[Mesa-users] shock_spread controls no supported on r23.05.1, and alternatives for resolving shocks with v_flag hydro?

[Jaime Roman Garza]

Hi,

I am using MESA r23.05.1 to model common envelope evolution. In a given time of the evolution the donor, due to the energy deposited in its envelope, starts to pulsate, similarly as in Clayton et al. 2017. This behaviour leads to pressure jumps of one order of magnitude between two consecutive cells; where the cells below this jump, in the radial coordinate, are expanding and the ones above are contracting. I am currently using the v_flag hydro to evolve the models where that issue is present. Switching to u_flag framework solves the issue on the discontinuity but the average timestep for the simulation drop three orders of magnitude making this option very expensive.

>From the documentation, as well from literature, I encounter the possibility to control the shock spread in MESA, something that might help on the issue I described above. Such controls are shock_spread_linear and shock_spread_quadratic, described in the MESA's 3rd  instrument paper.

In MESA r23.05.1 such controls are no longer available, the only similar things I found are RSP_Qvisc_linear and RSP_Qvisc_quadratic, only used when RSP_flag is switched on. And as an extra comment, by searching for those controls in the source code, it seems they are not used (see Terminal_ouput.txt file).

Is there an alternative to shock_spread_linear and shock_spread_quadratic in the later versions of MESA to help v_flag hydro when a shock is formed? And if possible, does someone knows why that form of artificial viscosity is no longer supported?

Kind regards,
Jaime.


[cid:9f61f649-53a1-42ba-8734-73b3406776c3]


Jaime ROMAN GARZA

Ph.D. candidate – Département d'Astronomie


______________________________________________________________________________________________________________________________________________________________________________________________________________________________________



GW sources | Stars, formation and evolution

Observatoire de Genève | 51 Chemin Pegasi - 1290 - Versoix - CH

• +41 22 379 24 17                 • : Jaime.RomanGarza at unige.ch<mailto:Jaime.RomanGarza at unige.ch>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20240701/b16c6b8a/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Outlook-05wmzvwj.png
Type: image/png
Size: 28771 bytes
Desc: Outlook-05wmzvwj.png
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20240701/b16c6b8a/attachment.png>
-------------- next part --------------
$ grep -Ir "RSP_Qvisc_quadratic"
./include/star_controls.inc:            RSP_cq, RSP_zsh, RSP_Qvisc_quadratic, RSP_Qvisc_linear, RSP_tol_max_corr, RSP_tol_max_resid, &
./docs/source/reference/controls.rst:    RSP_Qvisc_quadratic = 0d0
./docs/source/reference/controls.rst:      ! RSP_Qvisc_quadratic is analogous to shock_spread_quadratic
./star/defaults/controls.defaults:    RSP_Qvisc_quadratic = 0d0
./star/defaults/controls.defaults:      ! RSP_Qvisc_quadratic is analogous to shock_spread_quadratic
./star/private/ctrls_io.f90:    overshoot_scheme, overshoot_zone_type, overshoot_zone_loc, RSP_Qvisc_quadratic, &
./star/private/ctrls_io.f90:   s% RSP_Qvisc_quadratic = RSP_Qvisc_quadratic
./star/private/ctrls_io.f90:   RSP_Qvisc_quadratic = s% RSP_Qvisc_quadratic
./star/test_suite/rsp_save_and_load_file/inlist_rsp_common:         RSP_Qvisc_quadratic = 0d0
./star/test_suite/rsp_save_and_load_file/inlist_rsp_common:            ! RSP_Qvisc_quadratic is analogous to shock_spread_quadratic
./star_data/private/star_controls.inc:            RSP_cq, RSP_zsh, RSP_Qvisc_quadratic, RSP_Qvisc_linear, RSP_tol_max_corr, RSP_tol_max_resid, &
$ grep -Ir "RSP_Qvisc_linear"
./include/star_controls.inc:            RSP_cq, RSP_zsh, RSP_Qvisc_quadratic, RSP_Qvisc_linear, RSP_tol_max_corr, RSP_tol_max_resid, &
./include/star_controls.inc:            RSP_max_dt_times_min_rad_diff_time, RSP_Qvisc_linear_static, RSP_dq_1_factor, &
./docs/source/reference/controls.rst:    RSP_Qvisc_linear = 0d0
./docs/source/reference/controls.rst:      ! RSP_Qvisc_linear is analogous to shock_spread_linear
./docs/source/reference/controls.rst:    RSP_Qvisc_linear_static = 0d0
./star/defaults/controls.defaults:    RSP_Qvisc_linear = 0d0
./star/defaults/controls.defaults:      ! RSP_Qvisc_linear is analogous to shock_spread_linear
./star/defaults/controls.defaults:    RSP_Qvisc_linear_static = 0d0
./star/private/ctrls_io.f90:    overshoot_f, overshoot_f0, overshoot_D0, RSP_Qvisc_linear, dq_D_mix_zero_at_H_He_crossover, &
./star/private/ctrls_io.f90:   RSP_theta, RSP_thetat, RSP_thetau, RSP_wtr, RSP_wtc, RSP_wtt, RSP_gam, RSP_max_retries_per_step, RSP_Qvisc_linear_static, &
./star/private/ctrls_io.f90:   s% RSP_Qvisc_linear = RSP_Qvisc_linear
./star/private/ctrls_io.f90:   s% RSP_Qvisc_linear_static = RSP_Qvisc_linear_static
./star/private/ctrls_io.f90:   RSP_Qvisc_linear = s% RSP_Qvisc_linear
./star/private/ctrls_io.f90:   RSP_Qvisc_linear_static = s% RSP_Qvisc_linear_static
./star/test_suite/rsp_save_and_load_file/inlist_rsp_common:         RSP_Qvisc_linear = 0d0 
./star/test_suite/rsp_save_and_load_file/inlist_rsp_common:            ! RSP_Qvisc_linear is analogous to shock_spread_linear
./star/test_suite/rsp_save_and_load_file/inlist_rsp_common:         !RSP_Qvisc_linear_static = 0d0
./star_data/private/star_controls.inc:            RSP_cq, RSP_zsh, RSP_Qvisc_quadratic, RSP_Qvisc_linear, RSP_tol_max_corr, RSP_tol_max_resid, &
./star_data/private/star_controls.inc:            RSP_max_dt_times_min_rad_diff_time, RSP_Qvisc_linear_static, RSP_dq_1_factor, &