A serious open source VAWT in the making. How to scale an airfoil profile
fsec Registered Users Posts: 2 ✭
I am currently designing and prototyping a DIY VAWT that actually will produce useful output at 60 to 120 rpm. At least that is the goal.
Any higher rpm and blades can become projectile weapons in a game of lawn darts.
I am already well underway with the alternator and am now thinking about the turbine blades.
I have traced an 'optimized' airfoil profile from here;
Aerofoil optimization for improving the power performance of a vertical axis wind turbine using multiple streamtube model and genetic algorithm | Royal Society Open Science
Then I scaled it to have a width of +- 50cm so that it will have some body when I scale the whole turbine up to 2m diam. and 3m height. Now here comes my uncertainty. I can't find, or I have and simply did not see it, any resource that describes the relationship between VAWT turbine dimensions and the dimensions of the blades.
Please see a model of what I have planned. (turbine is 2m width x 3m height)
Can anyone please advice on how to proceed with airfoil profile scaling when going for this size helix VAWT?
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gen: http://tinyurl.com/LMR-Lister ,
www.otherpower.com (good forum for DIY Wind Power)
Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
Scoraig Wind "Recipe Book" for DYI Turbines (from Chris Olson... From his 4/11/2013 post)
www.greenpowertalk.org (added from "russ"--Like here but more wind/less solar)
Personally, I am not a fan of small wind. But horizontal axis wind turbines (HAWT) are much better than VAWT at harvesting wind and can be more mechanically more reliable.
Turbines need to be installed on towers, generally 30 feet or taller to get into "clean air" (60-120 ft tower is better) . Turbines need non-turbulent airflow (above up wind obstructions, buildings, trees). Turbulent air has very little useful energy--VAWT are sold as better for turbulent airflow--But they are not.
Not that I am in the "wind" business--But I have yet to see any VAWT that harvested more that a small amount of energy--And most seem to not harvest any energy at all.
Here is a turbine that seems to match your design--And a fairly large diameter VAWT rated at 2.5 kWatt (circa 2008):
And tested on a 10 meter / 33 foot tower in a "windy region" of Holland (flat land, no buildings/trees/etc.) produced (link to post in thread from 2009 testing of multiple small wind turbines "designed" for urban use):
Power: 2 kW with the supplier an estimated yield of 1485 kWh / year
If you want to experiment with small wind and VAWT--Have fun.
If you want to generate/harvest a useful amount of energy, I highly suggest starting with solar, or at the very least, use HAWT on a 30-60+ foot tower in a very windy location (see DIY links at beginning of this post).
VAWT is a dead end, but looks good.
On the Fieldlines.com: The Otherpower discussion board Vawt are being allowed to be discussed.
Some experimentation has taken place and the results are all there.
Like all wind turbines its matching blade efficiently against wind speed against generator load. All Have to be absolutely spot on.
Mechanically VAWT is a constantly stressed structure, and in the end they normally just disintegrate.
I have 3off 3.7m (12 footers) diameter HAWT flying and producing since 2007, and they are a Hugh Piggott design, and his stuff is one of the best designs in the World after his 45 years of work. But they still need servicing and keeping and eye on, and this year they all had there 5 year rebuilds.
But today 2021, they are just not economicall viable against PV. And advice those that ask that me, "Just Install PV."
Everything is possible, just give me Time.
The OzInverter man. Normandy France.
3off Hugh P's 3.7m dia wind turbines, (12 years running). ... 5kW PV on 3 Trackers, (8 years) .... 14kW PV AC coupled using Used/second hand GTI's, on my OzInverter created Grid, and back charging with the AC Coupling and OzInverter to my 48v 1300ah batteries.