Testing of aircraft models in wind tunnels gives valuable insight into aerodynamic behavior. Although much of aircraft design is now accomplished using computational fluid dynamics (CFD), wind tunnel testing is still necessary to validate CFD models. In the past, pressure measurement was limited to a few key locations on the model where mechanical pressure transducers could be placed. Now optical measurements of pressure can be done using "pressure-sensitive paint" or PSP. A wind tunnel model is covered with a paint formulation that fluoresces under short-wavelength excitation. As pressure is increased, collisions between oxygen and fluorescing paint quench the fluorescence. The change in fluorescence intensity can be used to calculate a pressure map of the surface.
Roper Scientific cameras are used to record the fluorescence. Both front- and back-illuminated CCDs are used, with large-pixel full well capacity being a common requirement. This allows maximum signal-to-noise ratio to be achieved, which is necessary to measure small changes in fluorescence.
Multiple-camera control from a single host computer, accurate and calibrated response, and a reputation for reliability in demanding environments are just some of the reasons why Roper Scientific cameras are used in all of the world's premier wind tunnel testing facilities.