DEUFRAKO: calculation of LAeq and Lden
DEUFRAKO: P2RN
Prediction and Propagation of rolling noise
LAeq

Geometries

The following table shows the ten typical road configurations for which the LAeq and Lden were analysed.

case nb. geometry parameter attenuation
case 1a
LAeq
  • Z→∞, Z(grass) and Z(P.A.)
  • ∂c/∂h=0
  • hs=0.05 m and hr=1.20 m
  • d(S,R)=7.50 m
LAeq
case 1b
LAeq
  • Z1→∞ and Z1=Z(P.A.), Z2=Z(grass)
  • ∂c/∂h=0
  • hs=0.05 m and hr=1.20 m
  • d(S,R)=7.50 m and d(S,disc.)=4 m
LAeq
case 1c
LAeq
  • Z→∞, Z(grass) and Z(P.A.)
  • ∂c/∂h=0 and ∂c/∂h>0 (0.25)
  • hs=0.05 m and hr=2 m
  • d(S,R)=200 m
LAeq
case 1d
LAeq
  • Z1→∞ and Z1=Z(P.A.), Z2=Z(grass)
  • ∂c/∂h=0 and ∂c/∂h>0 (0.25)
  • hs=0.05 m and hr=2 m
  • d(S,R)=200 m and d(S,disc.)=4 m
LAeq
case 2a
LAeq
  • Z→∞
  • ∂c/∂h=0 for d(S,R)=50 m
  • ∂c/∂h>0 (0.25) for d(S,R)=100 m
  • hs=0.05 m and hr=2 m/receiver level
  • d(S,slope)=4 m
  • hslope=1.5 m and θ=8°
LAeq
case 2b
LAeq
  • Z1→∞ and Z1=Z(P.A.), Z2=Z(grass)
  • ∂c/∂h=0 for d(S,R)=50 m
  • ∂c/∂h>0 (0.25) for d(S,R)=100 m
  • hs=0.05 m and hr=2 m/receiver level
  • d(S,slope)=4 m
  • hslope=1.5 m and θ=8°
LAeq
case 3a
LAeq
  • Z→∞
  • ∂c/∂h=0 for d(S,R)=50 m
  • ∂c/∂h>0 (0.25) for d(S,R)=100 m
  • hs=0.05 m and hr=2 m/receiver level
  • d(S,slope)=4 m
  • hslope=1.5 m and θ=8°
LAeq
case 3b
LAeq
  • Z1→∞ and Z1=Z(P.A.), Z2=Z(grass)
  • ∂c/∂h=0 for d(S,R)=50 m
  • ∂c/∂h>0 (0.25) for d(S,R)=100 m
  • hs=0.05 m and hr=2 m/receiver level
  • d(S,slope)=4 m
  • hslope=1.5 m and θ=8°
LAeq
case 4a
LAeq
  • Z→∞
  • ∂c/∂h=0
  • hs=0.05 m and hr=3 m level
  • d(S,barrier)=4 m
  • d(barrier;R)=4 m
LAeq
case 4b
LAeq
  • Z→∞
  • ∂c/∂h=0
  • hs=0.05 m and hr=3 m level
  • d(S,barrier)=4 m
  • d(barrier;R)=4 m
LAeq

with:

The ground impedance for Z→∞ and Z(grass) is calculated with the one parameter model developed by Delany and Bazley [1]. For porous asphalt the phenomenological model from Hamet and Bérengier [2] is used to calculate the ground impedance.

References

[1] Delany, M. E., Bazley, E. N., Acoustical properties of fibrous materials, Applied acoustics, 3 (1970), 105-116
[2] Hamet, J. F., Bérengier, M., Acoustical characteristics of porous pavements: a new phenomenoligical model, Internoise 93, Leuven, Belgium, 1993

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