Making a self-winding 5kW wind turbine

[Targol]

They really have a sense of practicality, in chapter 21 - supermarket ( http://www.eolprocess.com/start.php ), the blades can be used as advertising signs.

Yeah, I saw that too and, go figure why, it was not the argument that convinced me the most

[Cuicui]

They really have a sense of practicality, in chapter 21 - supermarket ( http://www.eolprocess.com/start.php ), the blades can be used as advertising signs.

Yeah, I saw that too and, go figure why, it was not the argument that convinced me the most

Certainly, but if that can help promote wind energy, so much the better.
The fact remains that the 2-speed transmission system for each blade is probably not within the reach of an average handyman. It would require mass production of these mechanisms.

[bham]

Hello go see on mumule there is a guy who provided the plans of a chrysler alternator traveling transform into a wind turbine, after qlq modifications of course! Kenavo

Hi David, you're nice, Bevet Breizh, but mumule, it doesn't get me so bcq. Would you have a usable link ???
Kenavo anyway.

[david29]

Hi abyssin3 e contact me by MP I will send you all I have as info! I have redownload them expressly because I knew that someone would ask me.

@+

Kénavo

[zac]

Too late, guys, the cyclone has passed twice, but has left now
@+

[Woodcutter]

Someone did it recently :
http://www.eolprocess.com/start.php the site is very well done elsewhere.

It's strange, it reminds me of the inventor who was featured on the M6 ​​show "inventor of the year" and that we have not seen again

in any case, the wind turbine looks wildly like the speech.

It's a bit normal, it's him ... (see home page of his site).

there was one at the invention of the year competition on M6, its blades were ordered to rotate and avoid the wind

but the guy didn't understand how a wind turbine works horizontal axis : he said that the air passing between the 3 pale "fines" did not produce useful recoverable energy (to enhance his invention), that was the thing not to say because big bullshit

bolt

It is also one of the arguments of:
http://www.eolprocess.com/start.php the site is very well done elsewhere.

Could you explain to us why, bolt?

Yes, bolt, could you?

If we rely on the formula giving the wind energy: E = 1 / 2.rhô.S.Vcube

with rhô = density of air
S = blade area
V = wind speed

we can see that indeed, the surface of a conventional wind turbine blade is not very large compared to the surface it sweeps during its rotation.
So unless the formula is wrong, I do not see where is the "big bullshit" which made our tractor driver go off its hinges. forumesque ...

[vincent27]

Yes, it is a general formula for the impact of wind on a surface. It does not apply to wind turbines with a horizontal axis or it is the swept surface that counts.

[Obelix]

If we rely on the formula giving the wind energy: E = 1 / 2.rhô.S.Vcube

with rhô = density of air
S = blade area
V = wind speed

we can see that indeed, the surface of a conventional wind turbine blade is not very large compared to the surface it sweeps during its rotation.
So unless the formula is wrong, I do not see where is the "big bullshit" which made our tractor driver go off its hinges. forumesque ...

Hello,

The formula is exact to a hair almost !!
=> S = is not the surface of the blade, but the surface swept by the system.
Maybe that's what he gave him a "Bolt"

Have a good day

Obelix

[bolt]

there was one at the invention of the year competition on M6, its blades were ordered to rotate and avoid the wind

but the guy didn't understand how a wind turbine works horizontal axis : he said that the air passing between the 3 pale "fines" did not produce useful recoverable energy (to enhance his invention), that was the thing not to say because big bullshit

Could you explain to us why, bolt?

Yes, bolt, could you?

