Originally Posted by
RetiredF4
I´m familiear what happens when a wing profile stalls (relative airflow from the underside of the profile), however in the case of the THS the relative wind hits the top of the profile, as the THS has the camber on the downside (producing downforce).
Could somebody explain the behavior of an airfoil like in that case? At what AOA would it loose it´s effecftiveness and could even a kind of "reversal" take place?
franzl
I would expect that NU input would not unstall the THS as the AoA at the leading edge remains unchanged. And that is where the separation occurs at a stall.What happens downstream won't change that.
NU input will only reduce drag and effective area, so reduces drag in the direction of movement, thereby reducing Pitch Down forces. At an AoA of 61 ° drag acts also as lift (Factor 0,87) .
ND Elevator on the other hand would increase drag and effective area, thereby increasing Pitch Down force.
Albeit probably not by much.
But I would not expect any inversion effects in this case.