Abstract: This paper presents the desige of the compound-bar transducer in which the usual central prestressed bar is replaced by the external prestressed tube and an unidirectional projector without baffle in obtained. This structure is shown to provide a good deep-water seal therefore it mey be applied to some arrays for deep-ocean operation. Finally, the construction and the test results of a cylindrical array for deep-ocean operation are described:
The data of the element: Radiating face: 9cm×9cm, Total long: 18 cm, Dimension of the PZT-8 ceramic disk: ϕ50mm×5mm, Resonant frequency: 10kHz, Band width: 3kHz, Transmitting Voltage response: 48 dB （re 1 μ ba/v）, Beam width: θ> 60°（±3 dB）, Elec iroacoustic efficiency: η_a/e>70%, Electric power P_e>500 W, Weight of the vibrator: 3.5Kg.
The data of the array: Electric power: 15 kW, Source level: 110 dB （re 1μ ba/m）, Fluctuation of horizontal directivity:2.5 dB, Vertical beam width θ>60, Electroacoustic efficiency: 50%, Total weight: about:300kg, Depth of operation: 1000m.