May 1-3

Log in

Abstract Details

files Add files

Abstracts

Author: A. Hassam
Requested Type: Poster
Submitted: 2017-03-16 11:38:28

Co-authors: J. Tenbarge, W. Dorland, M. Landreman, S. DeSouza_Machado (UMBC)

Contact Info:
Univ of Maryland
IREAP
college park, md   20742
US

Abstract Text:
A 3D nonlinear dissipative MHD code is developed to allow relaxation to low-beta MHD equilibrium inside a shaped 3D conducting boundary with prescribed conserved axial magnetic flux and no external current. Formation of magnetic islands is allowed. Heat sources would be eventually introduced to allow possible non-stationary convection depending on the MHD stability properties. The initial development is done using UMHD (Guzdar et al, PF, 1993). The initial emphasis will be on recovering expected physics in simpler 3D geometries. A primary objective is to minimize numerical boundary noise. In particular, codes which specify the normal magnetic field B.n on bounding surfaces are prone to boundary noise generation. We shape the boundary to conform to the desired field shape so that B.n is zero on the boundary, employing curvilinear coordinates. Significant noise reduction has is achieved by this approach. Boundary noise is strongly suppressed if the boundary is modeled as a sharp ramp-down in resistivity, allowing relaxation to equilibrium but no penetration outward. Initial results have been verified w.r.t. analytic calculation in the weak shaping limit. A rotational transform is observed in helical shaping. Hahm- Kulsrud island formation solution is also doable within this approach. - Work supported by US DOE.

Comments:
Prefer poster on Tuesday.