[1111a1333]

Hi,

I am attempting to simulate 3D Rayleigh–Bénard convection in OpenFOAM with a domain size of 100m x 100m x 500m and a grid resolution of 100 x 100 x 500 cells. The floor temperature is fixed at 333K, while the ceiling temperature is set to 285K, which corresponds to the temperature at a height of 500m in the US standard atmosphere. However, after 6000 seconds, I have observed that the temperature of the lowest grid cells remains unchanged, and turbulence has not been generated. Is this due to the grid size being too large, or is there a way to accelerate the heating of the lowest layer of grid cells? I am using the buoyantBoussinesqPimpleFoam solver.

Cheers

object T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 1 0 0 0];

internalField uniform 295;

boundaryField
{
floor
{
type fixedValue;
value uniform 333.15;
}

ceiling
{
type fixedValue;
value uniform 284.9;
}

sideWalls
{
type zeroGradient;
}

#includeEtc "caseDicts/setConstraintTypes"
}