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Related papers: Mixing in Supersonic Turbulence

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Turbulence plays a crucial role in shaping the structure of the interstellar medium. The ratio of the three-dimensional density contrast ($\sigma_{\rho/\rho_0}$) to the turbulent sonic Mach number ($\mathcal{M}$) of an isothermal,…

We investigate the nature and spatial variations of turbulence in the Small Magellanic Cloud (SMC) by applying several statistical methods on the neutral hydrogen (HI) column density image of the SMC and a database of isothermal numerical…

Astrophysics of Galaxies · Physics 2014-11-20 Blakesley Burkhart , Snezana Stanimirovic , Alex Lazarian , Grzegorz Kowal

This paper discusses the mutual interactions between a thin flexible aluminum plate and supersonic flow using two-dimensional (2D) numerical simulations. Calculations are performed using an open source library, SU2, that solves partial…

Fluid Dynamics · Physics 2025-01-16 Himakar Ganti , Luis Bravo , Anindya Ghosal , Prashant Khare

The present study aims to understand the process of turbulent entrainment into a jet, as affected by background turbulence, using scalar statistics. Planar-laser-induced fluorescence was employed to capture the orthogonal cross sections of…

Fluid Dynamics · Physics 2024-09-23 Khashayar F. Kohan , Susan J. Gaskin

We study the problem of optimal mixing of a passive scalar $\rho$ advected by an incompressible flow on the two dimensional unit square. The scalar $\rho$ solves the continuity equation with a divergence-free velocity field $u$ with…

Analysis of PDEs · Mathematics 2017-07-06 Gianluca Crippa , Christian Schulze

By using Direct Numerical Simulations (DNS) of bubbly flows with passive scalars, we show a transition in the scalar spectra from a $k^{-5/3}$ to a $k^{-3}$ scaling with the wavenumber $k$, in contrast with those of single-phase isotropic…

Fluid Dynamics · Physics 2023-05-17 Niklas Hidman , Henrik Ström , Srdjan Sasic , Gaetano Sardina

In order to understand the time scales for complete mixing in a supernova-driven ISM we used the model of Avillez (2000) to follow the mixing and dispersal of inhomogeneities with different length scales. We included tracer fields to follow…

Astrophysics · Physics 2007-05-23 Miguel A. de Avillez , Mordecai-Mark Mac Low

Scalar mixing fronts develop at the interface of agitated fluids of different solute concentrations. In such fronts, scalar fluctuations form at both microscopic and macroscopic scales, due to stretching-enhanced molecular diffusion and…

Fluid Dynamics · Physics 2026-05-18 Heyman Joris , Le Borgne Tanguy , Lester Daniel

The objective of this paper is to unravel any relations that may exist between turbulent shear flows and statistical mechanics, through a detailed numerical investigation in the simplest case where both can be well defined. The shear flow…

Fluid Dynamics · Physics 2013-01-01 Saikishan Suryanarayanan , Roddam Narasimha , N. D. Hari Dass

Radiative mixing layers arise wherever multiphase gas, shear, and radiative cooling are present. Simulations show that in steady state, thermal advection from the hot phase balances radiative cooling. However, many features are puzzling.…

Astrophysics of Galaxies · Physics 2021-07-12 Brent Tan , S. Peng Oh , Max Gronke

The effects of turbulent dynamic range on scalar mixing in stably stratified turbulence are investigated by an adaptation of the theoretical passive scalar modelling arguments of Beguier et al. (1978) and demonstrated statistically using…

Fluid Dynamics · Physics 2022-04-05 G. D. Portwood , S. M. de Bruyn Kops , C. P. Caulfield

We propose a model for the density statistics in supersonic turbulence, which play a crucial role in star-formation and the physics of the interstellar medium (ISM). Motivated by [Hopkins, MNRAS, 430, 1880 (2013)], the model considers the…

Astrophysics of Galaxies · Physics 2017-08-30 Jonathan Squire , Philip F. Hopkins

Supersonic turbulence is a large reservoir of suprathermal energy in the interstellar medium. Its dissipation, because it is intermittent in space and time, can deeply modify the chemistry of the gas. We further explore a hybrid method to…

Astrophysics of Galaxies · Physics 2009-11-13 Benjamin Godard , Edith Falgarone , Guillaume Pineau Des Forêts

Context. Supersonic disordered flows accompany the formation and evolution of MCs. It has been argued that turbulence can support against gravitational collapse and form hierarchical sub-structures. Aims. We study the time evolution of…

Astrophysics of Galaxies · Physics 2019-10-02 Roxana-Adela Chira , Juan~Camilo Ibáñez-Mejía , Mordecai-Mark Mac Low , Thomas Henning

Large-eddy simulations are conducted to contrast momentum and passive scalar transport over large, three-dimensional roughness elements in a turbulent channel flow. Special attention is given to the dispersive fluxes, which are shown to be…

Fluid Dynamics · Physics 2019-10-09 Qi Li , Elie Bou-Zeid

Mixing at the microfluidic scale is challenging due to the low Reynolds numbers and often high P\'eclet numbers. Without turbulence, mixing relies solely on diffusion, resulting in slow and inefficient mixing. We demonstrate enhanced mixing…

Fluid Dynamics · Physics 2026-03-18 Enrico Turato , Christelle N. Prinz , Jason P. Beech , Jonas. O Tegenfeldt

We investigate the dynamics of microcapsules in linear shear flow within a reduced model with two degrees of freedom. In previous work for steady shear flow, the dynamic phases of this model, i.e. swinging, tumbling and intermittent…

Soft Condensed Matter · Physics 2009-09-15 Steffen Kessler , Reimar Finken , Udo Seifert

We use three-dimensional simulations to study the statistics of supersonic turbulence in molecular clouds. Our numerical experiments describe driven turbulent flows with an isothermal equation of state, Mach numbers around 10, and various…

Astrophysics of Galaxies · Physics 2009-05-18 Alexei G. Kritsuk , Sergey D. Ustyugov , Michael L. Norman , Paolo Padoan

Theoretical and observational studies on the turbulence of the interstellar medium developed fast in the past decades. The theory of supersonic magnetized turbulence, as well as the understanding of projection effects of observed…

Astrophysics of Galaxies · Physics 2015-05-18 D. Falceta-Goncalves , A. Lazarian , M. Houde

Mixing in viscous fluids is challenging, but chaotic advection in principle allows efficient mixing. In the best possible scenario,the decay rate of the concentration profile of a passive scalar should be exponential in time. In practice,…

Fluid Dynamics · Physics 2013-09-24 Jean-Luc Thiffeault , Emmanuelle Gouillart , Olivier Dauchot
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