[Mesa-users] convergence problems of a white dwarf post entropy relaxation
Akaash Conhye
ac01283 at surrey.ac.uk
Mon Nov 30 13:45:49 EST 2020
Hi Francis,
Thanks for your suggestion, but the I am quite interested in the behaviour of this white dwarf during the first few thermal timescales as well. Thus, it's necessary for the star to undergo the entropy relaxation process.
Akaash
________________________________
From: Francis Timmes <fxt44 at mac.com>
Sent: 29 November 2020 01:12
To: Conhye, Akaash (UG - Physics) <ac01283 at surrey.ac.uk>
Cc: Frank Timmes <fxt44 at mac.com>; mesa-users <mesa-users at lists.mesastar.org>
Subject: Re: [Mesa-users] convergence problems of a white dwarf post entropy relaxation
imposing a chemical profile on a hot wd and letting it evolve
is standard fare in some parts of the wd seismology community.
one can explore this approach in mesa by experimenting with
josiah schwab's wd_builder https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fjschwab%2Fwd_builder&data=04%7C01%7Cac01283%40surrey.ac.uk%7C220e57c650904a0a819b08d89403d6fc%7C6b902693107440aa9e21d89446a2ebb5%7C0%7C0%7C637422091495467477%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=N0rtY%2FPWoi8kTDf6OVycGi%2BZJZwlUGtdR1KwZ0iPZA4%3D&reserved=0 .
i've found building such an ab initio wd to be a lot more useful
that the double relation approach being tried.
once such an out of thermal equilibrium wd starts evolves a few
thermal timescales and begins sliding down the cooling track, it largely
forgets thermodynamic-wise how it got there. that is, i suspect the
initial entropy profile does not matter much.
fxt
> On Nov 28, 2020, at 2:14 PM, Akaash Conhye <ac01283 at surrey.ac.uk> wrote:
>
> Hi Francis,
>
> What im trying to do is impose both chemical and entropy profiles and watch the white dwarf cool.
>
> Thanks
>
> Akaash
> From: Francis Timmes <fxt44 at mac.com>
> Sent: 28 November 2020 20:42
> To: Conhye, Akaash (UG - Physics) <ac01283 at surrey.ac.uk>
> Cc: Frank Timmes <fxt44 at mac.com>; mesa-users <mesa-users at lists.mesastar.org>
> Subject: Re: [Mesa-users] convergence problems of a white dwarf post entropy relaxation
>
> 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
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> > retry 130
> > retry 130
> > backup 130
> >
> > 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
> > https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.mesastar.org%2Fmailman%2Flistinfo%2Fmesa-users&data=04%7C01%7Cac01283%40surrey.ac.uk%7C220e57c650904a0a819b08d89403d6fc%7C6b902693107440aa9e21d89446a2ebb5%7C0%7C0%7C637422091495467477%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=kwYEIvhmFZAvjgfyljkP7OItNcceH%2BUk3z9e5YuaEu0%3D&reserved=0
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