Passive-active noise control of an acoustic duct

In the recent years, noise control has become a significant factor in the design of automotive and aircraft industries. In general, methods of the passive noise control are practical and most effective at mid and high frequencies. On the other hand, active noise control techniques are more efficient at the low frequency range. Combined solutions seem to be the most appropriate key to cover the whole frequency range of frequencies.
In the present study, a description of simulations for both feedback structural and acoustical structural control strategies are illustrated in order to maximize the damping within an acoustic duct by applying a passive foam layer bonded to an ``active'' surface.