' The wing tip vortices produce a swirling flow of air behind the wing which is very strong near the wing tips and decreases toward the wing root. No I dont think that reduced AoA cause higher drag, I am confused how reduced AoA can increase drag in explanation how wingtip vortices (induced drag topic) change (reduced )relative airflow on wing.

What's implicit is that the lower angles of attack are still generating the same amount of lift and are therefore at a higher speed. If the plane is flying at the maximum permissible speed, then there is an altitude at which the air density will be what is needed to keep it aloft while flying at the angle of attack that minimizes the drag.' That does imply that there is a best angle of attack, and that other angles of attack have higher drag. WHY do you think reduced reduced AOA causes a higher drag? And would you be convinced if I showed you a million web pages that says the opposite? This wing 'feel' effective airflow,so how smaller angle(=reduced AoA) can cause increase in drag? But if it helps, reduced AOA in the non-stall condition produces lower drag and lower lift.Īngle between chord line and effective airflow is smaller than angle between chrod line and freestream airflow. 'Induced drag has reduced effective AoA' I don't understand these words.