Laser Refractography: Principles and Applications in Studies of Thermophysical Processes in Liquids

摘要

This paper is devoted to the description of the method of laser refractography and the results of its application in experimental studies of physical processes in transparent liquids. Laser refractography is a novel information-measurement technique for diagnosing transparent optically inhomogeneous liquids and gases, based on the probing of fluid flows with a structured laser radiation (SLR), digital recording of the refraction images (refractograms) obtained, and their computer processing with a view to reconstructing the parameters of the flows. Block diagrams of measuring laser systems are shown, their operating principles are described, and libraries of typical refracrograms are presented. Laser refractography has been used to visualize temperature gradients in thin boundary layers in the vicinity of heated of cooled bodies placed in a transparent liquid, to determine the heating or cooling time of various bodies in liquids, to establish the setting time of laminar and turbulent convection conditions, and to find out the position of local temperature changes in liquids.