[sailor79]

Hi folks,

I want to simulate a block of steel which has a cooling channel (water) in it. A constant heat flux is applied on top of the block. You can see the geometry in the attached picture.

I applied the solidWallHeatFluxTemperature bc to the top. Unfortunately the heat flux at the top does not correspond to the heat flux removed by the water. Here are some values:

Heat flux density at the top: 50000 W/m²
Area at the top: 0.03 m²
--> total heat flux: 1500 W

Water velocity: 0.424 m/s
Channel diameter: 10e-3 m
Density: 997 kg/m³
cp: 4182 J/kg/K
difference in Temperature inlet - outlet: 22 K
--> removed heat flux: ~3005 W

All the faces of the block are set to zeroGradient concerning Temperature.

I checked the heat flux over the channel Wall with swak4foam:

qChannelWall
{
    type swakExpression;
    valueType patch;
    patchName mould_to_channel;
    verbose true;
    expression "-K*area()*snGrad(T)";
    accumulations (sum);
    region mould;
}

It is in the range of the applied heat flux at the top. Thermophysical properties of water are set to:

thermoType      hRhoThermo<pureMixture<constTransport<specieThermo<hConstThermo<incompressible>>>>>;
mixture         water 1 18 997.05 4182 0 890.08e-6 6.127; // 25°C

Does someone have an idea what else I might check?

Thanks in advance

Michael