Simultaneous 2D temperature and velocity measurement using a one-color-camera PLIF method combined with a physically constrained temperature tagging method

A time-resolved two-color laser induced fluorescence method is proposed for simultaneous 2D temperature and velocity measurements for complex multi-phase flow. A temperature sensitive dye molecule is used for temperature and velocity tagging at the same time. To effectively eliminate the temperature deviation due to image misalign-ment, which is commonly seen at the multi-phase boundary, a one-color-camera system is proposed that can decrease the temperature deviation from 30 degrees C-50 degrees C to <10 degrees C near the two-phase flow boundary with a high contrast ratio (0.41-0.43). Considering the strong influence of the thermal diffusion and convection processes to photo luminescence images' intensities, which can lead to significant velocity calculation deviation, a physically constrained temperature tagging method is introduced. Through both a theoretical model and measurement results, the relative velocity deviation can be decreased from 77.6% to <10% by this method. This work can effec-tively improve the temperature and velocity measurement accuracy of a temperature sensitive particle/molecule tagging method in multi-phase flow with strong coupling of temperature and velocity.(c) 2022 Optica Publishing Group