Process and transducers for emitting acoustic waves in a liquid with a pronounced directivity at low frequencies

摘要

The transducer (1) comprises a hollow rigid cylindrical box (2) centred on an axis (XX') and open at both ends. Inside the box two identical electroacoustic motors (13) are arranged coaxially with the box axis on either side of a central counterweight (14). Each of the ends are covered by a housing (15) matching the shape of the inside of the cylindrical box. Together the two housings and the outer cylindrical box (2) define two cavities (16) whose resonance corresponds to the required transmission frequency. The total length of the rigid box is such that it is with 20% of half the wavelength of the transmitted frequency.