Newbee with simple problem I think
Posted: 14 Sep 2010, 20:41
Hello Everyone,
I've downloaded and installed Elmer, and am trying to figure out how to run a simple simulation.
I have a large object at an ambient temperature of 299 Kelvin
It is placed in a large room which is 327.6 Kelvin for an extended period of time. (eventually I will simulate this temperature fluctuating over time, but for now this is not necessary)
I need to simulate how long it takes the object to reach a uniform temperature.
The object is a 300 gallon cube shaped container filled with liquid, I've chosen glycerol to start with, and am not trying to incorporate convection at this point.
I’ve tried my best to set up and run the simulation, I have loaded all 20 frames in the postprocessor, and the temperature gradient shows up in the render, but it doesn’t change over time no matter which frame I look at.
(My setup and the Sif printout are below my signature)
Any help or directions will be appreciated
Thank you
Don
My geometry is a cube with rounded corners, all boundaries merged into a single boundary. (A single body with a single boundary)
SETUP:
Max output level 4
Steady State max Iter 1
Timestepping method BDF
BDF Order 2 (tried 3 as well, same result)
Simulation Type “Transient”
Timestep intervals 20
Output intervals 1
Timestep sizes 1800 (is this seconds, I’ve tried different values from 5 to 1800000)
HEAT EQUATION:
Active checked (applied to Body 1)
MATERIAL:
Glycerol applied to Body 1
BODY FORCE:
None
INITIAL CONDITION:
Heat Equation – Temperature 299.8167
BOUNDARY CONDITION
Temperature 327.5944 Applied to Boundary 1
Tried setting External Temperature to the same value, no effect
SET BOUNDARY PROPERTIES
Checked
------------------------------------------------------------------------------
The Sif results are below
------------------------------------------------------------------------------
Header
CHECK KEYWORDS Warn
Mesh DB "." "."
Include Path ""
Results Directory ""
End
Simulation
Max Output Level = 4
Coordinate System = Cartesian
Coordinate Mapping(3) = 1 2 3
Simulation Type = Transient
Steady State Max Iterations = 1
Output Intervals = 1
Timestepping Method = BDF
BDF Order = 3
Timestep intervals = 20
Timestep Sizes = 5
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
Initial condition = 1
End
Solver 1
Equation = Heat Equation
Procedure = "HeatSolve" "HeatSolver"
Variable = -dofs 1 Temperature
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-8
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-8
Linear System Preconditioning = ILU0
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 1
Linear System Precondition Recompute = 1
End
Equation 1
Name = "Equation 1"
Active Solvers(1) = 1
End
Material 1
Name = "Glycerol (room temperature)"
Heat Conductivity = 0.28
Heat Capacity = 2400.0
Density = 1261.0
Viscosity = 1.49
Sound speed = 1904.0
Heat expansion Coefficient = 0.610e-3
End
Initial Condition 1
Name = "InitialCondition 1"
Temperature = 299.8167
End
Boundary Condition 1
Target Boundaries(1) = 1
Name = "BoundaryCondition 1"
Temperature = 327.5944
End
I've downloaded and installed Elmer, and am trying to figure out how to run a simple simulation.
I have a large object at an ambient temperature of 299 Kelvin
It is placed in a large room which is 327.6 Kelvin for an extended period of time. (eventually I will simulate this temperature fluctuating over time, but for now this is not necessary)
I need to simulate how long it takes the object to reach a uniform temperature.
The object is a 300 gallon cube shaped container filled with liquid, I've chosen glycerol to start with, and am not trying to incorporate convection at this point.
I’ve tried my best to set up and run the simulation, I have loaded all 20 frames in the postprocessor, and the temperature gradient shows up in the render, but it doesn’t change over time no matter which frame I look at.
(My setup and the Sif printout are below my signature)
Any help or directions will be appreciated
Thank you
Don
My geometry is a cube with rounded corners, all boundaries merged into a single boundary. (A single body with a single boundary)
SETUP:
Max output level 4
Steady State max Iter 1
Timestepping method BDF
BDF Order 2 (tried 3 as well, same result)
Simulation Type “Transient”
Timestep intervals 20
Output intervals 1
Timestep sizes 1800 (is this seconds, I’ve tried different values from 5 to 1800000)
HEAT EQUATION:
Active checked (applied to Body 1)
MATERIAL:
Glycerol applied to Body 1
BODY FORCE:
None
INITIAL CONDITION:
Heat Equation – Temperature 299.8167
BOUNDARY CONDITION
Temperature 327.5944 Applied to Boundary 1
Tried setting External Temperature to the same value, no effect
SET BOUNDARY PROPERTIES
Checked
------------------------------------------------------------------------------
The Sif results are below
------------------------------------------------------------------------------
Header
CHECK KEYWORDS Warn
Mesh DB "." "."
Include Path ""
Results Directory ""
End
Simulation
Max Output Level = 4
Coordinate System = Cartesian
Coordinate Mapping(3) = 1 2 3
Simulation Type = Transient
Steady State Max Iterations = 1
Output Intervals = 1
Timestepping Method = BDF
BDF Order = 3
Timestep intervals = 20
Timestep Sizes = 5
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
Initial condition = 1
End
Solver 1
Equation = Heat Equation
Procedure = "HeatSolve" "HeatSolver"
Variable = -dofs 1 Temperature
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-8
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-8
Linear System Preconditioning = ILU0
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 1
Linear System Precondition Recompute = 1
End
Equation 1
Name = "Equation 1"
Active Solvers(1) = 1
End
Material 1
Name = "Glycerol (room temperature)"
Heat Conductivity = 0.28
Heat Capacity = 2400.0
Density = 1261.0
Viscosity = 1.49
Sound speed = 1904.0
Heat expansion Coefficient = 0.610e-3
End
Initial Condition 1
Name = "InitialCondition 1"
Temperature = 299.8167
End
Boundary Condition 1
Target Boundaries(1) = 1
Name = "BoundaryCondition 1"
Temperature = 327.5944
End