Surface pressure measurements using luminescent coatings

An optical technique is described that is often used nowadays to measure su rface pressures on wind tunnel models and flight vehicles. The technique us es luminescent coatings, which are painted on the model surface, excited by light of appropriate wavelength, and imaged with digital cameras. The inte nsity of the emitted light is inversely proportional to the surface pressur e. Hence, the surface pressures can be measured efficiently and affordably with a high spatial resolution. The theory and chemistry of how such coatin gs work and the parameters that affect them are presented. The required har dware and software are described, with emphasis on the different measuremen t systems and procedures. The various error sources are discussed, and corr ection schemes that can be used to minimize them are presented. Sample resu lts, covering a wide range of conditions and applications, are presented an d discussed.