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Related papers: Jeans Instability in a viscoelastic fluid

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In this Letter we have derived the Jeans length in the context of the Kaniadakis statistics. We have compared this result with the Jeans length obtained in the non-extensive Tsallis statistics and discussed the main differences between…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-20 Everton M. C. Abreu , Jorge Ananias Neto , Edesio M. Barboza , Rafael C. Nunes

The second post-Newtonian hydrodynamic equations are analyzed within the framework of a plane wave solution. The hydrodynamic equations for the mass and momentum density are coupled with six Poisson equations for the Newtonian and…

General Relativity and Quantum Cosmology · Physics 2023-03-09 Gilberto M. Kremer

Viscosity, as a physical property of fluids, reflects an average effect over a chaotic microscopic motion described by Hamiltonian equations. It is proposed, as an example, that stationary states of an incompressible fluid subject to a…

Statistical Mechanics · Physics 2022-10-12 Giovanni Gallavotti

Growth rates for gravitational instabilities in a thick disk of gas and stars are determined for a turbulent gas that dissipates on the local crossing time. The scale heights are derived from vertical equilibrium. The accuracy of the usual…

Astrophysics of Galaxies · Physics 2015-05-28 Bruce G. Elmegreen

This fluid dynamics video presents experiments and simulations of gravity-driven particulate jets in viscous fluids at low Reynolds number. An initially straight jet is shown to develop varicose modulations of its diameter as it sediments…

Fluid Dynamics · Physics 2015-05-13 Florent Pignatel , Maxime Nicolas , Elisabeth Guazzelli , David Saintillan

The Jeans criterion is one cornerstone in our understanding of gravitational fragmentation. A critical limitation of the Jeans criterion is that the background density is assumed to be a constant, which is often not true in dynamic…

Astrophysics of Galaxies · Physics 2024-01-30 Guang-Xing Li

Gravity plays important roles at multiple scales in the universe. An important, yet often neglected, role of gravity is its ability in driving anisotropic fragmentation through tides. When tides dominate, fragmentation becomes anisotropic,…

Astrophysics of Galaxies · Physics 2025-09-24 Guang-Xing Li

We investigate the stability of bounded self-gravitating systems in the canonical ensemble by using a thermodynamical approach. Our study extends the earlier work of Padmanabhan [Astrophys. J. Supp. 71, 651 (1989)] in the microcanonical…

Astrophysics · Physics 2009-11-06 P. -H. Chavanis

We investigate the dynamics of interstellar dust particles in moderately high resolution ($512^3$ grid points) simulations of forced compressible transonic turbulence including self-gravity of the gas. Turbulence is induced by stochastic…

Astrophysics of Galaxies · Physics 2021-12-07 Lars Mattsson , Robert Hedvall

The effect of cosmic rays on the Parker-Jeans instability in magnetized self-gravitating gaseous disks is studied by three-dimensional magnetohydrodynamic (MHD) simulations with cosmic rays taken as a massless fluid with notable pressure.…

High Energy Astrophysical Phenomena · Physics 2020-08-26 Takuhito Kuwabara , Chung Ming Ko

Shocks in granular media, such as vertically oscillated beds, have been shown to develop instabilities. Similar jet formation has been observed in explosively dispersed granular media. Our previous work addressed this instability by…

Fluid Dynamics · Physics 2014-07-17 Nick Sirmas , Sam Falle , Matei Radulescu

Unlike the power-law model, the Ellis model describes the apparent viscosity of a shear-thinning fluid with no singularity in the limit of a vanishingly small shear stress. In particular, this model matches the Newtonian behaviour when the…

Fluid Dynamics · Physics 2023-02-03 Michele Celli , Antonio Barletta , Pedro V. Brandão

Warped astrophysical discs are usually treated as laminar viscous flows, which have anomalous properties when the disc is nearly Keplerian and the viscosity is small: fast horizontal shearing motions and large torques are generated, which…

Solar and Stellar Astrophysics · Physics 2015-06-15 Gordon I. Ogilvie , Henrik N. Latter

This work presents a study of the interfacial dynamics of thin viscoelastic films subjected to the gravitational force and substrate interactions induced by the disjoining pressure, in two spatial dimensions. The governing equation is…

Fluid Dynamics · Physics 2022-04-12 Valeria Barra , Shahriar Afkhami , Lou Kondic

We consider a continuum model of active viscoelastic matter, whereby an active nematic liquid-crystal is coupled to a minimal model of polymer dynamics with a viscoelastic relaxation time $\tau_C$. To explore the resulting interplay between…

Soft Condensed Matter · Physics 2016-03-30 E. J. Hemingway , M. E. Cates , S. M. Fielding

The gravitational instability of a fully ionized gas is analyzed within the framework of linear irreversible thermodynamics. In particular, the presence of a heat flux corresponding to generalized thermodynamic forces is shown to affect the…

Astrophysics · Physics 2009-06-23 A. Sandoval-Villalbazo , A. L. Garcia-Perciante

Context. We consider a simple self-gravitating disk, made of two fluid components characterized by different effective thermal speeds and interacting with one another only through gravity; two-component models of this type have often been…

Astrophysics · Physics 2009-11-11 Giuseppe Bertin , Antonio Cava

We present experimental observations and numerical simulations of a wrinkling instability that occurs at sufficiently high strain rates in the trembling regime of vesicle dynamics in steady linear flow. Spectral and statistical analysis of…

Soft Condensed Matter · Physics 2014-07-11 Michael Levant , David Abreu , Udo Seifert , Victor Steinberg

The stability of atmospheric stratified fluids is revisited to study the influence of the temperature-dependent density inhomogeneity due to thermal expansion in the Earth's lower atmosphere (with heights $0$ to $50$ km) under the action of…

Atmospheric and Oceanic Physics · Physics 2024-07-08 T. D. Kaladze , A. P. Misra

Interior stagnation point flows of viscoelastic liquids arise in a wide variety of applications including extensional viscometry, polymer processing and microfluidics. Experimentally, these flows have long been known to exhibit…

Fluid Dynamics · Physics 2007-05-23 Li Xi , Michael D. Graham