[Mesa-users] Relaxing Entropy from Profile Pairs?

[Ebraheem Farag]

Hello Charles,

See : get_entropy_for_relax_from_eos
<https://docs.mesastar.org/en/release-r22.11.1/reference/star_job.html#get-entropy-for-relax-from-eos>

Try setting the following in your &starjob section of your inlist:

get_entropy_for_relax_from_eos = 'eosDT'
-------------------------------------------
"when generating the number of shells and each of their q values (how much
mass is located outside the shell), is there a specific formula that
determines how I should determine those values?"

see below also from from star_job.defaults, get_entropy_for_relax_from_eos
<https://docs.mesastar.org/en/release-r22.11.1/reference/star_job.html#get-entropy-for-relax-from-eos>
(in
mesa-r22.11.1), please verify against the r10398 defaults:

When any of the eos* options is used, then each line in the input file must
contain three columns instead of two, specifying the values of the two
thermodynamic variables used in the order specified above. So, for example,
when using ‘eosDT’ the format of the input file is

1st line: num_pointsthen 1 line for for each point where define
desired entropyxq entropyxq = fraction of xmstar exterior to the
pointwhere xmstar = mstar - M_centerentropy = specific entropy in
units of erg/gr/K

-------------------------------------------

I hope this helps!
-EbF


On Sun, Apr 2, 2023 at 10:48 AM Charles Gibson via Mesa-users <
mesa-users at lists.mesastar.org> wrote:

> Hello,
>
> I am an undergraduate student working on taking a star evolved in MESA
> from an SPH code (StarSmasher) and inputting it back into MESA to observe
> its evolution. I have been working in the directory
>
> star/test_suite/relax_composition_j_entropy
>
> to ensure that I can accurately recreate a model from a previous mesa run.
> So far, I have succeeded in replicating the star's evolution through this
> method.
>
> However, the StarSmasher simulations that I am using do not supply direct
> values for entropy. I read in Appendix B of this paper
> <https://urldefense.com/v3/__https://iopscience.iop.org/article/10.3847/1538-4365/aaa5a8*apjsaaa5a8app2__;Iw!!IKRxdwAv5BmarQ!eAVuCwomn0wLGPlCi_4SqSvQrROsX2Y_TuBprfGga0bhSO6wXIJlmJc-W0u6zBGNWJ1gv92vrZBdqqf020zJGhiz$> that
> I can supply different pairs of profiles including (rho, T), (P_gas, T),
> and (rho, e) in the entropy's place. These are all quantities that I can
> easily obtain.
>
> When I run the relax model using (rho, T) in place of entropy, the run
> fails when processing the entropy file. I have it formatted the same as the
> entropy file, but with three values on each line instead of two. Is there a
> variable in the inlist that I have to alter to indicate that I am changing
> the type of supplied entropy data? If it helps, I am using v10398.
>
> Additionally, as a side question, when generating the number of shells and
> each of their q values (how much mass is located outside the shell), is
> there a specific formula that determines how I should determine those
> values? I haven't gotten to the point where I am extracting values from
> StarSmasher yet, but once I do, I want to make sure that I determine the
> values so that MESA can effectively read them.
>
> Thank you,
> Charlie
> _______________________________________________
> mesa-users at lists.mesastar.org
>
> https://urldefense.com/v3/__https://lists.mesastar.org/mailman/listinfo/mesa-users__;!!IKRxdwAv5BmarQ!eAVuCwomn0wLGPlCi_4SqSvQrROsX2Y_TuBprfGga0bhSO6wXIJlmJc-W0u6zBGNWJ1gv92vrZBdqqf02-SGqssJ$
>
>
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