Method of correcting rotational speed of screw propeller

摘要

The rotational speed of a screw propeller mounted on a propeller shaft of a ship is correctively increased or decreased by locally heating the back or face side of each blade of the propeller along a plurality of paths substantially parallel to and inward from the trailing edge of the blade in a region from a radial position about of 0.5 R to the blade tip, where R is the tip radius, particularly from 0.6 to 0.7 R, and cooling the parts thus locally heated thereby to form wash-back in each blade between the trailing edge and the heating paths thereof as a result of angular deformation accompanying plastic deformation due to the heating and cooling and thereby to decrease or increase the effective pitch of the propeller.