English
Related papers

Related papers: VADER: A Flexible, Robust, Open-Source Code for Si…

200 papers

We present solutions to the relativistic thin disc evolutionary equation using an ${\alpha}$-model for the turbulent stress tensor. Solutions with a finite stress at the innermost stable circular orbit (ISCO) give rise to bolometric light…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Andrew Mummery , Steven A. Balbus

Circumstellar disks of gas and dust are naturally formed from contracting pre-stellar molecular cores during the star formation process. To study various dynamical and chemical processes that take place in circumstellar disks prior to their…

Astrophysics of Galaxies · Physics 2017-09-27 Eduard I. Vorobyov , Yaroslav N. Pavlyuchenkov

In this article, we proceed to study convection as a possible factor of episodic accretion in protoplanetary disks. Within the model presented in Article~I, the accretion history is analyzed at different rates and areas of matter inflow…

Solar and Stellar Astrophysics · Physics 2020-09-17 L. A. Maksimova , Ya. N. Pavlyuchenkov , A. V. Tutukov

We present a numerical model for the dynamics of thin viscous threads based on a discrete, Lagrangian formulation of the smooth equations. The model makes use of a condensed set of coordinates, called the centerline/spin representation: the…

Almost all hydrodynamic accretion disk models parametrize viscosity with the dimensionless parameter alpha. There is no detailed model for alpha, so it is usually taken to be a constant. However, global simulations of magnetohydrodynamic…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Robert F. Penna , Aleksander Sadowski , Akshay K. Kulkarni , Ramesh Narayan

The spinning of slender viscous jets can be described asymptotically by one-dimensional models that consist of systems of partial and ordinary differential equations. Whereas the well-established string models possess only solutions for…

Mathematical Physics · Physics 2015-07-02 Walter Arne , Nicole Marheineke , Andreas Meister , Raimund Wegener

We add the effect of turbulent viscosity via the \alpha-prescription to models of the self-consistent formation and evolution of protostellar discs. Our models are non-axisymmetric and carried out using the thin-disc approximation.…

Astrophysics · Physics 2009-11-13 E. I. Vorobyov , Shantanu Basu

The morphology of crystalline thin films evolving on flat rigid substrates by condensation of extra film atoms or by evaporation of their own atoms in the surrounding vapor is studied in the framework of the theory of Stress Driven…

Analysis of PDEs · Mathematics 2024-11-05 Paolo Piovano , Francesco Sapio

We use one-dimensional two-zone time-dependent accretion disk models to study the long-term evolution of protostellar disks subject to mass addition from the collapse of a rotating cloud core. Our model consists of a constant surface…

Solar and Stellar Astrophysics · Physics 2015-05-18 Zhaohuan Zhu , Lee Hartmann , Charles Gammie

We present AstroVaDEr, a variational autoencoder designed to perform unsupervised clustering and synthetic image generation using astronomical imaging catalogues. The model is a convolutional neural network that learns to embed images into…

Instrumentation and Methods for Astrophysics · Physics 2020-12-02 Ashley Spindler , James E. Geach , Michael J. Smith

Recent developments in vortex particle methods for simulating three-dimensional incompressible flows are presented. A lightweight, dynamic Large-Eddy Simulation model is tested, featuring a dynamic procedure that relies solely on Lagrangian…

Fluid Dynamics · Physics 2026-01-13 Flavio A. C. Martins , Alexander van Zuijlen , Carlos J. Simao Ferreira

Vortex-induced vibration (VIV) remains a fundamental yet computationally challenging problem in computational fluid dynamics (CFD). This study develops a moving mesh Fluid-structure interaction (FSI) algorithm within a Runge-Kutta…

Fluid Dynamics · Physics 2025-04-04 Jia-Jun Zou , Yun-Long Liu , Qi Kong , A-Man Zhang

We consider linear scalar wave equations with a hereditary integral term of the kind used to model viscoelastic solids. The kernel in this Volterra integral is a sum of decaying exponentials (The so-called Maxwell, or Zener model) and this…

Numerical Analysis · Mathematics 2021-12-23 Yongseok Jang , Simon Shaw

We aim to examine the detailed disc structure that arises in a misaligned binary system as a function of the disc aspect ratio h, viscosity parameter alpha, disc outer radius R, and binary inclination angle gamma_F. We also aim to examine…

Earth and Planetary Astrophysics · Physics 2015-05-14 Moritz Fragner , Richard Nelson

The accurate and stable simulation of viscoelastic flows remains a significant computational challenge, exacerbated for flows in non-trivial and practical geometries. Here we present a new high-order meshless approach with variable…

Fluid Dynamics · Physics 2024-05-01 Jack R. C. King , Steven J. Lind

We explore the recently-proposed Virtual Element Method (VEM) for numerical solution of boundary value problems on arbitrary polyhedral meshes. More specifically, we focus on the elasticity equations in three-dimensions and elaborate upon…

Numerical Analysis · Mathematics 2015-07-22 Arun L. Gain , Cameron Talischi , Glaucio H. Paulino

We argue that the proper way to treat thin-thick accretion-disk transitions should take into account the 2-D nature of the problem. We illustrate the physical inconsistency of the 1-D vertically integrated approach by discussing a…

Astrophysics · Physics 2015-06-24 Marek A. Abramowicz , Gunnlaugur Bjornsson , Igor V. Igumenshchev

A toy model of a disk undergoing steady state accretion onto a black hole is presented. The disk is in a hydrostatic equilibrium for all radii r > r_{in}, with the inner disk radius located between the marginally stable and marginally bound…

Astrophysics · Physics 2007-05-23 Bohdan Paczynski

We present a simple and efficient variational finite difference method for simulating time-dependent Stokes flow in the presence of irregular free surfaces and moving solid boundaries. The method uses an embedded boundary approach on…

Computational Physics · Physics 2011-05-25 Christopher Batty , Robert Bridson

We have developed a three-dimensional numerical model and applied it to simulate plasma flows in semi-detached binary systems whose accretor possesses a strong intrinsic magnetic field. The model is based on the assumption that the plasma…

Solar and Stellar Astrophysics · Physics 2010-10-26 A. G. Zhilkin , D. V. Bisikalo