Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Influence of Yaw on the Unsteady Surface Pressures over a
  Two-Wheeled Landing-Gear Model   Landing-gear noise is an increasing issue for transport aircraft. A key
determinant of the phenomenon is the surface pressure field. Previous studies
have described this field when the oncoming flow is perfectly aligned with the
gear. In practice, there may be a cross-flow component; here its influence is
investigated experimentally for a generic, two-wheel, landing-gear model. It is
found that yaw angles as small as 5{\deg} cause significant changes in both
overall flow topology and unsteady surface pressures. Most notably, on the
outboard face of the leeward wheel, large-scale separation replaces
predominantly attached flow behind a leading-edge separation bubble. The effect
on unsteady surface pressures includes marked shifts in the content at
frequencies in the audible range, implying that yaw is an important parameter
for landing-gear noise, and that purely unyawed studies may not be fully
representative of the problem.

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The categories of this paper are: math-ph
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The categories of this paper are: econ
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The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
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The categories of this paper are: eess
7
The categories of this paper are: hep-th
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The categories of this paper are: nucl-th
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The categories of this paper are: nlin
33
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: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-lat
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The categories of this paper are: gr-qc
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The categories of this paper are: ao-sci
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The categories of this paper are: alg-geom