birdus
Well-Known Member
I'm going through the book GA Airfoils by Harry Riblett. Just trying to pick an airfoil for the plane I'm designing. One thing he talks about in the book is "cusps." Some of his airfoils have them and some don't. He says:
"...the characteristics of the cusp type sections are not shown; however, they are approximately the same as the no-cusp shapes, with 2 drag counts less drag."
I have two questions. First, what's a cusp? Second, based on the above sentence, it looks like the airfoil with the cusp has 2 drag counts (whatever that means) less drag. Why wouldn't I choose that one? I like less drag!
Thanks,
Jay
"...the characteristics of the cusp type sections are not shown; however, they are approximately the same as the no-cusp shapes, with 2 drag counts less drag."
I have two questions. First, what's a cusp? Second, based on the above sentence, it looks like the airfoil with the cusp has 2 drag counts (whatever that means) less drag. Why wouldn't I choose that one? I like less drag!
Thanks,
Jay
