• rotor bearings • rotor dynamics • electro-mechanical interaction between rotor and stator Studied azimuthing thruster was designed for an ice-breaking vessel. The vessel had two azimuthing thrusters symmetrically both side of the center line of the ship hull. The overall length of the vessel was 100 m. Propulsion power of one thruster was 6.5 MW and mass of the thruster was about 160 tons. Finite Element Modeling The whole azimuthing thruster was modeled as well as a part of the surrounding ship structure. Parabolic brick and tetrahedron elements were used for casting parts as well as for forged parts while parabolic shell elements were used for structures made of welded plates. A finite element model of the azimuthing thruster is shown in Fig. 1. The model was created using the commercial finite element software I-DEAS 12 NX. The model contained about 206 000 elements and 445 000 nodes (without model of surrounding water). Fig. 1 Finite Element Model of azimuthing thruster and part of the surrounding ship structure (cross section) Assembly Block and Surrounding Ship Structure Lowest modes of the azimuthing thruster are strongly affected by stiffness properties of the surrounding structure, i.e. assembly block and the surrounding ship structure. The thruster is supported by the slewing bearing at the upper part of the thruster 2
RkJQdWJsaXNoZXIy MTMzNzEzMQ==