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Centre d'Études techniques de l'Équipement de l'Est
Ministère de l'Écologie, de l'Énergie, du Développement durable et de l'Aménagement du Territoire
Thèse de doctorat,
université du Maine
Spécialité acoustique
Characterization of the
acoustic emission of vehicles
by equivalent point sources
F. Golay
Advisory committee:C. Ayrault LAUMG. Dutilleux LRSL. Simon LAUM
Introduction: urban noise
Emission
Reception
1Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: urban noise
Emission
Reception
1Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: urban noise
Emission
Reception
1Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: urban noise
Emission
Reception
propagation
1Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: research on emission
I modeling in France: [Guide du Bruit, 1972],[NMPB, 2008] [Dutilleux, AAuA, 2010]
I numerous emission models with signi�cantdi�erences
I need of additional indicators to LAeq inurban context (near �eld 6= far �eld)
2Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: research on emission
I modeling in France: [Guide du Bruit, 1972],[NMPB, 2008] [Dutilleux, AAuA, 2010]
I numerous emission models with signi�cantdi�erences
I need of additional indicators to LAeq inurban context (near �eld 6= far �eld)
2Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: research on emission
I modeling in France: [Guide du Bruit, 1972],[NMPB, 2008] [Dutilleux, AAuA, 2010]
I numerous emission models with signi�cantdi�erences
I need of additional indicators to LAeq inurban context (near �eld 6= far �eld)
2Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: problem statement
S(~v = ~cst)
S(~v = ~cst) Sei
y
z
x
Mj(~v = ~0)
d<10 m
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
3Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: problem statement
S(~v = ~cst) Sei
y
z
x
Mj(~v = ~0)
d<10 m
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
3Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: problem statement
S(~v = ~cst) Sei
y
z
x
Mj(~v = ~0)
d<10 m
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
3Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: problem statement
S(~v = ~cst) Sei
y
z
x
Mj(~v = ~0)
d<10 m
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation
3Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Introduction: problem statement
S(~v = ~cst) Sei
y
z
x
Mj(~v = ~0)
d<10 m
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation−1
3Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Table of contents
State of the art
Model improvements
Source height
Méthode Énergétique de Caractérisation de Source(MÉCS)
4Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Table of contents
State of the artEmission modelsPropagation modelsMeasurements methods
Model improvements
Source height
MÉCS
5Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Emission models
I 2 sorts of modelsI reference (physical): more
complex, a lot of input data
I engineering (heuristicapproach): less complex, a fewinput data
I vehicles are modeled bypoint sources
I number of sourcesI source heightI emission spectra (function
of vehicle, v ,. . . )
I numerous engineering modelswith di�erent characteristics
6Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Emission models
I 2 sorts of modelsI reference (physical): more
complex, a lot of input dataI engineering (heuristic
approach): less complex, a fewinput data
I vehicles are modeled bypoint sources
I number of sourcesI source heightI emission spectra (function
of vehicle, v ,. . . )
I numerous engineering modelswith di�erent characteristics
6Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Emission models
I 2 sorts of modelsI reference (physical): more
complex, a lot of input dataI engineering (heuristic
approach): less complex, a fewinput data
I vehicles are modeled bypoint sources
I number of sourcesI source heightI emission spectra (function
of vehicle, v ,. . . )
I numerous engineering modelswith di�erent characteristics
6Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Emission models
I 2 sorts of modelsI reference (physical): more
complex, a lot of input dataI engineering (heuristic
approach): less complex, a fewinput data
I vehicles are modeled bypoint sources
I number of sourcesI source heightI emission spectra (function
of vehicle, v ,. . . )
I numerous engineering modelswith di�erent characteristics
6Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Emission models
I 2 sorts of modelsI reference (physical): more
complex, a lot of input dataI engineering (heuristic
approach): less complex, a fewinput data
I vehicles are modeled bypoint sources
I number of sourcesI source heightI emission spectra (function
of vehicle, v ,. . . )
I numerous engineering modelswith di�erent characteristics
6Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: �xed sources
I harmonic point sources
I �at ground
I homogeneous: Rudnick's model
hij(f ) =− ω4π
1
Rde κR
d
+Q
R re κR
r
I discontinuity of impedance: Rasmussen's model
I ground impedance: Delany-Bazley-Miki's modelI meteorological e�ects neglected
SM
Rd
R rθg
0 5 000 10 000
−20
−10
0
f [Hz]
DSP
[dB]
7Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: �xed sources
I harmonic point sourcesI �at ground
I homogeneous: Rudnick's model
hij(f ) =− ω4π
1
Rde κR
d
+Q
R re κR
r
I discontinuity of impedance: Rasmussen's model
I ground impedance: Delany-Bazley-Miki's modelI meteorological e�ects neglected
SM
Rd
R rθg
0 5 000 10 000
−20
−10
0
f [Hz]
DSP
[dB]
7Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: �xed sources
I harmonic point sourcesI �at ground
I homogeneous: Rudnick's model
hij(f ) =− ω4π
1
Rde κR
d
+Q
R re κR
r
I discontinuity of impedance: Rasmussen's model
I ground impedance: Delany-Bazley-Miki's modelI meteorological e�ects neglected
SM
Rd
R rθg
0 5 000 10 000
−20
−10
0
f [Hz]
DSP
[dB]
7Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: �xed sources
I harmonic point sourcesI �at ground
I homogeneous: Rudnick's model
hij(f ) =− ω4π
1
Rde κR
d
+Q
R re κR
r
I discontinuity of impedance: Rasmussen's model
I ground impedance: Delany-Bazley-Miki's modelI meteorological e�ects neglected
SM
RdRd
R rθg
0 5 000 10 000
−20
−10
0
f [Hz]
DSP
[dB]
7Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: �xed sources
I harmonic point sourcesI �at ground
I homogeneous: Rudnick's model
hij(f ) =− ω4π
1
Rde κR
d
+Q
R re κR
r
I discontinuity of impedance: Rasmussen's model
I ground impedance: Delany-Bazley-Miki's modelI meteorological e�ects neglected
SM
RdRd
R rR rθg
0 5 000 10 000
−20
−10
0
f [Hz]
DSP
[dB]
7Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: �xed sources
I harmonic point sourcesI �at ground
I homogeneous: Rudnick's model
hij(f ) =− ω4π
1
Rde κR
d
+Q
R re κR
r
I discontinuity of impedance: Rasmussen's model
I ground impedance: Delany-Bazley-Miki's modelI meteorological e�ects neglected
SM
RdRd
R rR rθg
0 5 000 10 000
−20
−10
0
f [Hz]
DSP
[dB]
7Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: �xed sources
I harmonic point sourcesI �at ground
I homogeneous: Rudnick's model
hij(f ) =− ω4π
1
Rde κR
d
+Q
R re κR
r
I discontinuity of impedance: Rasmussen's model
I ground impedance: Delany-Bazley-Miki's modelI meteorological e�ects neglected
SM
RdRd
R rR rθg
0 5 000 10 000
−20
−10
0
f [Hz]
DSP
[dB]
7Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: �xed sources
I harmonic point sourcesI �at ground
I homogeneous: Rudnick's model
hij(f ) =− ω4π
1
Rde κR
d
+Q
R re κR
r
I discontinuity of impedance: Rasmussen's model
I ground impedance: Delany-Bazley-Miki's modelI meteorological e�ects neglected
SM
RdRd
R rR rθg
0 5 000 10 000
−20
−10
0
f [Hz]
DSP
[dB]
7Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: movingsources
I no need to take into accountmovement to compute Leq[van der Heijden and van Son,1982]
I heuristic approach based onRudnick's model, addingDoppler and convection e�ects[Li et al., 1998]
I Doppler Weyl Van der Polequation [Buret et al., 2006]
8Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: movingsources
I no need to take into accountmovement to compute Leq[van der Heijden and van Son,1982]
I heuristic approach based onRudnick's model, addingDoppler and convection e�ects[Li et al., 1998]
I Doppler Weyl Van der Polequation [Buret et al., 2006]
8Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Propagation models: movingsources
I no need to take into accountmovement to compute Leq[van der Heijden and van Son,1982]
I heuristic approach based onRudnick's model, addingDoppler and convection e�ects[Li et al., 1998]
I Doppler Weyl Van der Polequation [Buret et al., 2006]
8Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Measurements methods: reference
I acoustic arraysI sound intensity measurementI Equivalent Source Method
⇒ Not suitable for everyday outmeasurements:
I a lot of microphonesI data acquisitionI post-processing
I phase calibrationI is phase relevant outdoors near a
real source?
9Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Measurements methods: reference
I acoustic arraysI sound intensity measurementI Equivalent Source Method
⇒ Not suitable for everyday outmeasurements:
I a lot of microphonesI data acquisitionI post-processing
I phase calibrationI is phase relevant outdoors near a
real source?
9Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Measurements methods: reference
I acoustic arraysI sound intensity measurementI Equivalent Source Method
⇒ Not suitable for everyday outmeasurements:
I a lot of microphonesI data acquisitionI post-processing
I phase calibrationI is phase relevant outdoors near a
real source?
9Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Measurement methods: engineering
I Standard Pass-By methodI CPX methodI source height measurement,
two-microphone methodI transfer function matrix
⇒ none is adapted for a dynamicindicator
10Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Measurement methods: engineering
I Standard Pass-By methodI CPX methodI source height measurement,
two-microphone methodI transfer function matrix
⇒ none is adapted for a dynamicindicator
10Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
State of the art: conclusion
I emission models: numerous with di�erentparameters
I propagation models:I assume harmonic point sourceI no simple expression of the pressure produced by
a moving source
I existing measurement methods:I not applicable to dynamic indicatorsI often deal only with one equivalent source
I need for a new methodI easy measurementI easy post-processingI adapted to dynamic indicators
11Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
State of the art: conclusion
I emission models: numerous with di�erentparameters
I propagation models:I assume harmonic point sourceI no simple expression of the pressure produced by
a moving source
I existing measurement methods:I not applicable to dynamic indicatorsI often deal only with one equivalent source
I need for a new methodI easy measurementI easy post-processingI adapted to dynamic indicators
11Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Table of contents
State of the art
Model improvementsBroadband sourcesOne harmonic moving source
Source height
MÉCS
12Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband sources: measurement problems
Remarks from measurements
I di�erences betweenmeasurement and model
I localized at the interferencesminima
Loss of coherence due to
I turbulenceI model de�ned for harmonic
sourcesI uncertainties on geometrical
parameters
0 500 1 000 1 500 2 000
−40
−20
0
20
f [Hz]
Att21[dB]
13Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband sources: measurement problems
Remarks from measurements
I di�erences betweenmeasurement and model
I localized at the interferencesminima
Loss of coherence due to
I turbulenceI model de�ned for harmonic
sourcesI uncertainties on geometrical
parameters0 500 1 000 1 500 2 000
−40
−20
0
20
f [Hz]
Att21[dB]
13Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband sources: measurement problems
Remarks from measurements
I di�erences betweenmeasurement and model
I localized at the interferencesminima
Loss of coherence due to
I turbulenceI model de�ned for harmonic
sourcesI uncertainties on geometrical
parameters0 500 1 000 1 500 2 000
−40
−20
0
20
f [Hz]
Att21[dB]
13Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: theory
PSD(f ) =1
2
∣∣∣Pd (f )∣∣∣2 + |P r (f )|2 + 2 τcoh Re(P
d P r )
with
τcoh =
0 if (R r − Rd )/c > TI
1 if R r ≈ Rd
T′I
TIotherwise.
