3 ms·

The swept area of regular wind turbines seems enormous compared to sheerwind's turbine's. Even the combined area of those 8 entrances look much much smaller. Ho

by whage 13y ago

The swept area of regular wind turbines seems enormous compared to sheerwind's turbine's. Even the combined area of those 8 entrances look much much smaller. How in the world is this going to compete with those giants? What am I missing?

venomsnake 13y ago
That you could deploy them anywhere probably - if you put enough on rooftops you could squeeze enough juice for home operation and a change. I can see something like that as a complementary power generator - it is very cheap if produced correctly.
danmaz74 13y ago
Why would the "swept area" be meaningful? It's the blades that get the kinetic energy from the wind, not the space between the blades.
- whage 13y ago
  don't be silly, you just claimed that it doesn't matter whether you have 3 meter blades or 30 meter ones. Of course the swept area matters. P = 1/2 x ρ x A x v3 where ρ = air density, A = swept area and v = velocity of the wind
  - danmaz74 13y ago
    Don't be silly yourself. What happens if you add or remove a blade, or change their shape or pitch? The swept area stays the same, but the energy captured changes. The "swept area" is a useful abstraction that gives us the total energy that you can extract from - with your formula - but it's the blades being there with their length that extract that energy. These wind towers on the other hand capture and manipulate the whole air flow from the area of their intake, not just the part directly interacting with the blades of a traditional turbine. That's why it is physically possible to extract much more power than with a traditional turbine with an equivalent "swept area".
    - whage 13y ago
      That's right, the above formula is just the power of the wind, the amount of energy you are able to harvest from it does depend on the characteristics on the blade. The swept area is still a key factor. (see Betz limit for another interesting fact) You are right about the second part, those 'tunnels' do catch all the wind of their area.
      - danmaz74 13y ago
        Ok, I think you got my point. To sustain it: "Theoretically, an infinite number of blades of zero width is the most efficient, operating at a high value of the tip speed ratio. But other considerations lead to a compromise of only a few blades.[22]" http://en.wikipedia.org/wiki/Wind_turbine_design#Blade_count http://en.wikipedia.org/wiki/Wind_turbine_design#Blade_count
neumann 13y ago
Nothing important, I think you are on the money - the comparisons on their website are utter bogus - the swept area of the turbine they compare against are not the same.

by whage 13y ago

venomsnake 13y ago

That you could deploy them anywhere probably - if you put enough on rooftops you could squeeze enough juice for home operation and a change. I can see something like that as a complementary power generator - it is very cheap if produced correctly.

danmaz74 13y ago

Why would the "swept area" be meaningful? It's the blades that get the kinetic energy from the wind, not the space between the blades.

whage 13y ago
don't be silly, you just claimed that it doesn't matter whether you have 3 meter blades or 30 meter ones. Of course the swept area matters. P = 1/2 x ρ x A x v3 where ρ = air density, A = swept area and v = velocity of the wind
- danmaz74 13y ago
  Don't be silly yourself. What happens if you add or remove a blade, or change their shape or pitch? The swept area stays the same, but the energy captured changes. The "swept area" is a useful abstraction that gives us the total energy that you can extract from - with your formula - but it's the blades being there with their length that extract that energy. These wind towers on the other hand capture and manipulate the whole air flow from the area of their intake, not just the part directly interacting with the blades of a traditional turbine. That's why it is physically possible to extract much more power than with a traditional turbine with an equivalent "swept area".
  - whage 13y ago
    That's right, the above formula is just the power of the wind, the amount of energy you are able to harvest from it does depend on the characteristics on the blade. The swept area is still a key factor. (see Betz limit for another interesting fact) You are right about the second part, those 'tunnels' do catch all the wind of their area.
    - danmaz74 13y ago
      Ok, I think you got my point. To sustain it: "Theoretically, an infinite number of blades of zero width is the most efficient, operating at a high value of the tip speed ratio. But other considerations lead to a compromise of only a few blades.[22]" http://en.wikipedia.org/wiki/Wind_turbine_design#Blade_count http://en.wikipedia.org/wiki/Wind_turbine_design#Blade_count

neumann 13y ago

Nothing important, I think you are on the money - the comparisons on their website are utter bogus - the swept area of the turbine they compare against are not the same.