Thermophysical Properties of Pressure-Sensitive Paint

• Published in: Thermochimica acta 2023-12, Vol.730, p.179612, Article 179612
• Main Authors: Panas, Andrzej J., Szczepaniak, Robert, Wit, Stryczniewicz, Omen, Łukasz
• Format: Article
• Language: English
• Subjects: complex thermophysical study; heat capacity; pressure-sensitive paint; thermal conductivity; thermal diffusivity; thin layer properties
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/j.tca.2023.179612

•Complex thermophysical property study for the Pressure Sensitive Paint were conducted•Effective thermal diffusivity (TD) was obtained for a thin layer specimen detached from a substrate•Temperature oscillation study revealed relatively high TD values around 1.25 mm2/s•The TD results were complemented by specific heat values from DSC measurements The paper deals with the problem of the thermophysical properties of pressure-sensitive paint (PSP). The paint was used to determine the pressure distribution on the surface of models examined in wind tunnel aerodynamic tests. The aim of the study was to provide reliable data on the values of thermophysical parameters and their dependence on temperature. PSP is a thin-film structure that is applied layer by layer a specific number of times on a metallic substrate, and determining the thermal properties requires non-standard test procedures to obtain reliable results. The measurements were carried out on paint fragments separated from the flat substrate of a metallic thin film (molybdenum), from which samples were obtained for complementary studies of the thermophysical properties. The study includes weight measurements, thermogravimetric analysis, micro-calorimetric analysis, and measurement of effective thermal diffusivity using the temperature oscillation technique. The findings are complemented with structural test data collected by means of scanning electron microscopy, surface characterisation, and density determination by the displacement method. The analysis of the structural test data indicates the micro-structural isotropy of the examined material with geometric anisotropy of the layer as a whole. In this way, the results of thermal diffusivity tests can be properly evaluated, and reliable data can be obtained on the complete thermophysical properties of the PSP layer. The indirectly determined thermal conductivity, i.e., by recalculating the specific heat, density, and thermal diffusivity data, allows the test material to be classified as an insulator. Apart from the presentation of the test results and calculations, this paper also contains a brief discussion of the test procedures.