Hangar Flying

Hangar Flying => Hangar Flying => Topic started by: flyoz on October 28, 2010, 01:50:45 AM

Title: Rudder lift and Drag
Post by: flyoz on October 28, 2010, 01:50:45 AM

My path of reading CP's and testing my rudder cutting templates on some scrap foam continue , more blue dust maybe one day ......
My real question
The winglets ( rudders ) try to lift the tip in flight , so in my mind deflecting the rudder should increase that lift and try to lift the tip even more than the other wing and this then has
to be overcome by up deflection of the aileron on the same wing - sort of cancels out the effect . The only thing i can suspect is that the rudder deflection produces more drag and
the wing is dragged in that direction hence the turn .
I know the aircraft turns well so what is the turning theory with winglet rudders ?
Flyoz

Title: Re: Rudder lift and Drag
Post by: LongEZDaveA on October 28, 2010, 07:21:05 PM

When you deflect the rudder, it increases both lift and drag of the foil.  This causes the aircraft to yaw.  Since the wings are highly swept, there is a strong dihedral effect, that is...yawing causes it to roll.  The wing on the side where the rudder is deflected becomes more "swept" and therefore produces less lift.  The other wing likewise produces more lift, therefore you get roll.

Title: Re: Rudder lift and Drag
Post by: flyoz on October 29, 2010, 12:36:28 AM

OK makes sense .
Just looking at the concept - if the rudder deflected inwards it would still add drag and reduce the lift at the tip - same effect but maybe it was too much
Anyway i am not trying to redesign or change anything - just saying what if
Flyoz ;D