Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Instability of the shock wave/ sonic surface interaction   The work addresses 2D and 3D turbulent transonic flows past a wall with an
expansion corner. A curved shock wave is formed upstream of a cylinder located
above the corner. Numerical solutions of the Reynolds-averaged Navier-Stokes
equations are obtained on fine meshes with a finite-volume solver of the second
order accuracy. The solutions demonstrate the existence of adverse free-stream
Mach numbers which admit abrupt changes of the shock position at small
perturbations. This is explained by an instability of the closely spaced sonic
surface and shock wave on the wall.

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The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
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The categories of this paper are: econ
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The categories of this paper are: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom