NACA blades

[Cleifford]

Hello everyone!

I have been working with my thesis about horizontal micro wind turbines. Anyone here who has the idea where to buy NACA blades made of carbon fiber or fiberglass? Your help is highly appreciated. Thank you.

[stofanel]

I doubt that any of the small wind turbine blade manufacturers pay close attention to airfoil profiles. If you are doing any kind of aerodynamic study you will need to closely control the airfoil section profile as well as the twist. The only way to do that is to make your own blades. 

[clockmanFRA]

I use Hugh Piggotts type of design, http://scoraigwind.co.uk/  He has been at it a life time now and has got things really working well in the real World.

I don't know Hugh, never met him but his stuff works, I have 3 off his 3.7m diameter design. There are always compromises on the blade design so they work against load and weather conditions.

I have done my No 2 and No 3 with fiberglass blades, I made the moulds from an exact copy of Hugh's design.

 I see know reason to use Carbon Fibre at present, as the cost effective solution is still normal Fiberglass with this design.
 

[stofanel]

High Piggott uses an approximation of the Clark Y airfoil.

What is the hypothesis of your thesis? Are you doing a full aerodynamic analysis, or just studying the performance of simple DIY turbines?

[Cleifford]

Thank you for your responses. Actually I am just studying the overall performance of a DIY turbine in terms of power coefficient. One of my thesis panel member recommend me to use NACA blades profile as basis for comparison. The result will also be showcased in our university, that is why I am looking for a NACA blades made of fiberglass or carbon fiber. Thank you.
 

[Cleifford]

I use Hugh Piggotts type of design, http://scoraigwind.co.uk/  He has been at it a life time now and has got things really working well in the real World.

I don't know Hugh, never met him but his stuff works, I have 3 off his 3.7m diameter design. There are always compromises on the blade design so they work against load and weather conditions.

I have done my No 2 and No 3 with fiberglass blades, I made the moulds from an exact copy of Hugh's design.

 I see know reason to use Carbon Fibre at present, as the cost effective solution is still normal Fiberglass with this design.

Thank you for your reply. Yeah I have already visited Hugh Piggot's website and contacted him but I cannot use his design. One of my thesis panel member recommends me to use NACA blade profile. I'll be searching the web if this fiberglass NACA blades for micro wind turbine is available.

[SparWeb]

What size of blades do you need?
What NACA profile are you looking for?  They vary widely.

Your thesis advisor may have a good reason for suggesting something specific, but here's my concern:  Even if you purchase a set of blades that claim to be a specific airfoil, how will you show that they really are that?  When the span of the blade is 1 meter long, the chord will be less than 10 cm at the root.  If you want a NACA 2415 airfoil, the thickness will be 15 millimeters, and a variation in thickness by 1% will be a difference of 1 millimeter.  And what are the manufacturing tolerances of a plastic blade that is probably made in China?

I wouldn't get too hung up about the airfoil, as long as you can demonstrate (to your thesis advisor) that the blades you do use have reasonable proportions of chord, thickness, camber, twist and pitch to operate effectively in your wind turbine.

Try not to waste money on pretty WT blades just to make your school look good.  CF in micro-wind turbines is about as necessary as a flak jacket at a water-balloon fight.  I have personally pushed on the CF blade of a wind turbine set up in a show-room with one (1) finger and made the tip contact the tower.  When CF is used like the aircraft structural material should be, it is fantastically efficient.  When immersed in glue and injected into a plastic die, CF is the gimmick that makes you pay 2x as much for the same thing.

[midwoud1]

The best way make your blades wood hand carved . Airfoil NACA 4412 or Clark-Y. prop diam 2-3 meter.
A size to make measurements of properties .
Save a lot of time and money.

[Frank S]

Micro turbines are greatly effected by the size of the nacelle and the type of tower they are mounted on.
 Most I have seen in the 1 .5 meter diameter or less were mounted on pole towers guyed off. Although I do know of one man about 400 miles west of me who has 3 nearly identical turbines  each producing very different amounts of power. I say nearly Identical the blades and gennys are the same the main differences are the towers they are mounted on.1 being a guyed pole 1 is a free standing mono pole and the other being a lattice  tower.
 His turbine mounted on the guyed pipe produces the most during a day while the lattice is the worst, or I should say has the lowest watt hour output.
 I don't have any idea what his blade profiles are I just know all 3 turbines were of the same make and model none were DIY, excepting for the lattice and the guyed pole towers.
 I suspect that the free standing mono pole was in the middle purely due to its larger diameter than the guyed pole and the lattice was the lowest due to the amount of disruption of the laminar flow caused by the angle iron lattice work of that tower.
  By the way all of these were down wind turbines.