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Sand fences are often erected to reduce wind speed, prevent aeolian soil erosion, and induce sand deposition and dune formation in areas affected by sand encroachment and desertification. However, the search for the most efficient array of…

We derive the single-fluid evolution equations describing a mixture made of a gas phase and an arbitrary number of dust phases, generalising the approach developed in Laibe & Price (2014a). A generalisation for continuous dust distributions…

Earth and Planetary Astrophysics · Physics 2015-06-22 Guillaume Laibe , Daniel J. Price

The instability and nonlinear evolution of directional ocean waves is investigated numerically by means of simulations of the governing kinetic equation for narrow-band surface waves. Our simulation results reveal the onset of the…

Fluid Dynamics · Physics 2015-05-14 Bengt Eliasson , Padma K. Shukla

Interstellar dust is an important component of the galactic ecosystem, playing a key role in multiple galaxy formation processes. We present a novel numerical framework for the dynamics and size evolution of dust grains implemented in the…

Astrophysics of Galaxies · Physics 2018-05-23 Ryan McKinnon , Mark Vogelsberger , Paul Torrey , Federico Marinacci , Rahul Kannan

A mesoscopic continuum model is employed to analyse the transport mechanisms and structure formation during the redistribution stage of deposition experiments where organic molecules are deposited on a solid substrate with periodic…

Mesoscale and Nanoscale Physics · Physics 2018-07-24 Christoph Honisch , Te-Sheng Lin , Andreas Heuer , Uwe Thiele , Svetlana Gurevich

The saturation length of aeolian sand transport ($L_s$), characterizing the distance needed by wind-blown sand to adapt to changes in the wind shear, is essential for accurate modeling of the morphodynamics of Earth's sandy landscapes and…

Atmospheric and Oceanic Physics · Physics 2015-08-19 Thomas Pähtz , Amir Omeradžić , Marcus V. Carneiro , Nuno A. M. Araújo , Hans J. Herrmann

Relatively large dust grains (referred to as pebbles) accumulate at the outer edge of the gap induced by a planet in a protoplanetary disk, and a ring structure with a high dust-to-gas ratio can be formed. Such a ring has been thought to be…

Earth and Planetary Astrophysics · Physics 2021-11-24 Kazuhiro D. Kanagawa , Takayuki Muto , Hidekazu Tanaka

One of the most challenging steps in planet formation theory is the one leading to the formation of planetesimals of kilometre size. A promising scenario involves the existence of vortices able to concentrate a large amount of dust and…

Earth and Planetary Astrophysics · Physics 2015-06-11 H. Meheut , Z. Meliani , P. Varniere , W. Benz

Aims: Grain growth has been suggested as one possible explanation for the diminished dust optical depths in the inner regions of protoplanetary "transition" disks. In this work, we directly test this hypothesis in the context of current…

Solar and Stellar Astrophysics · Physics 2012-06-28 T. Birnstiel , S. M. Andrews , B. Ercolano

The transport of sediments by a fluid flow is commonly found in nature and in industry. In nature, it is found in rivers, oceans, deserts, and other environments. In industry, it is found in petroleum pipelines conveying grains, in sewer…

Fluid Dynamics · Physics 2016-08-17 Marcos Roberto Mendes Penteado , Erick de Moraes Franklin

Recently Squire & Hopkins showed that charged dust grains moving through magnetized gas under the influence of any external force (e.g. radiation pressure, gravity) are subject to a spectrum of instabilities. Qualitatively distinct…

Astrophysics of Galaxies · Physics 2022-03-18 Philip F. Hopkins , Jonathan Squire , Darryl Seligman

We show that the growth rate of dust grains in cold molecular clouds is enhanced by the high degree of compressibility of a turbulent, dilute gas. By means of high resolution (10243) numerical simulations, we confirm the theory that the…

Astrophysics of Galaxies · Physics 2020-11-18 Xiang-Yu Li , Lars Mattsson

We study the hydrodynamical behavior occurring in the turbulent interaction zone of a fast moving red supergiant star, where the circumstellar and interstellar material collide. In this wind-interstellar medium collision, the familiar bow…

Solar and Stellar Astrophysics · Physics 2011-05-31 Allard Jan van Marle , Zakaria Meliani , Rony Keppens , Leen Decin

Vortex ripples in sand are studied experimentally in a one-dimensional setup with periodic boundary conditions. The nonlinear evolution, far from the onset of instability, is analyzed in the framework of a simple model developed for…

Statistical Mechanics · Physics 2009-11-07 K. H. Andersen , M. Abel , J. Krug , C. Ellegaard , L. R. Soendergaard , J. Udesen

We present a series of simulations of turbulent stratified protostellar discs with the goal of characterizing the settling of dust throughout a minimum-mass solar nebula. We compare the evolution of both compact spherical grains, as well as…

Astrophysics of Galaxies · Physics 2015-05-14 D. A. Tilley , D. S. Balsara , S. D. Brittain , T. Rettig

Global stability analysis and direct numerical simulation (DNS) are performed to study boundary layer flows with an isolated roughness element. Wall-attached cuboids with aspect ratios $\eta=1$ and $\eta=0.5$ are investigated for fixed…

Fluid Dynamics · Physics 2022-10-05 Rong Ma , Krishnan Mahesh

A subcritical pattern-forming system with nonlinear advection in a bounded domain is recast as a slow-fast system in space and studied using a combination of geometric singular perturbation theory and numerical continuation. Two types of…

Pattern Formation and Solitons · Physics 2018-03-20 Daniele Avitabile , Mathieu Desroches , Edgar Knobloch , Martin Krupa

We present a new database of $>$300 layer-orientations from sedimentary mounds on Mars. These layer orientations, together with draped landslides, and draping of rocks over differentially-eroded paleo-domes, indicate that for the…

Earth and Planetary Astrophysics · Physics 2017-04-03 Edwin S. Kite , Jonathan Sneed , David P. Mayer , Kevin W. Lewis , Timothy I. Michaels , Alicia Hore , Scot C. R. Rafkin

Nonlinear numerical simulations are performed to investigate the density evolution in the dust layer of a protoplanetary disk due to the gravitational instability and dust settling toward the midplane. We assume the region where the radial…

Astrophysics · Physics 2009-11-11 Fumiharu Yamoto , Minoru Sekiya

Orbital evolution is a critical process that sculpts planetary systems, particularly during their early stages where planet-disk interactions are expected to lead to the formation of resonant chains. Despite the theoretically expected…

Earth and Planetary Astrophysics · Physics 2024-08-06 Vighnesh Nagpal , Max Goldberg , Konstantin Batygin