I'm trying to model a simple bar magnet beside a piece of iron. In my sif file I have set the 'Relative Permeability' of the material but it doesn't seem to have any effect, it's just treated like the surrounding air. I've attached my whole project including sif and mesh etc. in the attached file, but below is the sif file. Can anyone suggest what I might be doing wrong? I just can't see anything obvious.

Code: Select all

```
$filename = "elmer_rel_permeability_test"
! ======================================================================!
! HEADER !
! ======================================================================!
Header
CHECK KEYWORDS "Warn"
Mesh DB "." $filename
End
! ======================================================================!
! Simulation !
! ======================================================================!
Simulation
Max Output Level = 7
Coordinate System = "Cartesian 3D"
Coordinate Mapping(3) = 1 2 3
Simulation Type = Steady state
Steady State Max Iterations = 1
Output Intervals = 1
Use Mesh Names = Logical True
!Post File = $filename".ep" Postfile aus
End
! ======================================================================!
! Constants !
! ======================================================================!
Constants
Gravity(4) = 0 -1 0 9.82
Stefan Boltzmann = 5.67e-08
Permittivity of Vacuum = 8.8542e-12
Boltzmann Constant = 1.3807e-23
Unit Charge = 1.602e-19
End
! ======================================================================!
! Body, Material, Body Force, Initial Cond. !
! ======================================================================!
Material 1
Name = "Air"
Density = 1000
Electric Conductivity = 0.0
Relative Permeability = 1.0
End
Material 2
Name = "Magnet"
Density = 1000
Electric Conductivity = 0.0
Relative Permeability = 1.05
End
Material 3
Name = "Iron"
Density = 7500
Electric Conductivity = 0.0
Relative Permeability = 1000.0
End
Body 1
Name = "magnet"
Equation = 1
Material = 2
Body Force = 1
End
Body 2
Name = "air_box"
Equation = 1
Material = 1
End
Body 3
Name = "steel_piece"
Equation = 1
Material = 3
End
Body Force 1
Name = "Magnetization"
Magnetization 1 = Real 0.0
Magnetization 2 = Real 0.0
Magnetization 3 = Real 1000
End
! ======================================================================!
! Equations and Solvers !
! ======================================================================!
Solver 1
Equation = "MGDynamics"
Variable = "A"
Procedure = "MagnetoDynamics" "WhitneyAVSolver"
Fix Input Current Density = Logical True
Newton-Raphson Iteration = Logical True
Nonlinear System Max Iterations = 30
Nonlinear System Convergence Tolerance = 1e-6
Linear System Symmetric = Logical True
Linear System Solver = "Iterative"
Linear System Preconditioning = None
Linear System Convergence Tolerance = 1e-8
Linear System Residual Output = 100
Linear System Max Iterations = 5000
Linear System Iterative Method = CG
Steady State Convergence Tolerance = 1e-6
End
Solver 2
Equation = "MGDynamicsCalc"
Procedure = "MagnetoDynamics" "MagnetoDynamicsCalcFields"
Linear System Symmetric = True
Potential Variable = String "A"
Calculate Magnetic Field Strength = Logical True
Calculate Magnetic Vector Potential = Logical True
Steady State Convergence Tolerance = 0
Linear System Solver = "Iterative"
Linear System Preconditioning = None
Linear System Residual Output = 0
Linear System Max Iterations = 5000
Linear System Iterative Method = CG
Steady State Convergence Tolerance = 1e-6
Linear System Convergence Tolerance = 1.0e-8
End
Solver 3
Exec Solver = after all
Equation = "ResultOutput"
Procedure = "ResultOutputSolve" "ResultOutputSolver"
!Output File Name = $filename".dat"
Output File Name = $filename
Save Geometry Ids = Logical True
Vector Field 1 = String Magnetic Field Strength
Vector Field 2 = String Magnetic Flux Density
Vector Field 3 = String Magnetic Vector Potential
Potential Variable = String av
Show Variables = Logical True
Vtu format = Logical True
End
Equation 1
Name = "Coupled Equations"
Active Solvers(2) = 1 2
End
! ======================================================================!
! Boundary Condition Section !
! ======================================================================!
! ----- names for boundaries -----
!$ outer_bound = 1
Boundary Condition 1
Name = "outer_boundary"
A = Real 0.0
A {e} = Real 0.0
End
```