Re: [ULF-1] No dihedral in ULF-1?

From: Member 37
Date: 2010-04-29 12:24 UTC-07:00
Message: #0229

     Google  "pendulum effect" or "keel effect".  The web has some  
good descriptions as to why no dihedral is needed for the ULF-1 or any  
high wing aircraft.  Basically with a high wing aircraft the center of  
mass is below the center of lift and gravity keeps the aircraft in  
equalibrum. With a low wing the center of mass is above the center of  
lift. Dihedral is added to change lift characteristics as it begins to  
roll. Example, as an aircraft begins to roll to the right the right  
wing becomes perpindicular with gravity and makes more lift. And at  
the same time the left wing has all of the dihedral angle and will  
make less lift, resulting in the aircraft rolling to the left until  
level flight is achieved. Think, how much lift will be made with the  
wing on end.  Many high wing aircraft  have no taper at all to their  
wings, and fly fine(Piper Cub, Cessena 140) . This is done so the  
manufacturer makes only one rib, less cost.
                  Member 37

On Feb 18, 2010, at 5:28 PM, Member 55 wrote:

> Can anyone comment on why there is no dihedral in the ulf-1?  Does  
> some other feature give some roll stability?
>
> Thanks,  Bret
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