Changes between Version 12 and Version 13 of AstroBearProjects/MHDClumps


Ignore:
Timestamp:
07/20/11 17:42:35 (14 years ago)
Author:
Jonathan
Comment:

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  • AstroBearProjects/MHDClumps

    v12 v13  
     1[[PageOutline]]
     2
    13= MHD Clumps: Heterogeneity and Radiative Cooling =
    24We seek to understand the role magnetic field alignment and clump-clump spacing (''filling fraction'') have on the evolution of a host of randomly-distributed clumps overrun by a steady supersonic wind.
    … …  
    6062
    6163[[Image(By_sparse_00154.png, width=600)]]
     64
     65-----
     66
     67== Round II ==
     68 After looking at the final frame of the By_sparse [attachment:By_sparse_bad.gif movie]
     69
     70[[Image(By_sparse_bad.png)]]
     71
     72there were some striations - coming off of the magnetized rarefactions behind the clumps...  To investigate this I ran a set of simulations focusing on the region around the clump at [8, 14.5]
     73
     74Here is the same setup run out to frame 11.  On the left is the density with field lines and on the right is the temperature.  Notice the temperature protections in the magnetized rarefactions...
     75
     76[[Image(IO3CLLOF.png, width=600)]]
     77
     78I then ran the same setup in fixed grid to ensure that AMR noise was not responsible
     79
     80[[Image(IO3CLLOFFixedGrid.png, width=600)]]
     81
     82I then turned off the Local Oscillation Filter to see if that was reponsible
     83
     84[[Image(IO3CLNoLOF.png, width=600)]]
     85
     86As well as switching from Characteristic limiters to primitive limiters
     87
     88[[Image(IO3PLNoLOF.png, width=600)]]
     89
     90I then switched the interpolation order from 3 (PPM) to 1 (Gudonov)
     91
     92[[Image(IO1CL.png, width=600)]]
     93
     94And to order 2 (PLM)
     95
     96[[Image(IO2CL.png, width=600)]]
     97
     98Since lowering the order from 3 to 1 or 2 fixed the problem, i then checked that the Bx case also was well behaved
     99
     100[[Image(IO2CLBx.png, width=600)]]
     101
     102As well as the hydro case
     103
     104[[Image(IO2CLHydro.png, width=600)]]
     105
     106And finally I checked that the HLLC solver gave the same result as the HLLD solver by turning of MHD
     107
     108[[Image(IO2CLHydroHLLC.png, width=600)]]
     109
     110
     111I suspect the same oscillations seen in [ticket:127] are behind the pressure protections - but I'm not entirely sure. 
     112---