Influence of turbulent fluctuations of refractive index on PSF

摘要

Statistical properties of a turbulent flow have been investigated experimentally in a shock tube with a turbulence grid. The fluctuations of the refractive index were detected with the aid of a laser-schlieren technique. It was found that the structure function D_n(r) has the form: D_n(r) = c(l-exp(-br)sin(ar)/(ar)),a,b,C being constants, in contrast with Kolmogorov's two-thirds law. These data were used in order to determine the PSF and MTF. Numerical results for the image of an object in a turbulent flow are also presented.