Does anybody know of any ways of finding NACA foil sections, like a table or similar? Ive downloaded a program called ‘NACAGEN’ but the zip file its in refuses to open on windows xp. [:-banghead]
If its not blowing it sucks!
NACA 4 series airfoils are all based on formulae.
NACA 5 series and 6 series airfoils have formulae for the camber distribution and tables for the thickness distribution.
I have all of these at home in a textbook. I will try to bring it to work on Monday and give you what formulae I can. Have you tried looking on the web. Selig’s site has some airfoil data tables (you need to dig a bit but they are there). I bet you can find the NACA formulae out there somewhere…
- Will
Will Gorgen
I got a good program from Lester’s site. Under ‘Downloads’ look for ‘Bulb Calculator’
Don
Here is the database of coordinates from Mike Selig’s site:
http://www.aae.uiuc.edu/m-selig/ads/coord_database.html
Most of the NACA 4 series and 5 series airfoils are in there as well as many many more. Take a look at the Eppler foils if you are working on an asymmetric lifting body…
- Will
Will Gorgen
Just found that thru google and found a program to do the job. Thanks anyway. Im actualy woking on an excel aplication to work out the numbers for the cnc milling of rudder blade foamcores, using NACA foil sections.
If its not blowing it sucks!
Alright Matthew it’s time to come clean: what in hell are you working on? The insatiably curious need to know…
And by the way do you have access to a cnc machine that could carve out a 78"hull from foam with info from a dxf file? And do it for nearly free for some University students in Southampton?
Doug Lord
microsail.com
monofoiler.com
High Technology Sailing/Racing
Ahhh well you see…
If its not blowing it sucks!
Most of the fast monohulls are running 6% camber. Sterne , Swede , and Bantock. Does any know what the fast multi’s are running . My Nightmare fins are 15%
Matthew,
As far as the CNC foam cores are concerned, check out this guy:
http://www.cncfoamfactory.com/
I’ve been very happy with the cores he’s cut for my composite wingmasts & the price is very reasonable.
Perhaps you’ve come across this already, but many NACA foil shapes are easily generated & copied at:
http://www.pagendarm.de/trapp/programming/java/profiles/NACA4.html
Hope this helps!
Bill K
Hoj,
Did you mean 6% thickness?
Generally, the thinner you can make the foils the better. There is a lower limit (about 3% - maybe a little lower with good shaping), but for RC, it is really hard to hit that limit. You have to balance strength (bending) vs. thickness. You need thickness to make the blades strong enough. You want them thin for form drag. The shaping from there will help prevent ventilation and stall.
Hope that helps…
Matthew,
I would recommend that you work with the Wortman or a decambered Eppler foil. They will produce lower drag at the reynolds numbers that you are looking at. THe leading edge is key for symmetric foils and those sections have much nicer thickness distributions at the leading edge than any of the NACA airfoils (except perhaps the 63A series).
Don’t forget to offset your thickness to account for skin thickness. BTW, what type of foam are you using? If you are using really high density stuff, then OK, but if you are using blue or pink house insulation foam, it will not be dimensionally stable enough. You should consider balsa or even hardwood plywood if that is the case. It will give you a much better shape when you are done. In fact, if you use plywood, you could avoid the additional fiberglass work and simply paint them and be ready to sail…
Good luck and let us know how they turn out.
- Will
Will Gorgen
I’m actualy using this system for producing full size cat foils initaly but it will probaly be useable for models, I just asked on here because I was sure someone would know. Cheers guys!
If its not blowing it sucks!
Ah, well, if you are working with full sized boats, then your Reynold’s numbers will be a lot higher and that really opens up the choices for low drag airfoils. You will probably be able to go a bit thinner as well.
I would still take a look at the Wortman airfoils as I have had great sucess with those for windsurfer fins (similar Reynolds numbers). Any of the NACA 6 series arifoils will also work out really well. I would stay away from the NACA 4 series. They do well at high specific loads but sailboat foils never operate at those high specific loads. for lower specific loads (Cl’s below 0.3 or so) the NACA 6 series airfoils will have half the profile drag for a given thickness.
Good luck!
- Will
Will Gorgen