In the first 2 videos about airfoils we have imported airfoil curves into SolidWorks from airfoiltools.com. In the 3rd and 4th videos in the series of 5 we delve into physical interpretations of the performance parameters of airfoils. In this video we’ll deal with the coefficients of lift and drag Cl and Cd. Keep an eye out for the 4th video which deals with the most confusing performance parameter: coefficient of moment Cm. With this knowledge, you can choose the best airfoils and angles of incidence for the wings and stabilizers of your airplane.