Hydrostatic equilibrium

About: Hydrostatic equilibrium is a research topic. Over the lifetime, 2451 publications have been published within this topic receiving 62172 citations.

Expressions for the Viscosity of Liquid/Vapour Mixtures: Predicted and Measured Pressure Distributions in a Hydrostatic Bearing

Abstract: The present paper reports the correlation between the predicted performance and experimental data obtained from a hydrostatic thrust bearing under conditions designed to produce phase change due to viscous dissipation within the lubricant. The predicted values of pressure distribution indicate that the best correlation is obtained when the viscosity of a two-phase mixture is assumed to be the volume average of the viscosity of the individual phases.

A Note on the Atmospheric Solitary Wave.

Abstract: An attempt is made to show that a single elevation of permanent type may exist in a two-layer atmosphere at the interface between the two layers. The compressibility of the air, friction, the earth's rotation, and its spherical shape are neglected. It is assumed that the free surface of the upper layer remains undisturbed at all times, and that the hydrostatic relation holds in the upper layer when the lower layer is disturbed. It is found that, under these simplifying assumptions, internal solitary waves may exist in the atmosphere. The shape of these waves and the conditions attending their formation are found to be identical with those of shallow water waves as given by Keller.

Convective radiation fluid‐dynamics: formation and early evolution of ultra low‐mass objects

Abstract: The formation process of ultra low-mass objects is some kind of extension of the star formation process. The physical changes towards lower mass are discussed by investigating the collapse of cloud cores that are modelled as Bonnor-Ebert spheres. Their collapse is followed by solving the equations of fluid dynamics with radiation and a model of time-dependent convection that has been calibrated to the Sun. For a sequence of cloud-cores with 1 to 0.01 solar masses, evolutionary tracks and isochrones are shown in the mass-radius diagram, the Hertzsprung-Russel diagram and the effective temperaturesurface gravity or Kiel diagram. The collapse and the early hydrostatic evolution to ages of few Ma are briefly discussed and compared to observations of objects in Upper Scorpius and the low-mass components of GG Tau. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Stellar evolution of compact stars in curvature–matter-coupling gravity

Abstract: This paper is devoted to studying the stellar evolution of compact objects whose energy density and fluid pressure are interlinked by means of the MIT bag model and a realistic polytropic equation of state in the scenario of |$f(R,T,Q)$| gravity, where |$Q=R_{ab}T^{ab}$|⁠. We derive the field equations as well as the hydrostatic equilibrium equation and analyze their solutions numerically for an |$R+\delta Q$| functional form, with |$\delta$| being a coupling parameter. We discuss the dependence of various physical properties such as pressure, energy density, total mass, and surface redshift on the chosen values of the model parameter. The physical acceptability of the proposed model is examined by checking the validity of energy conditions, causality condition, and adiabatic index. We also study the effects arising due to the matter–curvature coupling of a compact stellar system. It is found that the maximum mass point lies within the observational range, which indicates that our model is appropriate to describe dense stellar objects.