New insight into two-color LIF thermometry applied to temperature measurements of droplets

• Published in: Experiments in fluids 2010-08, Vol.49 (2), p.547-556
• Main Authors: Labergue, A., Deprédurand, V., Delconte, A., Castanet, G., Lemoine, F.
• Format: Article
• Language: English
• Subjects: Applied sciences; Dissolution; Droplets; Energy; Energy. Thermal use of fuels; Engineering; Engineering Fluid Dynamics; Engineering Sciences; Engineering Thermodynamics; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fluid- and Aerodynamics; Fluorescence; Heat and Mass Transfer; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics; Reactive fluid environment; Research Article; Spectra; Spectral bands; Sprays; Temperature measurement; Thermal instruments, apparatus and techniques; Thermometry; Tracers
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/s00348-010-0828-x

When laser-induced fluorescence of droplets is used for measurements such as droplet temperature, a new dependence of the droplet size on the spectral distribution of fluorescence has been highlighted. The two-color laser-induced fluorescence technique applied to droplet temperature measurement requires a single fluorescent tracer and two spectral bands of detection for which the temperature sensitivity is different. Generally, the ratio of the intensities measured on each of the spectral bands of detection is assumed to be only temperature dependent. However, droplet dependence on diameter is also likely to influence the intensities ratio. This study provides some illustrations of the phenomenon, first on sprays with different mean statistical diameters and secondly on single droplets, for two temperature-sensitive fluorescent tracers in their solvents: sulforhodamine B dissolved in water and pyrromethene 597-8C9 dissolved in n-decane.