shell_3d_postprocess.prm

# A description of convection in a 3d spherical shell with
# a prescribed initial condition based on a harmonic
# perturbation

# Define the number of space dimensions we would like to
# work in:
set Dimension                              = 3

# Specify the time you want to let the model run for in
# years and the output directory. Here we only calculate
# the instantaneous solution.
set End time                               = 0
set Use years in output instead of seconds = true
set Output directory                       = output-shell_3d_postprocess

# The following variables describe how the pressure should
# be normalized. Here, we choose a zero average pressure
# at the surface of the domain
set Pressure normalization                 = surface
set Surface pressure                       = 0

# Here we specify the geometry of the domain, which is
# a spherical shell with inner radius of 3481km and
# outer radius of 6371km
subsection Geometry model
  set Model name = spherical shell

  subsection Spherical shell
    set Inner radius  = 3481000
    set Outer radius  = 6371000
  end
end

# This section specifies the temperature at the boundary of
# the domain. Here we set the temperature to be constant at
# bottom and top.
subsection Boundary temperature model
  set Fixed temperature boundary indicators = bottom,top
  set List of model names = spherical constant

  subsection Spherical constant
    set Inner temperature = 2000
    set Outer temperature = 1000
  end
end

# This section describes the gravity field, which is pointing
# towards the Earth's center with the same magnitude of 10 m/s^2
# everywhere
subsection Gravity model
  set Model name = radial constant

  subsection Radial constant
    set Magnitude = 10
  end
end

# This section prescribes the initial condition in the temperature
# field, which is chosen as a degree n=4, l=2 perturbation
subsection Initial temperature model
  set Model name = harmonic perturbation

  subsection Harmonic perturbation
    set Lateral wave number one     = 4
    set Lateral wave number two     = 2
    set Magnitude                   = 500
    set Reference temperature       = 1600
  end
end

# The material model is based on the simple material model, which assumes
# a constant density, and other parameters as stated below.
subsection Material model
  set Model name = simple

  subsection Simple model
    set Reference density                 = 3300
    set Viscosity                         = 1e21
    set Thermal expansion coefficient     = 3e-5
    set Reference temperature             = 1600
    set Thermal conductivity              = 4.125
    set Reference specific heat           = 1250
  end
end

# For this calculation we only do 2 global refinement steps. This resolution
# is too low to fully resolve the mantle flow, however it does capture
# the main features.
subsection Mesh refinement
  set Initial global refinement          = 2
  set Initial adaptive refinement        = 0
end

# We assume free slip at the inner and outer boundary
subsection Boundary velocity model
  set Tangential velocity boundary indicators = bottom,top
end

# We output the density, velocity, dynamic topography and geoid anomalies
subsection Postprocess
  set List of postprocessors = velocity statistics, dynamic topography, visualization, basic statistics, geoid

  subsection Visualization
    set Output format                 = vtu
    set List of output variables      = geoid, dynamic topography, density, viscosity, gravity
    set Number of grouped files       = 1
  end
end