Comparison of a 31 and 33 mode PZT cylinder in a broadband unlimited - PowerPoint PPT Presentation

UDT 2020 Session : Pro-Active Sonar: What's Happening in the World of Transducer Design & Characterisation ? Subject : Innovations and utilizations of piezoelectric ceramics in ocean acoustic sensors and transducers Comparison of a 31 and 33 mode PZT cylinder in a broadband unlimited depth transducer

Introduction Send-Receive Transducer Applications – Underwater communications – Beacons – Range Tracking – Acoustic Triggers

Introduction Send-Receive Transducer Requirements – Low Frequency Broadband (8-14kHz) – High Pressure – Hemispherical Beam

Approach PZT material selection Conceptual Design FEM Modelling Assembly

Approach

Approach PZT material selection Navy Type I Navy Type III (BM402) (BM800) Relative dielectric consant 1350 1000 Dissipation factor (%) 0.4 0.3 d 33 (10 -12 C/N) 305 225 k 33 0.71 0.64 k p 0.60 0.5

Approach Conceptual Design -High (Unlimited) Depth Options Free Flooded Ring – toroidal beam pattern Oil-Filled

Approach Conceptual Design PZT ceramic in 31 mode (classic inside/outside electrodes) PZT ceramic in 33 mode (striped electrodes), offering higher K and g33

Approach Conceptual Design -High (Unlimited) Depth Options Oil filled transducer – hemispherical beam pattern

Approach FEM Modelling

Approach FEM Modelling

Approach Assembly of Transducers a)Free Flooded Ring, 31 mode cylinder b) Oil Filled Transducer, 31 mode cylinder c) Oil Filled Transducer, 33 mode cylinder

Results

Results

Results Beam Pattern XY Radial Plane

Results Beam Pattern XZ Axial Plane

Future Work • Sea Trials • Turning the aspect ratio of the cylinders, to further couple the 8kHz Helmholtz resonance with the 13kHz radial resonance • Scaling the design, using same principle design for lower or higher frequencies