Three-Gate Lifetime Imaging System for Pressure-Sensitive Paint Measurements

A lifetime imaging system to measure simultaneously pressure and temperature images from a luminescent lifetime decay of pressure-sensitive paint (PSP) has been developed. The dependence of the luminescent lifetime decays on pressure and temperature was clarified by analysis of PtTFPP PSP using a streak camera. The method is proposed to acquire pressure and temperature images from three luminescent images. The three gated times of an intensified charge-coupled device camera were determined, referring to the analysis of streak camera data. The performance of the measurement system was evaluated over the wide range of pressures and temperatures using a PSP-coated coupon. The ratioed lifetime images could be fitted with a smooth function of pressure and temperature. This allowed reconstruction of pressure and temperature images from three luminescent lifetime images. As a verification test, pressure and temperature distributions induced by a sonic-jet impingement flow were visualized. PSP data agreed with pressure tap data, indicating that this lifetime imaging system was a useful tool to measure pressure and temperature fields on an aerodynamic model surface.