Turbulence driving

The block named &TURB_PARAMS contains the parameters related to the turbulence driving. Originally implemented by Andrew Mcleod

Overview of parameters

Variable name	Fortran type	Default value	Description
turb	boolean	.false.	Turn on or off driving
turb_seed	integer	-1	Random number generator seed. -1 = random
turb_type	integer	1	How the driving changes over time. 1=driven evolving, 3=decaying
instant_turb	boolean	.true.	Generate initial turbulence before start
comp_frac	float	0.3333	The weight of compressive over solenoidal modes
turb_T	float	1	Turbulent velocity auto-correlation time in code units.
turb_Ndt	integer	100	Number of timesteps per auto-correlation time
turb_rms	float	1	Root-mean-square turbulent forcing in code units.
turb_min_rho	float	1d-50	Minimum density for turbulence. Not forcing is added onto cellswith a density less than this value.
forcing_power_spectrum	string	parabolic	Power spectrum type of the forcing, which describes the relative strength of individual modes. Options are: power_law, parabolic, konstandin