composition_passive.prm

#########################################################
# This is a variation of the platelike-boundary.prm file.
# All settings are exactly the same with the exception
# of the ones that pertain to compositional fields.
#
# See the manual for more information about this setup.


set Dimension                              = 2
set Start time                             = 0
set End time                               = 20
set Use years in output instead of seconds = false
set Output directory                       = output-composition-passive

subsection Geometry model
  set Model name = box

  subsection Box
    set X extent = 2
    set Y extent = 1
  end
end

subsection Boundary temperature model
  set Fixed temperature boundary indicators = bottom, top
  set List of model names = box

  subsection Box
    set Bottom temperature = 1
    set Top temperature    = 0
  end
end

subsection Boundary velocity model
  set Tangential velocity boundary indicators = left, right, bottom
  set Prescribed velocity boundary indicators = top: function

  subsection Function
    set Variable names      = x,z,t
    set Function constants  = pi=3.1415926
    set Function expression = if(x>1+sin(0.5*pi*t), 1, -1); 0
  end
end

subsection Gravity model
  set Model name = vertical
end

subsection Initial temperature model
  set Model name = function

  subsection Function
    set Variable names      = x,z
    set Function expression = (1-z)
  end
end

subsection Material model
  set Model name = simple

  subsection Simple model
    set Thermal conductivity          = 1e-6
    set Thermal expansion coefficient = 1e-4
    set Viscosity                     = 1
  end
end

subsection Mesh refinement
  set Initial adaptive refinement        = 0
  set Initial global refinement          = 5
  set Time steps between mesh refinement = 0
end

subsection Postprocess
  set List of postprocessors = visualization, temperature statistics, composition statistics

  subsection Visualization
    set Time between graphical output = 0.1
  end
end

# This is the new part: We declare that there will
# be two compositional fields that will be
# advected along. Their initial conditions are given by
# a function that is one for the lowermost 0.2 height
# units of the domain and zero otherwise in the first case,
# and one in the top most 0.2 height units in the latter.
subsection Compositional fields
  set Number of fields = 2
end

subsection Initial composition model
  set Model name = function

  subsection Function
    set Variable names      = x,y
    set Function expression = if(y<0.2, 1, 0) ; if(y>0.8, 1, 0)
  end
end