Screw propeller nozzle for ships is mounted concentrically around a rotating propeller and configured with a cylindrical inner surface connected at the front and rear by a parabolic profile and radius of curvature to an outer surface

摘要

The nozzle has an outer surface (6) which has a greater external diameter (D1) at the front side and a cylindrical inside surface (7) with a diameter (D3) sized to provide a gap relative to the propeller diameter (D4). The nozzle profile in a plane through the rotation axis has radii of curvature (R1,R2) connecting the outer surface to inner surfaces with parabolic profiles (8,9) where the front side has a greater radius and a greater distance (L2) to the cylindrical surface.