How would this ship fare in a Force 11 storm?
18th September, 2013 @ 2:14 a.m. (California Time)
Not going under any bridges will limit access to some harbours.
I bet it would redefine sea sickness on a whole new plane too.
18th September, 2013 @ 2:25 a.m. (California Time)
"You can compare a symmetrical airfoil with a 'normal' sail"
To my knowledge lift of a 'normal' sail (or a plane's wing) is generated exactly because of its a-symmetrical shape. The lift is transformed into a forward directed movement thanks to the working of the keel, which takes me to another question for such a ship.
What does the text means by:"lift is generated when the wind comes from both port and starboard sides." ? Wind blows in only one direction at one particular moment, the movement of the ship also creates wind, but this is not what is meant here.
18th September, 2013 @ 5:10 a.m. (California Time)
I suppose it works in much the same way the blade of a Darrieus wind turbine does by using the forward force vector generated by the aerofoil shape. If that is the case, I wonder how much forward force is generated at the bow end when there is a tail wind.
60% saving seems optimistic, but I am no aerodynamicist.
It would be interesting to see if stacking containers in a teardrop shape on a conventional container ship would provide any fuel saving, and if so, would it be enough to compensate for the reduced number of containers carried per voyage. (Of course, the tail of the teardrop could take the form of a wind inflated tapering shape at the stern just big enough to maintain laminar flow.)
18th September, 2013 @ 6:08 a.m. (California Time)
Really bad idea, unless you have an adjustable ballast that would allow you to lower and raise the ship when storms come but this would take a significant amount of energy to raise a ship as large as this. Still in good weather you could skirt across the ocean quickly and when a storm came you could take on ballast and make the ship significantly more stable then most ships today with a greater ballast. I hope this is their concept.
18th September, 2013 @ 6:55 a.m. (California Time)
This looks like it would need a huge keel for stability, which would keep it out of most ports.
18th September, 2013 @ 7:10 a.m. (California Time)
well, we're not exactly naval engineers around here, but the idea seems to hold some... wind to it. There's ample wind in the sea, and it can be put to good use, why not?
I'm not sure how the ship (and its cargo) will fare on very rough seas, though. But I guess that's something naval engineers know how to solve :)
18th September, 2013 @ 7:42 a.m. (California Time)
It seems similar (using wind to help power the ship) to Jaques Cousteus ship that has turbo sails on it. It does look cool but one wanders if the wind could top over such a tall ship?
18th September, 2013 @ 8:15 a.m. (California Time)
I don't see the wind propulsion working well.
I would expect better than 80% reduction in emissions of pollution over a ship burning Bunker C just by going to burning methane and using a catalytic converter.
18th September, 2013 @ 8:27 a.m. (California Time)
The site of the 'designers' shows the ship being loaded by trucks. Presumably this is because some bright spark twigged that it will be impossible to load this baby with gantry cranes. Whoops.
They clearly have no understanding of how modern shipping works.
Hats off for having a go, though.
18th September, 2013 @ 8:44 a.m. (California Time)
I see a major problem with this design, unless there is a large counter ballast below the water line. Even so, I can't see this design working anywhere but in very calm seas. Sort of like the problems back the thirties with airship travel.
18th September, 2013 @ 10:41 a.m. (California Time)
It's not being loaded by trucks. The ship is an auto carrier. Those vehicles are being unloaded.
18th September, 2013 @ 10:57 a.m. (California Time)
I'll huff and I'll puff...some things spawn from weird ideas and other things, well they are just weird ideas that fade over time. So many restrictions on a ship like this, stability, loading and unloading, If tacking what about transit time? Time is money and if it takes two months to cross the Pacific, well not a good thing..
18th September, 2013 @ 12:18 p.m. (California Time)
Fundamental errors in the thinking are many, and include the thought that the ship acts like a wing - it will only do so when it obeys all the aerodynamic rules - a wing only generates lift at a positive angle of attack, and only with a persistent flow.
Flow separation and AOA stall kill this idea as the airflow in an aircraft is normalised through speed - i.e. when you accelerate the wing the greater proportion of the flow comes from the velocity, not the wind. If it is the latter then the capacity of the wing to expand the envelope between stall and speed and maximum speed will mean the wing cannot approach the levels of dynamic in the shape of a vessel.
Not only not possible, but dangerously gullible unless the vessel only and always operates to no mare than 15-20 degrees ogg-headwind. Daft ship will be careering all over the oceans looking for thrust...
18th September, 2013 @ 1:58 p.m. (California Time)
@EJ. Lift on a wing isn't determined by its asymmetrical shape nearly as much as it is by angle of attack. The air molecules at the wing's surface tend to stick to it (The Coanda Effect) so it is pulled in a curve. The reactionary force (equal and opposite) is what gives the wing its lift. The Bournelli effect (pressure difference between each side of the wing) is minor. That's why planes can fly upside down.
18th September, 2013 @ 4:24 p.m. (California Time)
Only good for cargo ships, not cruise liners unless sail transparent at deck levels outward.
like to see test ship make trip from CA to Hawaii or So Pacific alone,
Then later CA to Japan.
Use those winds for some power vs the age of sail alone.
