This technique provides a flexible and relatively inexpensive method and apparatus for continuous pressure mapping of aerodynamic surfaces. It is based on the use of a luminescent paint which consists of a phosphorescent compound, a platinum porphyrin dissolved in an oxygen permeable polymer. When the surface to be studied is coated with the paint and illuminated with ultraviolet light, it is observed to give a beautiful red luminescence. The intensity of the emitted light is found to be proportional to the inverse of the pressure at the surface because the air contains a constant fraction of oxygen independent of the total pressure. Luminescent images are captured with a CCD camera with computer interface.
Calibration is accomplished by obtaining a reference image with the wind tunnel fans off.
Compared to conventional pressure tap methods, luminescent barometry does not require drilling holes in the surface, provides a much faster response and maps the pressure over the entire surface. Figure Pressure profiles over the plane surface. Left half of plane describes the computational fluid dynamics model results. The right half of the plane reflects the pressures determined by pressure sensitive paint luminescence. Note the excellent agreement between experimental and theoretical results.