#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