Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fractal iso-level sets in high-Reynolds-number scalar turbulence   We study the fractal scaling of iso-levels sets of a passive scalar mixed by
three-dimensional homogeneous and isotropic turbulence at high Reynolds
numbers. The Schmidt number is unity. A fractal box-counting dimension $D_F$
can be obtained for iso-levels below about $3$ standard deviations of the
scalar fluctuation on either side of its mean value. The dimension varies
systematically with the iso-level, with a maximum of about $8/3$ for the
iso-level at the mean; this maximum dimension also follows as an upper bound
from the geometric measure theory. We interpret this result to mean that mixing
in turbulence is always incomplete. A unique box-counting dimension for all
iso-levels results when we consider the spatial support of the steep cliffs of
the scalar conditioned on local strain; that unique dimension is about $4/3$.

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The categories of this paper are: econ
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The categories of this paper are: solv-int
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The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: astro-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ex