Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamics and locomotion of flexible foils in a frictional environment   Over the past few decades, oscillating flexible foils have been used to study
the physics of organismal propulsion in different fluid environments. Here we
extend this work to a study of flexible foils in a frictional environment. When
the foil is oscillated by heaving at one end but not allowed to locomote
freely, the dynamics change from periodic to non-periodic and chaotic as the
heaving amplitude is increased or the bending rigidity is decreased. For
friction coefficients lying in a certain range, the transition passes through a
sequence of $N$-periodic and asymmetric states before reaching chaotic
dynamics. Resonant peaks are damped and shifted by friction and large heaving
amplitudes, leading to bistable states.
  When the foil is allowed to locomote freely, the horizontal motion smoothes
the resonant behaviors. For moderate frictional coefficients, steady but slow
locomotion is obtained. For large transverse friction and small tangential
friction corresponding to wheeled snake robots, faster locomotion is obtained.
Traveling wave motions arise spontaneously, and and move with horizontal speed
that scales as transverse friction to the 1/4 power and input power that scales
as transverse friction to the 5/12 power. These scalings are consistent with a
boundary layer form of the solutions near the foil's leading edge.

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The categories of this paper are: eess
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: math
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The categories of this paper are: astro-ph
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-lat
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: acc-phys
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The categories of this paper are: gr-qc
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The categories of this paper are: alg-geom