Discussion in 'Wood Construction' started by Speedboat100, Oct 4, 2019.
I changed the blue....now the white stripes.
I have no clue why the link did not work.
With rivets, at least you know just where the parts will break.
Curious how you propose to break Betz's limit. Seems unlikely.
If this fairing is as high as the blades of your VAWT, better make sure it CAN'T get loose, or someday when the wind is really tearing along, and your turbine is at high rpm's, it will hit a blade. You may get some interesting interactions between the direction of the fairing and the pulsed changes in wind direction from the passing of the blades. I think this would also be a problem with HAWT's, and a quick internet search indicated there's been some research on this. OTOH, the fairing might mean a bit less periodic stress on the blades, since they'd be passing through a smaller wake from the tower. I suppose if your blades are the spiral type, their wake wouldn't beat up on the fairing all that badly.
I only hope to brake the Betz's limit as it has been already in 1919 derived to show that the present day propellers are obsolete as the highest teorethical value for mechanical efficiency Cp is just 59,6 %.
There are about dozen CFD analyses done that show that H-Darreius type wind turbine with articulating blades can exceed the 59.6 value even by 12% .
Very few people has actually tried to exceed it to show that researchers are right...and have been right since 1978.
Anyway Paul Lipps has shown that as means of propulsion the propellers are 85% efficient. Numbers tell that they are anything but as harvesting the wind energy.
...so does that make sense?....I guess without spending the time I do not want to spend ......what is an 85% propulsion propeller.....do you actually get trust 85% of the measured HP out-put of the engine?.....and what is the measure of the turbine?.....flat blade drag of the blade vs harvested HP?
I seem to remember torque x rpm for propulsion....but is that thrust?
Yes Paul Lipps is a wizard ! You got the picture...albeit the language was poor.
There is also epoxy...rivets just ease the building.
I am starting to assemble the wing that I can start testing the system.
Almost as if it wasn't a wooden thing.
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