At the 62nd Meeting (2011) of the Marine Environment Protection Committee (henceforth MEPC), the IMO had adopted the proposed amendment adding to the MARPOL Annex Chapter Ⅵ making it mandatory the EEDI (Energy Efficiency Design Index) for new ships as well as the SEEMP (Ship Energy Efficiency Management Plan) for all ships. This was eventually for reducing GHG emissions from international shipping vessels, and has been effective since the 1st of January 2013 for ships weighing 400GT.Notably, at the 70th MEPC, the plan to develop a roadmap for the comprehensive IMO strategy on reducing GHGs from ships was approved, and as such, the plans including its shortterm, mid-term and long-term measures have been arranged in order to adopt the pertinent strategy by 2023.Following the approved roadmap, at the 72 nd MEPC (April, 2018), the first stage of reducing GHG emissions from ships was selected/passed as the Initial IMO strategy for the reduction of GHGs from ships (henceforth Initial IMO GHG Strategy), and at the 73 rd MEPC (October, 2018), subsequent programs following the Initial IMO GHG Strategy were arranged.In this paper, the following issues will be introduced and discussed 1) the initial IMO strategy for the reduction of GHG from ships, 2) the contents of the 73~74 MEPC meeting regarding the follow-up actions related GHG reduction programs until 2023 to be executed (including specific matters concerning the execution of potential short-term, mid-term and long-term measures) 3) the GHG reduction strategies, GHG response policies of IMO member states and 4) finally, trends in technological developments for GHG reduction from ships.
On 13 April 2018, the International Maritime Organization (IMO) published an initial strategy on reduction of greenhouse gas (GHG) emissions from ships. The ambitious vision of this strategy is to reduce the total annual GHG emissions from international shipping by at least 50% by 2050 compared to 2008. One of the solutions to achieve this vision is to operate vessels on alternative marine fuels that generate less or no GHG emissions, like liquefied natural gas (LNG), hydrogen, ammonia, methanol, ethanol, biofuel, synthetic fuel, electricity (produced by battery), and so on. The challenge is that each alternative fuel has its own characteristic on various aspects. For instance, some alternative fuels may generate no GHG emission but can have higher risk than conventional marine fuel. Other alternative fuels may generate no GHG emission with relatively low risk, but the capital and/or operational expenditure can be significantly higher than other fuels. The main objective of this paper is to explore the properties of selected alternative marine fuels and to emphasize the necessity of integrated evaluation of them. It is concluded that the alternative marine fuels need to be comprehensively evaluated with respect to environmental impact, risk to human, and business value.
Autonomous Underwater Vehicles (AUVs) provide a useful means of collecting detailed oceano-graphic information. The hull resistance of an AUV is an important factor in determining the power requirements and range of the vehicle. This paper describes a procedure using Computational Fluid Dynamics (CFD) for determining the hull resistance of an AUV under development, for a given propeller rotation speed and within a given range of AUV velocities. The CFD analysis results reveal the distribution of the hydrodynamic values (velocity, pressure, etc.) around the AUV hull and its ducted propeller. The paper then proceeds to present a methodology for optimizing the AUV profile in orderto reduce the total resistance. This paper demonstrates that shape optimization of conceptual designs is possible using the commercial CFD package contained in Ansys™. The optimum design to minimize the drag force of the AUV was identified for a given object function and a set of constrained design parameters.
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