Hamiltonian closures for two-moment fluid models derived from drift-kinetic equations

Hamiltonian closures for two-moment fluid models derived from drift-kinetic equations

We derive the conditions under which the fluid models obtained from the first two moments of Hamiltonian drift-kinetic systems of interest to plasma physics, preserve a Hamiltonian structure. The adopted procedure consists of determining closure relations that allow to truncate the Poisson bracket of the drift-kinetic system, expressed in terms of the moments, in such a way that the resulting o...

Hamiltonian structure of a drift-kinetic model and Hamiltonian closures for its two-moment fluid reductions

Hamiltonian fluid closures of the Vlasov-Ampère equations: From water-bags to N moment models

Moment systems derived from relativistic kinetic equations

In this paper, we are interested in the derivation of macroscopic equations from kinetic ones using a moment method in a relativistic framework. More precisely, we establish the general form of moments that are compatible with the Lorentz invariance and derive a hierarchy of relativistic moment systems from a Boltzmann kinetic equation. The proof is based on the representation theory of Lie alg...

Positive Filtered PN Moment Closures for Linear Kinetic Equations

Abstract. We propose a positive-preserving moment closure for linear kinetic transport equations based on a filtered spherical harmonic (FPN ) expansion in the angular variable. The recently proposed FPN moment equations are known to suffer from the occurrence of (unphysical) negative particle concentrations. The origin of this problem is that the FPN approximation is not always positive at the...