Oil filled free flooded ring transducer for deep submergence applications

Free flooded ring transducers can be used at unlimited depth in the ocean. General practice for encapsulation of these transducers is to use direct over moulding with rubber or polyurethane. Compared to direct moulding over the ceramic, an oil filled encapsulation provides better coupling with the medium and higher source level. In this study an oil filled free flooded ring transducer is modeled using ATILA, a finite element package for the design of underwater transducers. Modeling study is carried out to compare the performance of a directly molded transducer with an oil filled transducer. Effect of oil column thickness over the ceramic is also studied. One of the transducers modeled is also manufactured and the results are compared with the analysis. Characteristics of the transducers such as Transmitting Voltage Response and Receiving Sensitivity are reported.