FILM-BASED PRESSURE-SENSITIVE-PAINT MEASUREMENTS

A technique to measure surface pressure distributions by use of pressu re-sensitive paint and a novel film-based imaging system is described. An oxygen-permeable photoluminescent paint is excited by narrow-band light centered at 455 nn. The resulting red-shifted luminescence (>570 nm) is imaged with a 35-mm film camera and digitized with a film scan ner. The luminescence is quenched by oxygen, resulting in a logarithmi c relationship between film density and pressure. An image collected a t a reference condition is subtracted from an image obtained at the te st condition and calibrated with known pressures. The resulting images are, to our knowledge, the first quantitative global surface measurem ents made with pressure-sensitive paint by a film-based imaging techni que. (C) 1996 Optical Society of America.