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More 2-D Mach stem runs w/ cooling
Previous blog posts: ehansen04122016, ehansen04192016
Did a few runs with d/Rclump = 6 where the previous runs were closer together at d/Rclump = 4.
| Rclump/Lcool | At 50 years | Mach stem size |
|---|---|---|
| 2 |  | regular reflection |
| 1 |  | 0.3 Lcool |
| 0.5 |  | 0.4 Lcool |
Also did a run where we are no longer in the frame of reference of the clump and shock; both ambient and clump are moving now, but relative velocity is the same as before. With d/Rclump = 4 and Lcool = 0.05 Rclump. It looked the same, i.e. no instability.
Meeting Update 04/19/2016
Wire Turbulence
- Analyzing data for hydro and MHD (up to 197 frames) runs.
- Haven't done with MHD data yet. Current results of log(density) along middle section and plots for , , and can be found in this page. Will do the plots
- different pattern in the density pseudo color plots along mid-y and mid-z section for MHD.
- both hydro and MHD plots of velocity found strange data point in the center. Will check if it's coming from the analysis method or chombo data
- Density pseudo color plots show MHD run crashed at frame 196. So the restart will need to go from frame 195..
Meeting Update 04/19/2016 - Eddie
- Updated table on Mach stems and Lcool: ehansen04122016
- Checked to see if low resolution is cause of bow shock instability: doesn't appear to be, image below
- Checked if 3-D effects cause bow shock instability: plausible, image below
- Checked if even stronger cooling (Lcool = Rclump / 100) is the cause: also plausible, movie below.
- My thoughts: any small perturbation can trigger the instability whether it be numerical or physical. The stronger the cooling, the easier it is to perturb. I believe my simulations in the clumpy paper are more susceptible simply because they are 3-D; extra degree of freedom for motions and/or noise. Also, in the paper, we are not in the frame of reference of the fast clump.
Lcool = 0.1 Rclump, 2-D, low res 
Lcool = 0.1 Rclump, 3-D slice 
2-D, nice Mach stem, Lcool = 0.5 Rclump movie
2-D, unstable?, Lcool = 0.01 Rclump movie
- I should be able to finish up referee report and resubmit clumpy paper by end of week.
- Pat is working on cooling paper, and I will add some more details this week.
- Thesis is coming along nicely. Most of the writing is finished except for the conclusions section.
Testing
2 AMR level. 0.1 AU the finest resolution.
The radial velocity at the boundary varies as where .
Dust form at fixed radii, the radius is calculated by where is the dust absorption coefficient and is the dust formation temperature.
Meeting Update 04/12/2016 - Eddie
- HEDLA XI accepted my abstract, gave me a poster presentation
- While writing up the introduction for my thesis, I decided it would be nice to have a schematic of a disk-jet system so I drew one.
- In response to referee report on the 3-D clumpy paper, I am running some 2-D sims to look at Mach stem size when cooling is present. For each simulation, I change Rclump to see if Mach stem size is limited by Lcool !and/or Rclump.
All runs have M = 7 and Lcool = 12.7 AU.
1 computational unit = 1 Lcool.
separation distance d = 4 Rclump
| Rclump/Lcool | At 50 years | Mach stem size |
|---|---|---|
| 100 |  | regular reflection, unstable? |
| 20 |  | regular reflection |
| 10 |  | regular reflection |
| 2 |  | approximately 0.5 Lcool |
| 1 |  | approximately 1 Lcool |
| 0.5 |  | forming single bow |
So it does appear that when cooling is strong (Rclump/Lcool ≥ 1), the Mach stem size is limited by Lcool or it's even smaller. However, I'm not convinced that when cooling is weak, the Mach stem size will be limited by Rclump.
Turbulent Wire velocity plots
Hydro run frame 200
Collecting data for other frames …
