Potential Flow over a NACA Four-Digit Airfoil

Geometry parameters for a NACA four-digit airfoil

maximum camber digit

4

maximum thickness digits

12

discretization number

12

angle of attack α in degrees

8.

plot

aerodynamic properties

flow visualization

Flow visualization and surface pressure coefficient are plotted for potential flow over a member of the NACA four-digit family of airfoils. The geometry of the airfoil is controlled by varying the maximum camber and thickness. Controls are also available for discretizing the airfoil for the numerical computation, and for the angle of attack (

α

) the airfoil makes with the uniform onset flow. A panel method using straight-line vortex panels of linearly varying strength and external Neumann boundary conditions provides the potential-flow solution.

The default graphic is a plot of the surface pressure coefficient. The plot includes values for the lift coefficient

C

ℓ

, pitching moment coefficient about the leading edge

C

m

, and location of the center of pressure

x

cp

. The yellow dot on the graph shows the location of the center of pressure. Alternatively, you can chose to display a flow visualization graphic showing a stream plot of the velocity field. This is an important check on the plausibility of the potential-flow solution.