It's a pipe filled with water (actually I'm using the "cylinder_in_channel.iges" from the Elmer samples directory) with:

- a no-slip boundary condition on side walls and the square obstacle (Boundary Condition 1)

- no boundary conditions on inlet and outlet faces

- a body force along the axis of the pipe

and I'm aiming for a steady state solution with the Navier-Stokes and K-Epsilon solvers

I think I'm missing something obvious, but I can't find what is it.

Here my .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 = 1
Output Intervals = 1
Timestepping Method = BDF
BDF Order = 1
Solver Input File = case.sif
Post File = case.ep
End
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 1
Target Bodies(1) = 1
Name = "Body 1"
Equation = 1
Material = 1
Body Force = 1
End
Solver 3
Equation = K-Epsilon
Procedure = "KESolver" "KESolver"
Exec Solver = Always
Stabilize = True
Bubbles = False
Lumped Mass Matrix = False
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 = Diagonal
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 1
Linear System Precondition Recompute = 1
End
Solver 2
Equation = Navier-Stokes
Procedure = "FlowSolve" "FlowSolver"
Variable = Flow Solution[Velocity:3 Pressure:1]
Exec Solver = Always
Stabilize = True
Bubbles = False
Lumped Mass Matrix = False
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 = Diagonal
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 1
Linear System Precondition Recompute = 1
End
Solver 1
Equation = Result Output
Output Format = Vtk
Procedure = "ResultOutputSolve" "ResultOutputSolver"
Output File Name = case
Exec Solver = Always
End
Equation 1
Name = "FluidEquations"
Active Solvers(3) = 3 2 1
End
Material 1
Name = "Water (room temperature)"
Viscosity Model = K-Epsilon
Viscosity = 1.002e-3
Heat expansion Coefficient = 0.207e-3
Heat Conductivity = 0.58
Relative Permittivity = 80.1
Sound speed = 1497.0
Heat Capacity = 4183.0
Density = 998.3
End
Body Force 1
Name = "BodyForce 1"
Flow Bodyforce 1 = 1
End
Boundary Condition 1
Target Boundaries(1) = 2
Name = "wall"
Normal-Tangential Velocity = True
Noslip wall BC = True
End
```

Thanks to the Elmer Team and all contributors for providing this beautiful piece of free software ♡＾▽＾♡