Fractality in Turbulence

Abstract

Fractality is, as we introduce it, an attribute relating to any object or system where the existence of self-similar replication of the whole is present in any order and scale. This can be realized in any turbulent flow due to the self-similar flow structures in its energy cascade. This intrinsic natural fractality is dominant in any turbulence energy cascade. In this paper, we report how this natural fractality is affected by a forced fractality externally superimposed on turbulent flow in a circular wind tunnel. The forced fractality was created by a fractal orifice plate. The time correlation and energy spectra showed that the forced fractality excites the natural fractality significantly and increases flow mixing. Simultaneously, we found that the fractal orifice plate is much more efficient than the classical orifice plate with equal flow area in terms of the flow mixing and deemed to be a better orifice flow meter than its classical counterpart.