Simultaneous measurement method of pressure and temperature using dual-layer PSP/TSP with lifetime-based method

Abstract

Recently, the application field of pressure measurement technique using pressure sensitive paint (PSP) has been expanding. However, temperature dependence of PSP is one of a serious obstacle to accurate pressure measurement in low gauge pressure condition because PSP is absolute pressure sensor. Therefore, temperature information of PSP is indispensably required for accurate pressure measurement, especially in low gauge pressure condition. As a result, both temperature information and pressure information with a function of temperature are required simultaneously to use the PSP in low gauge pressure condition. Dual-layer PSP/TSP (DL-PTSP) is one solution, but simultaneous measurement of pressure and temperature requires two optical filters to separate luminescence of PSP and TSP, resulting in complex equipment and additional error caused by parallax. To solve the problem, we introduce lifetime-based method for DL-PTSP that allows simultaneous measurement of pressure and temperature. It is a method to separate each component of luminescence with different lifetimes. At first, The DL-PTSP developed in this study was optimized by reducing the luminescence intensity of the PSP with longer lifetime while maintaining the luminescence intensity of the TSP with shorter lifetime, considering the lifetime measurement method. Secondly, we have clarified the optimum time conditions the monolayer TSP and the monolayer PSP by the analysis of their luminescence decay process, by controlling the irradiation delay of light source relative to camera shutter. Thirdly, sensitivity of the DL-PTSP using the conditions optimized for mono-layer TSP and PSP was examined. The luminescence decay of the TSP component shows sufficient temperature dependence, while pressure dependence is very small. On the other hand, the dependence of the luminescence decay of the PSP component on temperature and pressure is almost equal to that of the mono-layer PSP. The results confirm the feasibility of simultaneous measurement of pressure and temperature using DL-PTSP.

Lifetime based pressure and temperature sensitive paint measurement on a civil aircraft wing under conditions near the onset of shock-induced separation

“…The image acquisition (gate) timings, denoted by t i (j) , where i is the gate number and j is the start and end of the gate, must be selected carefully because they affect pressure and temperature sensitivities and signal-to-noise ratio [35,[41][42][43][44][45]. Sugioka et al [43] suggested the following four criteria to obtain better sensitivity characteristics and a higher signal-tonoise ratio for the two-gate method of PSP.…”

The Art of Fluorescence Imaging with Chemical Sensors: The Next Decade 2012–2022

“…For temperature compensation, which is required for accurate pressure measurements, Ru(phen) 3 , whose lifetime is in the order of µs, was added as a temperature indicator to a PSP composed of PtTFPP in poly(TMSP). The luminescence lifetime of the porphyrin is about one order of magnitude larger than that of Ru(phen) 3 , thus, simultaneous measurements can be carried out using lifetime-based methods [237]. PtTFPP in a porous polymer/ceramic binder served also as a PSP for unsteady measurement on a helicopter blade.…”

Temperature Dependency Model in Pressure Measurement for the Motion-Capturing Pressure-Sensitive Paint Method

“…However, such sensors acquire pressure information at a single point, which is insufficient for comprehensive study of a flow field. Pressure-sensitive paint (PSP) has received significant attention as a nonintrusive method for surface pressure measurements [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. The luminescent intensity of PSP is sensitive to the partial pressure of oxygen in a test gas due to a photophysical process called oxygen quenching [ 15 ].…”