Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Improved assessment of the statistical stability of turbulent flows
  using extended Orr-Sommerfeld stability analysis   The concept of statistical stability is central to Malkus's 1956 attempt to
predict the mean profile in shear flow turbulence. Here we discuss how his
original attempt to assess this - an Orr-Sommerfeld analysis on the mean
profile - can be improved by considering a cumulant expansion of the
Navier-Stokes equations. Focusing on the simplest non-trivial closure (commonly
referred to as CE2) which corresponds to the quasilinearized Navier-Stokes
equations, we develop an extended Orr-Sommerfeld analysis (EOS) which also
incorporates information about the fluctuation field. A more practical version
of this - minimally extended Orr-Sommerfeld analysis (mEOS) - is identified and
tested on a number of statistically-steady and therefore statistically stable
turbulent channel flows. Beyond the concept of statistical stability, this
extended stability analysis should also improve the popular approach of
mean-flow linear analysis in time-dependent flows by including more information
about the underlying flow in its predictions.

32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph