Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An adverse-pressure-gradient turbulent boundary layer with
  nearly-constant $\boldsymbol{\beta \simeq 1.4}$ up to
  $\boldsymbol{Re_{\theta} \simeq 8,700}$   In this study, a new well-resolved large-eddy-simulation (LES) of an
incompressible near-equilibrium adverse-pressure-gradient (APG) turbulent
boundary layer (TBL) over a flat plate is presented. In this simulation, we
have established a near-equilibrium APG over a wide Reynolds-number range. In
this so-called region of interest (ROI), the Clauser--Rotta pressure-gradient
parameter $\beta$ exhibits an approximately constant value of around 1.4, and
the Reynolds number based on momentum thickness reaches $Re_{\theta}=8700$. To
the authors' knowledge, this is to date the highest $Re_{\theta}$ achieved for
a near-equilibrium APG TBL under an approximately constant moderate APG. We
evaluated the self-similarity of the outer region using two scalings, namely
the Zagarola--Smits and an alternative one based on edge velocity and
displacement thickness. Our results reveal that outer-layer similarity is
achieved, and the viscous scaling collapses the near-wall region of the mean
flow in agreement with classical theory. Spectral analysis reveals that the APG
displaces some small-scale energy from the near-wall to the outer region, an
effect observed for all the components of the Reynolds-stress tensor, which
becomes more evident at higher Reynolds numbers. Generally, the effects of the
APG are more noticeable at lower Reynolds numbers. For instance, the outer peak
of turbulent-kinetic-energy (TKE) production is less prominent at higher $Re$.
While the scale separation increases with $Re$ in zero-pressure-gradient (ZPG)
TBLs, this effect becomes accentuated by the APG. Despite the reduction of the
outer TKE production at higher Reynolds numbers, the mechanisms of energization
of large scales are still present.

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The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
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The categories of this paper are: math
37
The categories of this paper are: supr-con
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The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an