For years, Norwegian platform supply vessels (PSVs) have transported food, equipment and materials to oil and gas platforms on the Norwegian continental shelf.
The fewer waves a hull generates as it moves through the water, the less fuel the vessel needs. This results in lower emissions and reduces operating costs for the ship owner.
Researchers at SINTEF Ocean in Trondheim are combining data from countless experiments in the Towing Tank with new methods in data analysis and artificial intelligence.
This makes it possible to estimate the hull resistance of PSVs more quickly and with greater precision. Henning Borgen, CTO at Sirius Design & Integration and partner in the ZeroLog project, is pleased with the development of the tool.
“This type of tool is closely tied to our core business and enables us to perform faster and more accurate calculations. For us, the development of such useful tools for industrial use is the main motivation for participating in research projects,” says Borgen.
A model that keeps improving
One advantage of data-driven models is that they can easily be updated as more vessels are tested and new results become available.
“The method will continue to improve as we collect more data. So far, it has only been used to estimate resistance for PSVs, but the plan is to expand it with other tools as well,” says researcher Endre Sandvik.
Together with his research colleagues Thor Albrektsen and Øyvind Rabliås at SINTEF Ocean, Sandvik has worked through the ZeroLog project with the goal of developing the next generation of PSV concepts.
“The new method makes it possible for us and designers in the industry to test many different hull shapes while simultaneously assessing how changes affect resistance and energy efficiency,” says Albrektsen.
The trio believes there is significant potential in combining test results with artificial intelligence, and that new methods for use in the maritime industry will continue to emerge. This methodology can also be reused to develop new approaches for other ship types.
An ocean of opportunity
Over many years, SINTEF Ocean has tested most vessel types in its towing tanks. All results from these tests have now been compiled into a database that can be used in new models.
“We have started with data from calm water resistance tests, but we also want to expand with data from maneuvering and wave added resistance tests,” says Rabliås.
The data made available to the maritime industry when they conduct basin tests are crucial, both for design work and for verifying vessel performance before construction. Now, these data gain new value as they collectively form the foundation for new methods in ship design.
A number of models already exist for calculating ship resistance based on measurements and data. However, these established methods are largely designed for traditional merchant vessels. The Norwegian maritime industry works extensively with specialised vessels, such as PSVs, and for these vessels the traditional methods perform far less accurately.
“That is why we believe the newly developed method will be a valuable contribution for achieving more accurate estimates of calm water resistance for offshore vessels in the early stages of a project,” says Rabliås.
Although tools based on computational fluid dynamics calculations (CFD)—that is, computer models showing how water flows around the hull—can calculate calm water resistance accurately, these methods are still time-consuming.
There is therefore a need for simpler methods that can be used early in the design process or integrated into optimisation routines. The new models, which make it possible to explore energy efficient ship designs, will be made available to the maritime industry as new tools in the ShipX software.
