[Mesa-users] a problem of the relaxation

[曾耀田]

Hi Francis,




Thanks for your reply. 


I want to map 3D models to MESA. Therefore the first step I already have done is to convert 3D models into 1D models. However, these 1D models are out of hydrostatic equilibrium. To obtain 1D models that are in the hydrostatic equilibrium, I am trying to relax them for several dynamical timescales until the velocity and acceleration of each cell of a star are small enough. Considering I am not familiar with MESA, what is doing now is to relax the model that MESA itself can run to learn how to relax a star.




Best wishes
Yaotian Zeng


> -----原始邮件-----
> 发件人: "Francis Timmes" <fxt44 at mac.com>
> 发送时间: 2020-06-08 07:57:33 (星期一)
> 收件人: "曾耀田" <zengyaotian at ynao.ac.cn>
> 抄送: "Frank Timmes" <fxt44 at mac.com>, mesa-users <mesa-users at lists.mesastar.org>
> 主题: Re: [Mesa-users] a problem of the relaxation
> 
> hi yaotian,
> 
> it would be useful to know what you are trying to achieve,
> in addition to how you tried to achieve it. what is the goal?
> 
> fxt
> 
> 
> 
> 
> > On Jun 7, 2020, at 3:03 AM, 曾耀田 <zengyaotian at ynao.ac.cn> wrote:
> > 
> > 2020-06-07 17:52:11"曾耀田" <zengyaotian at ynao.ac.cn>写道：
> > 
> > 
> > Dear all,
> > 
> > 
> > 
> > I'm sorry to bother you, but for some reason the information in this letter is missing. I am new to MESA. I am trying to relax a model of a 1.5 solar mass star based on the result (final.mod) of 1.5M_with_diffusion in test_suite directory. To do this, as same as the example ofrelax_composition_j_entropy in the test_suite directory, I try to relax composition and entropy (but using get_entropy_for_relax_from_eos = ‘eosDT', see details below). It can run some steps but always ended with the error of dt < min_timestep_limit. I have tried to set different values for the comments in the inlist (shown below) but failed (e.g. changing the values of min_timestep_limit to 1d-30). I don't understand that even the input model has exactly the same entropy, density, and temperature profiles as the 1.5 solar mass star already had, the relaxation still doesn't work. So I try to understand the meaning of adjusting the values of these commands through the .defults file but I still don't have a clue. Now I am unsure of how and what parameters to adjust. Any ideas, suggestions, or help would be greatly appreciated!




祝好！

曾耀田
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