Project author here. The gallery is part of scientific software Aphros https://github.com/cselab/aphros for flow simulations. Examples in the gallery demonstrate what physical problems can be solved. The same configuration can be used on larger computers (including supercomputers). Intended for potential users of the software and those willing to learn some fluid mechanics.

Here's a post by the other author of the project https://news.ycombinator.com/item?id=26492582