Spiral waves and target patterns in the BZ reaction. The 2D Oregonator model captures the excitable medium dynamics producing chemical oscillations.
Initial condition
Excitability ε0.10
Stoichiometry f1.40
Diffusion D_u1.00
Time step dt0.10
Grid size
t = 0.0
Center u = —
Oregonator (Field-Körös-Noyes 1972):
ε ∂u/∂t = u(1−u) − fv(u−q)/(u+q) + D∇²u
∂v/∂t = u − v
where u = HBrO₂ (activator), v = Ce⁴⁺/Ferroin (inhibitor), q = 0.002. Spiral tip: rotates with period T ≈ 2πε/√(f−1). Smaller ε → faster rotation, tighter spiral. Click the grid to add perturbations and nucleate new waves.