Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Turbulent mixing of a slightly supercritical Van der Waals fluid at
  Low-Mach number   Supercritical fluids near the critical point are characterized by liquid-like
densities and gas-like transport properties. These features are purposely
exploited in different contexts ranging from natural products
extraction/fractionation to aerospace propulsion. Large part of studies
concerns this last context, focusing on the dynamics of supercritical fluids at
high Mach number where compressibility and thermodynamics strictly interact.
Despite the widespread use also at low Mach number, the turbulent mixing
properties of slightly supercritical fluids have still not investigated in
detail in this regime. This topic is addressed here by dealing with Direct
Numerical Simulations (DNS) of a coaxial jet of a slightly supercritical Van
der Waals fluid. Since acoustic effects are irrelevant in the Low Mach number
conditions found in many industrial applications, the numerical model is based
on a suitable low-Mach number expansion of the governing equation. According to
experimental observations, the weakly supercritical regime is characterized by
the formation of finger-like structures-- the so-called ligaments --in the
shear layers separating the two streams. The mechanism of ligament formation at
vanishing Mach number is extracted from the simulations and a detailed
statistical characterization is provided. Ligaments always form whenever a high
density contrast occurs, independently of real or perfect gas behaviors. The
difference between real and perfect gas conditions is found in the ligament
small-scale structure. More intense density gradients and thinner interfaces
characterize the near critical fluid in comparison with the smoother behavior
of the perfect gas. A phenomenological interpretation is here provided on the
basis of the real gas thermodynamics properties.

8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin