# Variational mean-fluctuation splitting and drift-fluid models

Source: [Variational mean-fluctuation splitting and drift-fluid models](<https://www.sota2.com/research/paper/68fa3b971e209131ce8d3cdb>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-25T00:40:57.041Z

Authors: Cesare Tronci

Published: 2019-10-30T14:27:52.000Z

## Abstract

After reviewing the variational approach to splitting mean flow and fluctuation kinetics in the standard Vlasov theory, the same method is applied to the drift-kinetic equation from Littlejohn's theory of guiding-center motion. This process sheds a new light on drift-ordered fluid (drift-fluid) models, whose anisotropic pressure tensor is then considered in detail. In addition, current drift-fluid models are completed by the insertion of magnetization terms ensuring momentum conservation. Magnetization currents are also shown to lead to challenging aspects when drift-fluid models are coupled to Maxwell's equations for the evolution of the electromagnetic field. In order to overcome these difficulties, a simplified guiding-center theory is proposed along with its possible applications to hybrid kinetic-fluid models.

## Recorded benchmark results

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## Original sources and implementation

[Original paper](<https://arxiv.org/abs/1910.13883>)

[PDF](<https://arxiv.org/pdf/1910.13883.pdf>)