and
T′I = TI −
R r − Rd
c
pd
pr
TI
T′I
14Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: theory
PSD(f ) =1
2
∣∣∣Pd (f )∣∣∣2 + |P r (f )|2 + 2 τcoh Re(P
d P r )
with
τcoh =
0 if (R r − Rd )/c > TI
1 if R r ≈ Rd
T′I
TIotherwise.
and
T′I = TI −
R r − Rd
c
pd
pr
TI
T′I
14Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: theory
PSD(f ) =1
2
∣∣∣Pd (f )∣∣∣2 + |P r (f )|2 + 2 τcoh Re(P
d P r )
with
τcoh =
0 if (R r − Rd )/c > TI
1 if R r ≈ Rd
T′I
TIotherwise.
and
T′I = TI −
R r − Rd
c
pd
pr
TI
T′I
14Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: theory
PSD(f ) =1
2
∣∣∣Pd (f )∣∣∣2 + |P r (f )|2 + 2 τcoh Re(P
d P r )
with
τcoh =
0 if (R r − Rd )/c > TI
1 if R r ≈ Rd
T′I
TIotherwise.
and
T′I = TI −
R r − Rd
c
tpd
pr
TI
T′I
14Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: theory
PSD(f ) =1
2
∣∣∣Pd (f )∣∣∣2 + |P r (f )|2 + 2 τcoh Re(P
d P r )
with
τcoh =
0 if (R r − Rd )/c > TI
1 if R r ≈ Rd
T′I
TIotherwise.
and
T′I = TI −
R r − Rd
c
t
tpd
pr
TI
T′I
14Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: theory
PSD(f ) =1
2
∣∣∣Pd (f )∣∣∣2 + |P r (f )|2 + 2 τcoh Re(P
d P r )
with
τcoh =
0 if (R r − Rd )/c > TI
1 if R r ≈ Rd
T′I
TIotherwise.
and
T′I = TI −
R r − Rd
c
t
tpd
pr
TI
T′I
14Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: theory
PSD(f ) =1
2
∣∣∣Pd (f )∣∣∣2 + |P r (f )|2 + 2 τcoh Re(P
d P r )
with
τcoh =
0 if (R r − Rd )/c > TI
1 if R r ≈ Rd
T′I
TIotherwise.
and
T′I = TI −
R r − Rd
c
t
tpd
pr
TI
T′I
14Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: theory
PSD(f ) =1
2
∣∣∣Pd (f )∣∣∣2 + |P r (f )|2 + 2 τcoh Re(P
d P r )
with
τcoh =
0 if (R r − Rd )/c > TI
1 if R r ≈ Rd
T′I
TIotherwise.
and
T′I = TI −
R r − Rd
c
t
tpd
pr
TI
T′I
14Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: theory
PSD(f ) =1
2
∣∣∣Pd (f )∣∣∣2 + |P r (f )|2 + 2 τcoh Re(P
d P r )
with
τcoh =
0 if (R r − Rd )/c > TI
1 if R r ≈ Rd
T′I
TIotherwise.
and
T′I = TI −
R r − Rd
c
t
tpd
pr
TI
T′I
14Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: simulations
SM
zS 1 m2 m yz
0 1 000 2 000 3 000 4 000 5 000
30
40
50
60
70
f [Hz]
PSD
[dB]
Simulation: broadband
15Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: simulations
SM
zS=0.1 m 1 m2 m yz
0 1 000 2 000 3 000 4 000 5 000
30
40
50
60
70
f [Hz]
PSD
[dB]
Simulation: broadband
15Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: simulations
SM
zS=0.1 m 1 m2 m yz
0 1 000 2 000 3 000 4 000 5 000
30
40
50
60
70
f [Hz]
PSD
[dB]
Simulation: broadband
Model: harmonic
15Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Broadband noise: simulations
SM
zS=0.1 m 1 m2 m yz
0 1 000 2 000 3 000 4 000 5 000
30
40
50
60
70
f [Hz]
PSD
[dB]
Simulation: broadband
Model: harmonic
Model: broadband
15Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: layout
M
S(τd )
~v
source pathS(τ r ) S(t)
x
yz
Rd (τd )R r (τ r )
S(tCPA)
16Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: layout
M
S(τd )
~v
source path
S(τ r ) S(t)
x
yz
Rd (τd )R r (τ r )
S(tCPA)
16Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: layout
M
S(τd )
~v
source path
S(τ r ) S(t)
x
yz
Rd (τd )R r (τ r )
S(tCPA)
16Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: layout
M
S(τd )
~v
source path
S(τ r )
S(t)
x
yz
Rd (τd )R r (τ r )
S(tCPA)
16Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: layout
M
S(τd )
~v
source path
S(τ r )
S(t)
x
yz
Rd (τd )
R r (τ r )
S(tCPA)
16Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: layout
M
S(τd )
~v
source pathS(τ r ) S(t)
x
yz
Rd (τd )R r (τ r )
S(tCPA)
16Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: existing model
I Temporal Model for one Moving Source (MTSM),Doppler Weyl van der Pol equation
p(t) =− ωA4π
×
CdeκR
d
Rd+ C r Q(w r )
eκRr
R r
︸ ︷︷ ︸pd
︸ ︷︷ ︸pr
I movement e�ects:
I convection e�ectI Doppler e�ect
17Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: existing model
I Temporal Model for one Moving Source (MTSM),Doppler Weyl van der Pol equation
p(t) =− ωA4π
×
CdeκR
d
Rd+ C r Q(w r )
eκRr
R r
︸ ︷︷ ︸pd
︸ ︷︷ ︸pr
I movement e�ects:
I convection e�ectI Doppler e�ect
17Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: existing model
I Temporal Model for one Moving Source (MTSM),Doppler Weyl van der Pol equation
p(t) =− ωA4π
×
CdeκR
d
Rd+ C r Q(w r )
eκRr
R r
︸ ︷︷ ︸pd
︸ ︷︷ ︸pr
I movement e�ects:
I convection e�ectI Doppler e�ect
17Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: existing model
I Temporal Model for one Moving Source (MTSM),Doppler Weyl van der Pol equation
p(t) =− ωA4π
×
CdeκR
d
Rd+ C r Q(w r )
eκRr
R r
︸ ︷︷ ︸pd
︸ ︷︷ ︸pr
I movement e�ects:I convection e�ect
I Doppler e�ect
17Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: existing model
I Temporal Model for one Moving Source (MTSM),Doppler Weyl van der Pol equation
p(t) =− ωA4π
