arXiv subjects

Sandra Jeyakumar

Publications and source records attributed to Sandra Jeyakumar.

2 recordsLinked to original sources

arXiv2024

Structure-preserving particle methods for the Landau collision operator using the metriplectic framework

We present a novel family of particle discretisation methods for the nonlinear Landau collision operator. We exploit the metriplectic structure underlying the Vlasov-Maxwell-Landau system in order to obtain disretisation schemes that automatically preserve mass, momentum, and energy, warrant monotonic dissipation of entropy, and are thus guaranteed to respect the laws of thermodynamics. In contrast to recent works that used radial basis functions and similar methods for regularisation, here we use an auxiliary spline or finite element representation of the distribution function to this end. Discrete gradient methods are employed to guarantee the aforementioned properties in the time discrete domain as well.

physics.plasm-ph↗

arXiv2023

A structure-preserving particle discretisation for the Lenard-Bernstein collision operator

Collisions are an important dissipation mechanism in plasmas. In one-dimensional modelling, a commonly used collision operator is the Lenard-Bernstein operator, or its modified energy- and momentum-conserving counterpart. When approximating such operators numerically, it is important to respect their structure in order to satisfy the laws of thermodynamics. It is, however, challenging to discretise such operators in a structure-preserving way when considering particle methods. In this work, we present a macro-particle discretisation of the Lenard-Bernstein collision operator that is energy and momentum preserving.

physics.plasm-ph↗