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Related papers: Mixing through shear instabilities

200 papers

A numerical shearing box is used to perform three-dimensional simulations of a 1 kpc stratified cubic box of turbulent and self-gravitating interstellar medium (in a rotating frame) with supernovae and HII feedback. We vary the value of the…

Astrophysics of Galaxies · Physics 2018-11-28 Cédric Colling , Patrick Hennebelle , Sam Geen , Olivier Iffrig , Frédéric Bournaud

Much progress has recently been made in understanding and quantifying vertical mixing induced by double-diffusive instabilities such as fingering convection (usually called thermohaline convection) and oscillatory double-diffusive…

Earth and Planetary Astrophysics · Physics 2014-01-07 Pascale Garaud

We demonstrate that in N-body simulations of isolated disc galaxies there is numerical vertical heating which slowly increases the vertical velocity dispersion and the disc thickness. Even for models with over a million particles in a disc,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 S. A. Rodionov , N. Ya. Sotnikova

There has been interest in recent years to assess the ability of astrophysical hydrodynamics codes to correctly model the Kelvin-Helmholtz instability. Smoothed particle hydrodynamics (SPH), in particular, has received significant…

Instrumentation and Methods for Astrophysics · Physics 2019-09-10 Terrence S. Tricco

We present a fluid dynamics video showing the results of a 9-billion atom molecular dynamics simulation of complex fluid flow in molten copper and aluminum. Starting with an atomically flat interface, a shear is imposed along the…

In this paper we study the effects of rotation in low-mass, low-metallicity RGB stars. We present the first evolutionary models taking into account self-consistently the latest prescriptions for the transport of angular momentum by…

Astrophysics · Physics 2009-11-11 A. Palacios , C. Charbonnel , S. Talon , L. Siess

We consider the stability of clouds surrounded by a hotter confining medium with respect to which they are in motion, against Kelvin-Helmholtz instabilities (KHI). In the presence of cooling, sound waves are damped by dissipation. Whenever…

Astrophysics · Physics 2009-10-30 Mario Vietri , Andrea Ferrara , Francesco Miniati

When a barotropic shear layer becomes unstable, it produces the well known Kelvin-Helmholtz instability (KH). The non-linear manifestation of KH is usually in the form of spiral billows. However, a piecewise linear shear layer produces a…

Fluid Dynamics · Physics 2015-06-11 Anirban Guha , Mona Rahmani , Gregory A. Lawrence

The linear stability of a stratified shear flow for smooth density profiles is studied. This work focuses on the nature of the stability boundaries of flows in which both Kelvin-Helmholtz and Holmboe instabilities are present. For a fixed…

Fluid Dynamics · Physics 2009-11-11 Alexandros Alexakis

The Kelvin--Helmholtz (KH) and tearing instabilities are likely to be important for the process of fast magnetic reconnection that is believed to explain the observed explosive energy release in solar flares. Theoretical studies of the…

A recent laboratory experiment (Blaauwgeers et al. 2003) suggests that a Kelvin-Helmholtz (KH) instability at the interface between two superfluids, one rotating and anisotropic, the other stationary and isotropic, may trigger sudden…

Astrophysics · Physics 2009-09-29 A. Mastrano , A. Melatos

Understanding how turbulence enhances irreversible scalar mixing in density-stratified fluids is a central problem in geophysical fluid dynamics. While isotropic overturning regions are commonly the focus of mixing analyses, we here…

Fluid Dynamics · Physics 2023-04-20 Miles M. P. Couchman , Stephen M. de Bruyn Kops , Colm-cille P. Caulfield

We present experimental measurements of a wall-bounded gravity current, motivated by characterizing natural gravity currents such as oceanic overflows. We use particle image velocimetry and planar laser-induced fluorescence to…

Fluid Dynamics · Physics 2020-12-25 Philippe Odier , Jun Chen , Robert E. Ecke

We study the effects of Kelvin Helmholtz Instability (KHI) on the cold streams that feed massive halos at high redshift, generalizing our earlier results to include the effects of radiative cooling and heating from a UV background, using…

Astrophysics of Galaxies · Physics 2020-04-08 Nir Mandelker , Daisuke Nagai , Han Aung , Avishai Dekel , Yuval Birnboim , Frank van den Bosch

The common feature of sheared flows of an ideal fluid and plasma in magnetic field is the Kelvin-Helmholtz instability. This instability is described by identical equations in mentioned two cases. The wave equation for the eigenmodes in the…

Plasma Physics · Physics 2012-07-31 A. Yu. Chirkov , V. I. Khvesyuk

Mixing a passive scalar field by stirring can be measured in a variety of ways including tracer particle dispersion, via the flux-gradient relationship, or by suppression of scalar concentration variations in the presence of inhomogeneous…

Fluid Dynamics · Physics 2010-11-08 Zhi Lin , Katarína Bodová , Charles R. Doering

The rotation rates of six weakly-magnetic neutron stars accreting in low-mass X-ray binaries have most likely been measured by Type I X-ray burst observations with RXTE. The nearly coherent oscillations detected during the few seconds of…

Astrophysics · Physics 2009-10-31 Andrew Cumming , Lars Bildsten

The recent development of tomographic analysis of radio data shows the presence of sheaths around several extragalactic jets. We have studied the Kelvin-Helmholtz instability of such stratified jets, describing them as inner relativistic…

Astrophysics · Physics 2007-05-23 M. Hanasz , H. Sol

Inside neutron stars, the hadron-quark mixed phase is expected during the first order phase transition from the hadron phase to the quark phase. The geometrical structure of the mixed phase strongly depends on the surface tension at the…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Hajime Sotani , Toshiki Maruyama , Toshitaka Tatsumi

Recently, there has been a significant level of discussion of the correct treatment of Kelvin-Helmholtz instability in the astrophysical community. This discussion relies largely on how the KHI test is posed and analyzed. We pose a…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Colin P. McNally , Wladimir Lyra , Jean-Claude Passy