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Title: Higher Order Lagrange Finite Elements In M3D

Technical Report ·
DOI:https://doi.org/10.2172/836490· OSTI ID:836490

The M3D code has been using linear finite elements to represent multilevel MHD on 2-D poloidal planes. Triangular higher order elements, up to third order, are constructed here in order to provide M3D the capability to solve highly anisotropic transport problems. It is found that higher order elements are essential to resolve the thin transition layer characteristic of the anisotropic transport equation, particularly when the strong anisotropic direction is not aligned with one of the Cartesian coordinates. The transition layer is measured by the profile width, which is zero for infinite anisotropy. It is shown that only higher order schemes have the ability to make this layer converge towards zero when the anisotropy gets stronger and stronger. Two cases are considered. One has the strong transport direction partially aligned with one of the element edges, the other doesn't have any alignment. Both cases have the strong transport direction misaligned with the grid line by some angles.

Research Organization:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Organization:
USDOE Office of Science (SC) (US)
DOE Contract Number:
AC02-76CH03073
OSTI ID:
836490
Report Number(s):
PPPL-4032; TRN: US0500614
Resource Relation:
Other Information: PBD: 17 Dec 2004
Country of Publication:
United States
Language:
English