Low frequency underwater radiated noise from shipboard machinery
* Presenting author
Abstract:
Underwater noise of ships is becoming of increasing interest not only for naval ships but also cruise ships and cargo vessels with respect to disturbance of life in the sea. One of the contributors to underwater radiated noise is the propulsion machinery of ships.Traditional methods to predict noise from machinery in particular the structure-borne noise part consider propagation in the hull and finally radiation into the sea depending on vibration velocity and radiation efficiency. In an attempt to improve the unsatisfactory performance of these models the traditional analytical description of radiation of a force on an infinite plate is evaluated and empirically adjusted to the particularities of ship structures. Finite element analysis is shown to perfectly match with analytical results. Application of numerical calculations of full-scale ships and comparison with radiated noise measurements show that under certain conditions very precise predictions are possible.