UIUC Low-Speed Airfoil Tests
The goals of the UIUC Low-Speed Airfoil Tests (UIUC LSATs) program are to design, analyze and wind tunnel test airfoils for low Reynolds number applications. The UIUC Applied Aerodynamics group has been a leader in this research area with new airfoil designs being applied to unmanned aerial vehicles, small wind turbines, model aircraft and many other applications. Over 200 low Reynolds number airfoils, many of them new designs, have been built and validated in the UIUC Subsonic Aerodynamics Lab 3x4 ft wind tunnel with the results being documented in books, reports, and journal/conference publications.
The airfoil performance data from these tests are have been published in several books that are available in pdf format here. Printed copies published by SoarTech Aero can still be purchased online through a donation to our ongoing wind tunnel test program (see below).
We maintain answers to our frequently asked questions here: LSATs FAQ.
Summary of Low-Speed Airfoil Data Books
[Download Vol. 1]
[Donate to our research, and receive printed copy of Vol. 1]
[Download Vol. 2]
[Donate to our research, and receive printed copy of Vol. 2]
[Download Vol. 3]
[Donate to our research, and receive printed copy of Vol. 3]
[Download Vol. 4 / NREL Report]
[Download Vol. 5]
Also available here online and in printed format by SoarTech Aero
Publications is the book Airfoils at Low Speeds (SoarTech 8),
which includes wind tunnel data on 54 airfoils tested at Reynolds
numbers ranging from 60,000 to 300,000. The book contains extensive
commentary and analysis. Testing was performed at Princeton
University during 1987 and 1988 by Michael Selig, John Donovan and
David Fraser. This work was the important precursor to the low Reynolds
number airfoil research at UIUC.
[Download Airfoils at Low Speeds (SoarTech #8)]
[Download SoarTech 8 tabulated airfoil data in zip format]
Low Reynolds Number Airfoil Data and Documentation
- Composite plots of airfoils tested
- Alphabetical listing of all airfoils tested
- Listing of available datasets in tabular form: [ Vol 1 | Vol 2 | Vol 3 | Vol 4 | Vol 5 ]
- All of the low Reynolds number airfoil data in Vols 1-4 and SoarTech 8 data are available here online in plain ASCII text files. The first two volumes include lift and drag coefficient data while the second two volumes also include pitching moment data. For SoarTech 8 tabulated airfoil data, see link above.
- Our tests are supported in large part by a group of dedicated model makers / volunteers focused on a common interest in model aviation. If you are interested in helping and want to make a wind tunnel model for testing at UIUC, see the wind tunnel model construction notes for more information. For flapped models, brackets are added to the ends to secure the flap for specific settings. If you have an interest in a particular airfoil that you would like to be tested at UIUC, please contact us.
- S1223 lift and pitching moment plots: The S1223 is a popular airfoil used in the SAE Aero Design Competition. The airfoil first appeared in UIUC LSATs Vol 1 without pitching moment data, but these data were taken after Vol 1 and posted here online. Additional data on the S1223 with Gurney flaps is in Vol 5.
- SG6050 and SG6051: These airfoils were designed and tested for the WindLite 8 kW wind turbine. They are semisymmetrical with an aft flat bottom for easy building. The experimental data was publically released in 2016 thanks to the agreement of the project sponsor.
- Low Reynolds number airfoils are defined by having a laminar separation bubble that causes an increase in drag. This bubble can be seen by injecting smoke into the boundary layer and also by a technique called oil flow visualization [graphics downloads].
Low Reynolds Number Airfoil Publications
In addition to Vols 1-5, some low Reynolds number airfoil publications from our group are listed below.
- Selig, M.S., Deters, R.W., and Williamson, G.A., "Wind Tunnel Testing Airfoils at Low Reynolds Numbers," 49th AIAA Aerospace Sciences Meeting, AIAA Paper 2011-875, Orlando, FL, January 2011. | PDF
- Selig, M.S. and McGranahan, B.D., "Wind Tunnel Aerodynamic Tests of Six Airfoils for Use on Small Wind Turbines," ASME Journal of Solar Energy Engineering, Vol. 126, November 2004, pp. 986-1001. | PDF
- Selig, M.S. and McGranahan, B.D., "Wind Tunnel Aerodynamic Tests of Six Airfoils for Use on Small Wind Turbines," AIAA Paper 2004-1188. | PDF
- Selig, M.S., "Low Reynolds Number Airfoil Design," VKI Lecture Series - Low Reynolds Number Aerodynamics on Aircraft Including Applications in Emerging UAV Technology, von Karman Institute for Fluid Dynamics (VKI) Lecture Series, RTO/AVT-VKI-104, November 2003. | PDF
- McGranahan, B.D. and Selig, M.S., "Surface Oil Flow Measurements on Several Airfoils at Low Reynolds Numbers," AIAA 42nd Applied Aerodynamics Conference, AIAA Paper 2003-4067, Orlando, FL, June 2003. | PDF
- Gopalarathnam, A., Broughton, B.A., McGranahan, B.D., and Selig, M.S., "Design of Low Reynolds Number Airfoils with Trips," Journal of Aircraft, Vol. 40, No. 4, 2003, pp. 768-775. | PDF
- Giguère, P. and Selig, M.S., "New Airfoils for Small Horizontal Axis Wind Turbines," ASME Journal of Solar Energy Engineering, Vol. 120, May 1998, pp. 108-114. | PDF
- Selig, M.S. and Guglielmo, J.J., "High-Lift Low Reynolds Number Airfoil Design," Journal of Aircraft, Vol. 34, No. 1, January-February 1997, pp. 72-79. | PDF
Some of our early newsletters/info and how we started is below. This stuff is old: