k-Epsilon thermal simulation
 

Dear All,

I'm using a temperature equation version of the simpleFoam solver. I did an isothermal periodic channel flow simulation with Re_tau=150 and used both k-epsilon and v2f turbulence models. It is a resolved simulation, so I used the low-Re version of the k-Epsilon model. The results are fairly reproduced the reference DNS data.

After I've switched to a heated case and there I got problem with the k-Epsilon (the v2f remained adequately good in therms of the momentum boundary layer). Surprisingly, the momentum BL has changed, though, the temperature should be only acts as a scalar transport (no buoyancy). Could anyone tell me what could go wrong? I've tried different boundary conditions, turbulent Pr numbers. I tried the 2 low-Re models. Whatever I did, the velocity gradient normal to the wall reduces with 30%, approximately.

Thank you for your help,
Lilla

Hi, I realise I am a bit late but I'd like to discuss this.
Did you check your thermophysical properties? There could be a thermal thinning term in there.
Also, how are you handling the T field periodically?