Wind NS

Full 3-D Incompressible Navier–Stokes · wind on terrain

Coarse: fast preview (41×41×20, 30 p-iter).
Refined: high precision (DEM res, 40 NZ, 80 p-iter).

Ambient Wind

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

Wind speed (m/s)

Wind speed (km/h)

Far-field wind at 100 m AGL. Logarithmic profile applied to inflow boundaries.

3-D Grid

Sim NX (W–E cells)

Sim NY (S–N cells)

Vertical levels NZ

Domain top (m AGL)

NX×NY: simulation horizontal resolution (DEM is bilinearly resampled). Populated from DEM after fetch. Domain top above highest terrain point.

Wind Profile (Log Law)

Roughness z₀ (m)

Ref. height z_ref (m)

Fallback z₀ used when no land cover is loaded. When land cover is fetched, each cell gets its own z₀ from ESA WorldCover. z_ref = height AGL where wind = U_ref.

NS Parameters

Viscosity ν (m²/s)

Pressure iter.

ν = turbulent kinematic viscosity. Jacobi iterations per step; increase for accuracy.

Solver

Sim time (s)

CFL (semi-Lagr.)

Max dt (s)

Diff. safety α

Pressure yield (iter)

CFL up to ~2.5 with semi-Lagrangian. dt = min(CFL·Δx/U, α·Δx²/ν, max_dt). Pressure yield: Jacobi iters between UI refreshes.