Splitter or baffle silencers are commonly used, for example, in heating ventilation and air conditioning (HVAC) systems and as inlet/outlet silencers on gas turbines. Another application is to reduce noise from the cooling fan inlet for large IC-engines. A splitter silencer can be seen as a periodic arrangement of parallel rectangular absorbers, which can be placed in a rectangular duct. The noise reduction afforded by parallel splitters depends not only on the physical properties of the lining but also upon the angle of incidence of the impinging sound waves, and the splitter and duct dimensions. In this paper, the potential of using splitters made of microperforated plates (MPPs) is investigated, with a particular focus on cooling fan inlet/outlet applications.

References

References
1.
Cummings
,
A.
,
1976
, “
Sound Attenuation in Ducts Lined on Two Opposite Walls With Porous Material, With Some Application to Splitters
,”
J. Sound Vib.
,
49
(
1
), pp.
9
35
.10.1016/0022-460X(76)90754-9
2.
Bies
,
D. A.
,
Hansen
,
C. H.
, and
Bridges
,
G. E.
,
1991
, “
Sound Attenuation in Rectangular and Circular Cross-Section Ducts With Flow and Bulk-Reacting Liner
,”
J. Sound Vib.
,
146
(
1
), pp.
47
80
.10.1016/0022-460X(91)90522-L
3.
Cummings
,
A.
, and
Sormaz
,
N.
,
1993
, “
Acoustic Attenuation in Dissipative Splitter Silencers Containing Mean Fluid Flow
,”
J. Sound Vib.
,
168
(
2
), pp.
209
227
.10.1006/jsvi.1993.1370
4.
Astley
,
R. J.
, and
Cummings
,
A.
,
1987
, “
A Finite Element Scheme for Attenuation in Ducts Lined With Porous Material: Comparison With Experiment
,”
J. Sound Vib.
,
116
(
2
), pp.
239
263
.10.1016/S0022-460X(87)81302-0
5.
Kirby
,
R.
,
2005
, “
The Influence of Baffle Fairings on the Acoustic Performance of Rectangular Splitter Silencers
,”
J. Acoust. Soc. Am.
,
118
(
4
), pp.
2302
2312
.10.1121/1.2010267
6.
Maa
,
D.-Y.
,
1998
, “
Potential of Microperforated Panel Absorber
,”
J. Acoust. Soc. Am.
,
104
(
5
), pp.
2861
2866
.10.1121/1.423870
7.
Allam
,
S.
, and
Abom
,
M.
,
2011
, “
A New Type of Muffler Based on Microperforated Tubes
,”
ASME J. Vib. Acoust.
,
133
(
3
), p.
031005
.10.1115/1.4002956
8.
Åbom
,
M.
, and
Allam
,
S.
,
2012
, “
On the Use of Micro-Perforates for Machinery and Vehicle Noise Control
,”
J. Acoust. Soc. Am.
,
132
(
3
), pp.
1887
10.1121/1.4754921.
9.
Ko
,
S.-H.
,
1971
, ‘‘
Sound Attenuation in Lined Rectangular Ducts With Flow and Its Application to the Reduction of Aircraft Engine Noise
,”
J. Acoust. Soc. Am.
,
50
(6 Part 1), pp.
1418
1432
10.1121/1.1912784.
10.
Allam
,
S.
,
Åbom
,
M.
, and
Wester
,
L.
,
2012
, “
Noise Control for Cooling Fans on Heavy Vehicles
,” International Conference on Fan Noise, Technology and Numerical Methods (FAN2012), Senlis,
France
, April 18–20.
11.
Pierce
,
A. D.
,
1981
,
Acoustic: An introduction to its Physical Principles and Application
,
McGraw–Hill, New York
.
12.
comsol multiphysics version 3.5a,
Acoustics Module
, Comsol Inc., Burlington, MA.
You do not currently have access to this content.