Which statement about the airflow around an airfoil is correct if the angle of attack increases?
Refer to figure.
When the angle of attack of a wing increases, the stagnation point moves down due to changes in the airflow pattern around the wing.
As the angle of attack increases, the wing presents a greater surface area to the oncoming airflow. With a higher angle of attack, the airflow approaching the wing is deflected more downward by the wing's lower surface. This deflection of airflow creates a pressure difference between the upper and lower surfaces of the wing.
The stagnation point is the point on the wing's surface where the airflow velocity momentarily drops to zero. As the angle of attack increases, the increased downward deflection of the airflow causes the stagnation point to move downward along the wing's leading edge. This occurs because the increased pressure on the lower surface of the wing shifts the stagnation point downward to maintain equilibrium.
The downward movement of the stagnation point affects the distribution of airflow over the wing, altering the lift characteristics. As the stagnation point moves downward, the wing generates more lift because of the increased pressure differential between the upper and lower surfaces of the wing.
In summary, as the angle of attack of a wing increases, the downward deflection of airflow causes the stagnation point to move downward along the wing's leading edge. This shift in the stagnation point contributes to changes in lift generation and overall aerodynamic performance of the wing.
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