PPolySim OS

3D CFD

Fluid dynamics in three dimensions. A dye plume rises and rolls through a fully 3D incompressible flow — scrub through z-slices to see inside the volume.

3D CFD StudioLive

Controls

A dye plume rises through a full 3D incompressible flow. Scrub the z-slice to inspect the volume.

Presets

▶ Run in Python

Data Inspector

Grid24³
Cells17,576
SchemeStam Stable Fluids
IncompressibleJacobi projection

Governing equation

Reading this result: At moderate force (30) the incompressible constraint is visible: each step the projection removes divergence, so fluid pushed up the center must fold back down along the sides.

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How it works

This extends Jos Stam's Stable Fluids method to a full 3D grid: three velocity components and dye density are diffused, advected with a 3D semi-Lagrangian scheme, and made incompressible by a Jacobi pressure-projection step that enforces a divergence-free field. It's genuine 3D Navier–Stokes, running on your device — the kind of volumetric CFD that normally needs a workstation.

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Frequently asked questions

Is this 3D CFD simulation tool really free?
Yes. 3D CFD runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.