On a fractal and an experimental approach to turbulence
Peinke, J × Castaing, B Chabaud, B Chilla, F Hebral, B Naert, Antoon #
Elsevier science publ b v
Fractals in the natural and applied sciences vol:41 pages:295-304
A fractal function deduced from a recently proposed generic model for fractal basin boundaries and a time series of velocities obtained from developed turbulence (Re = 58000) in an axi-symmetric jet of gaseous He-4 at low temperatures are compared on the background of their statistical features. For both data sets strong intermittency effects are shown. Evidence is presented that for a finite set of data points, intermittency can not be properely evaluated by means of multiaffinity or structure function exponents. As an alternative we present a direct evaluation of the probability densities which leads to an intermittency parameter. For the data of the fractal function we find Kolmogorov's refined scaling, whereas the experimental data display a different scaling behavior of the variational model.