Numerical Investigation and Optimization of Plate-Type Acoustic Metamaterials for Noise Reduction in Segmented Aircraft Fuselage Cabin Structure

The present work mainly focuses on the reduction of cabin noise using plate-type acoustic metamaterials (PAM) so that it creates a quiet environment inside the cabin for passenger comfort. Acoustic metamaterials have greater potential to attenuate the sound passing through them. Metamaterials are introduced between the aircraft’s fuselage walls to study sound attenuation behavior. The work is studied in two levels, attenuation at the coupon level and at segmented aircraft fuselage cabin level. Initially, the finite element-based fluid–structure interaction analysis (FSI) of PAM at coupon level has been carried out, which features all parts of the fuselage cabin, like the outer wall, trim panel, and cabin air modeled as fluid. Then the noise levels in terms of sound pressure levels (SPL) are compared with and without metamaterial conditions to evaluate the effectiveness of metamaterial in noise attenuation. Similarly, FSI on the segmented aircraft fuselage structure with PAM is carried out at the cabin level. From the study, it is evident that a considerable decrease in the SPL at a certain frequency both at the coupon level as well as at the segmented cabin level is seen. The optimized locations of the placement of PAM are also investigated to have better cabin comfort.