18th September, 2013 @ 5:33 p.m. (California Time)
That shape would be interesting if the vessel could take on enough water to be slightly submerged to ride out storms. Or maybe the deck could be used as a runway. It doesn't look like a cargo vessel and it doesn't look like a vacation type of cruise ship. What is its best use?
18th September, 2013 @ 7:40 p.m. (California Time)
Cannot imagine how much ballast - or very, very deep keel - needed here. I would think that the added travel time spent looking for the right (or any) winds on some oceans would negate fuel cost savings. Many old sailing stories relate spending a lot of time becalmed.
18th September, 2013 @ 7:59 p.m. (California Time)
They should have a look at the "Vasa". It was so tall it had the shortest maiden voyage of a military vessel ever, less than one mile. Tipped over before even getting out of the harbor.
The many tons of useless ornamental carvings and a weaponry fitment of 72 guns each capable of firing 24 pound projectiles, plus the high sterncastle made it very top heavy. Only took a little breeze to sink it.
This Vindskip would need lots of ballast and a very good computerized stability control system or it could meet the same fate as the Vasa.
18th September, 2013 @ 8:28 p.m. (California Time)
I imagine a big problem would be the inability to reef the "sail", so you are constantly dealing with a substantial thrust, whether it is helping or twarting your navigation.
18th September, 2013 @ 11:44 p.m. (California Time)
April Fools! This thing will never get off the ground!
19th September, 2013 @ 7:34 a.m. (California Time)
Symmetrical airfoils are quite workable. The airfoils on modern stunt-planes and fighters tend to be very close to symmetrical-- this facilitates inverted flight, and decreases stability, among other things. With a symmetrical airfoil, which way the lift is generated depends purely on the angle of attack.
19th September, 2013 @ 9:31 a.m. (California Time)
Can you add hydrofoils on outriggers for greater speed?
22nd September, 2013 @ 10:07 a.m. (California Time)
Yes a symmetric airfoil generates plenty of lift. Symmetric air foils are simple and the aerodynamic forces acting on the airfoil are more stable.
The symmetric foil allows for a nearly constant center of pressure which prevents excess twisting moments on the wing. Conversely, an asymmetric airfoil can put significant twisting moments as the center of pressure changes constantly with the angle of attack.
There are many theories of lift and many are wrong but they sure sounded right when we were taught them
I can't believe I flew for so many years with different theories of lift but somehow I managed to live through it despite the theories being proved wrong.
One thing that is SURE is, it is the large difference in pressure between the bottom and the top of a wing that lifts. More accurately it is the large negative pressure on top that generally sucks the wing upward. The pressure below the wing is not much different than atmospheric.
Using the Coanda effect to explain lift is also incorrect.
I think this ship is ingenious but I also doubt its practicality. If I'm proven wrong it only means I get to unlearn some previous notions.
Just like lift!
27th September, 2013 @ 7:41 p.m. (California Time)
You guys not watch the America's Cup ?
Check out their wing sails.
What to do in a storm ? Get up on the foils !
2nd October, 2013 @ 2:21 p.m. (California Time)
Symmetric airfoil sections - in fact, all airfoil sections - produce a component of lift that is slightly tipped forward. Nothing new in this - it is the reason that airplanes gliding in for landing have their noses level or even tilted slightly upward, but don't stall and fall out of the sky. It's counter-intuitive and takes some getting used to, but it is a fact. This scheme has to be symmetrical because it needs to get that slight thrust whether the wind comes from the starboard or the port beam. I have my doubts about the practicability of the scheme, because (1) it only works at a fairly narrow range of angles of attack, and (2) may even suffer a penalty when fighting a headwind (not necessarily, though, considering the awful aerodynamics of conventional ships' superstructures), and (3) because of the very short span (and consequent very high span loading) of the "wing" which will give it very high induced drag, possibly cancelling the desired thrust. I assume that model tests will be, or have been made. I hope so, anyway.
14th October, 2013 @ 8:39 p.m. (California Time)
It has been pointed out that a symmetrical aerofoil CAN work if it is presented at an angle of attack. There's a tiny problem: the wind needs to be at (roughly) a suitable angle to the sail, (which is inconvenient if you don't happen to want to go in that direction)
And there's a B I G problemm, which is that the sail then needs to be at an angle to the direction you want the boat to go.
The "sail" of this ship is permanently locked in the exact direction the boat is pointing; for this idea to work, the boat would have to crab at an angle, partly skidding sideways, and would need a series of rudders below the water to keep it on that track.
Which (along with the stability issues raised by others) makes this clearly a non-starter, almost as silly as the perpetual motion ideas nine year olds are famous for inventing.
19th October, 2013 @ 11:23 p.m. (California Time)
While I agree that there are many challenges to this and some of the wording is unclear I hope that a way can be found to make it work. Here are two suggestions. The difficulty is aligning the airfoil shape to make the best use of the available wind. If the floatation were provided by two hulls catamaran style , then the upper works cargo section could be aligned to work the wind while the hulls are on pivots and align with the direction of travel. For docking the 3 parts, line up to be thin.
The other concept is that the aerofoil shaped upper works could have side panels that are adjustable to modify the shape and allow more options for effective energy capture just as a wing modifies it's profile higher angles of attack at landing.
9th December, 2013 @ 7:06 a.m. (California Time)
It'll never fly!
5th July, 2014 @ 8:45 p.m. (California Time)