[FLASH-USERS] Checkerboard structure in magnetic field using USM solver

[Dongwook Lee]

Dear Rukmani,

It looks to me that they may come from numerical instability, although it
could be an issue related to the use of AMR. What reconstruction scheme and
CFL number are you using? Is this 2D or 3D?

Best,
Dongwook

On Sun, Oct 8, 2017 at 12:59 PM, Rukmani Vijayaraghavan <
rukmani at virginia.edu> wrote:

> Hi everyone,
>
> I get a strange, unphysical feature in the magnetic field structure with
> the USM solver, seen in the attached slices of B_z and the magnetic
> pressure. These features, as you can see, track the block boundaries and
> look like a checkerboard of varying magnetic field strength (and sign?) in
> individual grid cells. I've tried modifying every possible USM solver
> switch, including the Riemann solver, order, slope limiter, prolongation
> method, steepening, etc. Using Riemann Solver = HLLC instead of HLLD makes
> things a little better, since HLLC is more diffusive, but the feature still
> eventually appears. Any advice on solving this or even minimizing its
> effects would be helpful!
>
> Thanks,
>
> Rukmani
>
> --
> Rukmani Vijayaraghavan
> NSF Astronomy & Astrophysics Postdoctoral Fellow
> University of Virginia
> rukmani at virginia.edu
>
>


-- 

=========================================
Dongwook Lee, Ph.D., Assistant Professor
Applied Mathematics and Statistics
University of California, Santa Cruz
Baskin Engineering, Room 353C
1156 High Street, Santa Cruz, CA 95064
https://users.soe.ucsc.edu/~dongwook/
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