Heat transfer doesn´t happen between different domains

oliveira1820 · February 19, 2018, 23:30

Hi everybody!

I am studying a cyclotron target. The target is made of different solid parts that I set as solid domains and a liquid inside that I set as fluid domain. There is only one source of heat, the beam that i have defined as a energy source inside the fluid domain.

I can see the temperature rising inside the fluid domain, but there is no heat transfer or temperature variations in any other domain.

I have defined all the faces that correspond to an interface in the meshing to ease the interface definiton and I have defined all the interfaces with CGI connection and with a thermal contact resistance in the CFX-Pre, I have also defined all domains to Thermal Energy.

Even with all the interfaces well defined,and thermal energy and Heat Transfer activated I don´t obtain any heat transfer.

Can anybody help me?

ghorrocks · February 20, 2018, 05:24

it sounds like either you have not defined the GGI interfaces correctly, or you did not apply a heat source to generate any heat transfer.

How do you know the GGIs are well defined?

oliveira1820 · February 21, 2018, 02:42

To test the system I had defined a point source and I can see the temperature rising near the point source area, so I think the error does not happens because of the heat source.

About the GGI surfaces, what I did was define the faces as named selections on mesh, and on the CFX-Pre I constructed interfaces with the faces that touch each other on different domains. That´s all I did. Am I doing it wrong?

ghorrocks · February 21, 2018, 05:34

I have no idea what is wrong.

Can you post an image of what you are modelling and your CCL?

Opaque · February 21, 2018, 09:33

Q: Are you running a transient or steady state simulation?

If transient, what are the time scale of the process in the fluid and solid domains?

I would try steady state solution (use a large time step in the solid domains), and check the solid domains heat up at some point. If they do not, your setup has a problem somewhere; otherwise, your timescales are fairly different and you need to approach the modeling different or wait until the heat wave reaches the solids.

oliveira1820 · February 27, 2018, 00:44

I discover what was wrong!!

It was in the CFX-Post, I was treating the data and graphics the wrong way, Thanks for everything anyway guys!!!!

You´ve been helpful!!

February 19, 2018, 23:30	Heat transfer doesn´t happen between different domains	#1
oliveira1820 Senior Member Pedro Oliveira Join Date: Feb 2018 Location: Portugal Posts: 109 Rep Power: 8	Hi everybody! I am studying a cyclotron target. The target is made of different solid parts that I set as solid domains and a liquid inside that I set as fluid domain. There is only one source of heat, the beam that i have defined as a energy source inside the fluid domain. I can see the temperature rising inside the fluid domain, but there is no heat transfer or temperature variations in any other domain. I have defined all the faces that correspond to an interface in the meshing to ease the interface definiton and I have defined all the interfaces with CGI connection and with a thermal contact resistance in the CFX-Pre, I have also defined all domains to Thermal Energy. Even with all the interfaces well defined,and thermal energy and Heat Transfer activated I don´t obtain any heat transfer. Can anybody help me?

February 20, 2018, 05:24		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,830 Rep Power: 144	it sounds like either you have not defined the GGI interfaces correctly, or you did not apply a heat source to generate any heat transfer. How do you know the GGIs are well defined? __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

February 21, 2018, 05:34		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,830 Rep Power: 144	I have no idea what is wrong. Can you post an image of what you are modelling and your CCL? __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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February 21, 2018, 02:42		#3
oliveira1820 Senior Member Pedro Oliveira Join Date: Feb 2018 Location: Portugal Posts: 109 Rep Power: 8	To test the system I had defined a point source and I can see the temperature rising near the point source area, so I think the error does not happens because of the heat source. About the GGI surfaces, what I did was define the faces as named selections on mesh, and on the CFX-Pre I constructed interfaces with the faces that touch each other on different domains. That´s all I did. Am I doing it wrong?

February 21, 2018, 09:33		#5
Opaque Senior Member Join Date: Jun 2009 Posts: 1,860 Rep Power: 33	Q: Are you running a transient or steady state simulation? If transient, what are the time scale of the process in the fluid and solid domains? I would try steady state solution (use a large time step in the solid domains), and check the solid domains heat up at some point. If they do not, your setup has a problem somewhere; otherwise, your timescales are fairly different and you need to approach the modeling different or wait until the heat wave reaches the solids.

February 27, 2018, 00:44		#6
oliveira1820 Senior Member Pedro Oliveira Join Date: Feb 2018 Location: Portugal Posts: 109 Rep Power: 8	I discover what was wrong!! It was in the CFX-Post, I was treating the data and graphics the wrong way, Thanks for everything anyway guys!!!! You´ve been helpful!!