Visible enhanced scattering from air flow turbulence
Laboratoire de Physique et Technologie des Plasmas
(UMR 7648 du CNRS) École Polytechnique - 91128 Palaiseau Cedex,
2 Bogolyubov Institute for Theoretical Physics - 03143 Kyiv, Ukraine
Accepted: 8 June 2001
The scattering of visible laser light out of a jet of air has been investigated in an unprecedented range of scale and intensity variations. By exploring the scattering light intensity angular distribution, the turbulent air jet "form factor" has been measured continuously from unity to a value of order 1012. Four different length scales and physical phenomena are observed successively: from incoherent scattering out of molecular motion at 5 μm scale, to enhanced scattering at the dissipative scale (5-50 μm), then at the inertial range (50-800 μm) where a universal scaling of the Kolmogorov class is found, and finally at the production scale. The scattered intensity is large enough to be visible and pictures of turbulence are shown at different laser wavelength.
PACS: 42.25.Dd – Wave propagation in random media / 42.25.Fx – Diffraction and scattering / 47.27.-i – Turbulent flows, convection, and heat transfer
© EDP Sciences, 2001