Abstract
Porous pressure sensitive paint (PSP) having fast response and high pressure sensitivity will be a powerful measurement tool to diagnose flow properties in consumer turbomachinery. We have composed test facilities of a turbofan with a transparent casing, to apply a fast-response PSP to measurement of nonstationary pressure distribution on the casing surface of the turbofan. However, luminescent intensity of the PSP without a white undercoat acting as a screen layer is relatively low, which results in low signal-to-noise ratio for pressure measurement. In this study, we have examined the effect of white overcoat with high oxygen permeability made of boron nitrate (BN) nanoparticles, which functions as a screen layer to enhance the luminescence intensity of the PSP through a transparent surface. We have clarified that the BN overcoat can enhance the luminescence intensity and SN ratio of PSP without affecting the time response.