Abstract: A little volume low frequency resonator applicable to double wall confi guration of propeller-driven aircraft was designcd on the basis of the principle of Holmheltz resonator. The normal incidence absorption coefficient of the various single resonator has been measured. The agreement between theoretical and experimental results is encouraging. An array of resonators whose resonant frequency at 85Hz and 160Hz, respectively, are installed between aircraft double-pannel, and it has been shown that transmission loss of the double wall constrncture with resonators improve 4dB and 6.5dB in 1/3 octave bandwidth at 80Hz and 160Hz centre frequency, respectively, and 5dB and 7dB at resonant frequencies, compared with that of the double wall configuration without resonators.

Key words: resonator, transmission loss, absorption coefficicnt