×
CdeκR
d
Rd+ C r Q(w r )
eκRr
R r
︸ ︷︷ ︸pd
︸ ︷︷ ︸pr
I movement e�ects:I convection e�ectI Doppler e�ect
17Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: simpli�ed model
p
l
=− ωA4π
×
CdeκR
d
Rd+ C r Q(w r )
eκRr
R r
I a lot of variables are function of timeI simpli�cation on time intervals Il with
I either constantI or linear approximation
pl (t) ≈− ω A
4π×
{C̃dl
e(µdlt+νd
l)
Rdl
+ C̃ rl Ql
e(µrlt+νr
l)
R rl
}
18Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: simpli�ed model
p
l
=− ωA4π
×
CdeκR
d
Rd+ C r Q(w r )
eκRr
R r
I a lot of variables are function of time
I simpli�cation on time intervals Il with
I either constantI or linear approximation
pl (t) ≈− ω A
4π×
{C̃dl
e(µdlt+νd
l)
Rdl
+ C̃ rl Ql
e(µrlt+νr
l)
R rl
}
18Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: simpli�ed model
pl =− ωA4π
×
CdeκR
d
Rd+ C r Q(w r )
eκRr
R r
I a lot of variables are function of timeI simpli�cation on time intervals Il with
I either constantI or linear approximation
pl (t) ≈− ω A
4π×
{C̃dl
e(µdlt+νd
l)
Rdl
+ C̃ rl Ql
e(µrlt+νr
l)
R rl
}
18Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: simpli�ed model
pl =− ωA4π
×
Cdl
eκRd
Rdl
+ C rl Q(w r
l )eκR
r
R rl
I a lot of variables are function of timeI simpli�cation on time intervals Il with
I either constant
I or linear approximation
pl (t) ≈− ω A
4π×
{C̃dl
e(µdlt+νd
l)
Rdl
+ C̃ rl Ql
e(µrlt+νr
l)
R rl
}
18Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: simpli�ed model
pl =− ωA4π
×
Cdl
eκRdl
Rdl
+ C rl Q(w r
l )eκR
rl
R rl
I a lot of variables are function of timeI simpli�cation on time intervals Il with
I either constantI or linear approximation
pl (t) ≈− ω A
4π×
{C̃dl
e(µdlt+νd
l)
Rdl
+ C̃ rl Ql
e(µrlt+νr
l)
R rl
}
18Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: simpli�ed model
pl =− ωA4π
×
Cdl
eκRdl
Rdl
+ C rl Q(w r
l )eκR
rl
R rl
I a lot of variables are function of timeI simpli�cation on time intervals Il with
I either constantI or linear approximation
pl (t) ≈− ω A
4π×
{C̃dl
e(µdlt+νd
l)
Rdl
+ C̃ rl Ql
e(µrlt+νr
l)
R rl
}
18Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: simpli�ed model
pl =− ωA4π
×
Cdl
eκRdl
Rdl
+ C rl Q(w r
l )eκR
rl
R rl
I a lot of variables are function of timeI simpli�cation on time intervals Il with
I either constantI or linear approximation
pl (t) ≈− ω A
4π×
{C̃dl
e(µdlt+νd
l)
Rdl
+ C̃ rl Ql
e(µrlt+νr
l)
R rl
}
18Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: numerical results ofa worst case
−10 −5 0 5 1020
30
40
50
60
xS(t) [m]
Lpl[dB]
2 000 3 000 4 000 5 000
−50
−25
0
25
50
f [Hz]
PSD
[dB]
XS(t), f = 3010 Hz
M
2 mv = 130 km/h
19Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: numerical results ofa worst case
−10 −5 0 5 1020
30
40
50
60
xS(t) [m]
Lpl[dB]
2 000 3 000 4 000 5 000
−50
−25
0
25
50
f [Hz]
PSD
[dB]
XS(t), f = 3010 Hz
M
2 mv = 130 km/h
19Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: numerical results ofa worst case
−10 −5 0 5 1020
30
40
50
60
xS(t) [m]
Lpl[dB]
Model
2 000 3 000 4 000 5 000
−50
−25
0
25
50
f [Hz]
PSD
[dB]
XS(t), f = 3010 Hz
M
2 mv = 130 km/h
19Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: numerical results ofa worst case
−10 −5 0 5 1020
30
40
50
60
xS(t) [m]
Lpl[dB]
Model
Simpli�ed model
2 000 3 000 4 000 5 000
−50
−25
0
25
50
f [Hz]
PSD
[dB]
XS(t), f = 3010 Hz
M
2 mv = 130 km/h
19Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: numerical results ofa worst case
−10 −5 0 5 1020
30
40
50
60
xS(t) [m]
Lpl[dB]
Model
Simpli�ed model
2 000 3 000 4 000 5 000
−50
−25
0
25
50
f [Hz]
PSD
[dB]
XS(t), f = 3010 Hz
M
2 mv = 130 km/h
19Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: numerical results ofa worst case
−10 −5 0 5 1020
30
40
50
60
xS(t) [m]
Lpl[dB]
Model
Simpli�ed model
2 000 3 000 4 000 5 000
−50
−25
0
25
50
f [Hz]PSD
[dB]
XS(t), f = 3010 Hz
M
2 mv = 130 km/h
19Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source: numerical results ofa worst case
−10 −5 0 5 1020
30
40
50
60
xS(t) [m]
Lpl[dB]
Model
Simpli�ed model
2 000 3 000 4 000 5 000
−50
−25
0
25
50
f [Hz]PSD
[dB]
XS(t), f = 3010 Hz
M
2 mv = 130 km/h
19Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Model improvements
I Broadband sourceI heuristic approachI numerical validation
I Moving harmonic sourceI simpli�ed temporal modelI numerical validation
20Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Model improvements
I Broadband sourceI heuristic approachI numerical validation
I Moving harmonic sourceI simpli�ed temporal modelI numerical validation
20Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Model improvements
I Broadband sourceI heuristic approachI numerical validation
I Moving harmonic sourceI simpli�ed temporal modelI numerical validation
20Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Table of contents
