Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Water entry of spheres into a rotating liquid   The transient cavity dynamics during water entry of a heavy, non-rotating
sphere impacting a rotating pool of liquid is studied experimentally,
numerically, and theoretically. We show that the pool rotation advances the
transition of the cavity type - from deep seal to surface seal - marked by a
reduction in the transitional Froude number. The role of the dimensionless
rotational number $\mathcal{S} \equiv \omega R_0/U_0$ on the transient cavity
dynamics is unveiled, where $R_0$ is the sphere radius, $\omega$ the angular
speed of the liquid, and $U_0$ the impact velocity. The rotating background
liquid has two discernible effects on the cavity evolution. Firstly, an
increase in the underwater pressure field due to centripetal effects, and
secondly a reduction in the pressure of airflow in the cavity neck near the
water surface. The non-dimensional pinch-off time of the deep seal shows a
robust 1/2 power-law dependence on the Froude number, but with a reducing
prefactor for increasing $\omega$. Our findings reveal that the effects of a
rotating background liquid on the water entry can be traced back to the subtle
differences in the initial stage splash and the near-surface cavity dynamics.

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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: econ
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The categories of this paper are: chem-ph
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The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
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The categories of this paper are: solv-int
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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: q-alg
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The categories of this paper are: ao-sci
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The categories of this paper are: q-bio