Multifractal Nature of the Dissipation Field of Passive Scalars in Fully Turbulent Flows

Abstract

We present measurements of the curve of $f \mathrm{vs} \alpha$ from two-dimensional sections of the "dissipation" field of concentration fluctuations, and from one-dimensional sections of the dissipation field of passive temperature fluctuations, in turbulent jets. The results confirm the universality of the dissipation rate $\chi$ of scalar fluctuations and the applicability of Taylor's hypothesis, and show that the curve of $f \mathrm{vs} \alpha$ is the same for different components of $\chi$, that the additive properties of $f\left(\alpha \right)$ apply to intersections, and that the intermittency exponent of $\chi$ is considerably higher than that for the turbulent kinetic-energy dissipation.