[mesa-users] High Rotation Stellar Model Issues

Pablo Marchant pamarca at gmail.com
Mon Oct 17 07:20:36 EDT 2016


Hi Ethan. First, I'd strongly recommend you use the Ledoux criterion with
overshooting and semiconvection turned on.

If your star is evolving to critical rotation, it is likely that the source
of your problems is the wind mass loss enhancement due to rotation. This is
because by default mass loss rates go to infinity at critical rotation. To
correct for this, you can use the implicit wind scheme, which iterates a
step while adjusting the mass loss rate until the model remains below a
threshold in omega/omega_crit. To turn this on, you can set

max_mdot_redo_cnt = 50

Look for this option in

http://mesa.sourceforge.net/controls_defaults.html#mass_gain_or_loss

so that you understand what is being done.

Also, any reason for you to turn on the option for the hydrodynamics term?
This is what the v_flag does, and of course, if you want to resolve any
stellar dynamics you need timesteps well below a century.

On Oct 17, 2016 1:03 PM, "Ethan Payne" <epay1 at student.monash.edu> wrote:

> Dear Jakub,
>
> Sorry. So while the model is running at a low rotation, dt is around 10^5
> or so. However, as soon as omega/omegacrit reaches 0.9 to 1, the time step
> reduces to about 10^1 or 10^2.
> Once it reaches these time steps, it simply takes too long to run.
> Is there any more information you need?
>
> Thanks for the help,
>
> Ethan
>
> On 17 October 2016 at 21:55, Jakub Ostrowski <ostrowski at astro.uni.wroc.pl>
> wrote:
>
>> Dear Ethan,
>>
>> Can you elaborate on "serious issue with the optimisation/ timesteps"?
>> That would be useful.
>>
>> Jakub
>>
>> > On 17 Oct 2016, at 12:03, Ethan Payne <epay1 at student.monash.edu> wrote:
>> >
>> > <InlistHighRotation>
>>
>>
>
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