[Stefano Puggelli]

Dear Foamers,
I would like to simulate a very simple test case of mixing between air and methane using XiFoam. The test case that I have to simulate is reactive but for the moment I am considering isothermal conditions. I am trying to run a LES calculation of such case. For the moment, since I am having big problems with pressure field I choose to simulate an homogenous mixture composed only by air.
Maybe I made some mistakes in my settings but while the calculation is running some pressure oscillations arise out of the jet duct and the calculation become very unstable.
As attachment you can find some picture of the velocity field at the beginning of the simulation (it is named rhoPimpleFoam since I used such solver) and before it stops. At the end velocity field takes very high values and the calculation crashes.
The problem, on my opinion, seems to be related to the thermo library but I can't unserstand what it's wrong. Furthermore in parallel I am running the same test case with rhoPimpleFoam without any problems.
The version of OF that I am using is the 2.1.

[wenxu]

The direct cause of this is the different thermo type. XiFoam and reactingFoam are based on psiFoam while rhoPimpleFoam is based on rhoThermo. The difference between these two thermos can be found here.

regards,
Wen Xu