Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Simulating Surfactant Spreading: Impact of a Physically Motivated
  Equation of State   For more than two decades, a single model for the spreading of a
surfactant-driven thin liquid film has dominated the applied mathematics
literature on the subject. Recently, through the use of fluorescently-tagged
lipids, it has become possible to make direct, quantitative comparisons between
experiments and models. These comparisons have revealed two important
discrepancies between simulations and experiments: the spatial distribution of
the surfactant layer, and the timescale over which spreading occurs. In this
paper, we present numerical simulations that demonstrate the impact of the
particular choice of the equation of state (EoS) relating the surfactant
concentration to the surface tension. Previous choices of the model EoS have
been an ad-hoc decreasing function. Here, we instead propose an
empirically-motivated equation of state; this provides a route to resolving
some discrepancies and raises new issues to be pursued in future experiments.
In addition, we test the influence of the choice of initial conditions and
values for the non-dimensional groups. We demonstrate that the choice of EoS
improves the agreement in surfactant distribution morphology between
simulations and experiments, and impacts the dynamics of the simulations. The
relevant feature of the EoS, the gradient, has distinct regions for empirically
motivated choices, which suggests that future work will need to consider more
than one timescale. We observe that the non-dimensional number controlling the
relative importance of gravitational vs. capillary forces has a larger impact
on the dynamics than the other non-dimensional groups. Finally, we observe that
the experimental approach of using a ring to contain the surfactant could
affect the surfactant and fluid dynamics if it disrupts the intended initial
surfactant distribution. However, the meniscus itself does not significantly
affect the dynamics.

28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph