Final answer:
The zero lift angle of attack refers to the angle at which an airfoil generates zero lift. It is important because it determines the stall angle of an airfoil.
Step-by-step explanation:
The zero lift angle of attack refers to the angle at which an airfoil generates zero lift. It is the angle of attack at which the lift coefficient is zero. This angle is important because it determines the stall angle of an airfoil, which is the critical angle at which the flow separates from the airfoil and lift is greatly reduced.
In order to calculate the zero lift angle of attack, you would need the lift coefficient data for the particular airfoil. The lift coefficient is a function of the angle of attack, and you can plot a lift coefficient vs. angle of attack graph to determine the angle at which the lift coefficient is zero.
For example, if you have a lift coefficient vs. angle of attack graph and you see that the lift coefficient is zero at an angle of attack of 2 degrees, then the zero lift angle of attack for that particular airfoil would be 2 degrees.