A DISCRETE APPROACH FOR ANALYSIS OF SOUND TRANSMISSION IN PIPES COUPLED WITH COMPACT COMMUNICATING DEVICES

A new discrete method is presented for acoustic modelling of pipes that are coupled by compact devices. This is based on an approximate source analogy that allows the communicating devices to be modelled as continuous two-port elements. One of the areas in which this method finds application is the acoustic analysis of mufflers with multiple perforated pipes. For this case, the present formulation assumes fundamental mode propagation for simplicity. Also presented in the paper are applications in which perforate holes are modelled as continuous visco-thermal pipes, the results of which are compared with the lumped parameter modelling of perforate impedance. In general, the present method is computationally simpler and more versatile than the more commonly known distributed parameter method.