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Related papers: Modelling grain-size distributions in C-type shock…

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We investigate the role and behaviour of dust grains in C-type MHD shock waves in weakly ionized, dense molecular clouds. New shock models are presented for steady, oblique C-type shock structures with shock speed v_s=18km/s, n_H=10^5cm^-3,…

Astrophysics · Physics 2009-11-11 Jacqueline F. Chapman , Mark Wardle

We present a numerical approach for accurately evolving a dust grain-size distribution undergoing number-conserving (such as sputtering) and/or mass-conserving (such as shattering) processes. As typically observed interstellar dust…

Astrophysics of Galaxies · Physics 2020-04-08 Rosie Sumpter , Sven Van Loo

Using a time-dependent multifluid, magnetohydrodynamic code, we calculated the structure of steady perpendicular and oblique C-type shocks in dusty plasmas. We included relevant processes to describe mass transfer between the different…

Solar and Stellar Astrophysics · Physics 2009-11-13 S. Van Loo , I. Ashmore , P. Caselli , S. A. E. G. Falle , T. W. Hartquist

I examine the role of dust grains in determining the structure of steady, cold, oblique C-type shocks in dense molecular gas. Gas pressure, the inertia of the charged components, and changes in ionisation are neglected. The grain charge and…

Astrophysics · Physics 2009-10-30 Mark Wardle

We investigate the gas-grain relative drift velocity distributions of charged astrophysical dust grains in MHD turbulence. We do this using a range of MHD-PIC simulations spanning different plasma-$\beta$, sonic/Alfv\'en Mach number, and…

Astrophysics of Galaxies · Physics 2025-08-28 Eric R. Moseley , Romain Teyssier

This article presents a new force model for performing quantitative simulations of dense granular materials. Interactions between multiple contacts (MC) on the same grain are explicitly taken into account. Our readily applicable method…

Soft Condensed Matter · Physics 2018-10-22 Nicolas Brodu , Joshua A. Dijksman , Robert P. Behringer

We compute the evolution of the grain size distribution (GSD) in a suite of numerical simulations of an isolated Milky-Way-like galaxy using the $N$-body/smoothed-particle-hydrodynamics code {\sc Gadget-4}. The full GSD is sampled on a…

Astrophysics of Galaxies · Physics 2022-05-25 Leonard E. C. Romano , Kentaro Nagamine , Hiroyuki Hirashita

We developed a chemical network for modeling the chemistry and non-ideal MHD effects from the collapsing dense molecular clouds to protostellar disks. First, we re-formulated the cosmic-ray desorption rate by considering the variations of…

Solar and Stellar Astrophysics · Physics 2018-05-16 Bo Zhao , Paola Caselli , Zhi-Yun Li

Ever since the pioneering study of Spitzer, it has been widely recognized that grains play an important role in the heating and cooling of photo-ionized environments. A detailed code is necessary to model grains in a photo-ionized medium.…

Astrophysics · Physics 2009-11-10 P. A. M. van Hoof , J. C. Weingartner , P. G. Martin , K. Volk , G. J. Ferland

Supernova ejecta and stellar winds are believed to produce interstellar dust grains with relatively large sizes. Smaller grains can be produced via the shattering of large grains that have been stochastically accelerated. To understand this…

Astrophysics of Galaxies · Physics 2022-12-07 Eric R. Moseley , Romain Teyssier , B. T. Draine

Using the discrete element method (DEM), we study the splash processes induced by the impact of a grain on two types of granular beds, namely, randomly packed and FCC-structured beds.Good correspondence is obtained between our numerical…

Soft Condensed Matter · Physics 2017-03-08 Takahiro Tanabe , Tomoki Koike , Takashi Shimada , Nobuyasu Ito , Hiraku Nishimori

We study the fragment size distributions after crushing of single and many particles under uniaxial compression inside a cylindrical container by means of numerical simulations. Under the assumption that breaking goes through the bulk of…

Soft Condensed Matter · Physics 2019-01-16 Pavel S. Iliev , Falk K. Wittel , Hans J. Herrmann

Context. Grains in circumstellar disks are believed to grow by mutual collisions and subsequent sticking due to surface forces. Results of many fields of research involving circumstellar disks, such as radiative transfer calculations, disk…

Earth and Planetary Astrophysics · Physics 2010-09-20 T. Birnstiel , C. W. Ormel , C. P. Dullemond

This is the second in a series of papers on the effects of dust on multifluid, MHD shock waves in weakly ionized molecular gas. We investigate the influence of dust on the critical shock speed, v_crit, above which C shocks cease to exist.…

Astrophysics · Physics 2009-11-10 Glenn E. Ciolek , Wayne G. Roberge , Telemachos Ch. Mouschovias

Variations in the grain size distribution are to be expected in the interstellar medium (ISM) due to grain growth and destruction. In this work, we present a dust collision model to be implemented inside a magnetohydrodynamical (MHD) code…

Astrophysics of Galaxies · Physics 2021-03-24 L. Beitia-Antero , A. I. Gómez de Castro

Due to significant computational expense, discrete element method simulations of jammed packings of size-dispersed spheres with size ratios greater than 1:10 have remained elusive, limiting the correspondence between simulations and…

Uniform and multi-dispersed grain packs have been frequently used to conceptually study flow in porous media. Numerical simulations were previously used to address the effect of particle shape on characteristics, such as pore space fractal…

Geophysics · Physics 2021-11-16 Elnaz Rezaei , Kamran Zeinalzadeh , Behzad Ghanbarian

The collisional evolution of debris disks is expected to result in a characteristic wavy pattern of the grain size distributions, i.e., an under/overabundance of particles of specific sizes. This perturbed grain size distribution…

Earth and Planetary Astrophysics · Physics 2023-12-27 Minjae Kim , Sebastian Wolf

This is the first in a series of papers on the effects of dust on the formation, propagation, and structure of nonlinear MHD waves and MHD shocks in weakly-ionized plasmas. We model the plasma as a system of 9 interacting fluids, consisting…

Astrophysics · Physics 2009-11-07 Glenn E. Ciolek , Wayne G. Roberge

We study segregation and stratification of mixtures of grains differing in size, shape and material properties poured in two-dimensional silos using a microscopic lattice model for surface flows of grains. The model incorporates the…

Statistical Mechanics · Physics 2009-10-31 Hernan A. Makse , Hans J. Herrmann
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