swh:1:snp:75cdaf5164207cb3d00f07a3da10a0250b29d03b
Tip revision: 286359430454f22e0286d2e03bf86cba594b30fc authored by Timo Heister on 22 June 2018, 21:24:08 UTC
version 2.0.1
version 2.0.1
Tip revision: 2863594
stokes.prm
# A description of the Stokes benchmark for which an analytic solution
# is available. See the manual for more information.
############### Global parameters
# We use a 3d setup. Since we are only interested
# in a steady state solution, we set the end time
# equal to the start time to force a single time
# step before the program terminates.
set Dimension = 3
set Start time = 0
set End time = 0
set Use years in output instead of seconds = false
set Output directory = output-stokes
############### Parameters describing the model
# The setup is a 3d box with edge length 2890000 in which
# all 6 sides have free slip boundary conditions. Because
# the temperature plays no role in this model we need not
# bother to describe temperature boundary conditions or
# the material parameters that pertain to the temperature.
subsection Geometry model
set Model name = box
subsection Box
set X extent = 2890000
set Y extent = 2890000
set Z extent = 2890000
end
end
subsection Boundary velocity model
set Tangential velocity boundary indicators = left, right, front, back, bottom, top
end
subsection Material model
set Model name = simple
subsection Simple model
set Reference density = 3300
set Viscosity = 1e22
end
end
subsection Gravity model
set Model name = vertical
subsection Vertical
set Magnitude = 9.81
end
end
############### Parameters describing the temperature field
# As above, there is no need to set anything for the
# temperature boundary conditions.
subsection Boundary temperature model
set List of model names = box
end
subsection Initial temperature model
set Model name = function
subsection Function
set Function expression = 0
end
end
############### Parameters describing the compositional field
# This, however, is the more important part: We need to describe
# the compositional field and its influence on the density
# function. The following blocks say that we want to
# advect a single compositional field and that we give it an
# initial value that is zero outside a sphere of radius
# r=200000m and centered at the point (p,p,p) with
# p=1445000 (which is half the diameter of the box) and one inside.
# The last block re-opens the material model and sets the
# density differential per unit change in compositional field to
# 100.
subsection Compositional fields
set Number of fields = 1
end
subsection Initial composition model
set Model name = function
subsection Function
set Variable names = x,y,z
set Function constants = r=2e5, p=1.445e6
set Function expression = if(sqrt((x-p)*(x-p)+(y-p)*(y-p)+(z-p)*(z-p)) > r, 0, 1)
end
end
subsection Material model
subsection Simple model
set Density differential for compositional field 1 = 100
end
end
############### Parameters describing the discretization
# The following parameters describe how often we want to refine
# the mesh globally and adaptively, what fraction of cells should
# be refined in each adaptive refinement step, and what refinement
# indicator to use when refining the mesh adaptively.
subsection Mesh refinement
set Initial adaptive refinement = 4
set Initial global refinement = 4
set Refinement fraction = 0.2
set Strategy = velocity
end
############### Parameters describing what to do with the solution
# The final section allows us to choose which postprocessors to
# run at the end of each time step. We select to generate graphical
# output that will consist of the primary variables (velocity, pressure,
# temperature and the compositional fields) as well as the density and
# viscosity. We also select to compute some statistics about the
# velocity field.
subsection Postprocess
set List of postprocessors = visualization, velocity statistics
subsection Visualization
set List of output variables = density, viscosity
end
end