Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Is the Critical Reynolds Number Universal?   The laminar-turbulent transition in the circular pipe flow has been tested
experimentally. The critical Reynolds numbers for the flows of different gases
(He, Ne, Ar, Kr, Xe, N2, CO2, SF6) and liquids (H2O, D2O, C2H5OH) have been
compared. The difference up to 40% was observed. The possible reasons of
non-universality of critical Reynolds number are discussed. The conclusion is
the statistical approach is needed to penetrate into the nature of observed
phenomenon.

20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas