Passive noise control oriented design of aircraft headrests

Two Passive Noise Control (PNC) concepts were numerically evaluated in terms of their impact on the Sound Pressure Level (SPL) perceived by passengers of an aircraft flight. A concept was based on the shape optimization of the headrests, whereas the second one was based on the adoption of a high absorbing material, i.e. a nanofiber textile, to improve the acoustic performances of the headrests. To this aim, an aircraft seat was modelled with the Boundary Element Method (BEM) and loaded with a spherical distribution of monopole sources surrounding the seat. Different configurations of headrest shape and covering textiles were then compared in terms of the SPL calculated at passengers’ ears. The work shows how an acoustic-oriented design of the aircraft headrests could achieve an average SPL reduction for passengers up to 3 dBA.