KSNLF51 airfoil – high L/D, high lift, low to medium Re

I created this airfoil one day. I was looking for getting high L/D at low Re. This is pretty nice. I tried simulations as low as Re 100000-300000 (not included in here, you can try by yourself with QFLR5).

Airfoil KSNLF51:

KSNLF51 L/D graph:

Data file: http://www.katix.org/karoliina/airfoils/KSNLF51.DAT

Re 1 million, Mach 0.3

Re 3 millions, Mach 0.3

Re 5 millions, Mach 0.3

License: Creative Commons Share-a-like

Comparison between some airfoils:

    • Thad
    • October 6th, 2009

    I always thought low-Re airfoils had to have small leading edge radii and be fairly thin to not have separation problems — yours is wonderfully rounded and thick. How did you arrive at that design? I'm amazed at the low pitching moment too, with the cusp at the TE I would have thought it would substantially greater than that.

    The simulators don't lie, though — I've just got to do some more experimentation.

    • Thad
    • October 7th, 2009

    Nevermind ūüôā I do all of my airfoil analysis for model airplanes, and low Re to me is more like 1e5 not 1e6, and the rules are totally different at those Reynolds numbers. Check out the MH64 airfoil at


    for example.

    • Karoliina Salminen
    • October 20th, 2009

    It is not really ideal for really low Re, my low Re basically means here wing tip of tapered wing of full size aircraft at stall speed. Just calculated yesterday that the Re can get as low as 500000.

  1. No trackbacks yet.

You must be logged in to post a comment.
%d bloggers like this: