Urban Wind Simulation

What Urban Wind Simulation does

A design-stage screening of pedestrian wind comfort at urban / building-block scale. It solves the wind flow around your massing for each wind direction, combines the results with your site's wind rose, and colours the ground plane by how comfortable it is to sit, stand or walk there across the year — plus a wind-safety check for dangerous gust spots.

Input:

.3dm / .obj massing + EPW weather file

Engine:

Browser GPU CFD

Output:

Annual comfort map at 1.5 m + safety check

How it works

A real CFD solve runs in your browser on the GPU, then the directional results are weighted by your local wind climate into an annual comfort statistic per location.

• A GPU fluid solver runs each wind direction in your browser; checked against OpenFOAM.
• Each direction gives the wind speed at pedestrian height relative to the free wind.
• Your EPW becomes a wind rose, so the annual statistic reflects how often each direction blows and how hard.
• Cells are classified by Lawson LDDC / NEN 8100 / Davenport, with a danger check for gust spots.
• No GPU? A fast parametric estimator (wakes, corner acceleration, channelling) gives an approximate map.

How to use it

1. Upload your massing. Drop a .3dm (or .obj) of your building plus the surrounding context.
2. Load the site climate. Add an EPW weather file — the wind rose and speeds come from it.
3. Pick fidelity & directions. Choose draft / standard / fine and how many wind directions to solve.
4. Run the study. Each direction solves in turn; a draft map appears first, then sharpens.
5. Read the comfort map. Colours show sit / stand / stroll / walk comfort; click a spot for detail.
6. Export. Download the comfort map, CAD contours, or a PDF report.

Best used for

• Comparing massing or podium options for street-level windiness.
• Finding uncomfortable entrances, plazas and gap-between-buildings spots early.
• Orienting screens, canopies and planting before detailed design.
• Scoping whether a site needs a formal wind-tunnel study.

Not a substitute for

• A substitute for an accredited wind-tunnel test or certification-grade CFD.
• Thermal / buoyancy-driven (stack) wind effects — the solve is isothermal.
• Sign-off on a marginal site from a single coarse 4-direction run.

Known limits

• Accuracy depends on grid resolution and how complete the surrounding context model is.
• Gust / safety speeds are approximated from turbulence intensity, not directly resolved.
• The no-GPU fallback is qualitative — clearly labelled 'Approximate'.

Read the full Urban Wind Simulation guide →