Control of aircraft interior noise using heterogeneous (HG) blankets Free

This study is concerned with the passive control of vibration and sound radiation of interior cabin noise in aircraft at low frequencies (<500 Hz) using heterogeneous (HG) blankets. HG blankets consist of poro-elastic media with small embedded masses, which act similar to a distributed mass-spring-damper system. HG blankets have shown significant potential to reduce low-frequency radiated sound from structures, where traditional poroelastic materials have little effect. A mathematical model of a double panel system with an acoustic cavity and HG blanket was developed using mobility and impedance matrix methods. Theoretical predictions are validated with experimental measurements. Results indicate that proper tuning of the HG blankets can achieve in broadband reductions in sound transmission through the double panel system with less than 10% added mass. Future work includes expanding the model and experiment to multiple panel systems.