating Breakwater
,”
Ocean Eng.
,
31
(1), pp.
43
60
.
9.
Patarapanich
,
M.
,
1984
, “
Maximum and Zero Reflection From Submerged Plate
,”
ASCE J. Waterw. Port Coastal Ocean Eng.
,
110
(
2
), pp.
171
181
.
10.
Patarapanich
,
M.
,
1984
, “
Force and Moment on a Horizontal Plate Due to Wave Scattering
,”
Coastal Eng.
,
8
(3), pp.
279
301
.
11.
Patarapanich
,
M.
, and
Cheong
,
H. F.
,
1989
, “
Reflection and Transmission Characteristics of Regular and Random Waves From a Submerged Horizontal Plate
,”
Coastal Eng.
,
13
(2), pp.
161
182
.
12.
Liu
,
P. L. F.
, and
Iskandarani
,
M.
,
1991
, “
Scattering of Short-Wave Groups by Submerged Horizontal Plate
,”
ASCE J. Waterw. Port Coastal Ocean Eng.
,
117
(
3
), pp.
235
246
.
13.
Loukogeorgaki
,
E.
, and
Angelides
,
D. C.
,
2005
, “
Stiffness of Mooring Lines and Performance of Floating Breakwater in Three Dimensions
,”
Appl. Ocean Res.
,
27
(
4
), pp.
187
208
.
14.
Elchahal
,
G.
,
Younes
,
R.
, and
Lafon
,
L.
,
2008
, “
The Effects of Reflection Coefficient of the Harbour Sidewall on the Performance of Floating Breakwaters
,”
Ocean Eng.
,
35
(
11
), pp.
1102
1112
.
15.
Tay
,
Z. Y.
,
Wang
,
C. M.
, and
Utsunomiya
,
T.
,
2009
, “
Hydroelastic Responses and Interactions of Floating Fuel Storage Modules Placed Side-by-Side With Floating Breakwaters
,”
Mar. Struct.
,
22
(
3
), pp.
633
658
.
16.
Yong
,
L.
,
Cheng
,
L. Y.
, and
Bin
,
T.
,
2009
, “
Wave Motion Over Two Submerged Layers of Horizontal Thick Plates
,”
J. Hydrodyn.
,
21
(
4
), pp.
453
462
.
17.
Chwang
,
A. T.
,
1983
, “
A Porous Wavemaker Theory
,”
J. Fluid Mech.
,
132
, pp.
395
406
.
18.
Yu
,
X.
, and
Chwang
,
A. T.
,
1994
, “
Water Waves Above Submerged Porous Plate
,”
J. Eng. Mech.
,
120
(
6
), pp.
1270
1282
.
19.
Losada
,
I. J.
,
Silva
,
R.
, and
Losada
,
M. A.
,
1996
, “
3-D Non-Breaking Regular Wave Interaction With Submerged Breakwaters
,”
Coastal Eng.
,
28
(
1
), pp.
229
248
.
20.
Yu
,
X.
,
2002
, “
Functional Performance of a Submerged and Essentially Horizontal Plate for Offshore Wave Control: A Review
,”
Coastal Eng. J.
,
44
(
2
), pp.
127
147
.
21.
Mendez
,
F. J.
, and
Losada
,
I. J.
,
2004
, “
A Perturbation Method to Solve Dispersion Equations for Water Waves Over Dissipative Media
,”
Coastal Eng.
,
51
(
1
), pp.
81
89
.
22.
Liu
,
Y.
,
Li
,
Y. C.
, and
Teng
,
B.
,
2007
, “
Wave Interaction With a Perforated Wall Breakwater With Submerged Horizontal Porous Plate
,”
Ocean Eng.
,
34
(17–18), pp.
2364
2373
.
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