Vibration and noise control of the fuselage via dynamic absorbers

A closed, elastic cylindrical shell is used as a simple model of the aircraft's fuselage. For reducing the vibration of the fuselage and the subsequent interior sound pressure due to the propellers, several dynamic absorbers are attached to the shell. In the paper, we analytically derive the vibration and the interior sound pressure of the shell by employing the techniques of subsystem synthesis and modal expansion where the external distributed pressures are chosen according to experimental data of an actual aircraft. The absorbers are successful for attenuating the vibration and the noise. The effects of altering various parameters of the shell, the external pressures, and the absorbers, are also studied and discussed. Finally, some general guidelines of absorber design for vibration and noise control of the fuselage are presented.