#Note: units used are m-y-MPa
check keywords warn
Header
Mesh Db "." "box"
End
Simulation
Coordinate System = Cartesian 3D
Simulation Type = Steady State
Steady State Max Iterations = 1
Output Intervals = 1
Output File = "box.result"
Post File = "box.vtu"
Initialize Dirichlet Conditions = Logical False
End
Constants
Gravity(4) = 0 -1 0 9.81
Stefan Boltzmann = 5.67E-08
End
Body 1
Name = "box"
Equation = 1
Body Force = 1
Material = 1
Initial Condition = 1
End
Equation 1
Name = "Equation1"
Convection = "computed"
Flow Solution Name = String "Flow Solution"
Active Solvers(1) = 1
End
Body Force 1
Pressure = 5.0e4
End
Material 1
#Ice properties stolen from stokes diagnostic example
Name = "ice-ice-baby"
Density = Real $910.0*1.0E-06*(31556926.0)^(-2.0)
!----------------
! vicosity stuff
!----------------
Viscosity Model = String "Glen"
! Viscosity has to be set to a dummy value
! to avoid warning output from Elmer
Viscosity = Real 1.0
Glen Exponent = Real 3.0
Critical Shear Rate = Real 1.0e-10
! Rate factors (Paterson value in MPa^-3a^-1)
Rate Factor 1 = Real 1.258e13
Rate Factor 2 = Real 6.046e28
! these are in SI units - no problem, as long as
! the gas constant also is
Activation Energy 1 = Real 60e3
Activation Energy 2 = Real 139e3
Glen Enhancement Factor = Real 1.0
! the variable taken to evaluate the Arrhenius law
! in general this should be the temperature relative
! to pressure melting point. The suggestion below plugs
! in the correct value obtained with TemperateIceSolver
! Temperature Field Variable = String "Temp Homologous"
! the temperature to switch between the
! two regimes in the flow law
Limit Temperature = Real -10.0
! In case there is no temperature variable (which here is the case)
Constant Temperature = Real -3.0
! Heat transfer stuff (will come later)
!Temp Heat Capacity = Variable Temp
! Real MATC "capacity(tx)*(31556926.0)^(2.0)"
!Temp Heat Conductivity = Variable Temp
! Real MATC "conductivity(tx)*31556926.0*1.0E-06"
!Temp Upper Limit = Variable Depth
! Real MATC "273.15 - 9.8E-08 * tx * 910.0 * 9.81" !-> this is the correction of the presure melting point with respect to the hydrostatic overburden at the point
End
Solver 1
Equation = "Navier Stokes"
Optimize Bandwidth = Logical True #see solvman pg 28 - the Cuthill-McKee bandwidth optimization scheme is set to true (whatever that means)
Linear System Solver = Direct #see solvman pg 26 - so we are assuming the system is linear and picking the 'direct' solver (as opposed to iterative or multigrid) (could try iterative with GCR or BiCGStab)
Linear System Direct Method = "UMFPACK" #see pg 28 - a type of sparse matrix solver (could try Krylov subspace iterative solution)
Linear System Max Iterations = 5000 #see pg 27 - maximum number of "run throughs" to find a solution. If this limit is reached without convergence then ElmerSolver just continues with current value because we will set abort to false (otherwise it aborts)
Linear System Convergence Tolerance = 1.0E-06 #see pg 27 - solver will move on if the difference between iterations is less than this value (seems small to me)
Linear System Abort Not Converged = False #see pg 27 - refer to max iterations
Linear System Preconditioning = "ILU1" #see pg 27 - preconditioning makes the solutions less sensitive to small changes in the input i.e. it's a numerical methods technique
Linear System Residual Output = 1 #see pg 27 - (displays the residual norm after n iterations, we have set n to the default of 1
Steady State Convergence Tolerance = 1.0E-05 #see pgs 34,35 - solver will move on if the difference between iterations is less than this value
Stabilization Method = Stabilized #choices are Stabilized, P2/P1, Bubbles.
Nonlinear System Convergence Tolerance = 1.0E-04 #see pg 34 - solver will move on if the difference between iterations is less than this value
Nonlinear System Convergence Measure = Solution #see pg 33 - method of measuring the "difference" between the old and new solution
Nonlinear System Max Iterations = 50 #see pg 34 - maximum number of "run throughs" to find a solution
Nonlinear System Newton After Iterations = 3 #see pg 34 - changes the solver type to newton iteration after n iterations unless convergence tolerance is met
Nonlinear System Newton after Tolerance = 1.0E-01
Exported Variable 1 = -dofs 3 "Mesh Velocity"
End
Initial Condition 1
Velocity 1 = 0.0
Velocity 2 = 0.0
End
Boundary Condition 1
Name = "sides"
Target Boundaries(4) = 2 4 5 6
Depth = Real 0.0
Free Surface = Logical True
End
Boundary Condition 2
Name = "sheared surfaces"
Target Boundaries(2) = 1 3
End