DESIGN OF A PROPULSION DRIVE SYSTEM FOR LATERAL MOVEMENT OF VESSEL (THRUSTER)

This papers covers propulsion parameter optimization and motion study of bow thrusters. Thrusters parameters for production are decided in relation with vessel length. Lateral thruster parameters are decided in correlation with vessel length. Reason for it is that thrust force is given by value of ship hull resistance and desired speed of lateral movement. Analyzed vessel in this research was “Šibenik 800- working variant”. Model of ship is made in 3D software Solid Works 2017 by use of conceptual drawings provided by company Dunkić Ltd. Hull resistance represents complex physical phenomenon of fluid-structure interaction and very often for its analysis engineers are forced to use software for computational fluid dynamics. Ansys 17.2 with its CFX module was applied for structural analysis. Investigation was divided into two sections to decrease computation time: immersed and dry part. Required propulsion force was given by assumption that acceleration is equal to zero when vessel is moving with designed ultimate speed, whereas amount of propulsion force is equal to resistance force. Considering complex variation of hydrodynamic pressure as function of vessel speed, it is to be expected that acceleration will take infinite amount of time to achieve desired ultimate speed (asymptotic value)