Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Experimental evidence of flow destabilization in a 2D bidisperse foam   Liquid foam flows in a Hele-Shaw cell were investigated. The plug flow
obtained for a monodisperse foam is strongly perturbed in the presence of
bubbles whose size is larger than the average bubble size by an order of
magnitude at least. The large bubbles migrate faster than the mean flow above a
velocity threshold which depends on its size. We evidence experimentally this
new instability and, in case of a single large bubble, we compare the large
bubble velocity with the prediction deduced from scaling arguments. In case of
a bidisperse foam, an attractive interaction between large bubbles induces
segregation and the large bubbles organize themselves in columns oriented along
the flow. These results allow to identify the main ingredients governing 2D
polydisperse foam flows.

29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio