Skip to main content

Elementary Airfoil Interactive

Lift and Drag

With this simulator you can investigate how an airplane wing produces lift and drag. You can change the values of different factors that determine lift and drag by using the colored buttons located below the picture of the wing. The value of the lift and drag are presented by the thermometer gages on the lower right.

There are several other simulations based on FoilSim. You can investigate the role of aerodynamics in pitching a baseball by using CurveBall, the curve of a soccer ball by using SoccerNASA, or wind tunnel testing techniques by using TunnelSys.

Please note: the simulation below is best viewed on a desktop computer. It may take a few minutes for the simulation to load.

General Instructions

This program is designed to be interactive, so you have to work with the program. Input for this simple program is done with button widgets. To operate a button, move the cursor over the button and left click with the mouse.

Screen Layout

The program screen is divided into four main parts:

  1. On the top left side of the screen is the View Window. The view window has a picture of the airfoil that you are designing. Moving particles show the flow past the airfoil.
  2. On the upper right side of the screen is the Control Panel with the orange Reset button. At any time, you can return to the original default conditions, by clicking the Reset button.
  3. On the lower left side of the screen is the Input Window. You can change the value of lift and drag by varying the speed of the airplane, the altitude which affects the air density, the angle of attack of the airfoil, the camber, which is the curvature of the airfoil, the thickness, which is defined on the wing geometry web page, or the wing area. The current values of the design variables are presented in boxes located next to the red and blue buttons. Clicking a blue button decreases the value of the variable, clicking a red button increases the value. There are limits on all the variables, When you hit the maximum limit, the variable won’t increase. When you hit the minimum limit, the variable won’t decrease.
  4. On the lower right side of the screen is the Output Window. The output is presented as colored gages, or bar graphs, for the lift and drag. There is a number scale with a colored bar that moves up and down. The color of the bar changes depending on the value of the lift or drag. On the left side, we give you the “scale” to the color. (For example, if the lift bar is red [x 100] and reaches to the number 4 on the scale, the value is 4 x 100 = 400 pounds.) This display was chosen to help younger students learn how to read bar graphs. The student can also gain a sense for how sensitive the lift and drag are to certain input variables, by noting how far the bar moves. For some variables, the drag changes a lot and the lift does not change at all! At the top of the output window we show the numerical value of the lift and drag. This output can be used to as a source of data for students to generate graphs by hand.
Provide feedback