Div & Curl Lab

Interactive simulation to estimate divergence and curl of a vector field
© 2026 Stephan Pfannerer

Estimated Curl
0.00 k̂
Time
0.0
Speed 1.0x

Vector Field

Object Position

Simulation

5.0

Visuals

How it works

Select a simulation mode, then click on the canvas to place an object.

  • Divergence Mode: Places a deformable probe with a fixed center. Divergence is estimated from the probe's initial area change. The simulation runs for a fixed time, plotting log(Area) vs. Time live. The red line shows the theoretical change based on the estimated divergence.
  • Curl Mode: Places a paddlewheel that spins according to the local curl of the field. The curl is estimated by measuring the forces on the vertices of a tiny virtual polygon. The curl value is displayed with a k̂ unit vector, indicating its direction perpendicular to the 2D plane.