The use of pressure sensitive paints on rotating machinery

Abstract

The current work involves measuring the surface pressure on a rotating blade with a laser scanning pressure paint system. The pressure paint consists of a fluorescent molecule which is mixed with a binder than painted on the surface of interest. The laser is scanned across the model surface which excites the fluorescent molecule. The intensity with which the molecule emits light is dependent on the amount of oxygen quenching and therefore the local air pressure. The system can be calibrated in two ways. The first would be to take an intensity reading with the known pressure and then take a reading at the condition of interest. The Stern-Volmer relationship of intensities is used to calculate the pressure. A second way is to measure the decay time of the emitted intensity and calibrate that versus pressure. The purpose of the experiment is to get a complete surface map of the pressure on the rotating blade.