Version 42 (modified by 11 years ago) ( diff ) | ,
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3D MHD Shear Flows
Diameter | 40 pc |
Mach | 1.5 |
Shear Angles | 15, 30, 60 degrees |
Density | 1 cm-3 |
Beta | 1, 10, Hydro |
Initial B-field orientation | Uniform in x, y, z |
Cells/Jeans Length | 64 |
Cooling | II curve |
Final time | 20 Myr |
Resolution | 48 + 2 ~ 200 cells effective |
Box size | 62.5 x 75 x 75 pc in x,y,z |
Boundary conditions | Extrapolating, and multipole |
Self-gravity | On |
Orientation of Collision Interface
Plots showing the direction of the tilted interface:
Shear15 | Shear30 | Shear60 |
Interface is rotated about y.
Uniform X-field Case
Evolution of the tilted interface
A slice taken through the center of the box, in the x-z plane, shows that in the strong magnetic field case, the interface tends to realign so that it is vertical in z:
Interestingly, the hydro case might also straighten out..?
Column Density Maps
These column density maps are made by summing the density over all cells through a given dimension, using both the gas and sink components. You can use the above 3D plot for orientation. In the 'down the barrel case', the vertical dimension is z, and the horizontal axis is y. The axes are given in the other plots.
'Down the Barrel' | Down Y | Down Z |
movie | movie | movie |
A strong ring effect is present in the strong beta cases that isn't in the weaker B field and hydro case. The ripples are also interesting, not sure whether they are numerical or physical yet.
Peak Densities and Sink Particles
Run | Time when sink first appears | Number of sinks by end |
Beta1, Shear15 | Frame 160/200, t=1.32 | 8 |
Beta1, Shear30 | Frame 173/200, t=1.43 | 7 |
Beta1, Shear30 | No Sinks Form | 0 |
Beta10, Shear15 | Frame 184/200, t=1.5 | 5 |
Beta10, Shear30 | Frame 161/200, t=1.3 | 2 |
Beta10, Shear30 | Frame 196/200, t=1.6 | 1 |
Hydro, Shear15 | Frame 118/200, t=11 Myr | 6 |
Hydro, Shear30 | Frame 146/200, t=1.2 | 3 |
Hydro, Shear60 | No Sinks Form | 0 |
X, Y, & Z magnetic field cases
Beta = 1
Was not obvious which field orientation would be best to use for the transverse (i.e. perpendicular to the flow direction) field run, since the shear angle breaks the symmetry of the cylinder. So to compare the difference, here are 3D low runs of the Shear 15, Beta=1 case.
In column density, the transverse runs (y-field and z-field) are mirror images of each other. This can be seen at once looking down the barrel in x. When looking transversely, orient yourself to the direction of the incoming flow along x, then consider the direction of the field using the coordinate axes at bottom of each column. You will see that the same behavior is seen between the different orientations. That is, the middle box has same behavior as bottom right box, when you consider the relative directions of the field and the colliding flows.
And here are the 3 different initial conditions for orientation:
Bx
By
Bz
Further, peak densities were similar in the transverse cases and both did not form sinks,
B-field Direction | Peak Density at .25, .50, .75, 1 | Time first sink formed | No. of sinks by end |
x | 229, 947, 2383, 4934 | 15 Myr | 8 |
y | 27, 58, 69, 88 | -No sinks form- | 0 |
z | 22, 51, 50, 58 | -No sinks form- | 0 |
Beta = 10
B-field Direction | Peak Density at .25, .50, .75, 1 | Time first sink formed | No. of sinks by end |
x | 598, 1140, 1535, 1487 | 18 Myr | 5 |
y | 83, 210, 255, 225 | -No sinks form- | 0 |
z | 58, 132, 194, 163 | -No sinks form- | 0 |
Attachments (40)
- ColDensX_CF15_Beta1.gif (11.0 MB ) - added by 11 years ago.
- ColDensX_CF15_Beta10079.png (37.8 KB ) - added by 11 years ago.
- ColDensY_CF15_Beta10079.png (29.7 KB ) - added by 11 years ago.
- ColDensY_CF15_Beta1.gif (7.3 MB ) - added by 11 years ago.
- ColDensZ_CF150079.png (32.2 KB ) - added by 11 years ago.
- ColDensZ_CF15_Beta1.gif (8.4 MB ) - added by 11 years ago.
- down_x0114.png (145.9 KB ) - added by 11 years ago.
- down_x_coldens.gif (16.3 MB ) - added by 11 years ago.
- down_y0114.png (87.5 KB ) - added by 11 years ago.
- down_y_coldens.gif (13.5 MB ) - added by 11 years ago.
- down_z0114.png (116.9 KB ) - added by 11 years ago.
- down_z_coldens.gif (17.4 MB ) - added by 11 years ago.
- shear30axes.png (32.4 KB ) - added by 11 years ago.
- shear15axes.png (29.9 KB ) - added by 11 years ago.
- shear60axes.png (38.1 KB ) - added by 11 years ago.
- xz_plane_rho0029.png (62.1 KB ) - added by 11 years ago.
- xz_plane_rho.gif (9.7 MB ) - added by 11 years ago.
- Hydro.png (37.0 KB ) - added by 11 years ago.
- Beta10.png (36.7 KB ) - added by 11 years ago.
- Beta1.png (35.7 KB ) - added by 11 years ago.
- Bx_Init.png (39.9 KB ) - added by 11 years ago.
- Bz_Init.png (42.1 KB ) - added by 11 years ago.
- By_Init.png (46.1 KB ) - added by 11 years ago.
- diff_fields_compare.gif (21.1 MB ) - added by 11 years ago.
- b1s15ycdm.2.gif (16.6 MB ) - added by 11 years ago.
- b10s15zcdm.gif (19.2 MB ) - added by 11 years ago.
- b1s15zcdm.gif (12.8 MB ) - added by 11 years ago.
- b10s15ycdm.gif (18.2 MB ) - added by 11 years ago.
- b1s15ycdm.gif (16.6 MB ) - added by 11 years ago.
- b10s15xcdm.gif (31.1 MB ) - added by 11 years ago.
- b1s15xcdm.gif (22.1 MB ) - added by 11 years ago.
- HydroS60_nosinks.gif (21.2 MB ) - added by 11 years ago.
- B1S15CDM_sinks.gif (12.1 MB ) - added by 11 years ago.
- B10S30CDM_sinks.gif (18.8 MB ) - added by 11 years ago.
- B10S60CDM_sinks.gif (17.5 MB ) - added by 11 years ago.
- B10S15CDM_sinks.gif (17.9 MB ) - added by 11 years ago.
- B1S60CDM_nosinks.gif (14.2 MB ) - added by 11 years ago.
- B1S30CDM_sinks.gif (13.5 MB ) - added by 11 years ago.
- HydroS30_sinks.gif (21.5 MB ) - added by 11 years ago.
- HydroS15CDM_sinks.gif (20.0 MB ) - added by 11 years ago.