Clump Behavior w/ Alexei's Setup

Going back to basics, with a simulation setup that we know should work. Here are the parameters: 

nwind = 1000 cm-3
Twind = 5000 K
vwind = 74.53 km/s ==> M = 10

nclump = 500,000 cm-3 ==> X = 500
Tclump = 10 K (pressure equilibrium)
vclump = 0

I tested different Riemann solvers and different interpolation orders. I was only able to test the Sweep method, because MUSCL is only implemented for fixed grid and 1 proc.

Also, the HLL linear run had the most trouble. It only got through 61/100 frames in 2 hours on 64 procs. This may have to do with whatever happened around frame 45…looks like a density protection maybe. All the other runs got through the full 100, and usually in much less than 2 hours with 64 procs.

Exact HLL HLLC
1st Order (Godunov)
movie​ movie​ movie​
2nd Order (linear)
movie​ movie​ movie​


I also did a run with the 'default' solver settings (sweep, HLLC, linear), but with a lower CFL. The original CFL variables were 1, .5, .5, and the run below has .5, .2, .5.

movie​


Some Observations

  • All the Godunov runs are more diffusive which is expected.
  • Out of all 3 Godunov runs, only the HLLC solver produces asymmetries.
  • All of the 2nd order runs become asymmetric at some point with perhaps the Exact solver being most symmetric and HLLC most asymmetric.
  • Lowering the CFL did not seem to make a significant difference.

Attachments (14)

Comments

No comments.