8. Propeller noise and blade vibration

8.1 Propeller noise (self-noise, radiated noise)

For a ship, there are many sources of noise: propellers, machinery, fans, waves breaking along the hull, etc. Within the overall noise, it is not always easy to detect the main source of noise. Within the overall noise, it is not always easy to detect the main source of noise; for example, the influence of the propeller is not very noticeable at the bow of the ship, whereas it may be predominant at the stern.

Generally speaking, there are two kinds of noise:

• self-noise, which is perceived on board by personnel and listening devices for warships and research vessels;

• radiated noise, which is measured from a certain distance from the...