[mesa-users] Extension of the MESA test suite case wd_ignite

Tue May 5 17:23:40 EDT 2015

  Dear all,

  I have been working with the MESA test suite case wd_ignite, which models
an accreting white dwarf, and has the stopping condition
"power_nuc_burn_upper_limit = 1d8", i.e., log(Lnuc)=8. I have tried to go
further with a new stopping condition ("power_nuc_burn_upper_limit = 1d13")
but weird things happen. The time step becomes even smaller than one year
in the last saved history data and, at that moment, the center fraction of
C12 suddenly increases and then drops. It can also be seen in the HR
diagram: the final trace of the white dwarf has nothing to do with the
previous steps.

  I was wondering if any of you knew what is going on, whether the last
points of my model are physical or "diverge" due to numerical issues. I
have tried with time step controls like delta_lg_XC_cntr_max or
delta_lgL_nuc_limit, with an increase in the number of points for high
temperatures (mesh), but have not succeeded. I would really like to
understand what is going on, given that the last saved models/points are,
precisely, the most important for me.

  I hope I have been specific with my problem! When I plotted the history
data I realized something "was not working". I have attached the inlist,
which is the one of wd_ignite, as I said, with a conductive opacity, a new
stopping condition and some attempts of fixing the problem with the time
step controls. The rest was set by default in the test suite case.

  Any help would be deeply appreciated! Is it that the hydrostatic regime
does not hold anymore...? I am really confused.

  Sincerely,

  --
  Héctor

! inlist_wd_ignition

&star_job
      show_log_description_at_start = .false.

      load_saved_model = .true.
      saved_model_name = 'wd_ignite.mod'

      save_model_when_terminate = .true.
      save_model_filename = 'final.mod'

      write_profile_when_terminate = .true.
      filename_for_profile_when_terminate = 'final_profile.data'

      change_initial_net = .true.
      new_net_name = 'co_burn.net'

      set_rate_3a = 'FL87' ! Fushiki and Lamb, Apj, 317, 368-388, 1987
      set_rate_1212 = 'G05' ! Gasques, et al. Phys Review C, 72, 025806,
2005

      show_log_description_at_start = .false.

      ! shut off PC since get bad convergence for high gamma
      set_eos_PC_parameters = .true.
      mass_fraction_limit_for_PC = 1d-2 ! skip species if abundance < this
      logRho1_PC_limit = 20 ! 3.7d0 ! okay for pure PC for logRho > this
      logRho2_PC_limit = 20 ! 2.8d0 ! don't use PC for logRho < this (>=
2.8 or so because of PPT)
      log_Gamma_all_HELM = 1.60206d0 ! HELM for log_Gamma <= this
      log_Gamma_all_PC = 1.90309d0 ! PC for log_Gamma >= this

      change_v_flag = .true.
      new_v_flag = .true.

      set_Z_all_HELM = .true. ! if false, just use the eos default
      Z_all_HELM = 1.000001d0

      ! move the surface down to larger optical depth
      set_tau_factor = .true.
      set_to_this_tau_factor = 300

      !pgstar_flag = .true.

/ ! end of star_job namelist

&controls

      report_why_dt_limits = .true. !Information about the choice of the
timestep in the terminal output during evolution as a short string

      min_timestep_factor = 1.d0
      dt_limit_ratio_target = 1d0

      delta_lgL_nuc_limit = 0.5

      !delta_lgL_nuc_hard_limit = 0.1

      delta_lgT_cntr_limit = 0.1

      !delta_lgT_cntr_hard_limit = 0.1

      delta_lg_XC_cntr_max = -5

      delta_lg_XC_cntr_hard_limit = -7

      delta_lg_XO_cntr_max = -5

      delta_lg_XO_cntr_hard_limit = -7

      delta_lgL_limit_L_min = 0.01
      delta_lgL_limit = 0.05
      delta_lgTeff_limit = 0.01

      mesh_delta_coeff_for_highT = 0.01

      logT_min_for_highT_mesh_delta_coeff = 8.

      !mesh_dlog_burn_c_dlogP_extra = 0.01

      !newton_itermin = 1000

      !newton_iterations_limit = 7

      !newton_iterations_hard_limit = 10

      use_Type2_opacities = .true.
      Zbase = 0.02d0

      !power_nuc_burn_upper_limit = 1d8

      power_nuc_burn_upper_limit = 1d13    !   STOPPING CONDITION

      include_electron_conduction = .true.

      log_center_density_limit = 15

      varcontrol_target = 1d-3
      mesh_delta_coeff = 0.5

      logQ_limit = 1d6
      gamma_center_limit = 1d6

      photostep = 50
      profile_interval = 50
      history_interval = 10
      terminal_cnt = 10
      write_header_frequency = 10

      min_timestep_limit = 1d-8 ! seconds

      !delta_lgL_nuc_limit = 0.05 ! limit for magnitude of change in lgL_nuc

      T_mix_limit = 1d4

      which_atm_option = 'grey_and_kap'

      accrete_same_as_surface = .false.
      accrete_given_mass_fractions = .true.
      num_accretion_species = 2
      accretion_species_id(1) = 'c12'
      accretion_species_xa(1) = 0.25
      accretion_species_id(2) = 'o16'
      accretion_species_xa(2) = 0.75

      mass_change = 1d-7 ! rate of accretion (Msun/year)

      ! FOR DEBUGGING

      !report_hydro_solver_progress = .true. ! set true to see info about
newton iterations
      !report_ierr = .true. ! if true, produce terminal output when have
some internal error
      !hydro_show_correction_info = .true.

      !max_years_for_timestep = 3.67628942044319d-05

      !report_why_dt_limits = .true.
      !report_all_dt_limits = .true.

      !show_mesh_changes = .true.
      !mesh_dump_call_number = 5189
      !okay_to_remesh = .false.

      !trace_evolve = .true.

      ! hydro debugging
      !hydro_check_everything = .true.
      !hydro_inspectB_flag = .true.

      !hydro_numerical_jacobian = .true.
      !hydro_save_numjac_plot_data = .true.
      !small_mtx_decsol = 'lapack'
      !large_mtx_decsol = 'lapack'
      !hydro_dump_call_number = 195

      !trace_newton_bcyclic_solve_input = .true. ! input is "B" j k iter
B(j,k)
      !trace_newton_bcyclic_solve_output = .true. ! output is "X" j k iter
X(j,k)

      !trace_newton_bcyclic_matrix_input = .true. ! matrix before factor
      !trace_newton_bcyclic_matrix_output = .true. ! matrix after factor

      trace_newton_bcyclic_steplo = 905 ! 1st model number to trace
      trace_newton_bcyclic_stephi = 905 ! last model number to trace

      trace_newton_bcyclic_iterlo = 5 ! 1st newton iter to trace
      trace_newton_bcyclic_iterhi = 5 ! last newton iter to trace

      trace_newton_bcyclic_nzlo = 1 ! 1st cell to trace
      trace_newton_bcyclic_nzhi = 10000 ! last cell to trace; if < 0, then
use nz as nzhi

      trace_newton_bcyclic_jlo = 1 ! 1st var to trace
      trace_newton_bcyclic_jhi = 100 ! last var to trace; if < 0, then use
nvar as jhi

      !trace_k = 1852

/ ! end of controls namelist

&pgstar

!pause = .true.

         TRho_Profile_win_flag = .true.
         TRho_Profile_xmin = -2.5
         TRho_Profile_xmax = 11.0
         TRho_Profile_ymin = 5.1
         TRho_Profile_ymax = 10.0

         !History_Panels1_win_flag = .true.
         History_Panels1_yaxis_name(3) = 'log_R'
         History_Panels1_other_yaxis_name(3) = 'v_div_csound_surf'

/ ! end of pgstar namelist
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