Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Development and decay of vortex flows in viscoelastic fluids between
  concentric cylinders   We study the development and decay of vortex in viscoelastic fluids between
coaxial cylinders by means of experiments with solutions of polyacrylamide and
glycerin and numerical simulations. The transient process is triggered when the
inner cylinder is either abruptly started or stopped while the outer is kept
fixed. The azimuthal velocity, obtained by means of digital particle
velocimetry, exhibits oscillations before reaching the stationary state. The
development of the vortex is characterized by means of the overshoot, i.e. the
difference between the maximum and the stationary velocity. Analogously, in the
decay of the vortex, the azimuthal velocity changes its direction and the
relevant parameter is the undershoot defined as the maximum reversed transient
velocity. To get a deeper insight into this phenomenon, the experimental
results are supplemented with numerical simulations of rheological models as
the Oldroyd-B and White-Metzer. The results obtained with the first model
reveal the dependence of the overshoot and undershoot with the elasticity
number of the fluid. Using the White-Metzer model we explain the increase of
the overshoot produced by the reduction of the solvent viscosity in terms of
the shear-thinning effects.

30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