[Mesa-users] Questions about (step)Overshooting

[Aaron Dotter]

Hi Matheus,

You have

         history_interval = 5

in your inlist. This means you're only writing out every 5th timestep to
the history file.  Before you changing the timesteps, etc., in your inlist,
please set history_interval = 1 to get the full evolutionary track.

Aaron

On Fri, Sep 28, 2018 at 11:01 AM Matheus Bernini via Mesa-users <
mesa-users at lists.mesastar.org> wrote:

> Hi Richard,
>
> Indeed, at some points they are too squared (but the gray track it wasn't
> made by me, it is one of the public avaliable GENEC tracks, which I
> downloaded from Ekström's website). I used ~10000 mesh points,
> mesh_delta_coeff = 1.0 and set varcontrol_target = 1.0d-4 .Is this enough
> to have a converged state? Actually, is there a practical, or "standard
> way" to know if my models are properly converged?
>
> Thanks
>
> Em sex, 28 de set de 2018 às 10:25, RICHARD H D TOWNSEND <
> townsend at astro.wisc.edu> escreveu:
>
>> Hi Matheus --
>>
>> Your tracks in the HR diagram look rather jagged, and it may be that your
>> calculations aren't properly converged. Have you tried running with shorter
>> timesteps and/or a finer spatial grid?
>>
>> cheers,
>>
>> Rich
>>
>> > On Sep 27, 2018, at 6:39 PM, Matheus Bernini via Mesa-users <
>> mesa-users at lists.mesastar.org> wrote:
>> >
>> > Hello,
>> >
>> > I'm an undergraduate student and I'm studying evolution of massive
>> stars using MESA.
>> >
>> > I was "playing around" with step overshooting initial values (
>> overshoot_f0_...) for hydrogen helium and nonburn core/shell and I noticed
>> that slightly changes on f0 (but always keeping f - f0 = 0.1) caused great
>> changes on the post-MS phases [figure].
>> >
>> >
>> >     overshoot_f0_above_burn_h_core = 0.035
>> >     step_overshoot_f_above_burn_h_core = 0.135
>> >
>> > vs.
>> >
>> >     overshoot_f0_above_burn_h_core = 0.030
>> >     step_overshoot_f_above_burn_h_core = 0.130
>> >
>> > *For completeness, there was also an exponential overshooting on all of
>> the models of 0.001 on helium and hydrogen core/shell
>> >
>> > If I understood correctly, the f0 is the starting point for the
>> overshoot inward the region (core or shell) because the mixing coefficient
>> is 0 on the edge of the region, not allowing the computations to happen.
>> So, if f0 is just a "trick" to allow the computation of the overshoot, why
>> changing it a little causes important changes on the evolution?
>> >
>> > Thanks :)
>> >
>> > -----------------------------------------------------------------
>> > Matheus Bernini Peron
>> > Undergraduate student
>> > Observatório do Valongo,
>> > Universidade Federal do Rio de Janeiro
>> > Ladeira do Pedro Antônio, 43 - Saúde
>> > Rio de Janeiro - RJ - CEP 20080-090
>> > Brasil
>> > ___________________________________________________________
>> > Evolution 32Msun, no rotation, Z_init = 0.014, Y_init = 0.266
>> > red: 0.135 - 0.035
>> > blue: 0.130 - 0.030
>> > gray: GENEC (Ekstrom+2012)
>> > <image.png>
>> >
>> <inlist_massive_defaults><inlist_32M0><run_star_extras.f>_______________________________________________
>> > mesa-users at lists.mesastar.org
>> > https://lists.mesastar.org/mailman/listinfo/mesa-users
>> >
>>
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