[Mesa-users] Noisy Brunt–Väisälä frequency

[RICHARD H D TOWNSEND]

Hi Pedro --

Try looking into the following controls:

num_cells_for_smooth_brunt_B
threshold_for_smooth_brunt_B

cheers,

Rich

> On Aug 30, 2018, at 4:11 PM, Pedro Nuno David Gomes via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> 
> Dear MESA users,
> 
> I'm trying to calculate the square of Brunt–Väisälä frequency, N^2, for different life stages of a star with 1.5M_sun. However, the result is very noisy, and spiky. Besides this, I noticed that near the center N^2 assumes negative (although very small) values.
> 
> How can I solve this?
> 
> I attach two figures that show the behavior I mentioned, and below I send my inlist.
> 
> Thank you for your help,
> 
> Pedro
> 
> ------------------------------------------------------------
> 
> &star_job
> 
> 	change_lnPgas_flag = .true.
>        new_lnPgas_flag = .true.
>        pgstar_flag = .true.
> 
> 	save_model_when_terminate = .true.
> 	save_model_filename = 'final.mod'
> 
> 	set_initial_age = .true.
> 	initial_age = 0
> 
> / !end of star_job namelist
> 
> &controls
> 
> 	initial_mass = 1.5
> 	initial_z = 0.02
> 	use_Type2_opacities = .true.
> 	Zbase = 0.02
> 
>        calculate_Brunt_N2 = .true.
> 
> 	overshoot_f_below_nonburn_shell = 0.023
> 	overshoot_f_above_burn_h_shell = 0.023
> 	overshoot_f_above_burn_he_core = 0.023
> 
> 	overshoot_f0_below_nonburn_shell = 0.005
> 	overshoot_f0_above_burn_h_shell = 0.005
> 	overshoot_f0_above_burn_he_core = 0.005
> 
> 	photo_interval = 50
> 	profile_interval = 50
> 	history_interval = 1
> 	terminal_interval = 10
> 	write_header_frequency = 10
> 
> 	mesh_delta_coeff = 0.8
> 
>        log_Teff_lower_limit = 3.71 ! (stop here)
> 
> 
> / ! end of controls namelist
> 
> &pgstar
> 
> / ! end of pgstar namelist
> <brunt_1.png><brunt_2.png>_______________________________________________
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>