The necessity of reducing CO2 emissions has lead to an increased number of passenger cars that utilize turbocharging to maintain performance when the internal combustion (IC) engines are downsized. Charge air coolers (CACs) are used on turbocharged engines to enhance the overall gas exchange efficiency. Cooling of charged air increases the air density and thus the volumetric efficiency and also increases the knock margin (for petrol engines). The acoustic properties of charge coolers have so far not been extensively treated in the literature. Since it is a large component with narrow flow passages, it includes major resistive as well as reactive properties. Therefore, it has the potential to largely affect the sound transmission in air intake systems and should be accurately considered in the gas exchange optimization process. In this paper, a frequency domain acoustic model of a CAC for a passenger car is presented. The cooler consists of two conical volumes connected by a matrix of narrow ducts where the cooling of the air takes place. A recently developed model for sound propagation in narrow ducts that takes into account the attenuation due to thermoviscous boundary layers and interaction with turbulence is combined with a multiport representation of the tanks to obtain an acoustic two-port representation where flow is considered. The predictions are compared with experimental data taken at room temperature and show good agreement. Sound transmission loss increasing from 5 to over 10 dB in the range 50–1600 Hz is demonstrated implying good noise control potential.

References

1.
Rafael
,
H.
,
2000
, “
A Two-Port Model for a Turbo-Charger Compressor and Intercooler
,” M.Sc. thesis, Royal Institute of Technology, Stockholm, Sweden.
2.
Desantes
,
J. M.
,
Torregrosa
,
A. J.
,
Broatch
,
A.
, and
Climent
,
H.
,
2006
, “
Silencing Capabilities of Non-Silencer Elements: An Underused Potential?
,”
Fourth Styrian NVH Congress
, Graz, Austria, Nov. 15–17, pp.
105
122
.
3.
Knutsson
,
M.
, and
Åbom
,
M.
,
2007
, “
Acoustic Analysis of Charge Air Coolers
,”
SAE
Paper No. 2007-01-2208.
4.
Knutsson
,
M.
, and
Åbom
,
M.
,
2009
, “
Sound Propagation in Narrow Tubes Including Effects of Viscothermal and Turbulent Damping With Application to Charge Air Coolers
,”
J. Sound Vib.
,
320
(
1–2
), pp.
289
321
.
5.
Elnemr
,
Y.
,
2011
, “
Acoustic Modeling and Testing of Exhaust and Intake System Components
,”
Lic. Tech. thesis
, TRITA-AVE 2011:51, Royal Institute of Technology, Stockholm, Sweden.
6.
Mezher
,
H.
,
Chalet
,
D.
,
Migaud
,
J.
,
Raimbault
,
V.
, and
Chesse
,
P.
,
2013
, “
Transfer Matrix Measurements for Studying Intake Wave Dynamics Applied to Charge Air Coolers With Experimental Engine Validation in the Frequency Domain and the Time Domain
,”
Proc. Inst. Mech. Eng., Part D
,
227
(
9
), pp.
1348
1359
.
7.
Mezher
,
H.
,
Chalet
,
D.
,
Migaud
,
J.
,
Raimbault
,
V.
, and
Chesse
,
P.
,
2014
, “
Wave Dynamics Measurements and Characterization of a Charge Air Cooler at the Intake of an Internal Combustion Engine With Integration Into a Nonlinear Code
,”
Int. J. Engine Res.
,
15
(
6
), pp.
664
683
.
8.
Astley
,
R. J.
, and
Cummings
,
A.
,
1995
, “
Wave Propagation in Catalytic Converters: Formulation of the Problem and Finite Element Solution Scheme
,”
J. Sound Vib.
,
188
(
5
), pp.
635
657
.
9.
Dokumaci
,
E.
,
1995
, “
Sound Transmission in Narrow Pipes With Superimposed Uniform Mean Flow and Modelling the Automobile Catalytic Converters
,”
J. Sound Vib.
,
182
(
5
), pp.
799
808
.
10.
