Contribution
Comparison of Actuator Concepts for reducing Sound Reflection from Underwater Surfaces
* Presenting author
Abstract:
From a strategic point of view, it is necessary to protect underwater vehicles from reconnaissance. Modern sonar systems are capable of determining the exact position of those vehicles. They do this by emitting signals that reflect off the surface of the vehicles, which are then detected and evaluated. At low frequencies, reflection can be reduced by using an active system. The incoming sound waves are measured in front of the surface and then processed by a control system. The system drives an actuator applied to the surface that minimizes the reflection. Three different actuator concepts are compared in this study: First, a 3-3 mode piezoceramic patch transducer attached to steel; second, a bending actuator embedded in foam; and third, a multilayer structure made of Poly(vinylidenfluorid-Trifluorethylen) (PVDF-TrFE) film. Measurements in laboratory tests show the different characteristics of the actuators under the influence of sonar-like signals and under hydrostatic pressure from 1 to 40 bar.