If we consider the thrust line to be the strait line of travel then
screwing the wing so that the right leading edge is ahead of the left will
cause the model to turn the the left. The reason that this happens has to
do with two aerodynamic issues. The wing dihedral causes the tips to
function as rudders. Turning by the wing tips is the same idea as turning
by the rudder angle aerodynamically. The other issue that comes up is the
offset area. The lift vector field created by the wing is now lifting
"earlier" on the right side than on the left with respect to time as plane
travels through the air. This may cause the model to roll to the left ever
so slightly.
The offset of wing area has a much less dramatic affect on turning the
model than the offsetting the dihedrals. We know that it takes a
considerable amount of wing off set to combat the rubber torque. Therefore
the tip offset is likely what is turning the model.
Changing the wing mount angle probably isn't helping the model to fly
better ultimately. The reason we put the rudder as far back as possible is
to gain leverage on the model. The boom is acting as a lever arm so the
rudder's turning force is multiplied. If we steer from the wing we are
steering from near the center of the model. Thus, more surface area is
required to get the force required for the turn. More surface area means
more drag. There is also the potential for needing more left panel offset
to account for the lift distribution change.
Regards,
Nick
On Mon, Nov 5, 2012 at 10:57 AM, Akihiro Danjo <adanjo-373_at_mx1.ttcn.ne.jp>wrote:
> **
>
>
> >Normally a wing is mounted perpendicular to the motor stick in plan
> view. However, if the wing is mounted at an angle other than 90 degrees to
> the motor stick, for instance with the leading edge of the right side of
> the wing ahead of the leading edge of the left side of the wing, the plane
> will turn to the left. What is the aerodynamic reason for this?
>
> Gary san, Do you mean left thrust?
>
>
>
>
>
Received on Mon Nov 05 2012 - 09:10:48 CET