PPRuNe Forums - View Single Post - Why Do Aircraft fy? Flat Plate Lift Vs Bernoulli?
Thread: Why Do Aircraft fy? Flat Plate Lift Vs Bernoulli?
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Old 22nd Dec 2008, 19:23
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cwatters
 
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It's quite interesting to look at graphs (polars) of lift vs Angle of attack. Many produce positive lift even at negative AOA..

For NACA 4412 Cl peaks at about 1.4 but notice that CL is still positive right down to an AOA of MINUS 4 degrees. At an AOA of zero CL is just under 0.5 so Bernoulli is clearly contributing a significant percentage.

AOA = 0


AOA = -4




How do I... Read Polar Diagrams?
Last edited by cwatters; 22nd Dec 2008 at 19:39.
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