The core SU2 devs have a recent AIAA paper on verification/validation cases that they have successfully run with SU2 and compared favorably to other codes. One thing that is conspicuously absent is grid convergence studies to verify order of accuracy. This is an ideal place for the community to contribute because you don't have to have hugely in-depth knowledge of the source code base to run a grid convergence study or contribute a tutorial or test case (though you do have to be a fairly competent user). Much to their credit, the SU2 team is soliciting just this kind of contribution (my emphasis):
Expanded tutorials: we would like additional tutorials that complement the existing set found in the web-based documentation. The tutorials can either detail and explain the functionality of SU2 (shape optimization, parallel computing, mesh deformation, etc.) or demonstrate general CFD knowledge (highlighting good meshes vs. bad meshes, the importance of CFL number, etc.). Tutorials are intended to be tools for teaching and learning, and they should follow the same style as the existing tutorials. They must provide any mesh or config files that are necessary for their completion. New or unique verification and validation cases would be of particular interest here.
Exciting times in open source CFD!