Rectangular duct - Gaussian pulse

Simulation of the propagation of an acoustic plane wave (Gaussian pulse, standard deviation = 1ms) through a rectangular duct (110mmx190mmx1000mm). With a low frequency pulse, only the plane mode propagates. With a wider band pulse, several modes propagate as can be seen in this video.
This simulation has been done with Time Domain BEM solver SONATE© in LMS Virtual.Lab® (http://imacs.polytechnique.fr/SONATE.htm). It has been used to illustrate the master course on wave propagation of Dr. Isabelle Terrasse @ Ecole Polytechnique http://www.catalogue.polytechnique.fr/cours.php?id=2586&langue=FR.