Designing a study to explore geometric complexity of flow conduits
 

I would be very grateful for ideas on how to use a new code. My background is in another area, but I have been working on the code as a way of teaching myself coding and CFD. It can deal with flow in geometrically complex conduits.

What I mean is that I can divide my domain up into areas that have different permeabilities. So I can define a conduit as an area that has high permeability relative to its surroundings.

In my field, most similar codes can deal with much simpler geometries. It would be nice to demonstrate what my code can do by running several test cases (flow from left to right, pseudo-1D).

My problem is, I can't think of a systematic, sensible set of geometries to use in the test. I guess I could make several geometries that are complex and show that complex flow patterns and velocity differences result. But this doesn't seem satisfying.

If anyone has any experience with thinking about this sort of thing, I would love to hear suggestions on how to design a useful range of geometries that would show interesting differences in flow. For example, velocity differences (so that flow is very fast versus slow across the domain), conduit orientation differences. Intersecting conduits of different orientation and thickness. How do I do this without creating an encyclopedia? Maybe someone has dealt with this before? Thanks.