Vessel design process is complex and consists of many stages. These are the sum of activities aimed at detailing initial assumptions. In the initial design phase, we propose hull shape. It’s functioning is based on the mass prediction and centre of gravity location evaluation. Evaluation based on statistical data extracted from the similar ships database. At this particular design stage, fully aware of almost certain upcoming shape optimization, investing time and resources in other than empirical resistance prediction would be simply uneconomical.
As the project develops, level of detail increases. Preliminary resistance prediction located us in specific main drive power range. General Arrangement is already operational, so we are aware of essential components. Structures and systems designs have been implemented providing us with quite reliable mass data. Now it’s time to proceed with shape optimization based on CFD analyses. Many loops, man-hours and computing time later, we end up with optimised hull.
Simultaneously, detail design is already forming. Suppliers and contractors offer their devices and materials. Shipyard rubs their hands to work, urging to deliver documentation, however […] Considering the multi-million investment and the vessel's lifespan of not less than 30 years, during which each 1% reduction in energy demand will translate into millions of $ of savings on fuel - is it reasonable to refrain from verification and one last optimization attempt? Despite the significant cost, the answer is no – it is not worth resigning from scale model tests. We conduct them in their entirety, obtaining reliable information about resistance, efficiency of propulsion, nominal wake, manoeuvrability and seakeeping properties.