Affiliations: Lehrstuhl für Strömungslehre,
Universität GH Essen, D-45117 Essen, Germany | Heat & Mass Transfer Institute, Minsk, 220072,
Belarus
Abstract: A speckle photographic technique is used for visualizing the planar
distribution of the refractive deflection angles of light transmitted through
the compressible turbulent flow in a shock tube. Illumination by a short laser
pulse allows to freeze the instantaneous pattern of the deflection angles as
caused by the turbulent fluctuations of the gas density. Turbulent structures
are visible in the patterns of the deflection angles' isolines. A normal shock
wave propagating through the turbulent density field causes structural changes
of the observed patterns, which is quantified by determining the spatial
correlation functions of the deflection angles.