Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Wall laws for fluid flows at a boundary with random roughness   The general concern of this paper is the effect of rough boundaries on
fluids. We consider a stationary flow, governed by incompressible Navier-Stokes
equations, in an infinite domain bounded by two horizontal rough plates. The
roughness is modeled by a spatially homogeneous random field, with
characteristic size $\eps$. A mathematical analysis of the flow for small
$\eps$ is performed. The Navier's wall law is rigorously deduced from this
analysis.

11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg