[Mesa-users] Entropy Profiles and relaxation

[Francis Timmes]

hi akaash,

> The Y-axis has strange units or is normalised (see attachment). How can I get this in cgs units?


$MESA_DIR/star/defaults/profile_columns.list is your friend:

   !entropy ! specific entropy divided by (avo*kerg)

which says the entropy plotted is dimensionless. 
i'll leave it to you to explore other entropy-related entries 
in profile_columns.list to get a quantity with units of erg/g/K.


> Also is there a way to get multiple entropy profiles on one plot with pgplot?


not to my knowledge. if one wants to overplot several profiles it is best to
use a plotting package outside of mesa. python-based tools are popular these days.


> I'm attempting to relax the entropy of a star but it eventually
> runs into convergences issues after a number of steps. Is this normal ...

if, for example, the model being imported used a different equation of state than
mesa's or the model has large accelerations, then its possible that a relaxation 
may struggle to find a converged solution. 

fxt






> On Nov 27, 2020, at 10:41 AM, Akaash Conhye via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> 
> Hi all,
> 
> I want entropy profiles from pgplot but when I add the following lines:
>         
>          Summary_Profile_file_flag = .true.
>          Summary_Profile_name(:) = 'entropy'
>          Summary_Profile_file_interval = 200
>          Summary_Profile_num_lines = 1
>          Summary_Profile_name(1) = 'entropy'
>          Summary_Profile_legend(1) = 'entropy rel'
> 
> The Y-axis has strange units or is normalised (see attachment). How can I get this in cgs units? Also is there a way to get multiple entropy profiles on one plot with pgplot?
> 
> I also have a question about entropy relaxation. I'm attempting to relax the entropy of a star but it eventually runs into convergences issues after a number of steps. Is this normal i.e. theoretically can a star be relaxed through an infinite number of steps? or is this a sign of improper physics in my inlist file?
> 
> 
> Thanks
> 
> Akaash
> 
> <Summary_Profile_001000.png>_______________________________________________
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