Contra Rotating Diffuser and Shrouded Wind Turbine Design

[Generator]

LINK REMOVED BY MODERATOR (Sparweb)

[Mary B]

snake oil...

they do not work as advertised. There is only so much energy in low winds and any claims of extracting more than is there are a clue to run away it doesn't work.

[Generator]

snake oil...

they do not work as advertised. There is only so much energy in low winds and any claims of extracting more than is there are a clue to run away it doesn't work.

I don't think the creator have claimed to generate more energy than what is available. All he is saying is, it extracts maximum possible energy in given wind. So whatever is available in low wind speed its converted efficiently.

[Mary B]

And snake oil, you cannot extract more than the betz limit of 59.3% of available energy. And that number is very very hard to reach, not even the big commercial turbines reach it.

[topspeed]

And snake oil, you cannot extract more than the betz limit of 59.3% of available energy. And that number is very very hard to reach, not even the big commercial turbines reach it.

Betz's is limited to propeller types...but is valid also in this shrouded ..possibly.

[Adriaan Kragten]

This is the same wind turbine as in the post: "Most efficient wind turbine on planet". Why two discussions about the same subject?

[Generator]

And snake oil, you cannot extract more than the betz limit of 59.3% of available energy. And that number is very very hard to reach, not even the big commercial turbines reach it.

Betz's is limited to propeller types...but is valid also in this shrouded ..possibly.

I don't see anywhere the guy said he makes more energy than Betz limit. Betz theory is valid for open type rotors only, with standard condition assumptions. Big commercial companies can extract only up to 40% of available energy, that too at higher wind speeds. At low wind speeds they are of no use.     

[Generator]

This is the same wind turbine as in the post: "Most efficient wind turbine on planet". Why two discussions about the same subject?

I found this video was missing in original post, which shows simulation of how wind flows, how turbulence is created and something more than just claim. In earlier discussion someone was bashing about the strength of the turbine and price, but not power output. Not sure how it can be merged. Maybe admin can take down the first post.   

[Mary B]

And snake oil, you cannot extract more than the betz limit of 59.3% of available energy. And that number is very very hard to reach, not even the big commercial turbines reach it.

Betz's is limited to propeller types...but is valid also in this shrouded ..possibly.

I don't see anywhere the guy said he makes more energy than Betz limit. Betz theory is valid for open type rotors only, with standard condition assumptions. Big commercial companies can extract only up to 40% of available energy, that too at higher wind speeds. At low wind speeds they are of no use.   

I saw a claim on the page it produced at 1m/s wind speeds, 2.26mph... there is next to zero energy at those speeds.

[SparWeb]

I watched the video (sigh).

It claims to collect energy at 1m/s wind speed.  FALSE

It does claim a shrouded 8 ft rotor can collect 4kW power at 11m/s. IMPOSSIBLE

It ALSO claims a shrouded 8 ft contra-rotating rotor can collect 6kW power at 11m/s. IMPOSSIBLE^squared

The goal is marketing/sales.  No evidence of real world testing.  A bag made of sailcloth on a trailer is NOT EVIDENCE of a real test.

[SparWeb]

Because an active link to Youtube generates revenue to the channel owner on every click, and the channel is promoting free energy / overunity / snake oil, I cannot leave the link in place for people to click and give those quacks more money.

Fieldlines posting guidelines
This section is for anything related to producing your own electricity, with the exception of free energy/overunity/perpetual motion. These topics are forbidden on this board.

For this reason I'm removing the link in the OP and locking this thread.