In straight and level flight with a positively cambered aerofoil, what happens to the centre of pressure and the total lift force when speed is decreased?

In straight and level flight with a positively cambered aerofoil, as the speed decreases, the centre of pressure (CP) moves aft, and the total lift force decreases. The reasoning behind this is tied to the characteristics of the airfoil and the principles of lift generation.

When speed decreases, the angle of attack necessary to maintain level flight increases to compensate for the loss of lift due to lower airspeed. However, as the angle of attack increases, the pressure distribution over the wings changes. For most positively cambered airfoils, this results in the centre of pressure moving aft due to the shift in lift distribution along the wing.

The lift force itself is dependent on several factors, including airspeed, angle of attack, and wing area. When speed decreases, the lift generated by the wing diminishes in accordance with the lift equation (Lift = 0.5 * Cl * p * V^2 * A), where Cl is the lift coefficient, p is the air density, V is the velocity of the airflow, and A is the wing area. Thus, as speed decreases, although the angle of attack can momentarily increase to maintain lift, the overall lift force generated will ultimately decrease as the aircraft slows down.

Therefore, while