Ship performance upgrade
Ship hull can be updated in several different ways.
Form of the hull – 10 % saving potential
Shape of the hull can be optimized considering ship operability and its resistances. Hull lines are modified in order to get smooth and streamlined behavior. Design of bulbous bow and ducktail can be optimized as well as the stern with operating propulsion.
Propulsion – 10 % saving potential
Design of self-propulsion, free-floating ship in full scale includes such as detecting nominal and effective wakes and prediction of resistance, pressure pulses, cavitation and also noise. Propeller/hull interaction can be studied and propeller design tested for best possible performance. Different propulsion alternatives are easy to compare with the help of simulations.
Hull friction – 8 % saving potential
Designed air lubrication system can be optimized for skin friction reduction. Optimization is done with different air flow rates for different operational speeds and different positions of the air supply devices. It includes risk analysis for possible air entrance into the propellers and detection of the lubrication air spread in the flat bottom area as well as near the stern. Also the relations between the amount of air fed into the system, its behavior under the hull and the power required for air supply is found out.
Impact of friction on ship performance can be evaluated considering cleaning or usage of slithery paint on the hull surfaces. The effect of the surface roughness of propulsion devices can be checked as well.
Appendages – 10 % saving potential
By designing and optimizing essential and additional appendages the performance of the ship can be vastly improved. These actions include such as
- chamfers and grids in bow thruster tunnel
- chamfers and grids in stern thrusters
- recess and alignment of fin stabilizers
- profiles and alignments of bilge keels
- head boxes
- alignment of studs and rudders
- bulbous bow
Example - ELOGRID
New grid for bow thruster was designed in order to reduce ship resistance in motion and to improve the thrust forces. New design was tested in the general cruise ship hull and it resulted in 25 % lower resistance and 15 % additional thrust forces compared to conventional grids.