The cross-section of a wing is called an airfoil and airplanes use many different shapes of airfoils to cause changes in the flow, speed, and pressure of the air moving past them. These changes create an upward force called lift.

Your Goal

• A higher lift to drag ratio is a major goal of wing design. Can you find the best L/D for this plane? Adjust the angle of attack and watch the dots of air flow past the airfoil.
• Look for more dark blue dots above and red dots below the airfoil for increased L/D.
• Keep the dots flowing near the airfoil's surface to prevent additional drag. More drag decreases L/D.
• Watch the dots speed up as they flow past the airfoil. Is there a difference between their speed above and below the airfoil?

F-104 Note

Can you find the best L/D for each airspeed of the F-104? Every time you adjust the airspeed, alter the angle of attack to calculate the new L/D

Four things affect an airfoil’s ability to create lift: shape, angle of attack, airspeed, and air density. An airfoil’s ability to create lift is measured by it’s lift to drag (or L/D) ratio.