Hi everybody,
and … thanks to NREL for creating this Forum. One feels to be a part of a community of interests and of knowledge, even if that is 10000 km apart.
My question is maybe too simple but …
Are the coordinates data AND the lift and drag coefficients for the NREL family of airfoil public available? I mean for example S822, S823, S803 and so on. I made some searches, but without success.
As a side question, apart from the NREL developed airfoils, can someone point me to a good airfoil family to be used for very low wind speeds (so low Reynolds number) whose coordinates and performance data are available free of cost or with a low price?
Unfortunately, NREL licences the airfoil coordinates to interested manufacturers and therefore they are not publicly available. The exception to this is the S809 airfoil, which can be found in reports related to the NASA Ames wind tunnel experiment. These reports can be found on the NREL publications website.
There are other reports that you may find of interest that do have coordinates and performance data for non-NREL airfoils. Some also have performance comparisons to NREL airfoils, although no coordiantes. For example the following report has performance and coordinate data for the E387, FX63-137, & SD 2030 and performance for the S822, S834, and SH 3055.
TEROM SpA, the company where I work at the moment, IS a very small, very startup company . I will pass on the information about the licensing of airfoils data, and eventually take contact again on that subject.
May I suggest that NREL prepare a list of airfoils, and state which one is in public domain, and which one is not ? This may save many people’s searching works
Just to corret my earlier post above - after checking the NREL publications page, a lot of the NREL airfoils ARE publicly available now. Seems many were published in January 2005. Perhaps the patent ran out (?), so I’m not exactly sure if the licencing fee still applies. Happy airfoil hunting.
Hi everybody again…
After a certain delay, I am still looking for the “right” airfoil family. Thanks to all the suggestions above, I begin to see the … end of the tunnel . And in fact it IS true that most of the coordinates are now published.
Just for the sake of completeness, I still miss the following paper, that is a part of the list of Dan Somers. But, maybe due to the date (1987), it is not available under the NREL or OSTI publication search.
“Somers, Dan M.: The S801 through S808 Airfoils”
These airfoils should be also candidates for variable speed, variable pitch, small wind turbines. Can NREL somehow make this paper available, or are those profiles still proprietary?
Well thanks a lot everybody…
the paper was actually mentioned in the list by Mr. Somers, posted in this same thread … airfoils.com/pubs1.htm
Anyway I already contacted directly Mr. Somers, and he advised me that, of course, these airfoils are “technologically ancient” and better options exist.
The second edition of Dave Spera’s Wind Turbine Technology (ISBN: 978-0-7918-0260-1) is hot off the press and Appendix D is dedicated to the NREL S-series airfoils. You may want to take a look if you are interested in using the airfoils.
I am also working (at a low level) on a web page for the airfoils. The web page will have the information found in Spera’s book plus information about how to get licenses, lift and drag data, and even airfoil coordinates.
Hi,
I am designing a blade of small stall regulated wind turbine of about 11 meter rotor diameter. Currently I am looking for suitable airfoils which I can use for the blade. S822 and S823 airfoils from NREL appear to be most suitable for this size of blade. Can anyone please clarify that in order to use these airfoils do I have to obtain a license from NREL and what would be the license fee?
Can anyone recommend some other airfoils (apart from NREL and which are publicly available) which could be used for stall regulated wind turbines?
Thanks in advance,
I am studying the deflection failure on the wind turbine blades. I have done some analysis using ANSYS and matlab programans in order to calculate the blade deflection. FAST is a powerfull tool used in wind turbine calculation, so I want to compare the results with FAST results.
But I have a problem with airfoil data. I have all airfoil data correct except one. I need S818_30 airfoil data and I have S818_27 one. I know that the drag and lift coefficients are not the same. I haven’t found it, so I would greatly appreciate if you could provide me or help me.
What do you mean by “S818_30?” Is that S818 data for the 30th blade station or something? Generally, people get data at the “pure” locations and then have to interpolate between them to get the intermediate stations. I use our AirfoilPrep spreadsheet to do that.
I’m not sure what you mean by “scaled.” Our airfoil tables are all nondimensional. They all have a chord of 1.0 (unspecified) unit. There is a characteristic thickness to chord ratio for any given airfoil. The S818 is a 21% airfoil (maximum thickness/chord = 0.21). The lift and drag coefficients are independent of the scale of the airfoil. If you double all the dimensions, the lift and drag coefficients will be the same other than for Re effects.
. I will pass on the information about the licensing of airfoils data, and eventually take contact again on that subject.