Standard run
Here we describe the standard disk model present in discstruct.f90 and the parameter choices in the default run setup in setups/default.
Disk model
The default gas structure in discstruct.f90 is static and does not evolve and we use a power law disk model. The gas surface density is given by
where \(\Sigma_\mathrm{g0}\) is the gas surface density at 1 AU. This is defined in the function sigmag(x,time) which can be modified to suit the user’s needs.
The 2D distribution of gas is given by,
where \(H-g\) is the gas scale height. This is defined in the function densg(x,z, time)
We use a vertically isothermal disk temperature model where the sound speed given by,
where \(cs_0 = \sqrt{k_BT_0/m_{H_2}}\) is the sound speed at 1 AU. This is defined in the function cs(x).
The gas pressure is then given by,
This is defined in the function Pg(x,z,time)
The turbulent strength \(\alpha\) is defined in the function alpha(x) and is constant over time and space in the default model. The gas velocity is set to zero in the default model and can be changed in the function vgas(x,time).
Default run
Listed below are the parameters for the default simulation. We encourage the user to run the default setup first as a test run to ensure proper working of the code.
number_of_particles_per_cell - 256 (recommended to have atleast 200 particles a cell)number_of_radial_zones - 32number_of_vertical_zones - 16steps_between_outputs - 10000time_between_outputs_[yrs] - 250maximum_time_of_simulation_[yrs] - 10000minimum_radius_[AU] - 1maximum_radius_[AU] - 100monomer_radius_[cm] - 1e-4material_density_[g/cm3] - 1.2dmmax - 0.001evaporation_radius_[AU] - 0.99dust_to_gas_ratio - 0.01fragmentation_velocity_[cm/s] - 1000alpha - 1.e-3sigma_gas_[g/cm2] - 1000temperature_[K] - 280erosion_mass_ratio - 10data_directory - ‘data’