[Mesa-users] Run fails to stop and save using custom accreted_material_j
Ebraheem Farag
ekfarag at asu.edu
Sat Apr 29 08:21:25 UTC 2023
Hello Benjamin,
Comment out "max_star_mass_for_gain = 0.101", this is telling MESA to turn
off the mass_gain if the star_mass increases beyond 0.101 Msun during the
last timestep, which causes the solver to struggle and retry if it
overshoots the stopping condition with mass-loss on. This should resolve
your issue.
-------------
Some extra suggested controls to adopt
-------------
To hit the stopping condition more precisely, I would recommend setting:
! for 5th decimal precision on stopping condition, e.g. 0.1010[1...]
when_to_stop_rtol = 1d-5 ! relative tolerance
when_to_stop_atol = 1d-5 ! absolute tolerance
I would also recommend finding a control that helps limit the timesteps,
since the solver is max_increasing until it hits the stopping condition
For your case where you are only acretting 1d-3 Msun, perhaps the following
will help numerically resolve your model, especially near the end where the
mass loss is greatest:
delta_lg_star_mass_limit = 1d-4 ! limits mass change per timestep, I would
lower or increase depending on how much mass you are accreting.
delta_lg_star_mass_hard_limit = 1d-3 ! hard limit for mass_change per
timestep
Cheers :)
-EbF
On Fri, Apr 28, 2023 at 8:48 PM Roulston, Benjamin via Mesa-users <
mesa-users at lists.mesastar.org> wrote:
> Hi all,
>
> I have an odd issue with accreting mass and angular momentum that I can’t
> seem to understand why it is an issue.
>
> Background is I’m trying to accrete a specific abundance to some grid of
> models. I’m also trying to keep track of rotation and the angular momentum.
> So I am using
>
> mass_change = 1.0d-8
> max_star_mass_for_gain = 0.101
> star_mass_max_limit = 0.101
>
> use_accreted_material_j = .true.
> accreted_material_j = 1.0d12 ! this IS specific ang momentum
>
> accretion_dump_missing_metals_into_heaviest = .false.
> accrete_given_mass_fractions = .true.
>
> And this works fine! The mass is added as expected, and so is angular
> momentum. The run stops as expected when total mass hits 0.101Msun. Great!
>
> The issue is I want a more dynamic accreted_j, based on some fraction of
> the Keplarian value as the mass and radius of the accretor changes. Fine,
> there is a test case (that does run fine with my install) that does this!
> So I used that code in the run_star_extras.f90 to adapt to my case.
>
> subroutine extras_controls(id, ierr)
> integer, intent(in) :: id
> integer, intent(out) :: ierr
> type (star_info), pointer :: s
> ierr = 0
> call star_ptr(id, s, ierr)
> if (ierr /= 0) return
> ! this is the place to set any procedure pointers you want to change
> ! e.g., other_wind, other_mixing, other_energy (see star_data.inc)
>
> s% other_adjust_mdot => accretor_adjust_mdot
>
> subroutine accretor_adjust_mdot(id, ierr)
> integer, intent(in) :: id
> integer, intent(out) :: ierr
> type(star_info), pointer :: s
> call star_ptr(id, s, ierr)
>
> s% accreted_material_j = s% x_ctrl(1)*sqrt(standard_cgrav * s% mstar * s%
> photosphere_r*Rsun)
> write(*,*) "accreted_material_j = ", s% accreted_material_j
>
> !write(*,*) "debug", s% mstar_dot/Msun*secyer, 10**(s% x_ctrl(2))
> ! s% mstar_dot = s% mstar_dot + pow(10d0, s% x_ctrl(2))*Msun/secyer
>
> end subroutine accretor_adjust_mdot
>
> And
>
> mass_change = 1.0d-8
> max_star_mass_for_gain = 0.101
> star_mass_max_limit = 0.101
>
> accrete_same_as_surface = .false.
> premix_omega = .true.
>
> use_accreted_material_j = .true.
> use_other_adjust_mdot = .true.
>
> x_ctrl(1) = 0.1d0 ! ratio of accreted am to keplerian
>
> This is where it gets weird. This DOES run! It accretes the mass fine and
> the angular momentum. However, once the model reaches the mass limit (in
> this model 0.101Msun) instead of stopping and saving the model, it keeps
> trying to accrete and the time steps drop down to log_dt ~ -9 and never
> stops. It gives the following errors in the terminal output:
>
> accreted_material_j = 29212373139847368.
> 83 6.616617 3687.877 -2.810333 -2.810333 0.100900
> 0.100900 0.758355 0.000009 0.241465 6.528487 672 0
> 4.1761E+00 6.616617 -1.037625 -99.000000 -4.131714 -8.000000
> 0.000000 0.241465 0.000084 0.000180 0.610681 4
> 1.0001E+09 2.997841 -2.853451 -18.663860 -99.000000 -3.239033
> 0.000000 0.000031 0.000018 0.000180 -0.304E-09 max increase
>
> accreted_material_j = 29228061448833992.
> retry: set_omega_adjust_mass failed in adjust mass 84
> accreted_material_j = 29228061448833992.
> 84 6.617098 3688.133 -2.806102 -2.806102 0.100990
> 0.100990 0.758349 0.000009 0.241471 6.528698 675 1
> 3.9543E+00 6.617098 -1.037737 -99.000000 -4.127401 -8.000000
> 0.000000 0.241471 0.000084 0.000180 0.610356 4
> 1.0001E+09 2.998586 -2.853554 -18.186738 -99.000000 -3.238683
> 0.000000 0.000031 0.000018 0.000180 -0.335E-09 retry
>
> accreted_material_j = 29237325035824144.
> retry: set_omega_adjust_mass failed in adjust mass 85
> accreted_material_j = 29237325035824144.
> retry: set_omega_adjust_mass failed in adjust mass 85
> accreted_material_j = 29237325035824144.
> retry: set_omega_adjust_mass failed in adjust mass 85
> accreted_material_j = 29237325035824144.
> retry: set_omega_adjust_mass failed in adjust mass 85
> accreted_material_j = 29237325035824144.
>
> However, if I use the same code and functions, but just use a constant
> momentum
>
> s% accreted_material_j = 1d12
>
> It does work and the model stops and saves. But if I use a larger value
> like 1d18 it also doesn’t stop the run. So it seems it has issues with
> larger specific angular momentum. But the model runs fine until the exact
> point of the mass limit. And it’s not this specific mass limit, if I change
> the mass limit to 0.2 (or anything else) it runs fun until 0.2 (so it
> passes the previous limit of 0.101 fine) and then doesn’t stop and the time
> step limit drops to very low values again.
>
> I can’t seem to understand why the model can run fine until the exact
> point it’s supposed to be stopping. But only for “large” (really not that
> large) specific angular momentum.
>
> I hope I’ve explained this clearly, and I’ve included the necessary files
> to recreate this as well as my starting models. I’m using MESA version
> "mesa-r22.11.1”.
>
>
> Cheers,
> - Ben
> _______________________________________________
> mesa-users at lists.mesastar.org
>
> https://urldefense.com/v3/__https://lists.mesastar.org/mailman/listinfo/mesa-users__;!!IKRxdwAv5BmarQ!fw64IBlmWGjNsXCUvzv5ZXbsKzZ3D_8LCFryzQjfC0CJIcBLPdSkF3TGJtPoLCQB2KVZOYEFbMa8gZxYpb81Q1dK$
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20230429/d34894d3/attachment.htm>
More information about the Mesa-users
mailing list