5.3.9 Dust/Molecules

CO5BOLD can now handle a number of additional density arrays. They can be used to describe e.g. the mass density of dust distribution moments or number densities of molecules. These species are properly advected with the gas density. There is also already a small number of dust/molecule formation models available. These models have to be improved in the future and the influence on the radiation field (opacities, radiation pressure on dust) has to be taken into account.

• character dustscheme:
  A scheme for dust or molecule formation and transport can be selected e.g. with

  character dustscheme f=A80 b=80 n='Dust model' &
    c0='none (default), nosource, dust_simple_01, co_component01_01' &
    c1='dust_k3mon_01, dust_k3mon_02'
  dust_k3mon_01
  

  Possible values are (the list is hopefully expanded in the near future):
  • none, None: No handling of any dust/molecule density at all.
  • nosource: Skip source term step for dust/molecules entirely, but do the transport.
  • dust_simple_01: Simple and unrealistic 'dust' formation model (only for testing of the numerics).
  • co_component01_01: Simple CO formation (from Matthias Steffen) with one component only but realistic time scales.
  • dust_k3mon_01: Simple C-rich dust formation (from Susanne Höfner) with one component only but realistic time scales.
  • dust_k3mon_02: Simple C-rich dust formation (from Susanne Höfner) with two components for dust density and free carbon density.

• real c_dust0X:
  There are five parameters ( real c_dust01 to real c_dust05) to control each dust formation scheme in detail. A parameter can be given as in

  real c_dust01 f=E15.8 b=4 n='Dust parameter 1'
  0.0
  

  The meaning (and unit) can vary from scheme to scheme. The default value is 0.0 in each case.