looping elmer solver with different boundary condition

[siti.nurhasanah]

hi,
i want to do an electrostatic simulation which must do with alot of different boundary condition.My step is as follow:
first i make an electrotatic simulation with potential 10 V at "BoundaryCondition 1" and the other boundary is 0 V
second i want to make the same thing but with different boundary condition, etc potential 10 V at "BoundaryCondition 2" and the other boundary is 0 V
and next run until the number of boundary end. For every looping, I want to make the different .sif file,

this simulation will inconvenient if do manually, so i want to do this looping automatically, can elmer do this?

can anyone ever done this before?
if it is possible using other software outside elmer, what software is recommended?

thanks before

[raback]

Hi

You could put Simulation type to "scanning" and then let the potential depend on pseudo-time that now goes like 1,2,3,... So for example, in BCs

Code: Select all

Potential = Variable time
  Real
    1.0 10.0 
    2.0   0.0 
    3.0   5.0 
  End

Note that if you want to permute the values in order to compute capacitance matrix then this feature is already built in to the solver.

-Peter

[siti.nurhasanah]

I'm sorry before, I'm not really understand what you mean. What is mean function of "Scanning" ?
And where i can put the pseudo-time setting in my sif file?

can the elmer output make different sif file every different setting with this way?

thanks

[mzenker]

Hi,

I have never used the "scanning" simulation type, but it seems to me that it does the same (steady state?) simulation several times with the possibility to have parameters depend on "pseudo-time", as Peter wrote above. You can use timesteps as in a transient simulation, but it will not be "real" time.

As an alternative,you can also use the RUN command in the sif file, see "Running several sequences" in the Solver Manual.

HTH,

Matthias

@Peter: The Scanning simulation does not really seem to be documented, at least not in the Solver Manual. There are some mentions in the Models Manual, but it is not really explained. Did I overlook something? If not, some sentences on the simulation types (and in general on the Simulation section) in the Solver Manual would be helpful, and answer some FAQs...

[raback]

Hi Matthias

You're right. It should be better documented.

The "scanning" mode is like "transient" with two exceptions.
1) "time" goes always like 1,2,3,...
2) the individual solvers are called with flag "TransientSimulation = .FALSE."

-Peter

[mzenker]

Thank you!

Matthias

[siti.nurhasanah]

Hi, I try to do the simulation with scanning type

Code: Select all

Simulation
  Max Output Level = 5
  Coordinate System = Cartesian
  Coordinate Mapping(3) = 1 2 3
  Simulation Type = Scanning
  Steady State Max Iterations = 1
  Output Intervals = 1
  Timestepping Method = BDF
  BDF Order = 1
  Timestep intervals = 10
  Timestep Sizes = 1
  Solver Input File = case.sif
  Post File = case.ep
End

but i still confused about boundary condition setting
when i try to run the solver, solver log give error warning
ERROR:: Model Input:
ERROR:: Model Input: Unknown specifier: [target boundaries]
ERROR:: Model Input: In section: [boundary condition 1]
ERROR:: Model Input: For property name:[boundary condition 2]

can you check my sif ? what's wrong with this?

Code: Select all

Boundary Condition 1
  Target Boundaries(1) = 1
  Name = "BoundaryCondition 1"
  Potential = Variable time;0.0 14.0;1.0 0.0;2.0 0.0;3.0 0.0;4.0 0.0;5.0 0.0;
End

Boundary Condition 2
  Target Boundaries(1) = 2
  Name = "BoundaryCondition 2"
  Potential = Variable time;0.0 0.0;1.0 14.0;2.0 0.0;3.0 0.0;4.0 0.0;5.0 0.0;
End

Boundary Condition 3
  Target Boundaries(1) = 5
  Name = "BoundaryCondition 3"
  Potential = Variable time;0.0 0.0;1.0 0.0;2.0 14.0;3.0 0.0;4.0 0.0;5.0 0.0;
End

Boundary Condition 4
  Target Boundaries(1) = 6
  Name = "BoundaryCondition 4"
  Potential = Variable time;0.0 0.0;1.0 0.0;2.0 0.0;3.0 14.0;4.0 0.0;5.0 0.0;
End

[mzenker]

Hi,

there must be an "End" at the end of your table definition, see the systax in Peter's post.

HTH,

Matthias

[siti.nurhasanah]

Hi,
i have tried your suggestion about simulation setting, but the simulation still can't looping in way that i hope. The looping can run, but there are no change in boundary setting condition. Are there any other solution for this problem?

is there any possibility that boundary setting condition in Elmer performed by python/ matlab or something similar?

[mzenker]

Hi,

if you post your entire sif file, someone can have a look and maybe see what's wrong.

If you want to use an external program, the program would have to write the sif file and start the solver with a system call. IMHO it would be less effort to get the scanning simulation mode running...

HTH,

Matthias