Hello again,nnI spent some effort in running an LES case in a refined mesh, but also re-checked my RANS cases as well. I found that this discrepancy is occurring in transient simulations only, in other words, when I run steady RANS I have the expected oxygen concentration at the outlet of my combustor, which is 2-3 %. However when I switch my steady RANS to URANS, I have this problem too.nAlternatively, I ran a non-reacting LES cold flow, and my species fields are making sense in just the half of the combustor (as it moves downstream) but after the second half, eventhough I have no reaction mechanism enabled, my oxygen concentration is decreasing and my carbon dioxide is increasing. I don't understand what is happening... Any help would be appreciated..