کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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501663 | 863616 | 2014 | 11 صفحه PDF | دانلود رایگان |
This work focuses on the numerical simulation of the Wigner–Poisson–BGK equation in the diffusion asymptotics. Our strategy is based on a “micro–macro” decomposition, which leads to a system of equations that couple the macroscopic evolution (diffusion) to a microscopic kinetic contribution for the fluctuations. A semi-implicit discretization provides a numerical scheme which is stable with respect to the small parameter εε (mean free path) and which possesses the following properties: (i) it enjoys the asymptotic preserving property in the diffusive limit; (ii) it recovers a standard discretization of the Wigner–Poisson equation in the collisionless regime. Numerical experiments confirm the good behavior of the numerical scheme in both regimes. The case of a spatially dependent ε(x)ε(x) is also investigated.
Journal: Computer Physics Communications - Volume 185, Issue 2, February 2014, Pages 448–458