Help in designing an Archimedes Wind Turbine

[benfoot]

Help! i would like to design the blades of an Archimedes wind turbine, but I do not know how to start!

I would consider myself an intermediate, but infrequent user of FreeCAD and I have mainly used it to design rectangular and cylindrical shapes for 3D printing. Now, I would like to use FreeCAD to design the Archimedes blades (see attached image) in a DIY wind harvesting project. I would really appreciated any tips or help to set me off in the right direction.

energies-07-07893-g001.png (480.91 KiB) Viewed 1828 times

[chrisb]

You can try a helix with an angle, or a noral helix where you cut material away with a groove. Shortly before christmas I posted Roland's christmas tree which may serve as inspiration.

[papyblaise]

One exemple

[hammax]

... having some doubt concerning the aerodynamic efficiency of that prop,
here is a possible design method in FC.

ArchWindTurbine_3.PNG (49.47 KiB) Viewed 1779 times

[hammax]

... which way does the wind come from?

ArchWindTurbine_4.PNG (45.85 KiB) Viewed 1730 times

[thschrader]

... which way does the wind come from?

http://www.archimedesgreenenergys.com/about.htm

[papyblaise]

it is surprising it seems that there are only 2 propellers offset at 90 °, it must be unbalance

[hammax]

... my estimation is:
unrolling the blade gives a regular disc. Maybe some sector must be cut out => better not after some finetuning.
A simple part in aluminum with some bolts and a pipe as axle.
3 blades.

ArchWindTurbine_5.PNG (42.5 KiB) Viewed 1677 times

[GeneFC]

it is surprising it seems that there are only 2 propellers offset at 90 °, it must be unbalance

Some of the images seem to show only two blades, but when you look at more details it appears that three blades are used. Looks balanced. I have no idea if it is just "cute" or if it is really a good choice.

Gene

[papyblaise]

Ho jes , Ok , whith 3 blades we can to have a good equilibre