# HD Animation: Dynamic lift on the wing profile

The following animation illustrates the principle of dynamic lift. For this purpose, an aircraft with a Clark-Y airfoil is shown. The angle of attack of the wing can be changed. The acting forces, shown as vectors, adapt accordingly.

## Note on use

As with all animations, the windows can be enlarged or reduced by clicking on them.

After starting the application, you can view the animation in full-screen mode. To do this, click on “View” and then on “Full screen”:

To exit full screen mode, press the Esc key.

## Description of the animation

If you click on the large content window of the animation, further levels become visible. The polar diagram shows how the lift and drag coefficients of the wing relate to each other. An analytical diagram is also shown as an alternative to the polar diagram.

The amount of lift can be calculated using the following formula:

Ca: Coefficient of lift. The lift coefficient is different for each airfoil type and depends on the shape of the wing. The value is usually determined by measurements in a wind tunnel or by simulations.
ρ (Rho): Density of the air through which the wing moves. It is given in kilograms per cubic metre (kg/m³) and can vary depending on altitude, temperature and humidity.
v: Speed of the object through the air in metres per second (m/s)
A: Reference area. This is the surface on which the air pressure acts to generate the buoyancy. This is the upper and lower surface of the wing.

## Instructional idea

The phenomenon of dynamic lift is not understandable at first sight. As a layman, one would not expect that a wing with the angle of attack of 0 degrees would still cause lift. In the animation you can see a real Clark-Y profile. Actual measured coefficients for lift and drag are used. The aim is to make students think and marvel by showing them as true to the original as possible.

## Contributors

C. Hein, S. Rikowski

## Sources

• Idea and first concept: Tamara Riehle