[mturcios777]

So after my post on getting certain engine functionality from 1.6-dext into 2.1.x (layer addition/removal), I was finally able to compile the ext engine library (with engineTopoChangerMesh, layerAR/layerARGambit and some other capabilities) and get it work with 2.1.x (there were changes with the underlying mesh topology changer interface).

I've been running on the included kivaTest tutorial and a simple cylindrical piston mesh, and have been running into problems with the pressure on the expansion side. I've turned off combustion so that we're only looking at the compression and expansion of the gas. I'm posting a comparison of the volume averaged pressure, temperature and u' that are written to the logFile by engineFoam. The discontinuities occur at layer addition/removal for both cases, but in 2.1.x we see severe unphysical ones).

The 2.1.x version of the solver uses PIMPLE while 1.6-ext uses PISO, but all the fvSchemes are identical and fvSolution are comparable. The layer controls are identical. I haven't worked much with meshes with topological changes; I did a test with the movingCone topoChangerFvMesh (which is incompressible) as icoDyMFoam and saw similar pressure fluctuations in 2.1.x but wasn't sure what to make of them. Comparing the solvers from 1.6-ext and 2.1.x, it appears that I should be doing some flux correction, but I'm not exactly sure how I should do that. Any suggestions to deal with this would be most welcome.

Thanks in advance