PAFEC VibroAcoustics - SONAR Transducer Design

Active SONAR transducers are usually excited electrically by an alternating voltage applied across the electrodes of the piezoelectric ceramic elements. The motion generated is transmitted mechanically to the radiating face which is in contact with the water. For passive transducers the excitation in the fluid causes motion at the fluid-structure interface, vibration of the ceramic elements and consequently a detectable current.

The ceramic can be modelled with piezoelectric finite elements. Other mechanical parts can be discretized with standard finite elements. A boundary element or a combination of acoustic FE and wave envelope elements can be used to model the surrounding fluid.

Common transducer types

Analysis of transducer using PAFEC VibroAcoustics can predict

  • structural deformation - check for intended mode of vibration
  • surrounding pressure field - check for potential cavitation
  • directivity pattern
  • acoustic intensities
  • conductance/susceptance/admittance/impedance
  • performance in matching electrical circuit
  • stresses in structure

Pressure field around ring transducer in water

lower edge of picture is axis of symmetry

At low frequencies, below the breathing resonance, the maximum pressure often occurs on the inside surface of the ring.

At high frequencies, well above the breathing resonance, the maximum pressure often occurs on the axis of symmetry.