Torsional vibration in marine propulsion

Introduction This work is focusing on torsional vibrations in marine propulsion systems, the problems that occur and the means that today's technology has in order to overcome them. Marine prime mover power plants and propulsion powering arrangements will be analyzed from the scope of torsional vibration as well. 1.0Torsional vibrations Naval architects and propeller designers have often been faced with the problem of propeller and machinery, such as gear gearboxes, induced vibration. It is therefore; …

…in the ship's frictional wake behind the ship's stern when under way. Here the water is largely moving along with the ship, as compared with the water further out which is sueepping past at near ship speed. If the blade is skewed or swept back, the different parts of the blade pass the stern post at different instants so that the force pulses are spread out in time and the intensity of vibration is reduced.