Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mechanism of Tubular Pinch Effect of Dilute Suspension in a Pipe Flow   Experiments have shown that in dilute suspension flow at laminar state
through a circular tube particles migrate towards a concentric annular region
with a mean radius of about 0.6 of the tube radius. This phenomenon is
well-known as the tubular pinch effect, which is still not fully understood. In
this study, the energy gradient method is used to study this phenomenon. It is
found that at low Reynolds number particles will move to the position of
r/R=0.58. Based on the result, the mechanism of this phenomenon is well
explained.

26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc