RUS  ENG JOURNALS   PEOPLE   ORGANISATIONS   CONFERENCES   SEMINARS   VIDEO LIBRARY   PERSONAL OFFICE
 General information Latest issue Archive Impact factor Search papers Search references RSS Latest issue Current issues Archive issues What is RSS

 Nelin. Dinam.: Year: Volume: Issue: Page: Find

 Nelin. Dinam., 2014, Volume 10, Number 1, Pages 73–100 (Mi nd426)

Figures of equilibrium of an inhomogeneous self-gravitating fluid

Ivan A. Bizyaeva, Alexey V. Borisovbca, Ivan S. Mamaeva

a Udmurt State University, Universitetskaya 1, Izhevsk, 426034, Russia
b Institute of Mathematics and Mechanics of the Ural Branch of RAS, S. Kovalevskaja str. 16, Ekaterinburg, 620990, Russia
c National Research Nuclear University “MEPhI”, Kashirskoye shosse 31, Moscow, 115409, Russia

Abstract: This paper is concerned with the figures of equilibrium of a self-gravitating ideal fluid with density stratification and a steady-state velocity field. As in the classical setting, it is assumed that the figure or its layers uniformly rotate about an axis fixed in space. As is well known, when there is no rotation, only a ball can be a figure of equilibrium.
It is shown that the ellipsoid of revolution (spheroid) with confocal stratification, in which each layer rotates with inherent constant angular velocity, is at equilibrium. Expressions are obtained for the gravitational potential, change in the angular velocity and pressure, and the conclusion is drawn that the angular velocity on the outer surface is the same as that of the Maclaurin spheroid. We note that the solution found generalizes a previously known solution for piecewise constant density distribution. For comparison, we also present a solution, due to Chaplygin, for a homothetic density stratification.
We conclude by considering a homogeneous spheroid in the space of constant positive curvature. We show that in this case the spheroid cannot rotate as a rigid body, since the angular velocity distribution of fluid particles depends on the distance to the symmetry axis.

Keywords: self-gravitating fluid, confocal stratification, homothetic stratification, space of constant curvature.

Full text: PDF file (492 kB)
References: PDF file   HTML file

Document Type: Article
UDC: 532.253, 532.5
MSC: 76U05
Revised: 24.01.2014

Citation: Ivan A. Bizyaev, Alexey V. Borisov, Ivan S. Mamaev, “Figures of equilibrium of an inhomogeneous self-gravitating fluid”, Nelin. Dinam., 10:1 (2014), 73–100

Citation in format AMSBIB
\Bibitem{BizBorMam14} \by Ivan~A.~Bizyaev, Alexey~V.~Borisov, Ivan~S.~Mamaev \paper Figures of equilibrium of an inhomogeneous self-gravitating fluid \jour Nelin. Dinam. \yr 2014 \vol 10 \issue 1 \pages 73--100 \mathnet{http://mi.mathnet.ru/nd426}