Transmission loss optimization of multi-layer noise control treatments

The optimization of the diffuse field transmission loss through double-wall sound barriers is discussed. The sound barriers are made from a porous decoupling material sandwiched between an elastic skin and a septum. The study aims at optimizing the frequency band averaged diffuse field transmission loss of the three layer system. The optimization problem is implemented by combining the optimization engine to an acoustic-indicator engine for the transmission loss calculation. The aim is to tailor certain material properties of the porous layer to achieve the minimum noise condition.