In this paper, a new pressure-sensitive paint (PSP) formulation using a high polymer called poly (TMSP) is presented and its optimization for cryogenic wind tunnels is discussed. In our earlier work, we proved the feasibility of poly (TMSP)-PSP for pressure measurements at low temperature in low-oxygen environment of the cryogenic wind tunnel. However, we also found it difficult with this paint to achieve stable pressure measurements because its oxygen sensitivity was changed from a test to a test. In order to solve this problem, PSP samples with different polymer concentrations in solvent and/or dye concentrations were prepared and calibrated in air, low-Oxygen, and cryogenic conditions. We found from these systematic tests that the characteristics of poly (TMSP)-PSP was sensitive to its preparation procedure, particularly to polymer concentration in solvent. The PSP exhibited high sensitivity to oxygen when its polymer concentration was higher than a certain critical value. This dependency on polymer concentration was observed only at oxygen concentrations lower than 1000ppm. The sample tests at cryogenic temperatures showed that Poly (TMSP)-PSP had the maximum oxygen sensitivity when its polymer concentrations in solvent was from 8 to 10mg/ml. It was also found that dye concentration in PSP had an influence on the shape of a Stern-Volmer curve. To validate the results obtained from the sample tests, poly (TMSP)-PSP with the optimized formulation was tested on a circular-arc bump model in the NAL 0.1-m Cryogenic Wind Tunnel. It was confirmed that the optimized poly(TMSP)-PSP could provide a stable and high signal-to-noise pressure data at the temperature of 100 Kelvin and the oxygen concentration of 1000ppm.
|Number of pages||9|
|Journal||ICIASF Record, International Congress on Instrumentation in Aerospace Simulation Facilities|
|Publication status||Published - 2001|
ASJC Scopus subject areas
- Aerospace Engineering
- Condensed Matter Physics