Natsuki Hosono

A COMPARISON OF SPH ARTIFICIAL VISCOSITIES AND THEIR IMPACT ON THE KEPLERIAN DISK

Hydrodynamical simulations of rotating disk play important roles in the field of astrophysical and planetary science. Smoothed Particle Hydrodynamics (SPH) has been widely used for such simulations. It, however, has been known that with SPH, a cold and thin Kepler disk breaks up due to the unwanted angular momentum transfer. Two possible reasons have been suggested for this breaking up of the disk; the artificial viscosity (AV) and the numerical error in the evaluation of pressure gradient in SPH. Which one is dominant has been still unclear. In this paper, we investigate the reason for this rapid breaking up of the disk. We implemented most of popular formulations of AV and switches and measured the angular momentum transfer due to both AV and the error of SPH estimate of pressure gradient. We found that the angular momentum transfer due to AV at the inner edge triggers the breaking up of the disk. We also found that the classical von-Neumann-Richtmyer-Landshoff type AV with a high order estimate for

Particle Number Dependence of the N-body Simulations of Moon Formation

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FDPS: a novel framework for developing high-performance particle simulation codes for distributed-memory systems

can maintain the disk for

Simulations of below-ground dynamics of fungi: 1.184 pflops attained by automated generation and autotuning of temporal blocking codes

\sim 100

The giant impact simulations with density independent smoothed particle hydrodynamics

orbits even when used with the standard formulation of SPH.

Implementation and performance of FDPS: a framework for developing parallel particle simulation codes

The formation of the Moon from the circumterrestrial disk has been investigated by using

Fortran interface layer of the framework for developing particle simulator FDPS

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N-body simulation of Haumea ring formation

-body simulations with the number

Numerical simulations of the giant impact onto the magma ocean

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Numerical simulation of Saturn ring formation using SPH

of particles limited from