1,448 research outputs found
Smooth particle hydrodynamics in cylindrical coordinates
A derivation of the equations of Smooth Particle Hydrodynamics (SPH) in axisymmetric cylindrical coordinates is presented. The cylindrical SPH formulation is tested by solving two dimensional shock problems
Newtonian Hydrodynamics of the Coalescence of Black Holes with Neutron Stars I: Tidally locked binaries with a stiff equation of state
We present a detailed study of the hydrodynamical interactions in a Newtonian
black hole-neutron star binary during the last stages of inspiral. We consider
close binaries which are tidally locked, use a stiff equation of state (with an
adiabatic index Gamma=3) throughout, and explore the effect of different
initial mass ratios on the evolution of the system. We calculate the
gravitational radiation signal in the quadrupole approximation. Our
calculations are carried out using a Smooth Particle Hydrodynamics (SPH) code.Comment: Replaces previous version which had figures separate from the text of
the paper. Now 47 pages long with 19 embedded figures (the figures are the
same, they were renumbered) Uses aaspp4.st
Recent applications of the TĂĽbingen-Vienna Smooth Particle Hydrodynamics code
Here, we present the latest improvements and applications
of the TĂĽbingen-Vienna Smooth Particle Hydrodynamics
(SPH) code. By the use of modern graphics processing units
(GPUs), we have increased the performance of astrophysical
simulations in the field of hydrodynamics and solid mechanics by
porting an OpenMP code to the GPU with CUDA™. Recently, we
have added a porosity module and a soil module to our existing
framework. The code is freely available upon request
Inviscid SPH
In smooth-particle hydrodynamics (SPH), artificial viscosity is necessary for
the correct treatment of shocks, but often generates unwanted dissipation away
from shocks. We present a novel method of controlling the amount of artificial
viscosity, which uses the total time derivative of the velocity divergence as
shock indicator and aims at completely eliminating viscosity away from shocks.
We subject the new scheme to numerous tests and find that the method works at
least as well as any previous technique in the strong-shock regime, but becomes
virtually inviscid away from shocks, while still maintaining particle order. In
particular sound waves or oscillations of gas spheres are hardly damped over
many periods.Comment: 14 pages (15 in arXiv), 15 figures, accepted for publication in MNRA
Effects of a giant impact on Uranus
The effects of a giant impact on Uranus with respect to the axis tilt of Uranus and its satellites are discussed. The simulations of possible giant impacts were carried out using Cray supercomputers. The technique used is called smooth particle hydrodynamics (SPH). In this technique, the material in the proto-Uranus planet and in the impactor is divided into a large number of particles which can overlap one another so that local averages over these particles determine density and pressure in the problem, and the particles themselves have their own temperatures and internal energies. During the course of the simulation, these particles move around under the influence of the forces acting on them: gravity and pressure gradients. The results of model simulations are presented
Updated Lagrangian formulation for corrected smooth particle hydrodynamics
Smooth Particle Hydrodynamics (SPH) are, in general, more robust than finite elements for large distortion problems. Nevertheless, updating the reference configuration may be necessary in some problems involving extremely large distortions. If a standard updated formulation is implemented in SPH zero energy modes are activated and spoil the solution. It is important to note that the updated Lagrangian does not present tension instability but only zero energy modes. Here an stabilization technique is incorporated to the updated formulation to obtain an improved method without mechanisms
Updated Lagrangian formulation for corrected smooth particle hydrodynamics
Smooth Particle Hydrodynamics (SPH) are, in general, more robust than finite elements for large distortion problems. Nevertheless, updating the reference configuration may be necessary in some problems involving extremely large distortions. If a standard updated formulation is implemented in SPH zero energy modes are activated and spoil the solution. It is important to note that the updated Lagrangian does not present tension instability but only zero energy modes. Here an stabilization technique is incorporated to the updated formulation to obtain an improved method without mechanisms.Peer ReviewedPostprint (author’s final draft
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