Ground effect on an airfoil

The last of my steady-state animations before some far more interesting unsteady flows ;-) (code almost done). This video shows the effect of a ground plane on an aerofoil. The ground plane is created by having an image of the aerofoil below the ground, thereby creating a line of symmetry which is itself the ground plane. No flow crosses this plane. In terms of magnitude, the pressure field is considerably enhanced by the presence of the ground (here at 0.35c below the leading edge point). The result at positive angles of attack helps explain the phenomenon of light aircraft "floating" down the runway before touchdown. The augmented high pressure beneath the wing generates extra lift keeping the plane aloft despite reduction of speed. This effect increases nearer the ground. Also, the result at negative angles of attack explains the use of ground effect in some racing car underbody designs to dramatically increase suction toward the ground.

Category:

Education

Tags:

• airfoil
• aerofoil
• panel method
• inviscid
• fluid dynamics
• potential flow
• Laplace
• incompressible
• wing
• lift
• Kutta condition
• circulation
• vortex panel
• angle of attack