Determination of the efflux velocity from a ship's propeller

The wash produced by a ship's rotating propeller is known to cause scouring of the seabed. The design of suitable armour units to prevent such scouring requires an understanding of the velocities within the wash. Key to predicting velocity at any position within the wash is an accurate method for determining the maximum velocity as the wash exits the propeller. This value is known as the efflux velocity. This paper details a study that was undertaken to provide a means by which a more accurate estimation of this velocity can be obtained.