The recent adoption in 2013 of the IMO Energy Efficiency Design Index (EEDI) and Ship Energy Efficiency Management Plan (SEEMP) has resulted in a renewed interest to reduce overall ship fuel consumption and emissions. The IMO EEDI requirements can be achieved through adoption of innovative energy efficiency technologies. These technologies include hull coatings, surface drag reduction from air cavity and air lubrication (Figure 1), higher efficiency propeller design and wind assist-sails and Flettner rotors. The authors have been involved with the development and testing of air lubrication drag reduction systems. In performing the EEDI evaluation, it is necessary to estimate the net power savings by taking in account the power savings and the corresponding blower system power. As a contribution to this problem, the authors present the result of their study. The authors present the result of their study. They introduce the Air Lubrication System feasibility expression as the blower power PBlower should be less than the < PR as the drag reduction threshold power PR. (PBlower < PR).

The results are presented in a series of tables and graphs that present the net power savings as a function of the bottom area covered by air lubrication bubble injection. The results identify optimal design points that achieve the larger reduction in the EEDI. This approach has been enables a preliminary design of the ship with the air lubrication drag reduction system. Using this methodology, it is also possible to examine the cost benefits of air lubrication drag reduction.

The results are presented in a series of tables and graphs that present the net power savings as a function of the bottom area covered by air lubrication bubble injection. The results identify optimal design points that achieve the larger reduction in the EEDI. This approach has been enables a preliminary design of the ship with the air lubrication drag reduction system. Using this methodology, it is also possible to examine the cost benefits of air lubrication drag reduction.

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