ok, to clear up...the term destabilizing does not imply "ruin" the stability, but just make it less
stable. I don't think anyone here argues that SF generators do this. Less stable is often good, as in 3D airplanes for long and dir stability. I am also not stating that SF generators make the airplane UNSTABLE. This term would imply that a side force increases beta (angle of sideslip). This would be bad !! since this increase in beta would result in higher sideforces, which would increase beta further, until the airplane is in a spin.
The plane is NOT blown sideways since it's already drifting with the wind such that it only sees a direct on headwind at all times. The only times it'll see any side force is when the rudder is moved or for a moment when it moves into a volume of air where the velocity or direction or both is dffernet from the last volume (turbulence don'cha know). At that point it'll see a small side wind until the model is once again in direct headwind equilibrium.
IE: a dandelion seed drifing with the wind sees NO apparent wind force other than from below since it is always falling even if it IS a very slow fall.
uhh, yes, I do know, its called a wind perturbation. And and this very term is the basis for stability analysis. If everything was always in equilibrium, we would have no need for stability now would we? more specifically, directional stability is a measure of the airplanes ability reduce its angle-of-sideslip WITHOUT CONTROL INPUTS. Every airplane that flies sees perturbations in every axis every second, and its stability is DEFINED by how it responds to these perturbations.
BTW, if a dandelion sees no forces, how did it get moving??? F=ma...it sees forces every time it accelerates and decelerates!
I was under the impression that the very purpose of these devices was to increase the side force capability without affecting the directional stability. Hence, they are placed essentially on the CG.
no, They would have to be placed at the knife edge equivelant to the aerodynamic center (predominately made up of fuselage and Vtail) for them to have no effect on dir stability. for ALL dirctionally stable airplanes (this only excludes exotics like B-2) this is considerably aft of the cg.
much of the accepted theory of conventional aircraft seems to go goes right out the window after flying this type design.
no it doesn't! and these are not a new concept, just new to the hobby world.
A steady crosswind does not cause the airplane to turn, so no rudder or aileron pressure is required against a wind.
again, we aren't talking steady state here...or else we wouldn't be talking stability. a side perturbation (or side gust) can turn a directionally stable airplane (in the direction to reduce beta), while it won't turn a neutrally stable airplane, and it will turn a directionally unstable airplane the wrong way (increase beta)