Low-frequency spherical-shell projectors
J. B. Lee · The Journal of the Acoustical Society of America · 1977
The spherical-shell projector comprises a piezoelectric ceramic ring driving two concave spherical shell segments in flexure. One model resonant at 600 Hz in water weighs 15 kg and delivers a souce level of 201.5 dB re 1 μPa at 1 m. Its mechanical Q is 5 and efficiency 80% at resonance. An axially-symmetric finite element model is being used to study the performance of spherical-shell projectors and generally good agreement is achieved between the calculated and experimental results.