Two approaches are followed in Europe to model the acoustic characteristics of porous road surfaces: a phenomenological one and a microstructure one. Both introduce as sphysical parameters of the porous medium: the porosity of the air filled connected pores, the air flow resistivity (air flow resistance per unit length), and structure factors intended to take into account the tortuosity of the pores. Differences are observed between the respective predictions of absorption coefficient for low values of airflow resistivity (associated to high porosities). The major reason is that, while both models take into account the viscosity losses, only the microstructural model considers the possibility of losses due to thermal diffusion. In this paper a new formulation of the phenomenological model is proposed which includes this possibility. The differences between the predicted absorption coefficients are seen to be consequently greatly reduced.


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    Title :

    Acustic absorption of porous roads: a modified phenomenological model


    Additional title:

    Die Geräuschminderung bei dem Betrieb auf poröser Fahrbahnoberfläche: ein modifiziertes phänomenologisches Modell


    Contributors:
    Hamet, J.F. (author)


    Publication date :

    1992


    Size :

    7 Seiten, 6 Bilder, 8 Quellen


    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English