[Mesa-users] AGB convergence issue

[Francis Timmes]

hi art,

i changed the initial mass to 5 msun and the metallicity of z=1e-4 
in the inlists i sent. it ran without issue to the specified stopping condition 
of envelope_mass_limit < 1e-2 msun. screen shot attached of the final model.

these inlists are modified versions of the ones used in fields et al 2015
which you can grab from http://mesastar.org in the inlist section.

fxt





> On Mar 2, 2018, at 9:34 AM, Francis Timmes <fxt44 at mac.com> wrote:
> 
> hi art,
> 
> for a research project i happen to be looking at ~3 msun zams models
> evolved from the pre-ms to a hot co wd with r10108.
> 
> attached are a snapshot of my current exploratory research-grade inlists 
> (i.e, lots of things activated, commented out, … etc as i explore sensitivities). 
> see if they work for you when the initial mass is changed to 5 msun.
> 
> fxt
> 
> 
> 
> 
> 
>> On Mar 2, 2018, at 8:46 AM, Champagne, Arthur E <artc at physics.unc.edu> wrote:
>> 
>> Hi all,
>>     I’m fairly new to MESA - I’m running r10108 and various test models run fine. I’ve constructed a 5 M_sun, Z=1e-4 model, which evolves in a reasonable way to the start of the AGB. The first 2 pulses look good, but it bogs down on the 3rd pulse, which occurs after the He shall narrows. The problem is “hydro_newton_step failed to accept” and debugging indicates that the problem is occurring in the zones that include the edges of the He shell. No surprise. I’ve tried various approaches to improving resolution and convergence, without success. These have come from the inlists on the web page as well as the agb and 13C pocket models in the test suite. The most recent attempt included (from the agb model):
>> 
>> mesh_dlog_pp_dlogP_extra = 0.25
>> mesh_dlog_cno_dlogP_extra = 0.25
>> mesh_dlog_3alf_dlogP_extra = 0.225
>> mesh_dlog_burn_c_dlogP_extra = 0.225
>> mesh_dlog_burn_n_dlogP_extra = 0.225
>> mesh_dlog_burn_o_dlogP_extra = 0.225
>> mesh_logX_species(1) = 'h1'
>> mesh_logX_min_for_extra(1) = -6
>> mesh_dlogX_dlogP_extra(1) = 0.25
>> mesh_logX_species(1) = 'he4'
>> mesh_logX_min_for_extra(1) = -6
>> mesh_dlogX_dlogP_extra(1) = 0.25
>> xtra_coef_os_above_nonburn = 0.5
>> xtra_coef_os_below_nonburn = 0.25
>> xtra_coef_os_above_burn_h = 0.25
>> xtra_coef_os_below_burn_h = 0.15
>> xtra_coef_os_above_burn_he = 0.25
>> xtra_coef_os_below_burn_he = 0.25
>> xtra_coef_os_above_burn_z = 0.25
>> xtra_coef_os_below_burn_z = 0.25
>> 
>> xtra_dist_os_above_nonburn = 0.1
>> xtra_dist_os_below_nonburn = 0.2
>> xtra_dist_os_above_burn_h = 0.2
>> xtra_dist_os_below_burn_h = 0.2
>> xtra_dist_os_above_burn_he = 0.2
>> xtra_dist_os_below_burn_he = 0.2
>> xtra_dist_os_above_burn_z = 0.2
>> xtra_dist_os_below_burn_z = 0.2
>> 
>>    I have tried playing with the parameters some, but I don’t have a good intuition yet for what they’re doing. So I was wondering if someone who has encountered this problem might have some advice on how to proceed?
>>    Many thanks,
>>    Art Champagne
>> 
>> 
>> _________________________________________________________________
>> 
>> Yeah, he filled his head with notions, seemingly (George Harrison)
>> _________________________________________________________________
>> A.E. Champagne
>> Class of 1989 William C. Friday Professor of Physics
>> Dept. of Physics and Astronomy, Univ. of North Carolina
>> Office: Phillips 230, (919) 962-7205
>> and Director, Triangle Universities Nuclear Laboratory, Duke Univ.
>> Office: TUNL 414, (919) 660-2607
>> aec at tunl.duke.edu or artc at physics.unc.edu
>> _________________________________________________________________
> 
> 
> <inlist><inlist_project><inlist_pgstar>




-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20180305/0ae4c6af/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pms_to_wd_009127.png
Type: image/png
Size: 32749 bytes
Desc: not available
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20180305/0ae4c6af/attachment.png>