Added smoothing length correction limiter to Gizmo hydro_predict_extra.

For some reason, the smoothing length prediction in GIZMO sometimes goes completely wrong, causing the code to crash in space_regrid, see #271 (closed). To overcome this, I have added a limit on the increase in smoothing length during the prediction step for GIZMO. This appears to solve the issue @jwillis was having with the EAGLE_12 test (I am currently testing it on one of my machines, and it's still running after 6000 steps).

I'm not sure it is worth looking into the cause of the bad smoothing length predictions. The smoothing length update is computed based on a mixture of SPH and GIZMO variables, so this is bound to go wrong sometimes. Maybe there are smarter ways to do this.

mentioned in issue #271 (closed)

Title changed from Added smoothing length correction limiter to Gizmo hydro_predict_extra. to [WIP] Added smoothing length correction limiter to Gizmo hydro_predict_extra.

Changed to WIP since the bug still affects the EAGLE_12 run (albeit after many more steps).

Added 1 commit:

• f61ae185 - Added a debug check for negative mass/energy to Gizmo kick_extra. Fixed a typo in space.c.

Added 1 commit:

• 7d863453 - Added a basic flux limiter to the GIZMO scheme.

Added 1 commit:

• 6c265014 - Added condition number computation for Gizmo matrix + a mechanism to increase th…

Added 16 commits:

• 6c265014...3b974424 - 15 commits from branch master
• 37a9bafa - Merge branch 'master' into gizmo_fix

Would you like me to merge this in nevertheless ?

Yes, might be safer. I will hopefully have some time next week to start looking into this again.

Added 1 commit:

• 7d66272a - Rolled back change to src/space.c

Title changed from [WIP] Added smoothing length correction limiter to Gizmo hydro_predict_extra. to Added smoothing length correction limiter to Gizmo hydro_predict_extra.

Added 167 commits:

• 7d66272a...bd9b222b - 166 commits from branch master
• a5ab4a7f - Merge branch 'master' into gizmo_fix

Status changed to merged

mentioned in commit 571d2b94