Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Combined measurement of velocity and temperature in liquid metal
  convection   Combined measurements of velocity components and temperature in a turbulent
Rayleigh-B\'enard convection flow at a low Prandtl number of $\mathit{Pr}=
0.029$ and Rayleigh numbers between $10^6 \le \mathit{Ra} \le 6 \times 10^7$
are conducted in a series of experiments with durations of more than a thousand
free-fall time units. Multiple crossing ultrasound beam lines and an array of
thermocouples at mid-height allow for a detailed analysis and characterization
of the complex three-dimensional dynamics of the single large-scale circulation
(LSC) roll in the cylindrical convection cell of unit aspect ratio which is
filled with the liquid metal alloy GaInSn. We measure the internal temporal
correlations of the complex large-scale flow and distinguish between short-term
oscillations associated with a sloshing motion in the mid-plane as well as
varying orientation angles of the velocity close to the top/bottom plates and
the slow azimuthal drift of the mean orientation of the roll as a whole that
proceeds on an up to a hundred times slower time scale. The coherent LSC drives
a vigorous turbulence in the whole cell that is quantified by direct Reynolds
number measurements at different locations in the cell. The velocity increment
statistics in the bulk of the cell displays characteristic properties of
intermittent small-scale fluid turbulence. We also show that the impact of the
symmetry-breaking large-scale flow persists to small-scale velocity
fluctuations thus preventing the establishment of fully isotropic turbulence in
the cell centre. Reynolds number amplitudes depend sensitively on beam line
position in the cell such that different definitions have to be compared. The
global momentum and heat transfer scalings with Rayleigh number are found to
agree with those of direct numerical simulations and other laboratory
experiments.

1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin