2D Fluid Simulation

Navier-Stokes with vorticity — click to inject fluid

Incompressible Navier-Stokes: ∂u/∂t + (u·∇)u = −∇p/ρ + ν∇²u, ∇·u = 0. Solved with a stable fluids approach (Stam 1999): advect velocity backwards in time (semi-Lagrangian), diffuse with implicit solve, then project onto divergence-free field via Helmholtz decomposition. The vorticity colormap shows rotation (red=clockwise, blue=counter-clockwise). Click/drag to inject momentum. Reynolds number Re = UL/ν — decrease viscosity for more turbulent behavior.