Implementation of complex impedance conditions and PML boundaries into a transmission line matrix model for urban acoustics applications
Résumé
Most of models for sound propagation in urban areas are based on energetic approaches, mainly using geometrical acoustics assumptions. However, such models are not able to model acoustic interference patterns occurring during sound propagation, as well as complex boundary conditions. An alternative approach consists in using temporal methods like the finite difference in time domain one, or as in this paper, the transmission line matrix method. However, the two main difficulties regarding the application of such temporal approaches in urban areas is, firstly, the implementation of complex impedance conditions, and, secondly, the modeling of open boundaries. In this paper, solutions are proposed for the modeling of complex impedance boundary conditions as well as absorbent boundary conditions in the transmission line matrix approach. Lastly, several bi-dimensional applications are proposed in order to illustrate these implementations of complex boundary conditions for acoustic levels prediction in urban areas.