S. M. Muztaba Salim and Franck Nicolleau
The Journal of Mechanical Science and Technology, vol. 26, no. 5, pp.1311-1314, 2012

Abstract : "Fractality, as we introduce it, is 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 phenomenon 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 turbulent flow. This paper reports the effect of a forced fractality externally superimposed on a turbulent flow in a circular wind tunnel on this natural fractality. The forced fractality was created by a set of fractal orifice plates. The time correlation and energy spectra showed that the forced fractality significantly excites the natural fractality 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.

Keyword : Turbulence; Fractal; Hot-wire; Orifice; Wind tunnel