[Mesa-users] convergence problems of a white dwarf post entropy relaxation

[Francis Timmes]

hi akaash,

let's take a step back. at high-level, what are you trying to accomplish?
impose a chemical profile on a white dwarf and then watch the white dwarf cool?

fxt






> On Nov 27, 2020, at 1:11 PM, Akaash Conhye via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> 
> Hi all,
> 
> I'm trying to relax the entropy profile of a white dwarf from 3d hydrodynamic simulations (which used a helmholtz EOS without colomb corrections) but i run into convergence problems once the white dwarf has relaxed and begins its first real time evolution step. the white dwarf has a nickel-56 envelope and the star has a total mass of 0.6 solar masses. The terminal output is shown at the end.
> 
> I started by first relaxing the composition profile, saving this model, then relaxing entropy afterwards. the relative error I have is ~0.1526. The template im using is wd_cool_0.6M. It could be that I have some obvious improper physics in my inlist so I've attached a copy of it. the things ive tried to change are available to see on "inlist_wd_cool_0.6M" (my changes are denoted with !!, single ! are default comments) but if you find this distracting, I've also attached a copy of the inlist without the comments named "inlist_wd_cool_0.6M_uncommented".
> ...
> Terminated relax because of max_model_number instead or relax_time
>  net name approx21.net
>  use_gold_tolerances T
>  do_element_diffusion T
>                                       atm_option: T_tau
>  species
>      1   neut
>      2   h1
>      3   prot
>      4   he3
>      5   he4
>      6   c12
>      7   n14
>      8   o16
>      9   ne20
>     10   mg24
>     11   si28
>     12   s32
>     13   ar36
>     14   ca40
>     15   ti44
>     16   cr48
>     17   cr56
>     18   fe52
>     19   fe54
>     20   fe56
> 21   ni56
> 
>  kappa_file_prefix gs98
>  kappa_lowT_prefix lowT_fa05_gs98
>                                         OMP_NUM_THREADS          16
> 
> 
>  retry     130
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> 
> terminated evolution: dt_is_zero
> 
> termination code: dt_is_zero
> DATE: 2020-11-27
> TIME: 18:47:38
> 
> 
> Thanks for your help,
> 
> Akaash
> 
> 
> <inlist_wd_cool_0.6M><inlist_wd_cool_0.6M_uncommented>_______________________________________________
> mesa-users at lists.mesastar.org
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