[oswald]

Dear fellow foamers,

I am trying to simulate Rayleigh-Bénard-cells with buoyantFoam. Most things work quite well, but I get a strange temperature behaviour in a tiny region at one edge of the domain. Please have a look at the attached image. While top and bottom temperatures are 282 K and 294 K, respectively, in this small region the min and max temperatures reach ~280.9 K and 298.4 K. Does anyone have an idea, what could cause this behaviour? I also attached the relevant case files as an archive.

In this case, the walls are assumed to be adiabatic, so a zeroGradient condition is used for temperature. All the other BCs are more or less standard wall BCs.

Please fell free to ask, if something is unclear.

Best,
oswald

[oswald]

I think I found a solution. As mentioned in other threads, it was not a good idea to put the pRefCell for pRef at a boundary. Using an internal cell or point solved the problem for me.


Edit: It only moved the problem to the inside of the domain. Using "perfectGas" for the equationOfState was the better solution.