[mesa-users] Prevention convergent problem on helium flash

[Frank Timmes]

in short, mesa uses an implicit finite volume scheme with adaptive mesh refinement 
and sophisticated timestep controls. a special solution methodology is not 
used to get through the helium flash. aspects of mesa's solution method are 
described in the instrument papers with the first two being relevant

http://iopscience.iop.org/article/10.1088/0067-0049/192/1/3/meta
http://iopscience.iop.org/article/10.1088/0067-0049/208/1/4/meta

plus you can look at the code.

fxt






> On Dec 14, 2016, at 7:54 PM, 熊赫然 <xiongheran at ynao.ac.cn> wrote:
> 
> Hello every one MESA users:
>      I want to know how does MESA handle the convergent problem on He flash process. I had used other star evolution code and it stops on He flash, because the extreme increasing in Helium burning energy leads to a convergent problem: The finite-difference method is not convergent here, and Taylor's series expansion is not applicable to this kind of extreme change.  So i want to know which kind of numerical solution using in MESA that can prevent this convergent problem?
> --
> Heran XIONG
> Yunnan Observatories, Academia Sinica 
> Phoenix Mountain, East Suburb 
> Kunming, 650011 
> P.R. China 
> 
> Tel. +86-0871-67381984 (Office)      
>      +86-18501150931 (Mobile)
> Fax: +86-871-63920599 
> E-mail: xiongheran at ynao.ac.cn 
> 
>                                                                                                                                                          Sincerely, 
>                                                                                                                                                          Heran, Xiong
> 
> 
> 
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