Gas flow over ducted cavities can excite strong acoustic resonances within the confined volumes housing the cavities. When the wavelength of the resonant acoustic modes is comparable with, or smaller than, the cavity dimensions, these modes are referred to as trapped acoustic modes. The flow excitation mechanism causing the resonance of these trapped modes in axisymmetric shallow cavities has been investigated experimentally in a series of papers by Aly and Ziada (2010, “Flow-Excited Resonance of Trapped Modes of Ducted Shallow Cavities,” J. Fluids Struct., 26, pp. 92–120; 2011, “Azimuthal Behaviour of Flow-Excited Diametral Modes of Internal Shallow Cavities,” J. Sound Vib., 330, pp. 3666–3683; 2012, “Effect of Mean Flow on the Trapped Modes of Internal Cavities,” J. Fluids Struct., 33, pp. 70–84). In this paper, the same experimental set-up is used to investigate the effect of the upstream edge geometry on the acoustic resonance of trapped modes. The investigated geometries include sharp and rounded cavity corners, chamfering the upstream edge, and spoilers of different types and sizes. Rounding-off the cavity edges is found to increase the pulsation amplitude substantially, but the resonance lock-on range is delayed, i.e., it is shifted to higher flow velocities. Similarly, chamfering the upstream corner delays the onset of resonance, but maintains its intensity in comparison with that of sharp edges. Spoilers, or vortex generators, added at the upstream edge have been found to be the most effective means to suppress the resonance. However, the minimum spoiler size which is needed to suppress the resonance increases as the cavity size becomes larger.

References

References
1.
Aly
,
K.
, and
Ziada
,
S.
,
2010
, “
Flow-Excited Resonance of Trapped Modes of Ducted Shallow Cavities
,”
J. Fluids Struct.
,
26
, pp.
92
120
.10.1016/j.jfluidstructs.2009.07.008
2.
Aly
,
K.
, and
Ziada
,
S.
,
2011
, “
Azimuthal Behaviour of Flow-Excited Diametral Modes of Internal Shallow Cavities
,”
J. Sound Vib.
,
330
, pp.
3666
3683
.10.1016/j.jsv.2011.02.021
3.
Aly
,
K.
, and
Ziada
,
S.
,
2012
, “
Effect of Mean Flow on the Trapped Modes of Internal Cavities
,”
J. Fluids Struct.
,
33
, pp.
70
84
.10.1016/j.jfluidstructs.2012.05.011
4.
Tonon
,
D.
,
Hirschberg
,
A.
,
Golliard
,
J.
, and
Ziada
,
S.
,
2011
, “
Aeroacoustics of Pipe Systems With Closed Branches
,”
Int. J. Aeroacoustics
,
10
(
2
), pp.
201
276
.10.1260/1475-472X.10.2-3.201
5.
Ziada
,
S.
, and
Lafon
,
P.
,
2014
, “
Flow-Excited Acoustic Resonance: Excitation Mechanism, Design Guidelines and Counter-Measures
,”
ASME Appl. Mech. Rev.
66
, p. 011002.10.1115/1.4025788
6.
Arthurs
,
D.
, and
Ziada
,
S.
,
2009
, “
Flow-Excited Acoustic Resonances of Coaxial Side-Branches in an Annular Duct
,”
J. Fluids Struct.
,
25
, pp.
42
59
.10.1016/j.jfluidstructs.2008.03.007
7.
Ziada
,
S.
, and
Buhlmann
,
E. T.
,
1989
, “
Flow Impingement as an Excitation Source in Control Valves
,”
J. Fluids Struct.
,
3
, pp.
529
549
.10.1016/S0889-9746(89)80029-5
8.
NRC
,
2002
, “
Failure of Steam Dryer Cover Plate After a Recent Power Uprate
,” US Nuclear Regulatory Commission, Washington, DC, NRC Information Notice 2002-26.
9.
Howe
,
M. S.
,
1980
, “
The Dissipation of Sound at an Edge
,”
J. Sound Vib.
,
70
, pp.
407
411
.10.1016/0022-460X(80)90308-9
10.
Rockwell
,
D.
, and
Naudascher
,
E.
,
1978
, “
Review: Self- Sustaining Oscillations of Flow Past Cavities
,”
ASME J. Fluids Eng.
,
100
, pp.
152
165
.10.1115/1.3448624
11.
Evans
,
D. V.
,
Levitin
,
M.
, and
Vassiliev
,
D.
,
1994
, “
Existence Theorems for Trapped Modes
,”
J. Fluid Mech.
,
261
, pp.
21
31
.10.1017/S0022112094000236
12.
Kinsler
,
L. E.
,
Frey
,
A. R.
,
Coppens
,
A. B.
, and
Sanders
,
J. V.
,
2000
,
Fundamentals of Acoustics
,
John Wiley & Sons, Inc.
,
New York
.
13.
Hein
,
S.
, and
Koch
,
W.
,
2008
, “
Acoustic Resonances and Trapped Modes in Pipes and Tunnels
,”
J. Fluid Mech.
,
605
, pp.
401
428
.10.1017/S002211200800164X
14.
Cattafesta
,
L.
,
Williams
,
D. R.
,
Rowley
,
C. W.
, and
Alvi
,
F.
,
2003
, “
Review of Active Control of Flow-Induced Cavity Resonance
,
AIAA Fluid Dynamics Conference
, AIAA Paper No. 2003-3567.
15.
Bruggeman
,
J. C.
,
Hirschberg
,
A.
,
van Dongen
,
M. E. H.
,
Wijnands
,
A. P. J.
, and
Gorter
,
J.
,
1991
, “
Self-Sustained Aero-Acoustic Pulsations in Gas Transport Systems: Experimental Study of the Influence of Closed Side Branches
,”
J. Sound Vib.
,
150
, pp.
371
393
.10.1016/0022-460X(91)90893-O
16.
Karadogan
,
H.
, and
Rockwell
,
D.
,
1983
, “
Toward Attenuation of Self-Sustained Oscillations of a Turbulent Jet Through a Cavity
,”
ASME J. Fluids Eng.
,
105
, pp.
335
340
.10.1115/1.3241000
17.
Knotts
,
B. D.
, and
Selamet
,
A.
,
2003
, “
Suppression of Flow-Acoustic Coupling in Side-Branch Ducts by Interface Modification
,”
J. Sound Vib.
,
265
, pp.
1025
1045
.10.1016/S0022-460X(02)01254-3
18.
Nakiboglu
,
G.
, and
Hirschberg
,
A.
,
2010
, “
A Numerical Study of the Aeroacoustic Interaction of a Cavity With a Confined Flow: Effect of Edge Geometry in Corrugated Pipes
,”
Proceedings of ASME 3rd Joint US-European Fluids Engineering Summer Meeting and 8th International Conference on Nanochannels, Microchannels, and Minichannels
, FEDSM-ICNMM2010-30300.
19.
Smith
,
B. A.
, and
Luloff
,
B. V.
,
2000
, “
The Effect of Seat Geometry on Gate Valve Noise
,”
ASME J. Pressure Vessel Technol.
,
122
, pp.
401
407
.10.1115/1.1286031
20.
Elsayed
,
M.
,
2013
, “
Effect of Upstream Edge Geometry on the Trapped Mode Resonance of Ducted Cavities
,” Master thesis, McMaster University, Hamilton, Canada.
You do not currently have access to this content.