State of the art
Model improvements
Source heightFixed sourcesMoving source heightFixed vehicles, motor switched on
MÉCS
21Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: statement ofthe problem
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDjPSDjAtt21
propagation−1
22Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: statement ofthe problem
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
PSDjAtt21
propagation−1
22Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: statement ofthe problem
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
PSDjAtt21
propagation−1
22Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: statement ofthe problem
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
Emission• NSe
• (xSe ,ySe ,zSe)i• |Ai |2
PSDj
PSDjAtt21
propagation−1
22Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: statement ofthe problem
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
Emission• NSe
• (xSe ,ySe ,zSe)i• |Ai |2
PSDj
PSDjAtt21
propagation−1
22Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: synoptic
Measurement
Modelling
choose zS ∈ Z
AttMod21
(f )
AttMes21
(f )
Cost F (zS)
zopt
23Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: synoptic
Measurement Modelling
choose zS ∈ Z
AttMod21
(f )AttMes21
(f )
Cost F (zS)
zopt
23Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: synoptic
Measurement Modelling
choose zS ∈ Z
AttMod21
(f )AttMes21
(f )
Cost F (zS)
zopt
23Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: synoptic
Measurement Modelling
choose zS ∈ Z
AttMod21
(f )AttMes21
(f )
Cost F (zS)
zopt
23Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: synoptic
Measurement Modelling
choose zS ∈ Z
AttMod21
(f )AttMes21
(f )
Cost F (zS)
zopt
23Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: measurementresults (1/2)
0 0.5 1
0
0.5
1
Real height [m]
Computedheight[m
]
1SH
24Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: measurementresults (1/2)
0 0.5 1
0
0.5
1
Real height [m]
Computedheight[m
]
1SH
24Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: measurementresults (1/2)
0 0.5 1
0
0.5
1
Real height [m]
Computedheight[m
]
1SH
24Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: measurementresults (1/2)
0 0.5 1
0
0.5
1
Real height [m]
Computedheight[m
]
1SH
3SH
24Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: measurementresults (1/2)
0 0.5 1
0
0.5
1
Real height [m]
Computedheight[m
]
1SH
3SH
1SD
24Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: measurementresults (1/2)
0 0.5 1
0
0.5
1
Real height [m]
Computedheight[m
]
1SH
3SH
1SD
3SD
24Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: measurementresults for one point source (2/2)
0 1 2
5
10
zS [m]
Fcost
[dB]
0 2 000 4 000
−40
−20
0
20
f [Hz]
Att21[dB]
measurement
model
25Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed source height: measurementresults for one point source (2/2)
0 1 2
5
10
zS [m]
Fcost
[dB]
0 2 000 4 000
−40
−20
0
20
f [Hz]
Att21[dB]
measurement
model
25Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height: theory
Emission• NSe
• (xSe(t),ySe ,zSe)i• |Ai |2
Att21(t)
Three models tested:
I �xed sources (near tCPA)
I slow moving sources(without Doppler andconvection e�ects)
I moving sources, fromsimpli�ed temporal model
S(t) S(tCPA)
v
M1
M2
xy
z
26Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height: theory
Emission• NSe
• (xSe ,ySe ,zSe)i• |Ai |2
Emission• NSe
• (xSe(t),ySe ,zSe)i• |Ai |2
Att21
Att21(t)
Three models tested:
I �xed sources (near tCPA)
I slow moving sources(without Doppler andconvection e�ects)
I moving sources, fromsimpli�ed temporal model
S(t) S(tCPA)
v
M1
M2
xy
z
26Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height: theory
Emission• NSe
• (xSe(t),ySe ,zSe)i• |Ai |2
Att21(t)
Three models tested:
I �xed sources (near tCPA)
I slow moving sources(without Doppler andconvection e�ects)
I moving sources, fromsimpli�ed temporal model
S(t) S(tCPA)
v
M1
M2
xy
z
26Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height: theory
Emission• NSe
• (xSe(t),ySe ,zSe)i• |Ai |2
Att21(t)
Three models tested:
I �xed sources (near tCPA)
I slow moving sources(without Doppler andconvection e�ects)
I moving sources, fromsimpli�ed temporal model
S(t) S(tCPA)
v
M1
M2
xy
z
26Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height: theory
Emission• NSe
• (xSe(t),ySe ,zSe)i• |Ai |2
Att21(t)
Three models tested:
I �xed sources (near tCPA)I slow moving sources
(without Doppler andconvection e�ects)
I moving sources, fromsimpli�ed temporal model
S(t) S(tCPA)
v
M1
M2
xy
z
26Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height: theory
Emission• NSe
• (xSe(t),ySe ,zSe)i• |Ai |2
Att21(t)
Three models tested:
