Application of PSP to low density gas flows
Recently optical pressure measurement systems using pressure sensitive paints (PSP) have actively developed to measure continuous pressure distributions on solid surfaces. However, the pressure range has been almost limited above 130 Pa (about 1 Torr) and there is no application to lower pressure range because the pressure sensitivity seems to be not so high in that range. In this study, we have applied three types of PSP [two types are composed by organic dye and polymer (luminophore/binder); PtOEP/GP197 and PtTFPP/poly(TMSP), and another one is Bath-Ru adsorbed on anodized aluminum] to the rarefied gas flow mainly lower than 130 Pa and examine those fundamental properties such as pressure sensitivity, leading to selection of the most suitable PSP among them for the low-pressure range. Since PtTFPP/poly(TMSP) has the highest sensitivity, it is applied successfully to the measurement of the two-dimensional pressure distribution on the surface interacting with a low density supersonic free jet.
psp low density gas flow stern-volmer plot compressible flow