Howe
,
M. S.
,
1995
, “
The Damping of Sound by Wall Turbulent Shear Layers
,”
J. Acoust. Soc. Am.
,
98
(
3
), pp.
1723
1730
.
11.
Peters
,
M. C. A. M.
,
Hirschberg
,
A.
,
Reijnen
,
A. J.
, and
Wijnands
,
A. P. J.
,
1993
, “
Damping and Reflection Coefficient Measurements for an Open Pipe at Low Mach and Low Helmholtz Numbers
,”
J. Fluid Mech.
,
256
, pp.
499
534
.
12.
Knutsson
,
M.
, and
Åbom
,
M.
,
2010
, “
The Effect of Turbulence Damping on Acoustic Wave Propagation in Tubes
,”
J. Sound Vib.
,
329
(
22
), pp.
4719
4739
.
13.
Dokumaci
,
E.
,
2009
, “
On Attenuation of Plane Sound Waves in Turbulent Mean Flow
,”
J. Sound Vib.
,
320
(
4–5
), pp.
1131
1136
.
14.
Weng
,
C.
,
Boij
,
S.
, and
Hanifi
,
C.
,
2013
, “
The Attenuation of Sound by Turbulence in Internal Flows
,”
J. Acoust. Soc. Am.
,
133
(
6
), pp.
3764
3776
.
15.
Weng
,
C.
,
Boij
,
S.
, and
Hanifi
,
C.
,
2015
, “
On the Calculation of the Complex Wavenumber of Plane Waves in Rigid-Walled Low-Mach-Number Turbulent Pipe Flows
,”
J. Sound Vib.
,
354
, pp.
132
153
.
16.
Ronneberger
,
D.
, and
Ahrens
,
C. D.
,
1977
, “
Wall Shear Stress Caused by Small Amplitude Perturbations of Turbulent Boundary-Layer Flow: An Experimental Investigation
,”
J. Fluid Mech.
,
83
(
3
), pp.
433
464
.
17.
Elnady
,
T.
, and
Åbom
,
M.
,
2006
, “
SIDLAB: New 1D Sound Propagation Software for Complex Duct Networks
,”
13th International Congress on Sound and Vibration
(
ICSV
), Vienna, Austria, July 2–6, pp.
4262
4269
.
18.
Zwikker
,
C.
, and
Kosten
,
C. W.
,
1949
,
Sound Absorbing Materials
,
Elsevier
,
Amsterdam, The Netherlands
.
19.
Knutsson
,
M.
,
Lennblad
,
J.
,
Bodén
,
H.
, and
Åbom
,
M.
,
2011
, “
A Study on Acoustical Time-Domain Two-Ports Based on Digital Filters With Application to Automotive Air Intake Systems
,”
SAE Int. J. Passenger Cars—Mech. Syst.
,
4
(
2
), pp.
970
982
.
20.
Knutsson
,
M.
, and
Åbom
,
M.
,
2012
, “
Low Frequency Damping From Turbulence With Application to Charge Air Coolers
,” 41st International Congress and Exposition on Noise Control Engineering (
Inter-Noise
), New York, Aug. 19–22, pp.
9424
9433
.
21.
Montenegro
,
G.
,
Della Torre
,
A.
,
Onorati
,
A.
,
Fairbrother
,
R.
,
Elnemr
,
Y.
, and
Dolinar
,
A.
,
2012
, “
Quasi-3D Acoustic Modelling of Common Intake and Exhaust Components
,”
19th International Congress on Sound and Vibration
(
ICSV
), Vilnius, Lithuania, July 8–12, pp.
2430
2437
.
22.
Munjal
,
M. L.
,
1987
,
Acoustics of Ducts and Mufflers With Application to Exhaust and Ventilation System Design
,
Wiley
,
New York
.
23.
Dokumaci
,
E.
,
1997
, “
A Note on Transmission of Sound in a Wide Pipe With Mean Flow and Viscothermal Attenuation
,”
J. Sound Vib.
,
208
(
4
), pp.