I �xed sources (near tCPA)I slow moving sources
(without Doppler andconvection e�ects)
I moving sources, fromsimpli�ed temporal model
S(t) S(tCPA)
v
M1
M2
xy
z
26Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height:results
0 20 40 60 800
0.5
1
1.5
1.31
v [km.h−1]
zOpt
S[m
]
�xed sources
S(t) S(tCPA)
v
M1
M2
2 m
2 m
dPer=2 m
xy
z
27Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height:measurement results
0 20 40 60 800
0.5
1
1.5
1.31
v [km.h−1]
zOpt
S[m
]
�xed sources
S(t) S(tCPA)
v
M1
M2
2 m
2 m
dPer=2 m
xy
z
27Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height:measurement results
0 20 40 60 800
0.5
1
1.5
1.31
v [km.h−1]
zOpt
S[m
]
�xed sources
S(t) S(tCPA)
v
M1
M2
2 m
2 m
dPer=2 m
xy
z
27Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height:measurement results
0 20 40 60 800
0.5
1
1.5
1.31
v [km.h−1]
zOpt
S[m
]
�xed sources
slow moving sources
S(t) S(tCPA)
v
M1
M2
2 m
2 m
dPer=2 m
xy
z
27Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height:measurement results
0 20 40 60 800
0.5
1
1.5
1.31
v [km.h−1]
zOpt
S[m
]
�xed sources
slow moving sources
moving sources
S(t) S(tCPA)
v
M1
M2
2 m
2 m
dPer=2 m
xy
z
27Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height:measurements results, v = 73 km.h−1
0 2 44
6
8
10
12
1.31
zModS [m]
Fcost
[dB]
measurement
�xed sources
2 000 4 000
−20
0
20
f [Hz]
Att21[dB]
28Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height:measurements results, v = 73 km.h−1
0 2 44
6
8
10
12
1.31
zModS [m]
Fcost
[dB]
measurement
�xed sources
slow moving sources
moving sources
2 000 4 000
−20
0
20
f [Hz]
Att21[dB]
28Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Moving source height:measurements results, v = 73 km.h−1
0 2 44
6
8
10
12
1.31
zModS [m]
Fcost
[dB]
measurement
�xed sources
slow moving sources
moving sources
2 000 4 000
−20
0
20
f [Hz]Att21[dB]
28Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed vehicle source height:measurement results
29Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed vehicle source height:measurement results
0 2 4
2
4
6
8
zS [m]
Fcost
Measurement
0 2 000 4 000
−10
−5
0
f [Hz]
Att21[dB]
Measurement
29Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed vehicle source height:measurement results
0 2 4
2
4
6
8
zS [m]
Fcost
Measurement
0 2 000 4 000
−10
−5
0
f [Hz]
Att21[dB]
Measurement
29Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Fixed vehicle source height:measurement results
0 2 4
2
4
6
8
zS [m]
Fcost
Measurement
0 2 000 4 000
−10
−5
0
f [Hz]
Att21[dB]
Measurement
Model
29Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Source height: conclusion
I �xed sources:I theoryI numerical validationI experimental validation: mainly three sources
with discontinuity
I moving sources:I theoryI numerical simulationsI experimental validation
I measurement on �xed vehicles
30Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
Table of contents
State of the art
Model improvements
Source height
MÉCSTheoryNumerical validationLarge source simulation
31Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: problem statement
S
(~v = ~0)
Sei
yz
x
Mj(~v = ~0)
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation−1
32Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: problem statement
S(~v = ~0) Sei
yz
x
Mj(~v = ~0)
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation−1
32Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: problem statement
S(~v = ~0) Sei
yz
x
Mj(~v = ~0)
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation−1
32Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: problem statement
S(~v = ~0) Sei
yz
x
Mj(~v = ~0)
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation−1
32Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: problem statement
S(~v = ~0) Sei
yz
x
Mj(~v = ~0)
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation−1
32Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: problem statement
S(~v = ~0) Sei
yz
x
Mj(~v = ~0)
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation−1
32Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: synoptic
Measurement Modeling
choose e ∈ E
|Ai (f , e)|2
PSDModj (f )PSDMes
j (f )
Cost F (e)
eopt
Space E ofsolutions
I NSe
I
33Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: synoptic
Measurement Modeling
choose e ∈ E
|Ai (f , e)|2
PSDModj (f )PSDMes
j (f )
Cost F (e)
eopt
Space E ofsolutions
I NSe
I
33Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: synoptic
Measurement Modeling
choose e ∈ E
|Ai (f , e)|2
PSDModj (f )PSDMes
j (f )
Cost F (e)
eopt
Space E ofsolutions
I NSe
I (xSe , ySe , zSe)i
33Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: computation of |Ai(f , e)|2
Formulation ...
and LMS-solve
DSPMes ≈ |H(e)|2|A(e)|2
DSPMes1
(f1)...
