Module 1 Questions

Question 1

Does the location of Centre of Pressure (CP) change with AoA?

Answer 1

yes

Question 2

Does AoA affect pitch moment about the AC?

Answer 2

Moment about aerodynamic Centre does not change with aoa.

Question 3

Does the location of aerodynamic centre (AC) change with AoA?

Answer 3

No

Question 4

Does AoA affect the coefficient of pitch moment about the AC?

Answer 4

No

Question 5

Dose airspeed affect pitch moment about the AC?

Answer 5

Yes

Question 6

Can you find pitch moment coefficient about AC, if you know the pitch coefficient at zero-lift angle, when drag is small?
Why?

Answer 6

Yes, the magnitudes of the positive lit and negative lift are the same but they situate at different locations on the chord, (force couple).
Lift is zero so pitch moment is not, drag is relatively small so the moment at zero lift angle would be dominated by the lift force couple, which is independent of the location of the pivot point.
So can be treated as the same as pitch momeent about AC.