Ruthenium-based fast-responding pressure-sensitive paint for measuring small pressure fluctuation in low-speed flow field

A sprayable fast-responding pressure-sensitive paint (fast-PSP) has been developed to measure time-resolved small pressure fluctuation on model surfaces. To realize PSP with fast response, high robustness, and high luminescence intensity, we have developed a novel ruthenium complex-based fast-PSP. The binder layers of the proposed fast-PSP were prepared by mixing room-temperature-vulcanizing silicone (silicone) and titanium dioxide (TiO2) particles with different sizes and their effects on the properties including the time response, pressure sensitivity, and luminescence intensity were investigated. The effects of the hydrophilic and hydrophobic surface treatments of TiO2 particle on the structure and mechanical robustness of the binder layer were also studied. The developed fast-PSP was applied to the flow field measurements behind a square cylinder and was evaluated. We have succeeded in obtaining time-series data of pressure fluctuation with high accuracy even at a mean velocity of 20 m s−1.