Hi ASPECT,
Probably a basic question (I’m pretty new to ASPECT), but I’m looking at some unintuitive results that I think could be clarified quite quickly…
So I’ve run a simple isoviscous calculation with fixed T BCs in a 2D annulus to 1 billion years. At the end, I’m just wondering why, within the convective cells, the temperature is hot in the top half of the mantle and cold in the bottom half… rather than nearly isothermal (or, increasing, adiabatically with depth).
I’ve attached a screenshot (at 1 Gy). IThe parameters I’ve provided in the prm file (pasted below) include compressibility and expansion (so figured that the simulation would be adiabatic?).
I guess I have two basic Qs: is my weird result due to the calculation not being compressible?
And also, how would I adapt my parameter file to include it. I recently found the following input options: “Subsection”: Adiabatic conditions model: Parameter: “compute profile”.
Any help appreciated!
Thanks,
Harriet
PARAM file:
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TEMPLATE FOR MULTIPLE RUNS WHERE WE SWITCH INPUT PARAMTERS
DEPENDING ON MANAR’S RUNS.
Options to be switched out will be labeled “SWITCH”
in comment line above
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GLOBAL INPUTS:
set Dimension = 2
set Use years in output instead of seconds = true
set End time = 1e9
SWITCH
set Output directory = /oscar/data/hclau/hclau/out_0.0-1e23
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GRID OPTIONS:
subsection Geometry model
set Model name = spherical shell
subsection Spherical shell
set Inner radius = 3480000
set Outer radius = 6371000
set Opening angle = 360
end
end
subsection Mesh refinement
set Initial global refinement = 6
set Initial adaptive refinement = 0
set Time steps between mesh refinement = 0
end
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MODEL PARAMETERS:
subsection Gravity model
set Model name = radial constant
subsection Radial constant
set Magnitude = 9.81
end
end
SWITCH
subsection Material model
set Model name = depth dependent
subsection Depth dependent model
set Base model = simple
set Depth dependence method = File
set Data directory = /users/hclau/TPW/viscosity/
set Viscosity depth file = visc_0.0-1e23.dat
set Reference viscosity = 1e23
end
subsection Simple model
set Reference density = 4500
set Thermal expansion coefficient = 2.5e-5
set Viscosity = 1e23
set Reference specific heat = 1000
set Thermal conductivity = 4
end
end
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remove rotation
subsection Nullspace removal
set Remove nullspace = net rotation
end
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INITIAL CONDITIONS
SWITCH
ATTEMPt 1:
#subsection Initial temperature model
set Model name = function
subsection Function
set Coordinate system = spherical
set Variable names = r,phi
set Function constants = A=100, B=75, C=50, D=25, pi=3.1415926536, Ri=3480e3, Ro=6371e3, Ti=5500, To=1700
set Function expression = (r-Ri)/(Ro-Ri)(To-Ti)+Ti + Asin(7phi) + Bsin(13phi) + Ccos(0.123phi+pi/3) + Dcos(0.456*phi+pi/6)
end
#end
ATTEMPT 2:
subsection Initial temperature model
set Model name = spherical gaussian perturbation
subsection Spherical gaussian perturbation
set Amplitude = 0.01
set Angle = 0.8
set Non-dimensional depth = 0.2
set Sigma = 0.2
set Sign = 1
end
end
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BOUNDARY CONDITIONS
subsection Boundary velocity model
set Zero velocity boundary indicators =
set Tangential velocity boundary indicators = top, bottom
end
SWITCH ,
subsection Boundary temperature model
set Fixed temperature boundary indicators = top,bottom
set List of model names = spherical constant
subsection Spherical constant
set Inner temperature = 5000
set Outer temperature = 1600
end
end
SWITCH
#subsection Heating model
set List of model names = constant heating
subsection Constant heating
set Radiogenic heating rate = 1.95e-11
end
#end
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OUTPUT
subsection Postprocess
set List of postprocessors = velocity statistics, temperature statistics, heat flux statistics, visualization, particles, basic statistics
subsection Visualization
set Time between graphical output = 1e6
set Output format = vtu
set List of output variables = material properties
end
end