BuildingSystems icon indicating copy to clipboard operation
BuildingSystems copied to clipboard

Units in HAM.HeatAndMoistureTransport

Open thorade opened this issue 9 years ago • 1 comments

Advanced.PedanticModelica:=true;
checkModel("BuildingSystems.HAM.HeatAndMoistureTransport");

Looks like there are some units wrong.

thorade avatar Nov 19 '15 10:11 thorade

See e.g. BuildingSystems.HAM.HeatAndMoistureTransport.HeatAndMoistureTransport1D equation for Moisture flow rate at side 1

 moisturePort_x1.m_flow =
    CMd * (phi_x1 *  BuildingSystems.Utilities.Psychrometrics.Functions.saturationPressure(heatPort_x1.T)
     - phi * BuildingSystems.Utilities.Psychrometrics.Functions.saturationPressure(T))
     + CLt * (phi_x1 - phi);

Expressed in units, we have:

[kg/s] = [kg/(s.Pa)]*[1]*[Pa] + [kg/(s.m)]*[1]
         = [kg/s] + [kg/(s.m)] 

As the unit for a mass flow is obviously kg/s, either unit of Types.CoefficientOfLiquidTransport ([kg/(s.m)]) is wrong or this equation has to be multiplied with a mass (if so, this error has to be corrected at many places).

jmoeckel avatar Nov 20 '15 08:11 jmoeckel