Aerobatic .45 profile
10-01-2003, 04:13 PM
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Aerobatic .45 profile
Hi
I'm just finishing a .45 aerobatic airplane and I'm not sure I've choose the right wing profile... Is the Eppler E168 a good choice?
The airplane characteristics are:
Wing span: 1364 mm (53.7 in)
Wing root chord: 344 mm (13.54 in)
Wing tip chord: 209 mm (8.23 in)
Expected weight: 2.5 Kg (5.55 lb)
I would appreciate any one other profile suggestion.
Thank you
I'm just finishing a .45 aerobatic airplane and I'm not sure I've choose the right wing profile... Is the Eppler E168 a good choice?
The airplane characteristics are:
Wing span: 1364 mm (53.7 in)
Wing root chord: 344 mm (13.54 in)
Wing tip chord: 209 mm (8.23 in)
Expected weight: 2.5 Kg (5.55 lb)
I would appreciate any one other profile suggestion.
Thank you
10-02-2003, 07:58 AM
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RE: Aerobatic .45 profile
Ricardo,
I'm afraid the E168, although not a bad airfoil, is not the most appropriate for a profile, fun-fly type. It's too thin......From what I've seen the most recommended airfoil for these kind of airplanes is a thicker one, like 15 to 18%....If I'm not wrong, the E168 is 12.4%
The reasons for the thicker airfoil are the delayed stall characteristcs of them, which are beneficial for 3D maneuvers, also they recover from the stall easily, helping in the recovery of the meneuver, and another factor is that they produce higher lift then similar thinner symetrical profiles....In this link there's a further explanation to that:
http://www.rcuniverse.com/forum/m_54.../tm.htm#540690
So, if you haven't built the wing yet, try changing for a NACA 0016 or similar with the thickest point moved to 25% (generally they are at 30%) to help in the stall behaviour by blunting the leading edge....
Best Regards,
Rodrigo Maia
I'm afraid the E168, although not a bad airfoil, is not the most appropriate for a profile, fun-fly type. It's too thin......From what I've seen the most recommended airfoil for these kind of airplanes is a thicker one, like 15 to 18%....If I'm not wrong, the E168 is 12.4%
The reasons for the thicker airfoil are the delayed stall characteristcs of them, which are beneficial for 3D maneuvers, also they recover from the stall easily, helping in the recovery of the meneuver, and another factor is that they produce higher lift then similar thinner symetrical profiles....In this link there's a further explanation to that:
http://www.rcuniverse.com/forum/m_54.../tm.htm#540690
So, if you haven't built the wing yet, try changing for a NACA 0016 or similar with the thickest point moved to 25% (generally they are at 30%) to help in the stall behaviour by blunting the leading edge....
Best Regards,
Rodrigo Maia
10-02-2003, 10:24 AM
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RE: Aerobatic .45 profile
Hi Rodrigo
Well, the airplane is more to a F3A then to a Fun Fly. The thing is that I'm afraid with thicker profiles for I can loose the ease snap roll characteristics... What do yo think about it?
Regards,
Well, the airplane is more to a F3A then to a Fun Fly. The thing is that I'm afraid with thicker profiles for I can loose the ease snap roll characteristics... What do yo think about it?
Regards,
10-03-2003, 07:31 AM
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RE: Aerobatic .45 profile
Hi Ricardo
Yeah, if it's more for F3A then for fun-fly aerobatics, a thinner profile is better. As I said, a thick profile will have delayed stall characteristics and so it will be harder to fully stall the wing in order to snap roll it. Thick profiles are better for the low speed, high alpha 3D maneuvers (typical of fun-fly planes). But for F3A, I think the E168 is just about right. At least I heve never seen a F3A plane with fun-fly wings (thick airfoil). I think I misunderstood your goal when you said profile. I linked profile with fun-fly right away.
That will be an interesting plane...
Best Reagards,
Rodrigo Maia
Yeah, if it's more for F3A then for fun-fly aerobatics, a thinner profile is better. As I said, a thick profile will have delayed stall characteristics and so it will be harder to fully stall the wing in order to snap roll it. Thick profiles are better for the low speed, high alpha 3D maneuvers (typical of fun-fly planes). But for F3A, I think the E168 is just about right. At least I heve never seen a F3A plane with fun-fly wings (thick airfoil). I think I misunderstood your goal when you said profile. I linked profile with fun-fly right away.
That will be an interesting plane...
Best Reagards,
Rodrigo Maia
