Elmer Discussion Forum

I went to the test cases
HelmholtStructure
HelmholtStructure2
HelmholtStructure3

and change the density from 1 to 1000, and the sound speed from 300 to 1443.

In each one there was no difference in the structural result, but the pressure calculation changed.

and that is going to be impacted by mesh density, the finer the mesh the closer together they are. Think of the nodes as direct claculated values and the elemental as the average of all of the nodes. If the mesh is fine enough there is no difference, but it takes more computer solve the finer the me...

Regarding the 2 current densities one is data at the nodes
and the other is data at the element centroids (the one that ends in e)

"independent geometry densities between structure and fluid I can look at" In Elmer this requires the use of mortar boundary conditions. With mortar you have a master and slave so the mesh does not have to conform. Elmer Solver Manual Section 9.2 https://www.nic.funet.fi/pub/sci/physics/el...

https://github.com/mrkearden/toy

Here is a working 2D and 3D case, however I do not know if they are correct solutions.
I feel like the body force should be set to the current calculated from solver 1.

I made these changes

ElmerGrid writes the mesh to a subdirectory
The case file specifies looking for the mesh in the current directory.
I think it can't find the partitioned mesh

I can specify the potential at each end and let Elmer calculate the current density Boundary Condition 1 Target Boundaries(1) = 1 Name = "BoundaryCondition 1" Infinity BC = True Potential = 0 End Boundary Condition 2 Target Boundaries(1) = 2 Name = "BoundaryCondition 2" Potential...

That is a correct way to run it.
You can also use
ElmersSolver case.sif

The potential would depend on the boundary conditions, not sure I have them, may also be the problem in 3D

I was able to work through a 2D case, I will try and extend it to a 3d case.