Page 384 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

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CHAPTER 14 Underwater Acoustics
Transducer element
- Center bolt
- Insulation
- Bronze/steel tail
- Ceramics
- Aluminum head
- Electrical connections
Silver Ceramics deposits
Silver deposits
Ceramics V
Conversion from acoustic energy to electric energy
Conversion from electric energy to acoustic energy
Principle Transmit:
Electrical signal [converts to] mechanical ceramic vibrations [converts to] acoustic signal
Receive:
Acoustic signal [converts to] mechanical ceramic vibrations [converts to] electric signal
FIGURE 14.5
Cross-section of a typical ceramic transducer.
where
β 5 beam width in radians,
λ 5 wavelength,
L 5 linear dimension of the active transducer area (side for a rectangular area, diameter for a circular).
This rule is not valid for very small transducers, i.e., L , λ.
The theoretical beam pattern of a continuous line transducer is a sin x/x function, namely:
bðθÞ 5 ðsinðπL=λUsin θÞ=πL=λUsin θÞ2