Simultaneous temperature and 2D velocity measurements in a turbulent heated jet using combined laser-induced fluorescence and LDA

This paper presents an efficient technique for the characterization of ther mal transport properties in turbulent flows. The method is based on the tem perature dependence of fluorescence, induced by laser radiation, of an orga nic dye. The laser-induced fluorescence technique is combined with 2D laser Doppler anemometry, in order to measure in the same sample volume simultan eously and instantaneously the temperature and velocity. The technique is d emonstrated on a turbulent heated round jet: the mean and fluctuating dynam ic and thermal fields are investigated, and the temperature-velocity cross- correlations are determined in order to characterize the turbulent diffusiv ity and the turbulent Prandtl number.