Bomber wrote in Sat Jul 29, 2017 5:33 pm:Richard can you clear up what the axis and values are....
Looking at the graph with flaps up there doesn't seem to be any effect on the stabiliser untill 18degs.... which concurs with the table.... after this the values are different.
All of the above occurs with zero deflection of the elevators.. deflection of the elevators in effect increases/decreases the AoA that the h-stab see's.
My point being for flight modelling we can't separate the h-stab and elevator effects as is done presently
Spiraling' propwash doesn't exist
This table says that the AoA has no effect on the value of the elevator moment up to 18degs... and only after this value does it start to reduce.
This cannot be correct.
Bomber wrote in Sun Jul 30, 2017 12:11 pm:This chart seems to shows the effect of front wing (flaps up) and varying degrees of flaps deflection on the H-stab effectiveness with varying front wing angle of attacks.
Bomber wrote in Sun Jul 30, 2017 12:11 pm:With a h-stab that's in line with the main wing we should expect the downwash of the wing to effect the h-stab, maybe reducing the AoA that the h-stab see's by 2 degrees.
Bomber wrote in Sun Jul 30, 2017 12:11 pm:All of the above occurs with zero deflection of the elevators.. deflection of the elevators in effect increases/decreases the AoA that the h-stab see's.
Bomber wrote in Sun Jul 30, 2017 12:11 pm:So if we consider the elevator is deflected by 25degs downwards giving an effective AoA on the h-stab of 8 degs... if we conjecture the stall angle of the h-stabiliser airfoil being 12degs then there's only 4 degrees of of AoA that the airplane can see before the h-stab stalls out and the nose drops.
Bomber wrote in Sun Jul 30, 2017 12:11 pm:My point being for flight modelling we can't separate the h-stab and elevator effects as is done presently and explains why the elevator effectiveness can be too sharp when doing this.
The AoA is an angular measurement between an airfoils trailing edge and it's leading edge against the relative wind..
Maybe Thorsten can explain this as I can't.
Richard wrote in Sun Jul 30, 2017 3:23 pm:....pitch damping due to q dot (CMq), change in pitch moment due to alpha dot.
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