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 further to a 3D quarter model).
The transmit (active) excitation case will be considered:
The PZT4 ceramic is modelled with 3D piezoelectric elements.
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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.
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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.
 Animated deformed shape at 7500Hz. |
 The excitation has been defined so that rings 1 and 4 are in phase; ring 2 is 90o behind and ring 3 is 90o in front. |
Hydrophone node positions.
Graphs of SPL (dB) v Frequency (Hz) at selected hydrophone positions
 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.
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