Investigation of Temperature Sensitive Paint Formulation for the Use from Cryogenic to Ambient Condition

Abstract

The prediction of the boundary-layer transition is more important nowadays in the aircraft design for reduction of flight-related carbon dioxide emissions through the use of natural laminar flow technology. Temperature Sensitive Paint (TSP) is a useful optical measurement technique for visualization of the boundary-layer transition on a model surface. Currently single-component TSP (1C-TSP) has been commonly used for the visualization of the boundary-layer transition in the cryogenic temperature range but it is hard to use the same TSP in the ambient temperature due to reduction of the luminescent intensity. In a previous work, two-component TSP (2C-TSP) had been developed with a combination of two luminophores: one is suitable for the cryogenic temperature and another is for the ambient. This 2C-TSP could extend the application range from cryogenic to ambient temperature. However, this 2C-TSP requires two different excitation light wavelengths, one for each TSP luminophore. In this study, new candidates of the temperature molecules for 2C-TSP were investigated for the use from the cryogenic to ambient temperature. It is desirable to use the same excitation light around 470 nm wavelength for two luminophores as well as the same emission light wavelength for the same camera system. The spectra, the luminescent intensity and the temperature sensitivity of 2C-TSPs were investigated for different combinations of luminophores.