Anisotropic transport in MHD turbulence: experimental results using small das bubbles as local tracers

S. Eckert¹ - G. Gerbeth¹ - H. Langenbrunner¹ - W. Witke¹ - O. Lielausis² - I. Platnieks²

¹ Research Center Rossendorf, 01314 Dresden, Germany
² Institute of Physics, Latvian University, Salaspils-1, LV-2169, Latvia

Abstract
There is ongoing research in the FZR MHD group on local transport phenomena in a turbulent liquid-metal (LM) duct flow exposed to a transverse magnetic field. In this paper experimental results are presented concerning the local void distribution over the channel cross section depending on an external transverse magnetic field. The measured local dispersion of hubbies shows a significant anisotropy which can be explained in terms of 2D MHD turbulence. The coefficients of the turbulent dispersion of the gas bubbles perpendicular as well as parallel to the direction of the magnetic field were obtained from the local void distributions and displayed as functions of the Stuart number N. In addition to the measurements in the channel without inserts, special turbulence generators (system of cylinders with changeable angle (0-90ø) between their axes and the magnetic field lines) have been installed in the region of gas injection in order to increase the level of 2D turbulence and to observe their influence on the bubble dispersion. Figs 11, Refs 10.