faster
than the wind slower
stalled air

Surface pressure · Cp

A wind tunnel for things

Air blows in from the left. Put something in its way and watch what happens to the flow — and to the thing.

1. Pick something from the list and it drops in, held in place.
2. Drag it around; the orange handle turns it.
3. Hit Start the wind and watch the air bend around it.
4. Hit Let them go and the wind takes over.

Let me in

The airflow is a real fluid simulation running in your browser, and the drag readings are measured from it — though it's two-dimensional and scaled to fit a screen, so treat the numbers as honest about the tunnel rather than about a real cow. Object shapes from game-icons.net (CC BY 3.0).