Collapse of an axisymmetric cavity during slow movements of a cylinder in a liquid after a separation impact

Authors

UDC

519.634

DOI:

https://doi.org/10.31429/vestnik-21-2-62-69

Abstract

The axisymmetric problem of the vertical and separation impact of a cylinder of finite dimensions under the free surface of an ideal, incompressible, heavy fluid is considered. It is assumed that after the impact the cylinder moves deep into the liquid at a constant speed. An attached cavity is formed behind the body and a new internal free fluid boundary appears. It is required to study the process of cavity collapse at low cylinder speeds, which correspond to small Froude numbers. In the main asymptotic approximation, a problem with one-sided constraints is formulated, on the basis of which the dynamics of the circular separation line and the collapse time of a thin cavity are determined. An asymptotic analysis of the cavity shape is carried out taking into account solutions such as a boundary layer near the separation line. It is shown that at low Froude numbers the internal free boundary approaches the separation line at a right angle.

Keywords:

separation impact of a cylinder, dynamics of the separation zone, cavity collapse, small Froude numbers, boundary layer type solutions

Acknowledgement

The study did not have sponsorship.

Author Info

Mikhail V. Norkin

д-р физ.-мат. наук, доцент, профессор кафедры вычислительной математики и математической физики Южного федерального университета

e-mail: norkinmi@mail.ru

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Issue

2024. Vol. 21. No. 2

Section

Mechanics

Pages

62-69

Submitted

2024-05-27

Published

2024-06-28

How to Cite

Norkin M.V. Collapse of an axisymmetric cavity during slow movements of a cylinder in a liquid after a separation impact. Ecological Bulletin of Research Centers of the Black Sea Economic Cooperation, 2024, vol. 21, no. 2, pp. 62-69. DOI: https://doi.org/10.31429/vestnik-21-2-62-69 (In Russian)

Copyright (c) 2024 Norkin M.V.

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