engleski

Influence of the approximated mass characteristics of a ship on the added resistance in waves

Added resistance in waves is one of the main causes of the involuntary speed reduction of a ship. Total resistance force of the ship sailing at actual seaway should be determined instead of considering the calm water resistance and taking the Sea margin into account. The exact ship mass characteristics, i.e. position of the centre of gravity and gyration radii, are often unknown especially in the preliminary design phase of a ship. In order to calculate the ship response and loads acting on the ship hull in waves, the mass characteristics have to be approximated with sufficient accuracy. In this paper, the influence of the approximate determination of the ship’s centre of gravity and gyration radii on the added resistance in waves is investigated for KCS and S175 benchmark container ships and KVLCC2 ship which has a hull form of a typical large tanker. Added resistance in waves is calculated using 3D panel code based on the potential flow theory for various incoming wave frequencies. Ship mass characteristics are approximated and added resistance is calculated for full load and ballast condition considering that ship spends 40-50% of its total voyage time in the ballast condition. The obtained results for the added resistance are compared with the available experimental data from the literature.

added resistance, mass characteristics, potential flow

nije evidentirano