Radiation from a diamond array of ring transducers

The diamond array is made up of four radially polarised ceramic (e.g. PZT4) ring transducers. Each transducer is surrounded by an acoustically neutral, flexible waterproof plastic (not required in FE/BE model). The diamond array is symmetric about the XY plane; therefore it is sufficient to create only a 3D half model. (Note: there is also a YZ plane of symmetry which could have been utilised to reduce the model still futher to a 3D quarter model).

The transmit (active) excitation case will be considered:

The PZT4 ceramic is modelled with 3D piezoelectric elements.

The boundary element mesh, modelling the fluid consists of a continuous sequence of eight noded quadratic patches surrounding the structural elements.

The pressure field around the transducer is illustrated with a mesh of acoustic display elements on planes at Z=0m and X=0.120065m.

Note: Only the acoustic display element plane at Z=0 has been shown in the above diagram, so that the regions of acoustic boundary element patches can be clearly seen.

Hydrophone node positions.

Graphs of SPL (dB) v Frequency (Hz) at selected hydrophone positions

Animated deformed shape at 7500Hz.

The excitation has been defined so that rings 1 and 4 are in phase; ring 2 is 90^o behind and ring 3 is 90^o in front.

SPL distribution at 7500Hz.

Animation of pressure contours at 7500Hz.

Directivities from axis set 1
(global XY plane)

Directivities from axis set 31
(global YZ plane)

For the transmit (active) case graphs of admittance, impedance, conductance, susceptance, resistance and reactance may also be plotted.