A thin strip cross-sectional element is used to suppress vortex shedding from a plate with a width to thickness ratio of 4.0 at incidence angles in the range of 0–90 deg and a Reynolds number of $1.1×104$. The axes of the element and plate are parallel. The incidence angle of the element is 90 deg and the ratio of strip width to plate thickness is 0.5. Extensive measurements of wake velocities, together with flow visualization, show that vortex shedding from both sides of the plate is suppressed at incidence angles in the range of 0–55 deg if the element is placed at points in effective zones. Unilateral vortex shedding occurs if the element is applied at points in unilateral effective zones. The changes in sizes and locations of the effective and unilateral effective zones with the change in plate incidence are investigated, and the mechanism of the control is discussed. Two patterns of unilateral vortex shedding are observed. Pattern I occurs on the side where there is no element, and oppositely, pattern II occurs on the side where the element resides. A resonance model is proposed to illustrate the occurrence of pattern II unilateral shedding. The phenomenon of unilateral vortex shedding means that the vortex can be generated without strong interaction between the shear layers separated from the bluff body.

1.
Zdravkovich
,
M. M.
, 1981, “
Review and Classification of Various Aerodynamic and Hydrodynamic Means for Suppressing Vortex Shedding
,”
J. Wind. Eng. Ind. Aerodyn.
0167-6105,
7
, pp.
145
189
.
2.
Ged-el Hak
,
M.
, 2000,
Flow Control—Passive, Active and Reactive Flow Management
,
Cambridge University Press
,
Cambridge
.
3.
Chen
,
J. M.
, and
Fang
,
Y. C.
, 1996, “
Strouhal Numbers of Inclined Flat Plates
,”
J. Wind. Eng. Ind. Aerodyn.
0167-6105,
61
, pp.
99
112
.
4.
Sato
,
H.
,
Kusuhara
,
S.
,
Ogi
,
K. -I.
, and
Matsufuji
,
H.
, 2000, “
Aerodynamic Characteristics of Super Long-Span Bridges With Slotted Box Girder
,”
J. Wind. Eng. Ind. Aerodyn.
0167-6105,
88
, pp.
297
306
.
5.
Roshko
,
A.
, 1955, “
On the Wake and Drag of Bluff Bodies
,”
J. Aeronaut. Sci.
0095-9812,
22
, pp.
124
132
.
6.
Munshi
,
S. R.
,
Modi
,
V. J.
, and
Yokomizo
,
T.
, 1999, “
Fluid Dynamics of Flat Plates and Rectangular Prisms in the Presence of Moving Surface Boundary Layer Control
,”
J. Wind. Eng. Ind. Aerodyn.
0167-6105,
79
(
1–2
), pp.
37
60
.
7.
Alam
,
M. M.
,
Sakamoto
,
H.
, and
Moriya
,
M.
, 2003, “
Reduction of Fluid Forces Acting on a Single Circular Cylinder and Two Circular Cylinders
,”
J. Fluids Struct.
0889-9746,
18
, pp.
347
366
.
8.
Bouak
,
F.
, and
Lemay
,
J.
, 2001, “
Use of the Wake of a Small Cylinder to Control Unsteady Loads on a Circular Cylinder
,”
J. Visualization
1343-8875,
4
(
1
), pp.
61
72
.
9.
Sarioglu
,
M.
,
Akansu
,
Y. E.
, and
Yavuz
,
T.
, 2005, “
Control of Flow Around Square Cylinders at Incidence by Using a Rod
,”
AIAA J.
0001-1452,
43
(
7
), pp.
1419
1426
.
10.
Lesage
,
F.
, and
Gartshore
,
I. S.
, 1987, “
A Method of Reducing Drag and Fluctuating Side Forces on Bluff Bodies
,”
J. Wind. Eng. Ind. Aerodyn.
0167-6105,
25
(
2
), pp.
229
245
.
11.
,
A.
, and
Williamson
,
C. H. K.
, 1997, “
A Method for the Reduction of Bluff Body Drag
,”
J. Wind. Eng. Ind. Aerodyn.
0167-6105,
69–71
, pp.
