Smoothed Particle Hydrodynamics Confronts Theory: Formation of Standing Shocks in Accretion Disks and Winds around Black Holes

1993 ◽  
Vol 417 ◽  
pp. 671 ◽  
Author(s):  
Sandip K. Chakrabarti ◽  
Diego Molteni
Keyword(s):  
Black Holes ◽  
Accretion Disks ◽  
Smoothed Particle Hydrodynamics ◽  
Theory Formation ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

Smoothed Particle Hydrodynamics: Physical viscosity and the simulation of accretion disks

1994 ◽  
Vol 431 ◽  
pp. 754 ◽  
Author(s):  
O. Flebbe ◽  
S. Muenzel ◽  
H. Herold ◽  
H. Riffert ◽  
H. Ruder
Keyword(s):  
Accretion Disks ◽  
Smoothed Particle Hydrodynamics ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

scholarly journals Self-gravitating barotropic equilibrium configurations of rotating bodies with smoothed particle hydrodynamics

2020 ◽  
Vol 637 ◽  
pp. A61
Author(s):  
D. García-Senz ◽  
R. M. Cabezón ◽  
J. M. Blanco-Iglesias ◽  
P. Lorén-Aguilar
Keyword(s):  
Accretion Disks ◽  
Differential Rotation ◽  
Smoothed Particle Hydrodynamics ◽  
White Dwarfs ◽  
Initial Conditions ◽  
Relaxation Method ◽  
Equilibrium Configurations ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Rotating Bodies

Context. Self-gravitational rotating bodies do not have spherically symmetric geometries. The study of physical events appearing in fast-spinning compact stars and accretion disks, for example those due to localized thermonuclear ignitions in white dwarfs or to the role played by hydrodynamic instabilities in stars and disks, often requires 3D simulations. When the numerical simulations are carried out with the smoothed particle hydrodynamics (SPH) technique a critical point arises as to how to build a stable initial model with rotation because there is no well-established method for that purpose. Aims. We want to provide a portable, easy-to-implement methodology for SPH simulations to procedurally generate physically sound, stable initial conditions for rotating bodies. Methods. We explain and validate an easy and versatile novel relaxation method to obtain 3D equilibrium configurations of rotating bodies with SPH. As detailed below, this method is able to relax barotropic, P(ρ), structures either in rigid or differential rotation. The relaxation procedure strongly relies on the excellent conservation of angular momentum that characterizes the SPH technique. Results. We applied our proposal to obtain stable rotating structures of single white dwarfs, compact binaries harboring two white dwarfs, high-density stars approached as polytropes and accretion disks either in rigid or differential rotation. Conclusions. We present a novel relaxation method to build 3D rotating structures of barotropic bodies using the SPH technique. The method has been successfully applied to a variety of zero-temperature white dwarfs and polytropic self-gravitating structures. Our SPH results have been validated by comparing the main features (energies, central densities, and the polar-to-equatorial radius ratio) to those obtained with independent grid-based methods, for example, the self-consistent field method, showing that both methods agree within a few percent.

INVESTIGATION OF RADIATIVE OUTFLOWS AROUND COMPACT OBJECTS

2000 ◽  
Vol 09 (01) ◽  
pp. 57-69 ◽  
Author(s):  
INDRANIL CHATTOPADHYAY ◽  
SANDIP K. CHAKRABARTI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Smoothed Particle Hydrodynamics ◽  
Binary Systems ◽  
Active Galaxies ◽  
Compact Objects ◽  
Accretion Discs ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Radiative Acceleration

Winds and outflows form in active galaxies and in binary systems which are known to harbour compact objects such as black holes. Matter starting subsonically from a disc must be accelerated very close to the black hole in order to reach a velocity comparable to the velocity of light, which is actually observed. In the absence of magnetic fields, winds forming in inner regions of accretion discs could primarily be accelerated by radiations emitted from this region where centrifugal force is important. We study critical point behaviour of outflows in presence of this radiative acceleration. We show that the momentum deposition term changes the character of the solution drastically depending on the magnitude and the location of the deposition. We discuss the implications of these solutions in detail. Particularly important is the fact that matter were found to be pushed to infinity, even when they were originally bound energetically. We perform numerical simulations by smoothed particle hydrodynamics (SPH), and show that these new solutions are stable.

scholarly journals Hydrodynamic Modelling of Accretion Flows

2004 ◽  
Vol 194 ◽  
pp. 166-168
Author(s):  
J. R. Murray ◽  
M. R. Truss ◽  
S. B. Foulkes ◽  
C. A. Haswell ◽  
K. J. Manson
Keyword(s):  
Accretion Disks ◽  
Smoothed Particle Hydrodynamics ◽  
Numerical Scheme ◽  
Close Binary ◽  
Hydrodynamic Modelling ◽  
Accretion Flows ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

AbstractIn the proceedings of this, and of several recent close binary conferences, there have been several contributions describing smoothed particle hydrodynamics simulations of accretion disks. It is opposite therefore to review the numerical scheme itself with emphasis on its advantages for disk modelling, and the methods used for modelling viscous processes.

scholarly journals SPH Simulations of Tidally Unstable Accretion Disks

1996 ◽  
Vol 158 ◽  
pp. 115-116
Author(s):  
James Murray
Keyword(s):  
Accretion Disks ◽  
Orbital Period ◽  
Smoothed Particle Hydrodynamics ◽  
Inertial Frame ◽  
Feedback Mechanism ◽  
Mode Analysis ◽  
Two Dimensional ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Eccentric Disk

We use two dimensional Smoothed Particle Hydrodynamics simulations to investigate the the Tidal Resonance Instability (TRI) model for superhumps in SU UMa stars.In the TRI model, superhumps are the signature of an eccentric disk being periodically stressed by the binary system’s rotating tidal field. A slow prograde motion of the disk in the inertial frame is then responsible for the superhump period slightly exceeding the binary orbital period. The disk eccentricity is caused by a 3:1 resonance between orbits in the disk and the orbit of the binary itself. The development of the TRI model is due mainly to Whitehurst (1988), Hirose & Osaki (1990) and Lubow (1991a). Lubow in particular carried out a nonlinear mode analysis of a fluid disk’s response to a weak tidal field and identified the feedback mechanism responsible for disk eccentricity growth.

Sign in / Sign up

Export Citation Format

Share Document