Sails are not used to generate pressure differentials, they are intended to generate force.
It may be true though that a spinnaker is more toward the force directing mode since it is used when running before the wind, but that is not what the commenter said. Yet, even being right about that, the conclusion can be wrong...there would be difference in potentials where the turbine is driven.
The first concept that I had when I saw this was the small wind catching sails that we would place over the hatches on hot languid nights in the Caribbean. I'm betting on Russia on this one. Never underestimate their intelligence, always underestimate their knowledge.
Frank Delaney ~ Ireland
this looks like a water-type dam for a lighter fluid (air) where the ambition as with any dam for power -- a weir and mill, a megadam and turbines -- is to increase the psi at the point of capture by having a wide "bucket" to funnel water into the turbine.
mainsail of a yacht is a very different kettle of wind, using the aerofoil effect.
a spinny is a big bag of wind not using the aerofoil effect (downwind only), so somewhat similar, but it still doesn't collect air in order to drive it through a narrow opening at high velocity. what this app is most like, imho, is the old trick of using a balloon to make a rude noise. The difference between theory and practise in practise ...
Fluid mechanics is a bit tricky and there might have been some good modeling I do not know about involved, but from the look of it, I would expect that structure to have more force acting on it (increased risk of damages to the structure) but not that much higher output. Imagine if you like a big wave (water being the fluid we are generally most acquainted with) hitting that thing. Supposing it holds, how much of the water will pour through the turbine and how much will spill on the sides?
