PPolySim OS

2D Fluid Simulator (CFD)

Stir a real fluid in your browser. Click and drag to inject dye and momentum into an incompressible Navier–Stokes field and watch vortices, mixing, and turbulence emerge.

2D Fluid (CFD) StudioLive

Controls

Click and drag on the canvas to inject dye and velocity.

Presets

▶ Run in Python

Data Inspector

Grid96×96
Total dye0
Mean speed0.000
Max speed0.000
Enstrophy0.00e+0

Governing equation

Reading this result: Near-zero viscosity: momentum barely dissipates, so vortices persist and the flow tips into turbulent, chaotic mixing.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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How it works

This solver implements Jos Stam's Stable Fluids method: semi-Lagrangian advection for unconditional stability, Gauss–Seidel diffusion for viscosity, and a Jacobi pressure-projection step that enforces incompressibility (a divergence-free velocity field). It's the same algorithm family behind film-VFX fluids and browser CFD demos, running live on a grid on your device.

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Frequently asked questions

Is this fluid simulation tool really free?
Yes. 2D Fluid Simulator (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.