Wind Tunnel (CFD Sandbox)
A real computational-fluid-dynamics wind tunnel in your browser. Put a cylinder, an airfoil, a car or a building profile into the flow — or draw your own shape with the mouse — and a lattice-Boltzmann solver computes the air flow around it in real time. Smoke lines and dye show the flow field, a vorticity view reveals the swirling wake, and live gauges read out the drag and lift forces on your shape. Raise the wind speed and watch the wake go from smooth laminar flow to the rhythmic vortex street that makes flags flap, then tweak your shape and see the drag number drop — the same loop aerodynamicists run, minus the wind tunnel bill.
Runs 100% in your browser — simulations are computed locally on your device.
Read the full guide to this tool
Notes
- The solver is a D2Q9 lattice-Boltzmann method: instead of solving Navier–Stokes directly, particle populations stream and collide on a grid, and viscous fluid behaviour emerges — a method used in real engineering CFD.
- Drag and lift are measured the honest way, by summing the momentum exchanged between fluid and obstacle (momentum-exchange method), not from a lookup table.
- The von Kármán vortex street appears at moderate Reynolds numbers: the wake sheds alternating vortices at a regular beat — the reason chimneys get spiral strakes and power lines "gallop" in wind.
- Browser-scale CFD means a coarse grid and 2D flow: trends and flow patterns are physical, exact coefficients are not wind-tunnel-grade.
- Runs 100% in your browser — simulations are computed locally on your device.
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