Elmersolver either crashes or ends with 'invalid memory reference'. Here's what I have tried:
-Re-meshing with different mesh densities, including increasing mesh density along the boundary walls
-Changing the viscosity
-Lowering the convergence tolerance
-If I disable the Navier-Stokes solver and only run it with heat conduction I can get a solution. I tried this thinking there might be something wrong with the mesh I created (first time creating a 3D body)
This is the first time I have run a 3D case so I am sure I am missing something. If anybody has time to look at the case I would appreciate it.
Happy holidays!
-Clayton
Code: Select all
Header
CHECK KEYWORDS Warn
Mesh DB "." "wellmesh"
Include Path ""
Results Directory ""
End
Simulation
Max Output Level = 4
Coordinate System = Cartesian
Coordinate Mapping(3) = 1 2 3
Simulation Type = Transient
!Simulation Type = Steady state
Steady State Max Iterations = 35
Output Intervals = 1
Timestepping Method = BDF
BDF Order = 2
Timestep intervals = 10
Timestep Sizes = 0.25
Solver Input File = case.sif
Post File = case.vtu
Coordinate Scaling = 0.001
Output File = NC3D.result
End
Constants
Gravity(4) = 0 0 -1 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
Initial condition = 1
End
Solver 2
Equation = Heat Equation
Procedure = "HeatSolve" "HeatSolver"
Variable = Temperature
Stabilize = False
Bubbles = True
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-3
Nonlinear Timestepping = Logical True
Nonlinear System Convergence Tolerance = 1.0e-3
Nonlinear System Max Iterations = 1
Nonlinear System Newton After Iterations = 1000
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 0.6
Linear System Solver = Iterative
Linear System Iterative Method = GCR
Linear System Max Iterations = 500
Linear System Convergence Tolerance = 1.0e-6
Linear System Preconditioning = ILU0
Linear System Abort Not Converged = False
Linear System Residual Output = 10
End
Solver 1
Equation = Navier-Stokes
Procedure = "FlowSolve" "FlowSolver"
Variable = Flow Solution[Velocity:2 Pressure:1]
!Stabilize = False
Bubbles = True
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-3
Nonlinear Timestepping = Logical True
Nonlinear System Convergence Tolerance = 1.0e-3
Nonlinear System Max Iterations = 1
Nonlinear System Newton After Iterations = 1000
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 0.6
Linear System Solver = Iterative
Linear System Iterative Method = BiCGStab
Linear System Max Iterations = 500
Linear System Convergence Tolerance = 1.0e-8
Linear System Preconditioning = ILU2
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = True
Linear System Residual Output = 10
End
Equation 1
Name = "Natural Convection"
Convection = Computed
Active Solvers(2) = 2 1
End
Material 1
Name = "Air (room temperature)"
Reference Temperature = 298
Viscosity = 1.983e-5
Heat expansion Coefficient = 3.43e-3
Compressibility Model = Perfect Gas
Reference Pressure = 101325
Heat Conductivity = 0.0257
Relative Permittivity = 1.00059
Sound speed = 343.0
Heat Capacity = 1005.0
Density = 1.205
End
Body Force 1
Name = "Buoyancy"
Flow Bodyforce 3 = -9.82
!Pressure Single Node = real 0.0
End
Initial Condition 1
Name = "Initial Guess for Air"
Velocity 2 = 0.0
Velocity 1 = 1.0e-9
Temperature = 298
End
Boundary Condition 1
Target Boundaries(1) = 1
Name = "Top"
Temperature = 298
End
Boundary Condition 2
Target Boundaries(1) = 3
Name = "Bottom"
Temperature = 298.5
End
Boundary Condition 3
Target Boundaries(1) = 2
Name = "Side"
End
Boundary Condition 3
Target Boundaries(1) = 1 2 3
Name = "Drop Tube"
Noslip wall BC = True
End