Eddy Current Brake: Force–Velocity Curve

This simulation models a linear eddy-current rail brake — the same contactless braking principle used on high-speed trains and roller-coaster linear brakes. A magnet array is fixed above a conductive rail; as it slides along, relative motion induces eddy currents in the rail that generate an opposing (braking) force with no physical contact. Rather than a simple "more speed, more drag" relationship, the modeled force follows the real engineering force–velocity curve: it rises roughly linearly at low speed, peaks at a material-dependent critical velocity, and then falls off at high speed as the eddy currents' own self-inductance opposes further current growth. Switch between copper, aluminum and steel rails, and adjust flux density and air gap, to see how each shifts the peak and reshapes the deceleration.