Kelvin-Helmholtz Fluid Instability

🌊 KH Instability

Velocity shear ΔU: 1.0 m/s Density ratio ρ₂/ρ₁: 2.0 Wavenumber k: 2.0 Surface tension σ: 0.00

Growth rate γ—

Most unstable k—

Stable?—

e-fold time—

Kelvin-Helmholtz
γ = k·U/2 − √(k²g·Δρ/ρ̄ − k²U²/4·ρ₁ρ₂/ρ̄²)
Two fluid layers with velocity difference U. Surface waves amplified by shear → vortex rollup.