חברים,
נראה לי שמתחיל להתחמם פה וזו כנראה לא הייתה הכוונה של כל הכותבים.
מציע שנרגיע טיפה.
הסבר על אופן השימוש בהגה כיוון בכניסה לפנייה:
http://www.charlesriverrc.org/articl...rmalFlying.htm
הסבר נוסף:
It's important to realize that adverse yaw is mainly caused by a fore/aft rotation of lift forces due to roll rate, and not by a drag imbalance. This is illustrated in the attached PDF.
Yes, there will be some additional adverse yaw contribution from a left/right imbalance in profile drag. But if the airfoil and flap are designed appropriately, and the deflections are modest as is typical in thermalling (less than 5-10 degrees, say), the profile drag contribution to yaw moment will be quite small compared to the primary rotated-lift effect shown in the PDF. There will also be an additional yaw moment contribution from a left/right imbalance in induced drag, but again this is very small in a typical roll maneuver.
The reason why the drag contributions are small is because deflecting the ailerons causes surprisingly little lift imbalance between the left and right wings. The roll rate which ramps up in a fraction of a second after the ailerons are applied mostly cancels the aileron-caused lift imbalance. And if the left/right lift is nearly the same, the drag will also be nearly the same as long as the flow stays attached.
The drawback of aileron differential is that in order to be effective, it must intentionally create a large profile drag increase on the upward-deflected aileron side, typically via flow separation off the hinge. "Frise" ailerons actually promote this separation by protruding the aileron LE below the airfoil bottom contour. The reduction of drag on the downward-deflected aileron side will not be sufficient to signficantly cancel the adverse yaw if the flow there is clean to begin with --- can't reduce the profile drag very much if it's already close to the minimum "clean" level.