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Performance of Ships in Actual Seas Research Group

PERFORMANCE OF SHIPS IN ACTUAL SEAS

Accurate evaluation of required power toward ship speed and fuel consumption performance in actual seas with winds and waves enables highly efficient operation of ships.
This group is conducting research and development on design technology and energy-saving operation technology for ships with excellent propulsive efficiency in actual seas, and is aiming to improve the ship performance from both aspects of sectors of shipbuilding and shipping. In addition, we are tackling on solving technical issues about international regulations on GHG emissions from ships.

Members

(◎: Head of the Group)

Research Subjects

1. Ship Performance Simulator in Actual Seas: VESTA

VESTA is a ship performance simulator that estimates ship speed reduction and fuel consumption in actual seas with high accuracy based on the prediction method of added resistance in waves. It has acquired the program certification from ClassNK (Nippon Kaiji Kyokai) for the judgment function of the minimum propulsion power rule in the Energy Efficiency Design Index (EEDI).

2. Energy Saving Device for reduction of added resistance by waves: STEP

Ships in actual seas are affected by winds and waves, the resistance increases due to external forces, and propulsive efficiency is reduced by changes in the flow field around the propeller and its load condition. STEP has the effect of reducing the added resistance due to waves, which is the main external force that acts on the hull, and contributes to the reduction of GHG emissions from ships.

3. Energy Saving Device for reduction of added resistance by waves: COVE

COVE is one of the energy-saving devices having a bow shape with concaved frame lines above the water surface of static swell-up of bow waves, and it has an energy-saving effect of about 10% in actual sea conditions (wave height 3 m).

4. Energy saving method in ship operation: Optimal Trim setting

As a method to improve energy efficiency during ship operation, weather routing and deceleration operation of ships are known. In addition, attention has also been focused on techniques for decreasing resistance and improving propulsion performance by adjusting the trim of the ship according to the load condition.

5. Ice Sea Technology: Ice Sea Vessels

For the use of the Northern Sea Route for ships, which is expected as a measure against global warming, it is crucial to evaluate ice conditions and the speed and fuel efficiency of ships going on the ice sea. We are working to improve the accuracy of evaluation methods for speed and fuel consumption by utilizing Ice Tank and an estimation program that utilizes our knowledge accumulated so far.