DSPMesNM
(f1)......
DSPMes1
(fNf)
...DSPMes
NM(fNf
)
=
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . hij(fk) . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
|A1(f1, e)|2...
|ANS(f1, e)|2......
|A1(fNf, e)|2
...|ANS
(fNf, e)|2
34
Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: computation of |Ai(f , e)|2
Formulation ... and LMS-solve
DSPMes ≈ |H(e)|2|A(e)|2
DSPMes1
(f1)...
DSPMesNM
(f1)......
DSPMes1
(fNf)
...DSPMes
NM(fNf
)
=
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . hij(fk) . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
. . . . . . . . .
|A1(f1, e)|2...
|ANS(f1, e)|2......
|A1(fNf, e)|2
...|ANS
(fNf, e)|2
34
Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: con�gurations used fornumerical simulation
S1
S2
M1
M2
M3
M4
zS1
zS2
0.05 m0.45 m
0.5 m
0.5 m2 m
Hypotheses:• white noise • SNR 15 dB• uncertainties along X, Y, Z
35Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: con�gurations used fornumerical simulation
S1
S2
M1
M2
M3
M4
zS1
zS2
0.05 m0.45 m
0.5 m
0.5 m2 m
Hypotheses:• white noise • SNR 15 dB• uncertainties along X, Y, Z
35Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: con�gurations used fornumerical simulation
S1
S2
M1
M2
M3
M4
zS1
zS2
0.05 m0.45 m
0.5 m
0.5 m2 m
Hypotheses:• white noise • SNR 15 dB• uncertainties along X, Y, Z
35Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: con�gurations used fornumerical simulation
S1
S2
M1
M2
M3
M4
zS1
zS2
0.05 m0.45 m
0.5 m
0.5 m2 m
Hypotheses:• white noise • SNR 15 dB• uncertainties along X, Y, Z
35Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: con�gurations used fornumerical simulation
S1
S2
M1
M2
M3
M4
zS1
zS2
0.05 m0.45 m
0.5 m
0.5 m2 m
Hypotheses:• white noise • SNR 15 dB• uncertainties along X, Y, Z
35Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (1/4)
S1
S2M1
M2
M3
M4
0 2 000 4 0000
2
4
6
Z1 Z2 Z3
e =(zS1 ,zS2)
Fcost
[dB]
0 5 100.4
0.5
0.6
0.7
0.8
e =(zS1 ,zS2)
z S[m
]
zSimS
36Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (1/4)
S1
S2M1
M2
M3
M4
0 2 000 4 0000
2
4
6
Z1 Z2 Z3
e =(zS1 ,zS2)
Fcost
[dB]
0 5 100.4
0.5
0.6
0.7
0.8
e =(zS1 ,zS2)
z S[m
]
zSimS
36Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (1/4)
S1
S2M1
M2
M3
M4
0 2 000 4 0000
2
4
6
Z1 Z2 Z3
e =(zS1 ,zS2)
Fcost
[dB]
0 5 100.4
0.5
0.6
0.7
0.8
e =(zS1 ,zS2)
z S[m
]
zSimS
36Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (1/4)
S1
S2M1
M2
M3
M4
0 2 000 4 0000
2
4
6
Z1 Z2 Z3
e =(zS1 ,zS2)
Fcost
[dB]
0 5 100.4
0.5
0.6
0.7
0.8
e =(zS1 ,zS2)
z S[m
]
zSimS
zOptS
36Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (2/4)
S1
S2M1
M2
M3
M4
0 2 000 4 000
75
80
85
90
f [Hz]
PSDj[dB]
Measurement
Model
0 2 000 4 00085
90
95
100
105
f [Hz]
Lw
i[dB]
measurement
model
37Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (2/4)
S1
S2M1
M2
M3
M4
0 2 000 4 000
75
80
85
90
f [Hz]
PSDj[dB]
Measurement
Model
0 2 000 4 00085
90
95
100
105
f [Hz]
Lw
i[dB]
measurement
model
37Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (2/4)
S1
S2M1
M2
M3
M4
0 2 000 4 000
75
80
85
90
f [Hz]
PSDj[dB]
Measurement
Model
0 2 000 4 00085
90
95
100
105
f [Hz]
Lw
i[dB]
measurement
model
37Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (3/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 10
0
0.5
1
Con�guration
z Si[m
]
Simulated
38Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (3/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 10
0
0.5
1
Con�guration
z Si[m
]
Simulated
NSe = 1
38Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (3/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 10
0
0.5
1
Con�guration
z Si[m
]
Simulated
NSe = 1
NSe = 2
38Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (3/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 10
0
0.5
1
Con�guration
z Si[m
]
Simulated
NSe = 1
NSe = 2
NSe = 3
38Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (4/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 100
1
2
3
Con�guration
Fcost(e
opt)[dB] NSe = 1
0 2 000 4 00080
90
100
110
f [Hz]
Lw
i[dB]
�ctive source
39Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (4/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 100
1
2
3
Con�guration
Fcost(e
opt)[dB] NSe = 1
0 2 000 4 00080
90
100
110
f [Hz]
Lw
i[dB]
�ctive source
39Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (4/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 100
1
2
3
Con�guration
Fcost(e
opt)[dB] NSe = 1
NSe = 2
0 2 000 4 00080
90
100
110
f [Hz]
Lw
i[dB]
�ctive source
39Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (4/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 100
1
2
3
Con�guration
Fcost(e
opt)[dB] NSe = 1
NSe = 2
NSe = 3
0 2 000 4 00080
90
100
110
f [Hz]
Lw
i[dB]
�ctive source
39Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (4/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 100
1
2
3
Con�guration
Fcost(e
opt)[dB] NSe = 1
NSe = 2
NSe = 3
0 2 000 4 00080
90
100
110
f [Hz]
Lw
i[dB]
�ctive source
39Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: numerical results (4/4)
S1
S2M1
M2
M3
M4
1 2 3 4 5 6 7 8 9 100
1
2
3
Con�guration
Fcost(e
opt)[dB] NSe = 1
NSe = 2
NSe = 3
0 2 000 4 00080
90
100
110
f [Hz]
Lw
i[dB]
�ctive source
real sources
39Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: large source simulation
S
M1
M2
M3
M4
0.6 m0.9 m
0.05 m
0.45 m
0.5 m
0.5 m2 m
Hypotheses
I 50 sources modeling one large real sourceI di�erent spectraI uncertainties on localization
40Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: large source simulation
S
M1
M2
M3
M4
0.6 m0.9 m
0.05 m
0.45 m
0.5 m
0.5 m2 m
Hypotheses
I 50 sources modeling one large real sourceI di�erent spectraI uncertainties on localization
40Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: large source simulation results
S
M1
M2
M3
M4
0 2 4 6 8 100
0.2
0.4
0.6
0.8
1
Simulation
z S[m
]
41Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: large source simulation results
S
M1
M2
M3
M4
0 2 4 6 8 100
0.2
0.4
0.6
0.8
1
Simulation
z S[m
]
41Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: large source simulation results
S
M1
M2
M3
M4
0 2 4 6 8 100
0.2
0.4
0.6
0.8
1
Simulation
z S[m
]
Narrow bands
41Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: large source simulation results
S
M1
M2
M3
M4
0 2 4 6 8 100
0.2
0.4
0.6
0.8
1
Simulation
z S[m
]
Narrow bands
Third octave
41Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: conclusion
I theory:I inverse approachI LMS to compute |Ai (f )|2
I numerous simulations with two point sourcesI good agreement between measurement and
modelI stability of the best solution
I simulation of a large sourceI Fcost based on narrow bands gives often sources
near the groundI Fcost based on third octaves approaches physical
height
42Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: conclusion
I theory:I inverse approachI LMS to compute |Ai (f )|2
I numerous simulations with two point sourcesI good agreement between measurement and
modelI stability of the best solution
I simulation of a large sourceI Fcost based on narrow bands gives often sources
near the groundI Fcost based on third octaves approaches physical
height
42Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
State of the art Model improvements Source height MÉCS
MÉCS: conclusion
I theory:I inverse approachI LMS to compute |Ai (f )|2
I numerous simulations with two point sourcesI good agreement between measurement and
modelI stability of the best solution
I simulation of a large sourceI Fcost based on narrow bands gives often sources
near the groundI Fcost based on third octaves approaches physical
height
42Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Conclusion (1/3)
S(~v = ~cst) Sei
y
z
x
Mj(~v = ~0)
d<10 m
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation−1
43Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Conclusion (2/3)
I improvements of modelsI for broadband noiseI for moving sources
I two-microphone method for height of sourceI numerical simulationsI moving sourcesI vehicles
I MÉCSI theoryI numerical validation
44Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Conclusion (2/3)
I improvements of modelsI for broadband noiseI for moving sources
I two-microphone method for height of sourceI numerical simulationsI moving sourcesI vehicles
I MÉCSI theoryI numerical validation
Emission• NSe = 1• (xSe , ySe ,zSe)i• |Ai |2
Attj
propagation−1
44Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Conclusion (2/3)
I improvements of modelsI for broadband noiseI for moving sources
I two-microphone method for height of sourceI numerical simulationsI moving sourcesI vehicles
I MÉCSI theoryI numerical validation
Emission• NSe
• (xSe , ySe , zSe)i• |Ai |2
PSDj
propagation−1
44Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
MECS: Perspectives
Optimization and validation of MÉCS
I microphone localizationI space solution reductionI other sources con�gurationsI LMS with positivity constraint
I Measurements
45Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
MECS: Perspectives
Optimization and validation of MÉCS
I microphone localizationI space solution reductionI other sources con�gurationsI LMS with positivity constraintI Measurements
45Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
MECS: Perspectives
Optimization and validation of MÉCS
I microphone localizationI space solution reductionI other sources con�gurationsI LMS with positivity constraintI Measurements
Theoritical improvements
I movementI broadband noiseI measurement in real conditionsI directivity
45Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
MECS: Perspectives
Optimization and validation of MÉCS
I microphone localizationI space solution reductionI other sources con�gurationsI LMS with positivity constraintI Measurements
Theoritical improvements
I movementI broadband noiseI measurement in real conditionsI directivity
45Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
MECS: Perspectives
Optimization and validation of MÉCS
I microphone localizationI space solution reductionI other sources con�gurationsI LMS with positivity constraintI Measurements
Theoritical improvements
I movementI broadband noiseI measurement in real conditionsI directivity
45Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
Acknowledgments
Close supervision
I Christophe AYRAULT, LAUMI Guillaume DUTILLEUX, LRSI Laurent SIMON, LAUM
Monitoring committee
I Fabienne ANFOSSO-LEDEE, LCPCI David ÉCOTIÈRE, LRSI Franck POISSON, SNCF
Other
I Charlotte, Thérèse, Auguste, Gustave. . .I
Chritophe H., Thierry F., Jean-Louis A., Loic T., Laurent B.46
Thesis 31/08/10, Le MansCharacterization of the acoustic emission of vehicles by equivalent point sources F. Golay
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Ministère de l'Écologie, de l'Énergie, du Développement durable et de l'Aménagement du Territoire
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