653
655
.
24.
Davies
,
P. O. A. L.
, and
Doak
,
P. E.
,
1990
, “
Spherical Wave Propagation in a Conical Pipe With Mean Flow
,”
J. Sound Vib.
,
137
(
2
), pp.
343
346
.
25.
Davies
,
P. O. A. L.
, and
Doak
,
P. E.
,
1990
, “
Wave Transfer to and From Conical Diffusers With Mean Flow
,”
J. Sound Vib.
,
138
(
2
), pp.
345
350
.
26.
Easwaran
,
V.
, and
Munjal
,
M. L.
,
1991
, “
Transfer Matrix Modeling of Hyperbolic and Parabolic Ducts With Incompressible Mean Flow
,”
J. Acoust. Soc. Am.
,
90
(
4
), pp.
2163
2172
.
27.
Easwaran
,
V.
, and
Munjal
,
M. L.
,
1992
, “
Plane Wave Analysis of Conical and Exponential Pipes With Incompressible Mean Flow
,”
J. Sound Vib.
,
152
(
1
), pp.
73
93
.
28.
Åbom
,
M.
,
1987
, “
An Analytical Model for Reactive Silencers Based on Bragg-Scattering
,”
J. Sound Vib.
,
112
(
2
), pp.
384
388
.
29.
Allam
,
S.
, and
Åbom
,
M.
,
2005
, “
Modeling and Testing of After-Treatment Devices
,”
ASME J. Vib. Acoust.
,
128
(
3
), pp.
347
356
.
30.
LMS International N.V.
,
2005
, “
SYSNOISE Rev. 5.6, User's Manual
,” LMS-Numerical Technologies, Leuven, Belgium.
31.
Peat
,
K. S.
,
1994
, “
A First Approximation to the Effects of Mean flow on Sound Propagation Through Capillary Tubes
,”
J. Sound Vib.
,
175
(
4
), pp.
475
489
.
32.
Ih
,
J.-G.
,
Park
,
C.-M.
, and
Kim
,
H.-J.
,
1996
, “
A Model for Sound Propagation in Capillary Ducts With Mean Flow
,”
J. Sound Vib.
,
190
(
2
), pp.
163
175
.
33.
Jeong
,
K.-W.
, and
Ih
,
J.-G.
,
1996
, “
A Numerical Study on the Propagation of Sound Through Capillary Tubes With Mean Flow
,”
J. Sound Vib.
,
198
(
1
), pp.
67
79
.
34.
Weng
,
C.
, and
Bake
,
F.
,
2016
, “
An Analytical Model for Boundary Layer Attenuation of Acoustic Modes in Rigid Circular Ducts With Uniform Flow
,”
Acta Acust. Acust.
,
102
(
6
), pp.
1138
1141
.
35.
Vennard
,
J. K.
, and
Street
,
R. L.
,
1982
,
Elementary Fluid Mechanics
,
Wiley
,
New York
.
36.
Allam
,
S.
, and
Åbom
,
M.
,
2006
, “
Investigation of Damping and Radiation Using Full Plane Wave Decomposition in Ducts
,”
J. Sound Vib.
,
292
(
3–5
), pp.
519
534
.
37.
Ronneberger
,
D.
,
1975
, “
Genaue Messung der Schalldämpfung und der Phasengeschwindigkeit in Durchströmten Rohren in Hinblick auf die Wechselwirkung zwischen Schall und Turbulenz
,” Habilitation thesis, Mathematisch-Naturwissenschaftliche Fakulttät der Universität Göttingen, Göttingen, Germany.
38.
Åbom
,
M.
,
1991
, “
Measurement of the Scattering-Matrix of Acoustical Two-Ports
,”
Mech. Syst. Signal Process.
,
5
(
2
), pp.
89
104
.
39.
Eckert
,
E. R. G.
, and
Irvine
,
T. E.
,
1956
, “
Flow in Corners of Passages With Noncircular Cross Sections
,”
Trans. ASME
,
78
, pp.
709
718
.
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