If we rely on the formula giving the wind energy: E = 1 / 2.rhô.S.Vcube

with rhô = density of air
S = blade area
V = wind speed

we can see that indeed, the surface of a conventional wind turbine blade is not very large compared to the surface it sweeps during its rotation.
So unless the formula is wrong, I do not see where is the "big bullshit" which made our tractor driver come off its hinges forumesque ...

hello lumberjack and citro (I hadn't seen citro's message: already 3 months, excuse me! )

you could find all alone by browsing explanations here and there on the net (like I did, moreover, 1 year ago I only knew dale in the wind principle)

I will try to make you understand with my logic of poor "cincier" ("peasant" in patois):

The energy of the wind (or of the water of a watercourse) depends (to start) only on its kinetic energy: either in watt / sec:
P = 1/2 m V²
V in m / sec
m being the mass (of the fluid) / sec, this is equivalent to: its specific weight (1,25 kg / m3 for air) x its "flow" (flow = volume / sec)

note: P being a power (work per unit of time) m is therefore a "mass per unit of time"
if we only took inertia we would have:
E = 1/2 M V² with M being only a mass

flow (Q) which is, itself: a surface advancing in a direction at a certain speed (Q = S x V)
Q in m3 / sec
S in m²
V in m / sec

therefore, the kinetic energy of a fluid is:
P = 1/2 m V² which, broken down, is also

P = 1/2 x rhô x S x V ^ 3
rhô being the specific weight of the fluid in kg / m3
S being the concerned surface of the fluid in question
V being the speed in m / sec of the fluid in question

that's why (and it took me a while to explain it to myself ) the energy is proportional to the cube of the speed and not to the square of the speed of the fluid

it was to explain the "starting" power of the wind

and the only way to take energy from this "continuous kinetic energy" is to break it, in other words to reduce its speed.
and as the power of the wind is proportional to the cube of this speed, even decreasing it slightly is particularly worth the candle

now, exploiting it is another story: to this formula, we must add a coefficient of performance due to air friction on the blades (or the blade)

and as the pressure drops (as in a water pipe or an air duct) are proportional to the contact surface where friction is created, the less surface, the better
and as it suffices to lower the wind speed very little to recover a lot of energy (relationship with the cube of the speed)

it is much better to lower the speed of a large area with little propeller blade area a little than to have the same propeller area for little "slowed up wind" area

as a power is expressed by a couple x by a speed; high speed is welcome

what matters is to break the kinetic energy of the speed and mass of the wind without selling it off with non-recoverable friction of energy: it is enough to punctually take a spot from the sky where the air is well launched, capture that momentum instantly; but when the momentum of this place is broken, it is not worth much to linger there, it is better to capture its neighbor as slender as possible

they even made wind turbines to 2 see a single pale with the pain of having to add diametrically opposite a counterweight

the guy from M6 is only right for the start-up time: the surface normally swept by a 3 blades is then not precisely swept and the inertia of the wind is only broken by the surface of the blades

but for the question it is necessary to take into account the swept surface and not the windward surface of the pale only

that said, I do not know the performance of its principle in comparison with a 3 pale wind turbine

large wind turbines have a propeller diameter of 80 m, and the tip of the blades can exceed the speed of 400 km / h I believe

so it quickly passes from one place to another to break the kinetic energy of the air

there is certainly a compromise to be found between the friction forces (whose energy is lost) generated by the surface in touch and air penetration speed with energy recoverable at the output of the propeller axis

imagine a wind turbine with 3 blades of which 9 would have been added to make 12 blades, it is not at all sure that the energy produced is greater, except perhaps at low speed where the wind speed is low, the forces friction is reduced and a 3 blades would break the kinetic energy of the wind at too low frequency (the wind would have, between each pale, much more than the time necessary to recover its cruising speed)

he said that the air passing between the 3 pale "fines" did not produce useful recoverable energy

it is true that by taking the words quoted, the air passing between the fine pale does not touch anything, so can not logically advance anything, but the principle is not so simple

What do you think

bolt

[I Citro]

Thank you bolt for this text explanation.

Come to think of it, this makes perfect sense and also applies to hydro power. We cannot indeed recover all the energy ...
If in a dam, the turbine wanted to recover all the hydraulic energy, it would oppose the Hydraulic Force a resistive torque such that the turbine would no longer rotate and therefore prevent the flow of water, therefore the production of energy. .

For the wind turbine, the problem is the same, if we want to recover all the Aeolian force in the swept surface, we oppose to aeolus a too large surface and the wind turbine becomes an obstacle which only slows down the wind, l stop, and therefore does not recover any energy ...