INTRODUCTION Pressure-sensitive pai

INTRODUCTION Pressure-sensitive paint (PSP) is employed to obtain a visual map of air pressure on the surface of models placed in a wind tunnel.1–5 Conventional PSP consists of a luminescent dye embedded in a film of an oxygen-permeable polymer, such as polysiloxane,6–10 fluorinated polymers11–21 such as poly(isobutyl methacrylate-co-2,2,2-trifluoroethyl methacrylate) [poly(IBM-co-TFEM)] or polyacetylenes such as poly(3-trimethylsilyl-1-propyne).22 When the luminescent dye is excited, the luminescence intensity reflects the local concentration of a quencher, i.e., oxygen molecules (O2). The local O2 concentration is proportional to the local air pressure if Henry’s law holds. Consequently, an air pressure map at the sur- face of a model can be obtained by measuring and analyzing the luminescence image from a PSPcoated model. However, the luminescence intensity depends not only on the local O2 concentration, but also on the local temperature, and appropriate correction for the temperature effect is critical to obtain an accurate air pressure map.