I have worked with the Navier Stokes equations before but I'm a physicist. I was talking to a mathematician and they use a complete different notation and I am very lost.
First of all, I use the Control Volume method for discretization and they use Finite Element.
Second, they talk about variational forms and H and Q spaces \Omega domains, which I have seen for the first time.
Can anybody point my way to a document, or book, or small chapter where I can understand the mathematical variational point of view of the Navier Stokes equation as simple as possible? (I'm interested in the incompressible stationary case for a fluid, so, very simple.)