FV Vector Auxvars

[joe61vette]

Hello:

I am trying to add a vector auxvar to an input file for a FV fluid problem. The input is:

[AuxVariables]
[porosity]
order = CONSTANT
family = MONOMIAL
fv = true
components = 3
initial_condition = '1.0 1.0 1.0'
[]
[]

This fails with the message:

*** ERROR ***
Error creating ArrayMooseVariable name with base name porosity

If I set fv to false, it works fine. Am I doing something wrong? If not, should I just go ahead and use it as an FEM auxvar as it is constant in time.

Thanks,
Joe Kelly

[GiudGiud]

Hi Joe

I would recommend using a regular FV variable for porosity, as a single component should suffice. ArrayVariable support is increasing in FV, but is not ready yet. You could also specify 3 auxVariables to represent each component, as we do with u, v, w for the velocity variable in most of the tests in modules/navier_stokes/test/tests/finite_volume

FE (aux)variables, and FE array variables currently cannot be coupled to FV problems. This is also planned to be supported in the future.

Best,
Guillaume

[joe61vette]

Thanks Guillaume:

For my application, I will have anisotropic porosity. As I am just beginning the work on this, I can use one auxvar for now. Thanks again for the help.

Joe

[GiudGiud]

Ok we will make sure to support this.

In the 3 separate auxVariables approach, most (but likely not all, I will have to check the equations) kernels will be fine with accepting the relevant porosity component. In the kernel definition:
[kernel_name_x_component]
type = PINSFVSomething
porosity = porosity_x
[]