miniapp with multiple fields

[fnrizzi]

We need a miniapp, similar to the adv-diffusion, that has multiple fields.
For example we use the adv-diffusion to evolve multiple concentrations.
This is needed to test/show the tensor galerkin formulation.

[jtencer]

Would a 2nd order wave equation where we track both the displacement and velocity as separate fields work for this?

[fnrizzi]

I think so! Basically anything where we evolve multiple quantities. Also, it only works for explicit Galerkin

[fnrizzi]

@jtencer see this test: https://github.com/Pressio/pressio4py/blob/master/regression_tests/unsteady_galerkin_multifield_correctness/test_unsteady_galerkin_multifield_correctness.py

[jtencer]

I have a little python app that does this using explicit timestepping.