KR published the "Numerical Calculation Guidelines for the Determination of the Attained EEDI " on May 12 through joint research with HD Hyundai Heavy Industries and Samsung Heavy Industries. The guidelines establish a standard for an evaluation method based on computational fluid dynamics (CFD), replacing the physical model tests that have until now been used to verify a ship's energy efficiency.

As the IMO greenhouse gas reduction regulations have tightened in recent years, the shipbuilding industry has applied a range of energy-saving technologies — such as air lubrication and wind-assisted propulsion systems — to improve energy efficiency and reduce carbon emissions. Demonstrating their effects, however, has had to rely on physical model tests using scaled-down ships in large tanks or wind tunnels,* a limitation that imposed considerable time and cost.

*Wind tunnel: a facility that artificially generates wind to test the dynamic characteristics of an object's surface or of the air around it.

CFD-based numerical analysis, which uses computers to precisely calculate the flow of water and air around the hull, has accordingly drawn attention as an alternative. Yet because results can vary with the analysis conditions and configuration, the need for objective and consistent verification criteria has been raised continually.

The new guidelines systematize the procedure for calculating the EEDI reference speed (Vref) by CFD into three stages — qualification, verification and calibration, and the main calculation — and secure the reliability and reproducibility of results by clearly defining the analysis methodology and reporting criteria. Crucially, they set out detailed modelling requirements and classification verification criteria for evaluating the performance of air lubrication and wind-assisted propulsion systems, areas not yet specified even in the guidelines of the IMO and the International Association of Classification Societies (IACS).

The guidelines are also significant in that KR developed them with HD Hyundai Heavy Industries and Samsung Heavy Industries, Korea's leading shipbuilders, drawing on experience from actual design sites and verification data. This is expected to improve the efficiency of the classification approval process and substantially shorten shipyards' design and analysis times.

KR stated that the joint development has established an advanced technical standard for a proactive response to international maritime regulations, adding that it plans to keep expanding its technical support so the shipbuilding industry can strengthen its digital engineering capabilities and lead the eco-friendly ship market.

The guidelines have been published in both Korean and English and can be downloaded from the attached file below. Full text is also available on the KR website (Rules & Solutions > Classification Technical Rules > Classification Technical Rules Service).