heat flux on boussinesq
 

Dear Foam's,

Im trying to set heat flux as a boundary condition of my buoyantboussinesqSimpleFoam case. But my solution is too dependent of the mesh resolution, as I refine my mesh the final temperature of the fluid descreases each time more.

Qflux = k*(gradT)
gradT = qflux/k ; k=0,17 , Qflux = 10000

so Im setting in the T file :

fixedWalls
{
type fixedGradient;
gradient uniform 58823;
}

Can anyone tell me what am I doing wrong ?

Thanks for the attention.

(Im considering K constant...)

does the temperature become less than the temperature that you calculate with the a simple heat balance?

what kind of turbulence modeling do you use?

Yes, it become less then that i calculated with simple heat balance as I refine mesh.

Its a laminar flow.

what kind of geometry are we talking about, what is your yPlus of your first cell and what kind of fluid do u treat (Pr = 1, Pr > 1 or Pr < 1)

Its a simple rectangular channel section flow with constant heatflux on the fixed walls (4 walls), ethanol is the fluid (Pr ~ 16.5).