As the angle of attack of an aerafoil increases, which of the following statements about the airflow are correct?

As the angle of attack of an airfoil increases, fundamental changes occur in the airflow over the wing. When the angle of attack rises, it typically results in an increase in lift up to a certain point, known as the critical angle of attack. Beyond this angle, airflow begins to separate from the upper surface, leading to stall.

The correct statement implies that with an increase in angle of attack, the lift increases while still maintaining some level of flow attachment over the airfoil. Additionally, it indicates that the airflow characteristics, like changes in pressure distribution across the airfoil, are also affected, supporting the lift development up to the stall point.

The airfoil's ability to generate lift is directly tied to the airflow that circulates around it, induced by the angle of attack. Therefore, both statements about the airflow changing positively and negatively with the increase in angle of attack, including phenomena such as lift increase or airflow separation leading to stall, being correct is a common understanding in aerodynamics.

Thus, when both statements accurately describe aspects of airflow in relation to the changing angle of attack, the choice that affirms the correctness of both statements captures the essence of aerodynamic principles governing airfoil performance.