volume heat source

superlinzl · August 28, 2009, 04:37

Hello all, I´m a new Star-CD user, can someone help me please? Wich way is the best to enter the volume heat-source in Star-CD? I´m prepairing model of small nuclear reactor, fuel elements I put in like a distributed resistance material. Thank you and sorry for my bad english.

Pauli · August 28, 2009, 10:36

It depends what you are trying to accomplish.

If you are just modeling coolant flow you can apply a heat flux wall boundary. This assumes you have "holes" in your mesh where the fuel rods should be located.

If you are trying to predict temperatures within the fuel rod (conjugate heat transfer analysis with fluid & solid cells), you will need an enthalpy source user subroutine applied to the solid cells.

You mentioned a distributed resistance. Are you using a porous media? Is so, how?
If you have no fuel rod "holes" & are meshing the entire core using porous media, you will need a volume source (enthalpy source user subroutine). I am not sure if you can use enthalpy sources with porous media. (Porous media adds restrictions to your model.)

If you are using porous media with fuel rod "holes", you should carefully consider what is happening at the walls (y+ & it's implications upon heat transfer coefficient calculation.)

August 28, 2009, 04:37	volume heat source	#1
superlinzl New Member Jakub Join Date: Jul 2009 Posts: 2 Rep Power: 0	Hello all, I´m a new Star-CD user, can someone help me please? Wich way is the best to enter the volume heat-source in Star-CD? I´m prepairing model of small nuclear reactor, fuel elements I put in like a distributed resistance material. Thank you and sorry for my bad english.

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August 28, 2009, 10:36		#2
Pauli Senior Member Pauli Join Date: Mar 2009 Posts: 189 Rep Power: 17	It depends what you are trying to accomplish. If you are just modeling coolant flow you can apply a heat flux wall boundary. This assumes you have "holes" in your mesh where the fuel rods should be located. If you are trying to predict temperatures within the fuel rod (conjugate heat transfer analysis with fluid & solid cells), you will need an enthalpy source user subroutine applied to the solid cells. You mentioned a distributed resistance. Are you using a porous media? Is so, how? If you have no fuel rod "holes" & are meshing the entire core using porous media, you will need a volume source (enthalpy source user subroutine). I am not sure if you can use enthalpy sources with porous media. (Porous media adds restrictions to your model.) If you are using porous media with fuel rod "holes", you should carefully consider what is happening at the walls (y+ & it's implications upon heat transfer coefficient calculation.)