DEUFRAKO: P2RN | |
Prediction and Propagation of rolling noise |
The calculation of the L_{Aeq} based on a method developed by Bérengier et al. [1]. The following input parameter are needed:
The figure above shows the principle of the calculation of the L_{Aeq}. First the L_{Aeq} for a single vehicle, a reference period T (typically 1 hour) at a reference receiver R_{ref} (distance source↔receiver: D_{ref}) is calculated:
In a second step the L_{Aeq} at a distance D_{meas} for a single vehicle is calculated as follows:
All these calculations are made for passenger cars as well as for heavy trucks. To compute the L_{Aeq} depending on the traffic volume for each hour the calculated L_{Aeq},T(v,D) must sum up logarithmical:
where n_{pc} and n_{ht} are, respectivly, the number of passenger cars and heavy trucks in the traffic flow during the period T. L_{Aeq}(pc) and L_{Aeq}(ht) are the L_{Aeq} for one representative vehicle of each family on the reference period one hour.
Afterwards the L_{den} is calculated from the L_{Aeq}:
[1] | M. Bérengier, Y. Pichaud, J.-F. Le Fur, Effect of low-noise pavements on traffic noise propagation over large distances: influence of ground and atmospheric conditions, Internoise 2000, Nice, 2000. |
[2] | ISO 11819-1, Acoustics: Method for measuring the influence of road surfaces on traffic noise - Part 1: Statistical pass-by method, 1996 |