Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Influence of Horizontal Boundaries on Ekman Circulation and Angular
  Momentum Transport in a Cylindrical Annulus   We present numerical simulations of circular Couette flow in axisymmetric and
fully three-dimensional geometry of a cylindrical annulus inspired by Princeton
MRI liquid gallium experiment. The incompressible Navier-Stokes equations are
solved with the spectral element code Nek5000 incorporating realistic
horizontal boundary conditions of differentially rotating rings. We investigate
the effect of changing rotation rates (Reynolds number) and of the horizontal
boundary conditions on flow structure, Ekman circulation and associated
transport of angular momentum through the onset of unsteadiness and
three-dimensionality. A mechanism for the explanation of the dependence of the
Ekman flows and circulation on horizontal boundary conditions is proposed.

23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