Experiments on the thermal stratification in the branch of NPP

Simultaneous 3D temperature and velocity field measurements of micro-flow with laser-induced fluorescence and micro-digital holographic particle tracking velocimetry: Numerical study

“…This is due to the lack of a temperature sensor that is efficient at arbitrary depth positions. Commonly, some nonintrusive methods such as laser-induced fluorescence (LIF) [7,8] or thermo-liquid crystal (TLC) [9] thermometry are only efficient when the test area is in the focal plane, rendering them 2D techniques. Recently, defocused two-color LIF [10] and astigmatic TLC [11] imaging methods have been developed to estimate the 3D temperature field.…”

“…In two-color LIF thermometry, the fluorescence intensity of the temperature-sensitive dye is usually dependent on temperature, while the temperature-insensitive dye is used as the reference dye. The intensity ratio of the two fluorescence emissions on a tracer particle is used to determine the temperature and can be directly expressed as [8]…”