[minecraftgp]

Hi everyone,

The case is a sealed room with 80W output heat source. The problem I met is that the total enthalpy increase inside the whole room in 1s is 75J. A buoyantPimpleFoam solver with boussinesq equation of state is used for the case.

The setting of the heat source is to use scalarSemiImplicitSource, which used part of the room air as a cellSet heat source. The code is shown as follow

heat1
 {
        type            scalarSemiImplicitSource;
        enabled         true;
        active          true;
        scalarSemiImplicitSourceCoeffs
        {
        selectionMode   cellSet;
        cellSet        heat1;
        volumeMode      absolute;
        injectionRateSuSp
            {
                    h
                    {
                        Su table
                        (
                            (0 80)
                        );
                        Sp      0.0;
                    }
            }
        }
    }

To measure the enthalpy increase inside the room, a swak4Foam code is used as follow, where 298.15 is the reference temperature T0, 1000 is the mass heat capacity Cp, and vol() is the volume for each cell.

T_volSum_room
 {
        name        T_volSum_room;
        type        swakExpression;
        valueType   cellSet;
        libs        ("libsimpleSwakFunctionObjects.so" );
        outputControlMode  timeStep;
        outputInterval     10;
        writeStartTime  no;
        setName    room;
        expression  "(T-298.15)*1000*vol()*rho";
        autoInterpolate   true;
        accumulations   (sum);
        verbose     true;
    }

For the issue I have considered 3 possibilities
1. It is due to the boussinesq equation of state.
2. It is caused by the configuration of the heat source, which means the heat source I am using is output less than 80W
3. It is due to the incorrect way of measuring, which means the expression "(T-298.15)*1000*vol()*rho" above cannot measure the enthalpy increase rate properly.

Any suggestion would be appreciated

Regards
Pu