155
167
.
12.
Igarashi
,
T.
, 1997, “
Drag Reduction of a Square Prism by Flow Control Using a Small Rod
,”
J. Wind Eng. Ind. Aerodyn.
,
69–71
, pp.
141
153
.
13.
Tsutsui
,
T.
, and
Igarashi
,
T.
, 2002, “
Drag Reduction of a Circular Cylinder in an Air Stream
,”
J. Wind. Eng. Ind. Aerodyn.
0167-6105,
90
(
4–5
), pp.
527
541
.
14.
Igarashi
,
T.
, and
Nobuaki
,
T.
, 2002, “
Drag Reduction of a Flat Plate Normal to air Stream by Flow Control Using a Rod
,”
J. Wind. Eng. Ind. Aerodyn.
0167-6105,
90
(
4–5
), pp.
359
376
.
15.
Sakamoto
,
H.
, and
Haniu
,
H.
, 1994, “
Optimal Suppression of Fluid Forces Acting on a Circular Cylinder
,”
ASME J. Fluids Eng.
0098-2202,
116
, pp.
221
227
.
16.
Wang
,
J. J.
,
Zhang
,
P. F.
,
Lu
,
S. F.
, and
Wu
,
K.
, 2006, “
Drag Reduction of a Circular Cylinder Using an Upstream Rod
,”
Flow, Turbul. Combust.
1386-6184,
76
(
1
), pp.
83
101
.
17.
Strykowski
,
P. J.
, and
Sreenivasan
,
K. R.
, 1990, “
On the Formation and Suppression of Vortex Shedding at Low Reynolds Numbers
,”
J. Fluid Mech.
0022-1120,
218
, pp.
71
83
.
18.
Shao
,
C. P.
, and
Wang
,
J. M.
, 2007, “
Control of Mean and Fluctuating Forces on a Circular Cylinder at High Reynolds Numbers
,”
Acta Mech. Sin.
0459-1879,
23
(
2
), pp.
133
143
.
19.
Shao
,
C. P.
, and
Wei
,
Q. D.
, 2008, “
Control of Vortex Shedding From a Square Cylinder
,”
AIAA J.
0001-1452,
46
(
2
), pp.
397
407
.
20.
Shao
,
C. P.
,
Wang
,
J. M.
, and
Wei
,
Q. D.
, 2007, “
Visualization Study on Suppression of Vortex Shedding From a Cylinder
,”
J. Visualization
1343-8875,
10
(
1
), pp.
57
64
.
21.
Shao
,
C. P.
, and
Wang
,
J. M.
, 2006, “
Control of Vortex Shedding at Relatively High Reynolds Numbers
,”
Chin. J. Theoret. Appl. Mech.
,
38
(
2
), pp.
153
161
.
22.
Shao
,
C. P.
, 2008, “
Advances in the Study of Methods and Mechanism of Bluff Body Wake Control
,”
0137-3722,
38
(
3
), pp.
314
328
.
23.
Gerrard
,
J. H.
, 1966, “
The Mechanics of the Formation Region of Vortices Behind Bluff Bodies
,”
J. Fluid Mech.
0022-1120,
25
, pp.
401
413
.
24.
Green
,
R. B.
, and
Gerrard
,
J. H.
, 1993, “
Vorticity Measurements in the Near Wake of a Circular Cylinder at Low Reynolds Numbers
,”
J. Fluid Mech.
0022-1120,
246
, pp.
675
691
.
25.
Unal
,
M. F.
, and
Rockwell
,
D.
, 1988, “
On Vortex Formation From a Cylinder, Part 2: Control by Splitter-Plate Interference
,”
J. Fluid Mech.
0022-1120,
190
, pp.
491
512
.
26.
Fage
,
A.
, and
Johansen
,
F. C.
, 1927, “
On the Flow of Air Behind an Inclined Flat Plate of Infinite Span
,”
Proc. R. Soc. London, Ser. A
0950-1207,
116
, pp.
170
197
.