A Wind Tunnel Wing That Glows Pink-Purple So Cameras Can Watch the Air

NASA describes a test at its Langley Research Center's Transonic Dynamics Tunnel as a first of its kind for that tunnel: researchers used unsteady pressure-sensitive paint to study how air flows around a standard wind tunnel model known as the Benchmark Supercritical Wing.

The paint is the visible part of the trick. Exposed to special ultraviolet lights, it made the model wing glow pink-purple as the test ran, while high-speed cameras captured the details. The glow isn't decoration — it's the measurement, a surface that reports on the air moving over it in a form a camera can record.