Effect of Oxygen Mole Fraction on Static Properties of Pressure-Sensitive Paint

TL;DR

This study investigates how varying oxygen mole fractions affect the static properties of different pressure-sensitive paints, revealing optimal oxygen levels for accurate pressure measurements depending on the PSP type and ambient conditions.

Contribution

It provides a detailed analysis of the relationship between oxygen mole fraction and PSP properties, introducing a method to determine optimal oxygen levels based on partial pressure.

Findings

$B_{local}$ peaks at different oxygen partial pressures depending on PSP type.

Optimal oxygen mole fraction varies with ambient pressure and PSP type.

Intensity change with pressure is affected by oxygen partial pressure, influencing measurement accuracy.

Abstract

The effects of oxygen mole fraction on the static properties of pressure-sensitive paint (PSP) were investigated. Sample coupon tests using a calibration chamber were conducted for polymer-based PSP (PHFIPM-PSP), polymer/ceramic PSP (PC-PSP), and anodized-aluminium PSP (AA-PSP). The oxygen mole fraction was set to be between 0.1-100% and the ambient pressure was set to be between 0.5-140 kPa. The localized Stern-Volmer coefficient $B_{\rm local}$ once increases and then decreases as the oxygen mole fraction increases. The value of $B_{\rm local}$ depends on both ambient pressure and oxygen mole fraction, but the effect of this parameter can be characterized as a function of the partial pressure of oxygen. The value of $B_{\rm local}$ of AA-PSP and PHFIPM-PSP, which are low-pressure type and relatively low-pressure type PSP, have a peak at the relatively low partial pressure of oxygen, and $B_{\rm local}$ of PC-PSP, which are atmospheric pressure type PSP, has a peak at the relatively high partial pressure of oxygen. The peak of the intensity change with respect to pressure fluctuation proportional to the ambient pressure $S_{\mathcal{PR}}$ appears at the lower partial pressure of oxygen than that of $B_{\rm local}$. This is because the intensity of PSP becomes quite low at the high partial pressure of oxygen even if $B_{\rm local}$ is higher. Hence, an optimal partial oxygen mole fraction exists depending on the type of PSP and ambient pressure range of the experiment, and its optimal value can be found based on the partial pressure of oxygen.