Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: UrbanFlow: Designing Comfortable Outdoor Areas   Design decisions in urban planning have to be made with particular
carefulness as the resulting constraints are binding for the whole
architectural design that follows. In this context, investigating and
optimizing the airflow in urban environments is critical to design comfortable
outdoor areas as unwanted effects such as windy areas and the formation of heat
pockets have to be avoided. Our UrbanFlow framework enables interactive
architectural design allowing for decision making based on simulating urban
flow. Compared to real-time fluid flow simulation, enabling interactive
architecture design poses an even higher computational efficiency challenge as
evaluating a design by simulation usually requires hundreds of time steps. This
is addressed based on a highly efficient Eulerian fluid simulator in which we
incorporate a unified porosity model which is devised to encode digital urban
models containing objects such as buildings and trees. UrbanFlow is equipped
with an optimization routine enabling the direct computation of design
adaptations improving livability and comfort for given parameterized
architectural designs. To ensure convergence of the optimization process,
instead of the classical Navier-Stokes equations, the Reynolds-averaged
Navier-Stokes equations are solved as this can be done on a relatively coarse
grid and allows for the decoupling of the effects of turbulent eddies which are
taken into account using a separate turbulence model. As we demonstrate on a
real-world example taken from an ongoing architectural competition, this
results in a fast convergence of the optimization process which computes a
design adaptation avoiding heat pockets as well as uncomfortable windy areas.

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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: stat
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The categories of this paper are: gr-qc
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The categories of this paper are: econ
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The categories of this paper are: q-bio
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: chem-ph
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The categories of this paper are: math
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The categories of this paper are: funct-an
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The categories of this paper are: hep-ex