TurbGen.par

# ********************************************************************************
# *** Input parameter file for controlling turbulence driving                  ***
# *** Please see Federrath et al. (2010, A&A 512, A81) for details and cite :) ***
# ********************************************************************************
ndim               = 3              # N-dimensional turbulence driving (1 or 2 or 3).
                                    # Note that ndim = 1.5 or 2.5 will create 2 or 3 vector field components, respectively.
L                  = 1.0            # Length of simulation domain (box) in [x[y[z]]] (can be comma-separated list to set each component).
velocity           = 1.0            # Target turbulent velocity dispersion.
                                    # The following parameters (ampl_factor) is used to adjust the driving amplitude in [x[y[z]]],
                                    # to approach the desired target velocity dispersion. Note that it scales as velocity/velocity_measured,
                                    # e.g., given a target velocity dispersion of 'velocity' and a measured velocity dispersion of 'velocity_measured',
                                    # scale the current value of ampl_factor by velocity/velocity_measured, such that
                                    # ampl_factor(new) = ampl_factor(previous) * velocity / velocity_measured. This will need adjustment, because
                                    # different codes and numerical resolutions/schemes will result in somewhat different dissipation.
                                    # Further, if the driving range and/or solenoidal weight (see below) are changed, these parameters will also need
                                    # to be adjusted, so the target turbulent velocity dispersion is reached in x[y[z]].
ampl_factor        = 1.0            # Adjust [x[y[z]]] amplitude (can be comma-separated list to set each component).
ampl_auto_adjust   = 0              # Automatic amplitude adjustment switch (0: off, 1: on).
k_driv             = 2.0            # Characteristic driving scale in units of 2pi / L[x].
                                    # L[x], k_driv, and velocity are used to set the Ornstein-Uhlenbeck auto-correlation time.
k_min              = 1.0            # Minimum driving wavenumber in units of 2pi / L[x].
k_max              = 3.0            # Maximum driving wavenumber in units of 2pi / L[x].
                                    # Note that while this is set based on L[x] only, the driving is still going to be isotropic,
                                    # even if L[x] != L[y] != L[z], because the actual modes are set based on L[x], L[y], L[z] during initialisation.
sol_weight         = 0.5            # 1.0: solenoidal driving, 0.0: compressive driving, 0.5: natural mixture.
spect_form         = 1              # Spectral form of the driving amplitude. 0: band/rectangle/constant, 1: paraboloid, 2: power law.
power_law_exp      = -2.0           # If spect_form = 2, this sets the spectral power-law exponent (e.g., -5/3: Kolmogorov; -2: Burgers)
angles_exp         = 1.0            # If spect_form = 2, this sets the number of modes (angles) in k-shell surface,
                                    # such that it increases as k^angles_exp.
                                    # For full sampling, angles_exp = 2.0; for healpix-type sampling, angles_exp = 0.0.
random_seed        = 140281         # Random number seed for driving sequence.
nsteps_per_t_turb  = 10             # Number of turbulence driving pattern updates per turnover time.
# ***************************************************************************************************