Fluid Vortex Dynamics

Point vortex system — Hamiltonian mechanics: dxᵢ/dt = -∂H/∂yᵢ, dyᵢ/dt = ∂H/∂xᵢ

Controls

System State

H = —
Vortices: 0

Physics

H = -1/4π Σᵢ<ⱼ ΓᵢΓⱼ ln|rᵢⱼ|

Conserved quantities:
• Hamiltonian H
• Linear impulse Σ Γᵢxᵢ
• Angular impulse Σ Γᵢrᵢ²

Vortex pairs (Γ>0, Γ<0) → straight propagation. Same-sign → orbit center of vorticity.