Home▸Physics & Mechanics▸Kite Flight Physics (2D): Lift, Torque & a Sagging Tether

Kite Flight Physics (2D): Lift, Torque & a Sagging Tether

A 2D rigid-body kite driven by real lift/drag from its angle of attack, tension-only torque from an off-centre bridle point, and a Verlet-simulated tether that sags under its own weight — dial the wind, reel the line and launch to see it settle into flight.

Physics & Mechanics2DModerate60 FPS📱 Mobile-adapted⇄ 3D version

This 2D companion keeps the 3D original's full rigid-body model instead of simplifying it away: lift and drag are computed from the angle of attack between the kite's face and the relative wind, the only torque on the kite comes from tension pulling on an off-centre bridle point so it genuinely weathervanes on its line, and the tether is its own Verlet-simulated chain that sags under gravity rather than a straight rod — reel the line in and out, dial up the gusts, and launch to watch it settle into a stable flying angle.

⚙ Under the hood

Lift coefficient sin(2·AoA) and a stall-shaped drag curve act through the kite's centre of mass; a spring-damper tether tension at an offset bridle point is the sole source of torque; the tether line is a separate Verlet-integrated chain of segments that sags under gravity.

kite flightaerodynamicslift and dragtorqueverlet integrationtether tension

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install