14. starptautiskā konference 2012 - Latvijas Jūras akadēmija

Proceedings of 14th International conference „Maritime Transport and Infrastructure - 2012”Table 1Main engine particularsMAN 8 L 32/40Piston Stroke40 cmCylinder bore32 cmNumber of cylinders 8Power4000 KWSpeed750 rpmThe torsional angles have obtained by running the matlab programs. Ship main engine, shaftand propeller system was analyzed with undamped and different torsional damped coefficient.Displacement amplitudes are shown in figure 3 and figure 4. Torsional speed of change valuesindicated in Fig. 5 and Fig. 6.Fig. 3 Torsional angular displacement at shaftFig. 4 Propeller torsional angular displacementFig. 5 Torsional angular speed change at shaftFig. 6 Variation speed of the propeller torsionalangular velocityAmplitude of shaft torsional angular occurred as a unstable position in the undampedcondition, unstable condition has been seen just for first two second than amplitude continue todecreased with effecting from torsional damper coefficient value at. Other simulationhave proceeded withcoefficient and understand that the amplitude with using thisdamper has determine better damping coefficient because amplitude have settled at reference line atthe end of the first ten second.Propeller amplitude is behaved continuously as a sinusoidal without damping coefficient.Propeller angular displacement decrease from 0.43 rad to 0.37 rad when thedampingcoefficient effected, in case of damping coefficient implemented to system as a, theamplitude rate decreases to 0.32 rad in ten seconds.130