Angle of Attack

Angle of attack changes lift and drag. Flaps change camber and low-speed performance.
A stall begins when airflow can no longer stay attached to the wing.

Scenario

You are testing a classroom airfoil model based on the Piper Cub. Change the angle of attack, flap deflection, and airspeed, then watch how the flow field and force indicators respond.

Use the display to compare attached flow, high-lift flap settings, and stall behavior. The black test area stays isolated so students can focus on the aerodynamic changes.

AoA: 0.0°
Cl: 0.00
Cd: 0.000
L/D: 0.0
q-scale: 1.00×
ATTACHED FLOW — NORMAL FLIGHT
Angle of Attack
AoA 0.0°
Flap Deflection
Flap 0°
Airspeed
Speed 100%

What You Are Seeing

The blue traces represent airflow around the wing. Green and red arrows show lift and drag. The HUD reports coefficients, while airspeed changes only the visual force scale.

Try this: Start at 0° angle of attack. Then raise AoA toward 12° and compare the airflow pattern with the changing lift coefficient. Add flap to see how the high-lift configuration changes the result.

Vocabulary

Angle of Attack

The angle between the wing chord line and the incoming airflow. Raising angle of attack usually increases lift at first, but only up to a critical point. Beyond that point, the wing can stall.

Attached Flow

Airflow that follows the contour of the wing surface. Attached flow allows the pressure pattern around the wing to stay organized, which supports strong lift and predictable handling.

Lift

The aerodynamic force that acts roughly perpendicular to the oncoming airflow. In this demo, the lift arrow grows with coefficient and airspeed scale, but the displayed Cl remains a true coefficient.

Drag

The aerodynamic force that resists motion through the air. Drag usually rises with both angle of attack and flap deflection, and it rises sharply once the wing approaches stall.

Stall

A condition where the airflow can no longer remain attached over enough of the wing surface. Lift drops, drag rises, and the wake becomes more turbulent. A stall is caused by angle of attack, not just low speed.

Flaps

Trailing-edge surfaces that increase the effective camber of the wing. Flaps improve low-speed lift, but they also add drag and can slightly change the wing's critical angle behavior.

Coefficient

Lift coefficient (Cl) and drag coefficient (Cd) are dimensionless values that describe aerodynamic performance independent of scale. They are not the same thing as force, which also depends on dynamic pressure.

L/D Ratio

The lift-to-drag ratio compares useful aerodynamic force to aerodynamic cost. Higher L/D generally indicates more efficient flight, while lower L/D often appears at high-drag or stall-like conditions.