Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: From two-dimensional to three-dimensional turbulence through
  two-dimensional three-component flows   The relevance of two-dimensional three-components (2D3C) flows goes well
beyond their occurrence in nature, and a deeper understanding of their dynamics
might be also helpful in order to shed further light on the dynamics of pure
two-dimenional (2D) or three-dimensional (3D) flows and vice versa. The purpose
of the present paper is to make a step in this direction through a combination
of numerical and analytical work. The analytical part is mainly concerned with
the behavior of 2D3C flows in isolation and the connection between the geometry
of the nonlinear interactions and the resulting energy transfer directions.
Special emphasis is given to the role of helicity. We show that a generic 2D3C
flow can be described by two stream functions corresponding to the two helical
sectors of the velocity field. The projection onto one helical sector
(homochiral flow) leads to a full 3D constraint and to the inviscid
conservation of the total (three dimensional) enstrophy and hence to an inverse
cascade of the kinetic energy of the third component also. The coupling between
several 2D3C flows is studied through a set of suitably designed direct
numerical simulations (DNS), where we also explore the transition between 2D
and fully 3D turbulence. In particular, we find that the coupling of three 2D3C
flows on mutually orthogonal planes subject to small-scale forcing leads to
stationary 3D out-of-equilibrium dynamics at the energy containing scales. The
transition between 2D and 3D turbulence is then explored through adding a
percentage of fully 3D Fourier modes in the volume.

21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th