Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mechanics of drag reduction of an axisymmetric body of revolution with
  shallow dimples   In this article, the mechanics of drag reduction on an axisymmetric body of
revolution by shallow dimples is presented by using the high-fidelity Reynolds
Stress Modeling based simulations. Experimental results of drag evolution from
published literature at different Reynolds numbers are used to validate the
model predictions. The numerical predictions show good agreement with the
experimental results. It is observed that the drag of the body is reduced by a
maximum of $31\%$ with such shape modification (for the depth to diameter ratio
of $7.5\%$ and coverage ratio of $52.8\%$). This arises due to the reduced
level of turbulence, flow stabilization and suppression of flow separation in
the boundary layer of the body. From the analysis of turbulence states in the
anisotopic invariant map (AIM) for the case of the dimpled body, we show that
the turbulence reaches an axisymmetric limit in the layers close to the surface
of the body. There is also a reduced misalignment between the mean flow
direction and principal axis of the Reynolds stress tensor, which results in
such drag reduction. The dimple depth to diameter and coverage ratio are also
varied to evaluate its effect on drag evolution.

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The categories of this paper are: acc-phys
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The categories of this paper are: supr-con
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The categories of this paper are: eess
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: cs
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The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: math
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The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
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The categories of this paper are: q-fin