Display Abstract

Title Expansion of a singularly perturbed equation with a two-scale converging convection term

Name Alexandre Mouton
Country France
Email alexandre.mouton@math.univ-lille1.fr
Co-Author(s)
Submit Time 2014-02-26 05:22:01
Session
Special Session 94: Homogenization based numerical methods
Contents
In many physical contexts, evolution convection equations may present some very large amplitude convective terms. As an example, in the context of magnetic confinement fusion, the distribution function which describes the plasma satisfies the Vlasvov equation in which some terms are of the same order as $\epsilon^{-1}$, $\epsilon \ll 1$ being the characteristic gyrokinetic period of the particles around the magnetic lines. In this paper, we aim to present a model hierarchy for modeling the distribution function for any value of $\epsilon$ by using some two-scale convergence tools. Following Fr\'enod \& Sonnendr\"ucker's recent work, we choose the framework of a singularly perturbed convection equation where the convective terms admits a high amplitude part which periodically oscillates in time with high frequency $\epsilon^{-1} \gg 1$. In this abstract framework, we derive an expansion with respect to the small parameter $\epsilon$ and we recursively identify each term of this expansion. Finally, we apply this new model hierarchy to the context of a linear Vlasov equation in the presence of a high amplitude external magnetic field.