Facultad de Ingeniería Mecánica y Eléctrica
Relationship between the Coefficient of Lift (CL) and the angle of attack (α)Relationship between the Coefficient of Lift (CL) and the angle of attack (α)
The angle of attack is the acute angle formed by the wing chord and relative wind direction,i.e., the angle at which the air strikes on the wings.
The lift coefficient is found experimentally using the following equation;
If you see a basic relation between thesetwo properties we can obtain the next chart. When we have a little angle of attack have practically very little lift coefficient and when we increase this angle of attack we are going toobtain a more efficient Lift coefficient.
It is called the critical angle to that which produces more lift, and from which an increased angle of attack does not translateinto increased support.
In particular, V∞ will be the smallest when CL a maximum is.
In the range of angles of attack for normal flight (between about 3 °and 10 °) case that:
The liftcoefficient is proportional to the angle of attack.
The induced drag coefficient is proportional to the square of the angle of attack, and
the drag coefficient is essentially constant.
Inthe following chart shows a graphic with the relationship between these things. It is also mention the drag coefficient and its relation but in this case we going to focus only in liftcoefficient.
The loss occurs with a certain angle of attack.
The best angle of climb is an angle of attack.
The best rate of climb is given with a specific angle.
Thebest glide ratio occurs with a certain angle.
When the plane makes up in depth, you are actually selecting an angle of attack.
The lowest rate of decline in glide occurs with a particular angle.