PLUTO Test Problems
4.4-patch2
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Advection of a magnetic field loop. More...
Functions | |
void | InitDomain (Data *d, Grid *grid) |
This problem consists of a weak magnetic field loop being advected in a uniform velocity field. Since the total pressure is dominated by the thermal contribution, the magnetic field is essentially transported as a passive scalar. The preservation of the initial circular shape tests the scheme dissipative properties and the correct discretization balance of multidimensional terms.
Following [GS05][MT10][MTB10] (see also references therein), the computational box is defined by discretized on
grid cells (Ny=64). Density and pressure are initially constant and equal to 1. The velocity of the flow is given by
with . The magnetic field is defined through its magnetic vector potential as
with . A slightly different variant is used for the finite difference schemes as explained in [MTB10]:
where .
Double periodic boundary conditions are imposed.
A snapshot of the solution on a 128x64
grid at t=0.2 is shown below.
References