Wind

2-D Shallow-Water Equations · wind on terrain

Ambient Wind

0° from SW
U = +6.1 m/s V = +5.3 m/s
Drag the compass to change

Wind speed (m/s)

Ambient far-field speed. Inflow applied on all upwind boundaries.

Sim zoom 11 ≈ 56 m/px. Mesh zoom for 3-D viewer only.

Atmospheric Layer

Layer depth H₀ (m)

Red. gravity g′ (m/s²)

Mountains taller than H₀ block flow. g′ controls wave speed and hydraulic-jump Froude.

Friction & Diffusion

Drag C_d

Viscosity ν (m²/s)

C_d = bottom roughness. ν = turbulent diffusion (prevents sharp shocks).

Solver

Sim time (s)

CFL factor

Min depth h_min (m)

3600 s ≈ 5 domain transit times at 8 m/s → near-steady state. h_min is the wet/dry threshold — lower values resolve thin flow over ridges but may destabilise.

Output

Arrow step (px)

Arrow min speed (m/s)

Arrow step: density (every N-th cell). Min speed: hide arrows below this threshold.