I've seen a few mentions to the 'Component' keyword but found it to be poorly documented in the sense of how to actually use it to obtain the desired results.

My question is essentially: what's the best practice for extracting magnetic forces from a body? Would rather not manually post process from nodal forces.

.sif file:

Code: Select all

```
Header
CHECK KEYWORDS Warn
Mesh DB "." "."
Include Path ""
Results Directory ""
End
Simulation
Max Output Level = 5
Coordinate System = Cartesian
Coordinate Mapping(3) = 1 2 3
Simulation Type = Steady state
Steady State Max Iterations = 100
Output Intervals(1) = 10
Solver Input File = case.sif
Post File = case.vtu
End
Constants
Gravity(4) = 0 -1 0 9.82
Stefan Boltzmann = 5.670374419e-08
Permittivity of Vacuum = 8.85418781e-12
Permeability of Vacuum = 1.25663706e-6
Boltzmann Constant = 1.380649e-23
Unit Charge = 1.6021766e-19
End
Body 1
Target Bodies(1) = 1
Name = "1"
Equation = 1
Material = 2
Body Force = 1
End
Body 2
Target Bodies(1) = 2
Name = "2"
Equation = 2
Material = 3
End
Body 3
Target Bodies(1) = 3
Name = "3"
Equation = 2
Material = 1
End
Solver 2
Equation = MgDyn
Use Elemental CoilCurrent = True
Fix Input Current Density = True
Procedure = "MagnetoDynamics" "WhitneyAVSolver"
Exec Solver = Always
Stabilize = True
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-5
Nonlinear System Convergence Tolerance = 1.0e-7
Nonlinear System Max Iterations = 30
Nonlinear System Newton After Iterations = 3
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 1
Linear System Solver = Iterative
Linear System Iterative Method = BiCGStab
Linear System Max Iterations = 500
Linear System Convergence Tolerance = 1.0e-10
BiCGstabl polynomial degree = 2
Linear System Preconditioning = ILU0
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 10
Linear System Precondition Recompute = 1
End
Solver 1
Equation = MgDynPost
Procedure = "MagnetoDynamics" "MagnetoDynamicsCalcFields"
Skip Nodal Fields = False
Calculate Current Density = True
Discontinuous Bodies = True
Calculate Nodal Forces = True
Exec Solver = Before Saving
Stabilize = True
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-5
Nonlinear System Convergence Tolerance = 1.0e-7
Nonlinear System Max Iterations = 20
Nonlinear System Newton After Iterations = 3
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 1
Linear System Solver = Iterative
Linear System Iterative Method = BiCGStab
Linear System Max Iterations = 500
Linear System Convergence Tolerance = 1.0e-10
BiCGstabl polynomial degree = 2
Linear System Preconditioning = ILU0
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 10
Linear System Precondition Recompute = 1
End
Solver 3
Equation = CoilSolver
Coil Closed = True
Coil Normal(3) = 0 0 1
Narrow Interface = True
Normalize Coil Current = True
Desired Coil Current = 1000
Procedure = "CoilSolver" "CoilSolver"
Fix Input Current Density = True
Exec Solver = Before Simulation
Stabilize = True
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-5
Nonlinear System Convergence Tolerance = 1.0e-7
Nonlinear System Max Iterations = 20
Nonlinear System Newton After Iterations = 3
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 1
Linear System Solver = Iterative
Linear System Iterative Method = BiCGStab
Linear System Max Iterations = 500
Linear System Convergence Tolerance = 1.0e-10
BiCGstabl polynomial degree = 2
Linear System Preconditioning = ILU0
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 10
Linear System Precondition Recompute = 1
End
Equation 1
Name = "coil"
Active Solvers(3) = 2 1 3
End
Equation 2
Name = "air"
Active Solvers(2) = 2 1
End
Material 1
Name = "air"
Heat Conductivity = 0.0257
Relative Permeability = 1.00000037
Heat Capacity = 1005.0
Viscosity = 1.983e-5
Sound speed = 343.0
Heat expansion Coefficient = 3.43e-3
Density = 1.205
Relative Permittivity = 1.00059
End
Material 2
Name = "alu"
Electric Conductivity = 3.526e7
Relative Permeability = 1
End
Material 3
Name = "Iron (generic)"
Mesh Poisson ratio = 0.29
Density = 7870.0
Youngs modulus = 193.053e9
Heat Conductivity = 80.2
Sound speed = 5000.0
Electric Conductivity = 10.30e6
Heat expansion Coefficient = 11.8e-6
Heat Capacity = 449.0
Relative Permeability = 200000
End
Body Force 1
Name = "coil current"
Current Density Multiplier = 1
End
Boundary Condition 1
Target Boundaries(6) = 25 26 27 28 29 30
Name = "inf"
AV {e} = 0
Jfix = real 0.0
End
Component 1
Calculate Magnetic Force = True
Master Bodies = 1
End
```

Code: Select all

```
ComputeChange: NS (ITER=1) (NRM,RELC): ( 0.10940997E-02 2.0000000 ) :: mgdynpost
5 0.9004E-11
ComputeChange: NS (ITER=2) (NRM,RELC): ( 0.10972690E-02 0.28924992E-02 ) :: mgdynpost
5 0.5368E-11
ComputeChange: NS (ITER=3) (NRM,RELC): ( 0.15190562E-02 0.32242726 ) :: mgdynpost
SolveLinearSystem: Solution trivially zero!
SolveLinearSystem: Solution trivially zero!
SolveLinearSystem: Solution trivially zero!
WARNING:: ListFind:
WARNING:: ListFind: Requested property: [Name], not found
WARNING:: ListFind:
WARNING:: ListFind:
WARNING:: ListFind: Requested property: [Name], not found
WARNING:: ListFind:
MagnetoDynamicsCalcFields: Eddy current power: 0.000000E+00
MagnetoDynamicsCalcFields: ElectroMagnetic Field Energy: 4.491436E+00
ResultOutputSolver: -------------------------------------
ResultOutputSolver: Saving in unstructured VTK XML (.vtu) format
ResultOutputSolver: -------------------------------------
ElmerSolver: *** Elmer Solver: ALL DONE ***
ElmerSolver: The end
SOLVER TOTAL TIME(CPU,REAL): 146.70 146.70
ELMER SOLVER FINISHED AT: 2022/10/14 16:21:33
```