Benjamin K. Bergen — Page 3

arXiv2020

FleCSPH: The Next Generation FleCSIble Parallel Computational Infrastructure for Smoothed Particle Hydrodynamics

FleCSPH is a smoothed particle hydrodynamics simulation tool, based on the compile-time configurable framework FleCSI. The asynchronous distributed tree topology combined with a fast multipole method allows FleCSPH to efficiently compute hydrodynamics and long range particle-particle interactions. FleCSPH provides initial data generators, particle relaxation techniques, and standard evolution drivers, which can be easily modified and extended to user-specific setups. Data input/output uses the H5part format, compatible with modern visualization software.

physics.comp-ph↗

arXiv2013

On the velocity space discretization for the Vlasov-Poisson system: comparison between Hermite spectral and Particle-in-Cell methods. Part 1: semi-implicit scheme

We discuss a spectral method for the numerical solution of the Vlasov-Poisson system where the velocity space is decomposed by means of an Hermite basis. We describe a semi-implicit time discretization that extends the range of numerical stability relative to an explicit scheme. We also introduce and discuss the effects of an artificial collisional operator, which is necessary to take care of the velocity space filamentation problem, unavoidable in collisionless plasmas. The computational efficiency and the cost-effectiveness of this method are compared to a Particle-in-Cell (PIC) method in the case of a two-dimensional phase space. The following examples are discussed: Langmuir wave, Landau damping, ion-acoustic wave, two-stream instability, and plasma echo. The Hermite spectral method can achieve solutions that are several orders of magnitude more accurate (at a fraction of the cost) with respect to the PIC method.

physics.plasm-ph↗