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Matthieu Schaller authoredMatthieu Schaller authored
parameter_example.yml 18.12 KiB
# Define the system of units to use internally.
InternalUnitSystem:
UnitMass_in_cgs: 1 # Grams
UnitLength_in_cgs: 1 # Centimeters
UnitVelocity_in_cgs: 1 # Centimeters per second
UnitCurrent_in_cgs: 1 # Amperes
UnitTemp_in_cgs: 1 # Kelvin
# Values of some physical constants
PhysicalConstants:
G: 6.67408e-8 # (Optional) Overwrite the value of Newton's constant used internally by the code.
# Cosmological parameters
Cosmology:
h: 0.6777 # Reduced Hubble constant
a_begin: 0.0078125 # Initial scale-factor of the simulation
a_end: 1.0 # Final scale factor of the simulation
Omega_m: 0.307 # Matter density parameter
Omega_lambda: 0.693 # Dark-energy density parameter
Omega_b: 0.0455 # Baryon density parameter
Omega_r: 0. # (Optional) Radiation density parameter
w_0: -1.0 # (Optional) Dark-energy equation-of-state parameter at z=0.
w_a: 0. # (Optional) Dark-energy equation-of-state time evolution parameter.
# Parameters for the hydrodynamics scheme
SPH:
resolution_eta: 1.2348 # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel).
CFL_condition: 0.1 # Courant-Friedrich-Levy condition for time integration.
h_tolerance: 1e-4 # (Optional) Relative accuracy of the Netwon-Raphson scheme for the smoothing lengths.
h_max: 10. # (Optional) Maximal allowed smoothing length in internal units. Defaults to FLT_MAX if unspecified.
max_volume_change: 1.4 # (Optional) Maximal allowed change of kernel volume over one time-step.
max_ghost_iterations: 30 # (Optional) Maximal number of iterations allowed to converge towards the smoothing length.
initial_temperature: 0 # (Optional) Initial temperature (in internal units) to set the gas particles at start-up. Value is ignored if set to 0.
minimal_temperature: 0 # (Optional) Minimal temperature (in internal units) allowed for the gas particles. Value is ignored if set to 0.
H_mass_fraction: 0.755 # (Optional) Hydrogen mass fraction used for initial conversion from temp to internal energy. Default value is derived from the physical constants.
H_ionization_temperature: 1e4 # (Optional) Temperature of the transition from neutral to ionized Hydrogen for primoridal gas.
# Parameters for the self-gravity scheme
Gravity:
mesh_side_length: 32 # Number of cells along each axis for the periodic gravity mesh.
eta: 0.025 # Constant dimensionless multiplier for time integration.
theta: 0.7 # Opening angle (Multipole acceptance criterion).
comoving_softening: 0.0026994 # Comoving softening length (in internal units).
max_physical_softening: 0.0007 # Physical softening length (in internal units).
rebuild_frequency: 0.01 # (Optional) Frequency of the gravity-tree rebuild in units of the number of g-particles (this is the default value).
a_smooth: 1.25 # (Optional) Smoothing scale in top-level cell sizes to smooth the long-range forces over (this is the default value).
r_cut_max: 4.5 # (Optional) Cut-off in number of top-level cells beyond which no FMM forces are computed (this is the default value).
r_cut_min: 0.1 # (Optional) Cut-off in number of top-level cells below which no truncation of FMM forces are performed (this is the default value).
# Parameters for the task scheduling
Scheduler:
nr_queues: 0 # (Optional) The number of task queues to use. Use 0 to let the system decide.
cell_max_size: 8000000 # (Optional) Maximal number of interactions per task if we force the split (this is the default value).
cell_sub_size_pair_hydro: 256000000 # (Optional) Maximal number of interactions per sub-pair hydro task (this is the default value).
cell_sub_size_self_hydro: 32000 # (Optional) Maximal number of interactions per sub-self hydro task (this is the default value).
cell_sub_size_pair_grav: 256000000 # (Optional) Maximal number of interactions per sub-pair gravity task (this is the default value).
cell_sub_size_self_grav: 32000 # (Optional) Maximal number of interactions per sub-self gravity task (this is the default value).
cell_sub_size_pair_stars: 256000000 # (Optional) Maximal number of interactions per sub-pair stars task (this is the default value).
cell_sub_size_self_stars: 32000 # (Optional) Maximal number of interactions per sub-self stars task (this is the default value).
cell_split_size: 400 # (Optional) Maximal number of particles per cell (this is the default value).
cell_subdepth_grav: 2 # (Optional) Maximal depth the gravity tasks can be pushed down (this is the default value).
max_top_level_cells: 12 # (Optional) Maximal number of top-level cells in any dimension. The number of top-level cells will be the cube of this (this is the default value).
tasks_per_cell: 0 # (Optional) The average number of tasks per cell. If not large enough the simulation will fail (means guess...).
mpi_message_limit: 4096 # (Optional) Maximum MPI task message size to send non-buffered, KB.
# Parameters governing the time integration (Set dt_min and dt_max to the same value for a fixed time-step run.)
TimeIntegration:
time_begin: 0. # The starting time of the simulation (in internal units).
time_end: 1. # The end time of the simulation (in internal units).
dt_min: 1e-6 # The minimal time-step size of the simulation (in internal units).