Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Flow simulation in a 2D bubble column with the Euler-Lagrange and
  Euler-Euler method
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org