WP2: Noise Sources |
Leader: University of Genoa
Contact person: Prof. Enrico Rizzuto, University of Genoa, (enrico.rizzuto@unige.it) |
![]() ![]() Prediction Model Scale |
Main objectives
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Task 2.1 Derivation of ship URN patternsFor different types of vessels, an underwater radiated noise pattern is defined by a representation of spectral noise vs. frequency. The novelty of the approach proposed here is to split the global radiated noise into several components, one for machinery noise, the other for propeller without cavitation, and the last one to account for cavitation. For each component a semi-empirical formula was introduced to account for ship size and speed. Deliverable R2.9Task 2.2 Predictive theoretical models for propeller URN![]() Wave pattern prediction ![]() ![]() Numerical wake prediction
(RANSE)
Coupled approach
for self-propulsion
![]() Cavitation prediction ![]() ![]() Full RANS approach for
self-propulsion
LES propeller vortex evaluation
In this task the characterisation of the propeller as a source for
underwater radiated noise will be considered from a theoretical
viewpoint. Predictive methods are implemented and validated
with experimental surveys.
Task 2.3 Experimental investigations in model scale
![]() ![]() ![]() Screenshot of propeller cavitation Cavitation tunnel setup Propeller model scale radiated noise results Results are analysed in order to provide feed-back and validation to the prediction models developed in the various steps of task 2.2; further validations come from full scale surveys (WP3). Two complete hull models are built for towing tank tests (CEHIPAR, SSPA) and cavitation tunnel (SSPA). Three propeller models are tested in cavitation tunnels. In the large cavitation tunnel (SSPA), the propeller are tested behind a complete ship model. In the medium sized cavitation tunnels (CEHIPAR, UNIGE), the propellers are tested behind wire mesh screens (or dummys). Deliverable D2.5Task 2.4 Propeller-hull vibro-acoustic interactionMain objective of the task is to determine how much vibro-acoustic response of ship structure amplifies the direct radiated noise from the propeller. Two main phenomena are involved:
For modelling interaction between ships structure and the surrounding fluid, structural models are required of a considerable part of the aft ship where the mass elastic behaviour represents the propeller generated underwater noise. Task 2.5 - Synthesis: impact of propeller noise on global URNIn this task, the noise contributions from the cavitating and/or non-cavitating propeller are compared with other noise sources (in particular machinery). A synthesis of all contribution into a total ship radiated noise pattern is sought. The effect of running at different propeller loads and ship speeds is also studied. Deliverable D2.8 |
WP2 Partners: |
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