ideal aerofoil

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Lendo

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Feb 6, 2013
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801
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Brisbane
PiperCruisen, The NACA 63A Airfoils are very similar to the Riblett designs, maybe the Riblett Airfoil is slightly better in Stall.

The people with lots of money get their Airfoils developed by Engineers with Lots of Computer and Software power with lots of experience - you choose. Even they (the experts) get it wrong sometimes.

Personally I'm happy with Riblett and the varied options he provided in his Book, makes life lots easier- and might I say cost-effective. Riblett gives his reasons he finds some Airfoils are unsuitable and some fixes for others, you should study those remarks.
George
 

davidjgall

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Oct 7, 2010
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130
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Northern California, USA
PiperCruisen, The NACA 63A Airfoils are very similar to the Riblett designs, maybe the Riblett Airfoil is slightly better in Stall.
These are the NACA profiles that Riblett used to build his airfoils: 0015, 63-015, 64-015, 65-015, 30-015, 63-A015, 64-A015, 40-A015. So, YES, his airfoils are "very" similar. He also uses the NACA mean lines ("camber lines") which he modifies at the leading edge so, yes, Riblett's airfoils are "very" similar -- almost indistinguishable. :)
The people with lots of money get their Airfoils developed by Engineers with Lots of Computer and Software power with lots of experience - you choose. Even they (the experts) get it wrong sometimes.
A little time spent with XFLR5 could not hurt an amateur to understand just how forgiving the field of low speed airfoil design actually is, then we could stop this constant fretting over insignificant details and all just settle down. The design space is quite thoroughly explored and what works is well known in the speed and Reynolds number range of interest to "most" of us. Dean Wilson and Wayne Ison (Larry Isreal?) knew what they were doing when they used a "Graphite No. 2" airfoil. Max Munk wrote a nice little treatise in about 1920 for the NACA that's well worth the look-see.
Personally I'm happy with Riblett and the varied options he provided in his Book, makes life lots easier- and might I say cost-effective. Riblett gives his reasons he finds some Airfoils are unsuitable and some fixes for others, you should study those remarks.
Absolutely excellent advice. I may quibble over how Riblett assembled his airfoils (contrary to the NACA way of doing so) but, at the end of the day, his airfoils work as advertised and his reasoning is sound. The equivalent NACA airfoils that Riblett claims to "improve" are just as worthy if one follows the conservative selections that Riblett does.
 
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