# turbulentHeatFluxTemperature heat capacity of what material?

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 May 7, 2014, 13:22 turbulentHeatFluxTemperature heat capacity of what material? #1 Senior Member   Andrew Somorjai Join Date: May 2013 Posts: 175 Rep Power: 13 Hello everyone, Looking at the source for the turbulentHeatFluxTemperatureFvPatchScalarField class at https://github.com/OpenFOAM/OpenFOAM...hScalarField.H The heat capacity at constant pressure is listed Code: ```hotWall { type turbulentHeatFluxTemperature; heatSource flux; // power [W]; flux [W/m2] q uniform 10; // heat power or flux alphaEff alphaEff; // alphaEff field name; // alphaEff in [kg/m/s] Cp Cp; // Cp field name; Cp in [J/kg/K] value uniform 300; // initial temperature value }``` If I had a box full of air with a wall made of steel transferring heat would I use the heat capacity of air or steel. I don't suppose the steel part would even matter for the simulation but I'm just not sure if it's simply the air Cp that would be needed. If it's for steel then how come there's no length requirement for the conductor (from the formula for thermal conductivity)? thanks to anyone for clearing it up.

 May 20, 2014, 11:19 #2 Senior Member   Joachim Herb Join Date: Sep 2010 Posts: 650 Rep Power: 21 With the turbulentHeatFluxTemperatureFvPatchScalarField boundary conditions you transfere a certain amount of heat (either defined as flux, a.k. power/area or total power for the whole surface) into the fluid. Heat conduction in the boundary is not considered, so the heat capacity is the one of the fluid. If you want to simulation also the solid and the heat conduction inside it, you have to go with the multi region solver (see the corresponding tutorias, e.g. heatTransfer/chtMultiRegionFoam etc.) massive_turbulence likes this.

May 20, 2014, 16:16
#3
Senior Member

Andrew Somorjai
Join Date: May 2013
Posts: 175
Rep Power: 13
Quote:
 Originally Posted by jherb With the turbulentHeatFluxTemperatureFvPatchScalarField boundary conditions you transfere a certain amount of heat (either defined as flux, a.k. power/area or total power for the whole surface) into the fluid. Heat conduction in the boundary is not considered, so the heat capacity is the one of the fluid. If you want to simulation also the solid and the heat conduction inside it, you have to go with the multi region solver (see the corresponding tutorias, e.g. heatTransfer/chtMultiRegionFoam etc.)
Thank you, that's exactly what I was thinking too but I didn't know about the multi region solver.

 May 20, 2014, 17:47 #4 Senior Member   Joachim Herb Join Date: Sep 2010 Posts: 650 Rep Power: 21 Also have a look at this boundary condition: https://github.com/OpenFOAM/OpenFOAM...hScalarField.H This might also apply in your case.

 Tags heat capacity, thermal coductivity