Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On primitive formulation in fluid mechanics and fluid-structure
  interaction with constant piecewise properties in velocity-potentials of
  acceleration   Discrete mechanics makes it possible to formulate any problem of fluid
mechanics or fluid-structure interaction in velocity and potentials of
acceleration; the equation system consists of a single vector equation and
potentials updates. The scalar potential of the acceleration represents the
pressure stress and the vector potential is related to the rotational-shear
stress. The formulation of the equation of motion can be expressed in the form
of a splitting which leads to an exact projection method; the application of
the divergence operator to the discrete motion equation exhibits, without any
approximation, a Poisson equation with constant coefficients on the scalar
potential whatever the variations of the physical properties of the media. The
a posteriori calculation of the pressure is made explicitly by introducing at
this stage the local density. Two first examples show the interest of the
formulation presented on classical solutions of Navier-Stokes equations;
similarly as other results obtained with this formulation, the convergence is
of order two in space and time for all the quantities, velocity and potentials.
This formulation is then applied to a two-phase flow driven by surface tension
and partial wettability. The last case corresponds to a fluid-structure
interaction problem for which an analytical solution exists.

9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys