Plasma and Fusion Research

Volume 18, 1203005 (2023)

Rapid Communications

Viscous-Flux Approximation Modeling in Anisotropic-Ion-Pressure Fluid Scheme
Satoshi TOGO, Tomonori TAKIZUKA1), Kenzo IBANO1), Yuki HOMMA2), Naomichi EZUMI and Mizuki SAKAMOTO
Plasma Research Center, University of Tsukuba, Tsukuba 305-8577, Japan
Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
National Institutes for Quantum Science and Technology, Rokkasho 039-3212, Japan
(Received 19 November 2022 / Accepted 14 December 2022 / Published 23 January 2023)


Anisotropic-Ion-Pressure (AIP) fluid model describes more accurately the characteristics of plasmas in open-magnetic-field systems, e.g., magnetic mirror, scrape-off layer, and divertor. AIP model combined with the virtual divertor model has a merit to be free from the boundary condition of flow speed at the end plate [S. Togo et al., J. Comput. Phys. 310, 109 (2016); Contrib. Plasma Phys. 58, 556 (2018)]. In order to compare the AIP modeling with the conventional plasma fluid modeling by using only a single AIP code, we introduce a kind of “viscous-flux approximation (VFA)” into the AIP energy equations, where the anisotropic pressure relaxation term is modified artificially to equalize the pressure anisotropy with the parallel viscous stress. One-dimensional simulations are carried out with the original AIP modeling and with the VFA-AIP modeling, respectively. Expected numerical results are obtained for a simple mirror configuration.


plasma fluid simulation, anisotropic ion pressure, viscous flux, open magnetic field

DOI: 10.1585/pfr.18.1203005


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