[rbauwens]

Hi,

I just started using OpenFOAM about a week or two ago to see if it is applicable as a tool for the estimation maximum overpressures achieved in vented deflagrations but seem to have run into a problem that maybe someone could help me with.

I'm using Xoodles as it appears to be the appropriate solver for this case. After running a few test cases with just a simple box, 60x60x60 cells with a 5cm cell length and ignition at the center of the box, it appears that the flame front propagates (at least initially) in a diamond shape, ie. faster in the directions normal to the cell faces. Now I've tried changing a number of things to see what is causing this. I've tried changing the discretization schemes, the turbulence model, as well as the combustion and ignition properties but the only thing that has so far managed to remove this effect was to use the Smagorinsky LES model. The Smagorinsky model however, ended up greatly increasing the flame's propagation speed. After a bit more checking it appears that it is this higher flame speed that is causing this effect to disappear. This isn't ideal as this higher flame speed will greatly increase the maximum pressure achieved in a vented enclosure.

Has anyone else come across this or have any suggestions that could help resolve this problem? I'm still pretty new at using openFOAm so maybe there's something simple that I'm overlooking.

Any suggestions or help would be greatly appreciated,

Thanks,
-Regis