Marine

New navigation module to help future freighters act as their own sails

New navigation module to help ...
The hull of the cargo ship Vindskip acts as a large wing sail (Image: Lade AS)
The hull of the cargo ship Vindskip acts as a large wing sail (Image: Lade AS)
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The hull of the cargo ship Vindskip acts as a large wing sail (Image: Lade AS)
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The hull of the cargo ship Vindskip acts as a large wing sail (Image: Lade AS)

In 2013, Norway's Lade AS unveiled designs for Vindskip, a "hybrid" merchant ship which aims to harness the wind courtesy of a specially-shaped hull, in the process taking the burden off of its natural-gas powered engines and saving fuel. Researchers from the Fraunhofer Institute's Center for Maritime Logistics and Services (CML) have been working to help realize this goal by developing an algorithm that will allow the Vindskip's navigation system to use the combination of power and sail at its most economical.

For old clipper captains, the ideal voyage was one where they caught the wind at just the right strength and angle so they could tie off the sails and read a book for the next six weeks. It's not as simple as all that of course, especially when you are dealing with a modern ship design that uses the hull instead of sails to take advantage of the wind.

So what difference can a sea breeze make to a hulking cargo vessel? "At angles close to headwind the wind generates a force in the ship’s direction," says a spokesperson for Lade. "Since the hull is shaped like a symmetrical air foil, the oblique wind on the opposite side – leeward – has to travel a longer distance. This causes a vacuum that pulls the ship forward."

CML is developing a weather routing module that takes into account the ship's course, hydrography, weather predictions, and many other factors to carry out a complex calculation to come up with a combination of the best route and the best course, so the aerodynamic hull works to its best advantage with speeds up to 19 knots.

Fraunhofer says the first version of the module went online in December and will be handed over to Lade AS this month.

Lade AS says that the first Vindskip freighter will be on the seas by 2019 after model tank tests have been completed.

Source: Fraunhofer

3 comments
lat1865
Okay, nothing new about the use of hulls affecting speed, but the design is significant. No description of what is underwater, in front of the bow, or the subsequent angle of heel that the hull will experience to effect the loads and course.
Let's see some real numbers. When does the ship make changes...with only the chance to make more speed or use less fuel? Commercial vessels generally have to arrive on time....not within a window of time.
ezeflyer
With wind prediction software, captains of older vessels should be able to choose favorable routes and could use more efficient sails already developed.
warren52nz
"Since the hull is shaped like a symmetrical air foil, the oblique wind on the opposite side – leeward – has to travel a longer distance. This causes a vacuum that pulls the ship forward."
This sounds suspiciously like the mistake aerodynamic engineers made about wings and what gives them lift. The implication was that because the air on one side has a longer distance to travel it has to move faster than the air on the other side. This causes a difference in pressure between the two sides which causes the force (The Bernoulli Effect).
The mistake was assuming that when two adjacent molecules of air split apart at the leading edge to take their different routes they had a "date" to meet up at the other end so one had to go faster. No such date exists so the air doesn't have to go faster, it just has further to go.
They discovered that what creates lift in a wing wasn't the Bernoulli Effect but the "Coanda Effect" (molecules of air next to the wing's surface tend to stick to it). So when it went around the curved upper surface of the wing it accelerated downwards. The acceleration needed to do this caused an equal and opposite force which provides the lift. Nothing to do with pressure differences.
That's why a plane can fly upside down. If the old school theory was right that wouldn't work because the curved surface is on the bottom. This is more than overcome by the Coanda Effect when the angle of attack is increased sufficiently.
I just wonder if the force on this hull is the Coanda Effect too. Sounds like it.