Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Normalizing Flows as a Novel PDF Turbulence Model   In this paper, we propose normalizing flows (NF) as a novel probability
density function (PDF) turbulence model (NF-PDF model) for the
Reynolds-averaged Navier-Stokes (RANS) equations. We propose to use normalizing
flows in two different ways: firstly, as a direct model for the Reynolds stress
tensor, and secondly as a second-moment closure model, i.e. for modeling the
pressure-strain and dissipation tensor in the Reynolds stress transport
equation. In classical PDF closure models, a stochastic differential equation
has to be modeled and solved to obtain samples of turbulent quantities. The
NF-PDF closure model allows for direct sampling from the underlying probability
density functions of fluctuating turbulent quantities, such that
ensemble-averaged quantities can then be computed. To illustrate this approach
we demonstrate an application for the canonical case of homogeneous shear
turbulence. Training data are extracted from high-fidelity direct numerical
simulations (DNS).

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The categories of this paper are: q-bio
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The categories of this paper are: nucl-th
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The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
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The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
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The categories of this paper are: econ
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The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: funct-an